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Sample records for african cichlid species

  1. Microsatellites Cross-Species Amplification across Some African Cichlids.

    PubMed

    Bezault, Etienne; Rognon, Xavier; Gharbi, Karim; Baroiller, Jean-Francois; Chevassus, Bernard

    2012-01-01

    The transfer of the genomic resources developed in the Nile tilapia, Oreochromis niloticus, to other Tilapiines sensu lato and African cichlid would provide new possibilities to study this amazing group from genetics, ecology, evolution, aquaculture, and conservation point of view. We tested the cross-species amplification of 32 O. niloticus microsatellite markers in a panel of 15 species from 5 different African cichlid tribes: Oreochromines (Oreochromis, Sarotherodon), Boreotilapiines (Tilapia), Chromidotilapines, Hemichromines, and Haplochromines. Amplification was successfully observed for 29 markers (91%), with a frequency of polymorphic (P(95)) loci per species around 70%. The mean number of alleles per locus and species was 3.2 but varied from 3.7 within Oreochromis species to 1.6 within the nontilapia species. The high level of cross-species amplification and polymorphism of the microsatellite markers tested in this study provides powerful tools for a wide range of molecular genetic studies within tilapia species as well as for other African cichlids.

  2. Microsatellites Cross-Species Amplification across Some African Cichlids

    PubMed Central

    Bezault, Etienne; Rognon, Xavier; Gharbi, Karim; Baroiller, Jean-Francois; Chevassus, Bernard

    2012-01-01

    The transfer of the genomic resources developed in the Nile tilapia, Oreochromis niloticus, to other Tilapiines sensu lato and African cichlid would provide new possibilities to study this amazing group from genetics, ecology, evolution, aquaculture, and conservation point of view. We tested the cross-species amplification of 32 O. niloticus microsatellite markers in a panel of 15 species from 5 different African cichlid tribes: Oreochromines (Oreochromis, Sarotherodon), Boreotilapiines (Tilapia), Chromidotilapines, Hemichromines, and Haplochromines. Amplification was successfully observed for 29 markers (91%), with a frequency of polymorphic (P95) loci per species around 70%. The mean number of alleles per locus and species was 3.2 but varied from 3.7 within Oreochromis species to 1.6 within the nontilapia species. The high level of cross-species amplification and polymorphism of the microsatellite markers tested in this study provides powerful tools for a wide range of molecular genetic studies within tilapia species as well as for other African cichlids. PMID:22701809

  3. The species flocks of East African cichlid fishes: recent advances in molecular phylogenetics and population genetics

    NASA Astrophysics Data System (ADS)

    Salzburger, Walter; Meyer, Axel

    With more than 3,000 species, the fish family Cichlidae is one of the most species-rich families of vertebrates. Cichlids occur in southern and central America, Africa, Madagascar, and India. The hotspot of their biodiversity is East Africa, where they form adaptive radiations composed of hundreds of endemic species in several lakes of various sizes and ages. The unparalleled species richness of East African cichlids has been something of a conundrum for evolutionary biologists and ecologists, since it has been in doubt whether these hundreds of species arose by allopatric speciation or whether it is necessary to invoke somewhat less traditional models of speciation, such as micro-allopatric, peripatric, or even sympatric speciation or evolution through sexual selection mediated by female choice. Ernst Mayr's analyses of these evolutionary uniquely diverse species assemblages have contributed to a more direct approach to this problem and have led to a deeper understanding of the patterns and processes that caused the formation of these huge groups of species. We review here recent molecular data on population differentiation and phylogenetics, which have helped to unravel, to some extent, the patterns and processes that led to the formation and ecological maintenance of cichlid species flocks. It is becoming apparent that sexually selected traits do play an important role in speciation in micro-allopatric or even sympatric settings. Species richness seems to be roughly correlated with the surface area, but not the age, of the lakes. We observe that the oldest lineages of a species flock of cichlids are often less species-rich and live in the open water or deepwater habitats. While the species flocks of the Lake Malawai and the Lake Victoria areas were shown to be monophyletic, the cichlid assemblage of Lake Tanganyika seems to consist of several independent species flocks. Cichlids emerge as an evolutionary model system in which many fundamental questions in

  4. Do estimated and actual species phylogenies match? Evaluation of East African cichlid radiations.

    PubMed

    Huang, Huateng; Tran, Lucy A P; Knowles, L Lacey

    2014-09-01

    A large number of published phylogenetic estimates are based on a single locus or the concatenation of multiple loci, even though genealogies of single or concatenated loci may not accurately reflect the true history of species diversification (i.e., the species tree). The increased availability of genomic data, coupled with new computational methods, improves resolution of species relationships beyond what was possible in the past. Such developments will no doubt benefit future phylogenetic studies. It remains unclear how robust phylogenies that predate these developments (i.e., the bulk of phylogenetic studies) are to departures from the assumption of strict gene tree-species tree concordance. Here, we present a parametric bootstrap (PBST) approach that assesses the reliability of past phylogenetic estimates in which gene tree-species tree discord was ignored. We focus on a universal cause of discord-the random loss of gene lineages from genetic drift-and apply the method in a meta-analysis of East African cichlids, a group encompassing historical scenarios that are particularly challenging for phylogenetic estimation. Although we identify some evolutionary relationships that are robust to gene tree discord, many past phylogenetic estimates of cichlids are not. We discuss the utility of the PBST method for evaluating the robustness of gene tree-based phylogenetic estimations in general as well as for testing the clade-specific performance of species tree estimation methods and designing sampling strategies that increase the accuracy of estimated species relationships.

  5. Back to Tanganyika: a case of recent trans-species-flock dispersal in East African haplochromine cichlid fishes.

    PubMed

    Meyer, Britta S; Indermaur, Adrian; Ehrensperger, Xenia; Egger, Bernd; Banyankimbona, Gaspard; Snoeks, Jos; Salzburger, Walter

    2015-03-01

    The species flocks of cichlid fishes in the East African Great Lakes are the largest vertebrate adaptive radiations in the world and illustrious textbook examples of convergent evolution between independent species assemblages. Although recent studies suggest some degrees of genetic exchange between riverine taxa and the lake faunas, not a single cichlid species is known from Lakes Tanganyika, Malawi and Victoria that is derived from the radiation associated with another of these lakes. Here, we report the discovery of a haplochromine cichlid species in Lake Tanganyika, which belongs genetically to the species flock of haplochromines of the Lake Victoria region. The new species colonized Lake Tanganyika only recently, suggesting that faunal exchange across watersheds and, hence, between isolated ichthyofaunas, is more common than previously thought.

  6. Phylogeny of African cichlid fishes as revealed by molecular markers.

    PubMed

    Mayer, W E; Tichy, H; Klein, J

    1998-06-01

    The species flocks of cichlid fish in the three great East African Lakes, Victoria, Malawi, and Tanganyika, have arisen in each lake by explosive adaptive radiation. Various questions concerning their phylogeny have not yet been answered. In particular, the identity of the ancestral founder species and the monophyletic origin of the haplochromine cichlids from the East African lakes have not been established conclusively. In the present study, we used the anonymous nuclear DNA marker DXTU1 as a step towards answering these questions. A 280 bp-fragment of the DXTU1 locus was amplified by the polymerase chain reaction from East African lacustrine species, the East African riverine cichlid species Haplochromis bloyeti, H. burtoni and H. sparsidens, and other African cichlids. Sequencing revealed several indels and substitutions that were used as cladistically informative markers to support a phylogenetic tree constructed by the neighbor-joining method. The topology, although not supported by high bootstrap values, corresponds well to the geographical distribution and previous classification of the cichlids. Markers could be defined that: (i) differentiate East African from West African cichlids; (ii) distinguish the riverine and Lake Victoria/Malawi haplochromines from Lake Tanganyika cichlids; and (iii) indicate the existence of a monophyletic Lake Victoria cichlid superflock which includes haplochromines from satellite lakes and East African rivers. In order to resolve further the relationship of East African riverine and lacustrine species, mtDNA cytochrome b and control region segments were sequenced. The mtDNA-based trees support the notion of the monophyly of the Lake Victoria superflock but are ambiguous with respect to the phylogenetic position of the Lake Malawi flock.

  7. How many species of cichlid fishes are there in African lakes?

    PubMed

    Turner, G F; Seehausen, O; Knight, M E; Allender, C J; Robinson, R L

    2001-03-01

    The endemic cichlid fishes of Lakes Malawi, Tanganyika and Victoria are textbook examples of explosive speciation and adaptive radiation, and their study promises to yield important insights into these processes. Accurate estimates of species richness of lineages in these lakes, and elsewhere, will be a necessary prerequisite for a thorough comparative analysis of the intrinsic and extrinsic factors influencing rates of diversification. This review presents recent findings on the discoveries of new species and species flocks and critically appraises the relevant evidence on species richness from recent studies of polymorphism and assortative mating, generally using behavioural and molecular methods. Within the haplochromines, the most species-rich lineage, there are few reported cases of postzygotic isolation, and these are generally among allopatric taxa that are likely to have diverged a relatively long time in the past. However, many taxa, including many which occur sympatrically and do not interbreed in nature, produce viable, fertile hybrids. Prezygotic barriers are more important, and persist in laboratory conditions in which environmental factors have been controlled, indicating the primary importance of direct mate preferences. Studies to date indicate that estimates of alpha (within-site) diversity appear to be robust. Although within-species colour polymorphisms are common, these have been taken into account in previous estimates of species richness. However, overall estimates of species richness in Lakes Malawi and Victoria are heavily dependent on the assignation of species status to allopatric populations differing in male colour. Appropriate methods for testing the specific status of allopatric cichlid taxa are reviewed and preliminary results presented.

  8. The genomic substrate for adaptive radiation in African cichlid fish

    PubMed Central

    Malinsky, Milan; Keller, Irene; Fan, Shaohua; Simakov, Oleg; Ng, Alvin Y.; Lim, Zhi Wei; Bezault, Etienne; Turner-Maier, Jason; Johnson, Jeremy; Alcazar, Rosa; Noh, Hyun Ji; Russell, Pamela; Aken, Bronwen; Alföldi, Jessica; Amemiya, Chris; Azzouzi, Naoual; Baroiller, Jean-François; Barloy-Hubler, Frederique; Berlin, Aaron; Bloomquist, Ryan; Carleton, Karen L.; Conte, Matthew A.; D'Cotta, Helena; Eshel, Orly; Gaffney, Leslie; Galibert, Francis; Gante, Hugo F.; Gnerre, Sante; Greuter, Lucie; Guyon, Richard; Haddad, Natalie S.; Haerty, Wilfried; Harris, Rayna M.; Hofmann, Hans A.; Hourlier, Thibaut; Hulata, Gideon; Jaffe, David B.; Lara, Marcia; Lee, Alison P.; MacCallum, Iain; Mwaiko, Salome; Nikaido, Masato; Nishihara, Hidenori; Ozouf-Costaz, Catherine; Penman, David J.; Przybylski, Dariusz; Rakotomanga, Michaelle; Renn, Suzy C. P.; Ribeiro, Filipe J.; Ron, Micha; Salzburger, Walter; Sanchez-Pulido, Luis; Santos, M. Emilia; Searle, Steve; Sharpe, Ted; Swofford, Ross; Tan, Frederick J.; Williams, Louise; Young, Sarah; Yin, Shuangye; Okada, Norihiro; Kocher, Thomas D.; Miska, Eric A.; Lander, Eric S.; Venkatesh, Byrappa; Fernald, Russell D.; Meyer, Axel; Ponting, Chris P.; Streelman, J. Todd; Lindblad-Toh, Kerstin; Seehausen, Ole; Di Palma, Federica

    2015-01-01

    Cichlid fishes are famous for large, diverse and replicated adaptive radiations in the Great Lakes of East Africa. To understand the molecular mechanisms underlying cichlid phenotypic diversity, we sequenced the genomes and transcriptomes of five lineages of African cichlids: the Nile tilapia (Oreochromis niloticus), an ancestral lineage with low diversity; and four members of the East African lineage: Neolamprologus brichardi/pulcher (older radiation, Lake Tanganyika), Metriaclima zebra (recent radiation, Lake Malawi), Pundamilia nyererei (very recent radiation, Lake Victoria), and Astatotilapia burtoni (riverine species around Lake Tanganyika). We found an excess of gene duplications in the East African lineage compared to tilapia and other teleosts, an abundance of non-coding element divergence, accelerated coding sequence evolution, expression divergence associated with transposable element insertions, and regulation by novel microRNAs. In addition, we analysed sequence data from sixty individuals representing six closely related species from Lake Victoria, and show genome-wide diversifying selection on coding and regulatory variants, some of which were recruited from ancient polymorphisms. We conclude that a number of molecular mechanisms shaped East African cichlid genomes, and that amassing of standing variation during periods of relaxed purifying selection may have been important in facilitating subsequent evolutionary diversification. PMID:25186727

  9. A gene expression study of dorso-ventrally restricted pigment pattern in adult fins of Neolamprologus meeli, an African cichlid species

    PubMed Central

    Sefc, Kristina M.

    2017-01-01

    Fish color patterns are among the most diverse phenotypic traits found in the animal kingdom. Understanding the molecular and cellular mechanisms that control in chromatophore distribution and pigmentation underlying this diversity is a major goal in developmental and evolutionary biology, which has predominantly been pursued in the zebrafish model system. Here, we apply results from zebrafish work to study a naturally occurring color pattern phenotype in the fins of an African cichlid species from Lake Tanganyika. The cichlid fish Neolamprologus meeli displays a distinct dorsal color pattern, with black and white stripes along the edges of the dorsal fin and of the dorsal half of the caudal fin, corresponding with differences in melanophore density. To elucidate the molecular mechanisms controlling the differences in dorsal and ventral color patterning in the fins, we quantitatively assessed the expression of 15 candidate target genes involved in adult zebrafish pigmentation and stripe formation. For reference gene validation, we screened the expression stability of seven widely expressed genes across the investigated tissue samples and identified tbp as appropriate reference. Relative expression levels of the candidate target genes were compared between the dorsal, striped fin regions and the corresponding uniform, grey-colored regions in the anal and ventral caudal fin. Dorso-ventral expression differences, with elevated levels in both white and black stripes, were observed in two genes, the melanosome protein coding gene pmel and in igsf11, which affects melanophore adhesion, migration and survival. Next, we predicted potential shared upstream regulators of pmel and igsf11. Testing the expression patterns of six predicted transcriptions factors revealed dorso-ventral expression difference of irf1 and significant, negative expression correlation of irf1 with both pmel and igsf11. Based on these results, we propose pmel, igsf11 and irf1 as likely components of

  10. The Impact of the Geologic History and Paleoclimate on the Diversification of East African Cichlids

    PubMed Central

    Danley, Patrick D.; Husemann, Martin; Ding, Baoqing; DiPietro, Lyndsay M.; Beverly, Emily J.; Peppe, Daniel J.

    2012-01-01

    The cichlid fishes of the East African Great Lakes are the largest extant vertebrate radiation identified to date. These lakes and their surrounding waters support over 2,000 species of cichlid fish, many of which are descended from a single common ancestor within the past 10 Ma. The extraordinary East African cichlid diversity is intricately linked to the highly variable geologic and paleoclimatic history of this region. Greater than 10 Ma, the western arm of the East African rift system began to separate, thereby creating a series of rift basins that would come to contain several water bodies, including the extremely deep Lakes Tanganyika and Malawi. Uplifting associated with this rifting backponded many rivers and created the extremely large, but shallow Lake Victoria. Since their creation, the size, shape, and existence of these lakes have changed dramatically which has, in turn, significantly influenced the evolutionary history of the lakes' cichlids. This paper reviews the geologic history and paleoclimate of the East African Great Lakes and the impact of these forces on the region's endemic cichlid flocks. PMID:22888465

  11. The impact of the geologic history and paleoclimate on the diversification of East african cichlids.

    PubMed

    Danley, Patrick D; Husemann, Martin; Ding, Baoqing; Dipietro, Lyndsay M; Beverly, Emily J; Peppe, Daniel J

    2012-01-01

    The cichlid fishes of the East African Great Lakes are the largest extant vertebrate radiation identified to date. These lakes and their surrounding waters support over 2,000 species of cichlid fish, many of which are descended from a single common ancestor within the past 10 Ma. The extraordinary East African cichlid diversity is intricately linked to the highly variable geologic and paleoclimatic history of this region. Greater than 10 Ma, the western arm of the East African rift system began to separate, thereby creating a series of rift basins that would come to contain several water bodies, including the extremely deep Lakes Tanganyika and Malawi. Uplifting associated with this rifting backponded many rivers and created the extremely large, but shallow Lake Victoria. Since their creation, the size, shape, and existence of these lakes have changed dramatically which has, in turn, significantly influenced the evolutionary history of the lakes' cichlids. This paper reviews the geologic history and paleoclimate of the East African Great Lakes and the impact of these forces on the region's endemic cichlid flocks.

  12. Parallel evolution of opsin gene expression in African cichlid fishes.

    PubMed

    O'Quin, Kelly E; Hofmann, Christopher M; Hofmann, Hans A; Carleton, Karen L

    2010-12-01

    Phenotypic evolution may occur either through alterations to the structure of protein-coding genes or their expression. Evidence for which of these two mechanisms more commonly contribute to the evolution of a phenotype can be garnered from examples of parallel and convergent evolution. The visual system of East African cichlid fishes is an excellent system with which to address this question. Cichlid fishes from Lakes Malawi (LM) and Victoria together exhibit three diverse palettes of coexpressed opsins and several important protein-coding mutations that both shift spectral sensitivity. Here we assess both opsin expression and protein-coding diversity among cichlids from a third rift lake, Lake Tanganyika (LT). We found that Tanganyikan cichlids exhibit three palettes of coexpressed opsins that largely overlap the short-, middle-, and long-wavelength-sensitive palettes of LM cichlids. Bayesian phenotypic clustering and ancestral state reconstructions both support the parallel evolution of the short- and middle-wavelength palettes among cichlids from LT and LM. In each case, these transitions occurred from different ancestors that expressed the same long-wavelength palette. We also identified similar but distinct patterns of correlated evolution between opsin expression, diet, and lens transmittance among cichlids from LT and LM as well. In contrast to regulatory changes, we identified few functional or potentially functional mutations in the protein-coding sequences of three variable opsins, with the possible exception of the SWS1 (ultraviolet) opsin. These results underscore the important contribution that gene regulation can make to rapid phenotypic evolution and adaptation.

  13. Multiple episodic evolution events in V1R receptor genes of East-African cichlids.

    PubMed

    Nikaido, Masato; Ota, Tomoki; Hirata, Tadashi; Suzuki, Hikoyu; Satta, Yoko; Aibara, Mitsuto; Mzighani, Semvua I; Sturmbauer, Christian; Hagino-Yamagishi, Kimiko; Okada, Norihiro

    2014-05-06

    Fish use olfaction to detect a variety of nonvolatile chemical signals, and thus, this sense is key to survival and communication. However, the contribution of the olfactory sense to social-especially reproductive-interactions in cichlids is still controversial. To obtain insights into this issue, we investigated the genes encoding V1Rs-possible candidates for reproductive pheromone receptors-among East-African cichlids. Interestingly, we found an excess of nonsynonymous over synonymous substitutions in four of six V1R genes in multiple cichlid lineages. First, we found that highly dimorphic V1R2 allele groups were shared among the cichlids inhabiting all East-African Great Lakes emerged through the episodic accumulation of the nonsynonymous substitutions prior to the radiation of the Lake Tanganyika species flock. We further detected such episodic events in V1R1 of the tribe Tropheini, and in V1R3 and V1R6 of the tribe Trematocarini. The excess of nonsynonymous substitutions in these examples were indicated as dN/dS > 1, which were all statistically significant by Fisher's exact test. Furthermore, we speculate that the amino acid changes in these episodic events are likely functional switch because they occurred in the putative ligand-binding pocket. Our finding of the occurrence of multiple episodic events and the unexpected gene diversity in one unique gene family is suggestive of the contribution of the V1R to the species diversification and the social interaction in cichlids.

  14. Genetic and developmental basis for fin shape variation in African cichlid fishes.

    PubMed

    Navon, Dina; Olearczyk, Nathan; Albertson, R Craig

    2017-01-01

    Adaptive radiations are often characterized by the rapid evolution of traits associated with divergent feeding modes. For example, the evolutionary history of African cichlids is marked by repeated and coordinated shifts in skull, trophic, fin and body shape. Here, we seek to explore the molecular basis for fin shape variation in Lake Malawi cichlids. We first described variation within an F2 mapping population derived by crossing two cichlid species with divergent morphologies including fin shape. We then used this population to genetically map loci that influence variation in this trait. We found that the genotype-phenotype map for fin shape is largely distinct from other morphological characters including body and craniofacial shape. These data suggest that key aspects of fin, body and jaw shape are genetically modular and that the coordinated evolution of these traits in cichlids is more likely due to common selective pressures than to pleiotropy or linkage. We next combined genetic mapping data with population-level genome scans to identify wnt7aa and col1a1 as candidate genes underlying variation in the number of pectoral fin ray elements. Gene expression patterns across species with different fin morphologies and small molecule manipulation of the Wnt pathway during fin development further support the hypothesis that variation at these loci underlies divergence in fin shape between cichlid species. In all, our data provide additional insights into the genetic and molecular mechanisms associated with morphological divergence in this important adaptive radiation.

  15. Convict cichlids benefit from close proximity to another species of cichlid fish.

    PubMed

    Lehtonen, Topi K

    2008-12-23

    The coexistence of species with overlapping resource use is often thought to involve only negative fitness effects as a consequence of interspecific competition. Furthermore, the scarce empirical research on positive species interactions has predominantly focused on sessile organisms. Here, I experimentally assessed the effect of close proximity of a potential brood predator and competitor on reproductive success of a neotropical cichlid fish. I demonstrate that convict cichlid (Archocentrus nigrofasciatus) broods have a higher survival rate near territories of the Nicaragua cichlid (Hypsophrys nicaraguensis), and that escape from predation and nest takeovers is the most likely explanation for the decreased offspring mortality.

  16. Evolution of genomic structural variation and genomic architecture in the adaptive radiations of African cichlid fishes

    PubMed Central

    Fan, Shaohua; Meyer, Axel

    2014-01-01

    African cichlid fishes are an ideal system for studying explosive rates of speciation and the origin of diversity in adaptive radiation. Within the last few million years, more than 2000 species have evolved in the Great Lakes of East Africa, the largest adaptive radiation in vertebrates. These young species show spectacular diversity in their coloration, morphology and behavior. However, little is known about the genomic basis of this astonishing diversity. Recently, five African cichlid genomes were sequenced, including that of the Nile Tilapia (Oreochromis niloticus), a basal and only relatively moderately diversified lineage, and the genomes of four representative endemic species of the adaptive radiations, Neolamprologus brichardi, Astatotilapia burtoni, Metriaclima zebra, and Pundamila nyererei. Using the Tilapia genome as a reference genome, we generated a high-resolution genomic variation map, consisting of single nucleotide polymorphisms (SNPs), short insertions and deletions (indels), inversions and deletions. In total, around 18.8, 17.7, 17.0, and 17.0 million SNPs, 2.3, 2.2, 1.4, and 1.9 million indels, 262, 306, 162, and 154 inversions, and 3509, 2705, 2710, and 2634 deletions were inferred to have evolved in N. brichardi, A. burtoni, P. nyererei, and M. zebra, respectively. Many of these variations affected the annotated gene regions in the genome. Different patterns of genetic variation were detected during the adaptive radiation of African cichlid fishes. For SNPs, the highest rate of evolution was detected in the common ancestor of N. brichardi, A. burtoni, P. nyererei, and M. zebra. However, for the evolution of inversions and deletions, we found that the rates at the terminal taxa are substantially higher than the rates at the ancestral lineages. The high-resolution map provides an ideal opportunity to understand the genomic bases of the adaptive radiation of African cichlid fishes. PMID:24917883

  17. Comparative Transcriptomics in East African Cichlids Reveals Sex- and Species-Specific Expression and New Candidates for Sex Differentiation in Fishes

    PubMed Central

    Böhne, Astrid; Sengstag, Thierry; Salzburger, Walter

    2014-01-01

    Males and females of the same species differ largely in gene expression, which accounts for most of the morphological and physiological differences and sex-specific phenotypes. Here, we analyzed sex-specific gene expression in the brain and the gonads of cichlid fishes from Lake Tanganyika belonging to four different lineages, so-called tribes (Eretmodini, Ectodini, Haplochromini, and Lamprologini), using the outgroup Nile tilapia (Oreochromis niloticus) as reference. The comparison between male and female brains revealed few differences between the sexes, consistent in all investigated species. The gonads, on the other hand, showed a large fraction of differentially expressed transcripts with the majority of them showing the same direction of expression in all four species. All here-studied cichlids, especially the three investigated mouth-breeding species, showed a trend toward more male- than female-biased transcripts. Transcripts, which were female-biased in expression in all four species, were overrepresented on linkage group (LG)1 in the reference genome and common male-biased transcripts showed accumulation on LG23, the presumable sex chromosomes of the Nile tilapia. Sex-specific transcripts contained candidate genes for sex determination and differentiation in fishes, especially members of the transforming growth factor-β-superfamily and the Wnt-pathway and also prominent members of the sox-, dm-domain-, and high mobility group-box families. We further confirmed our previous finding on species/lineage-specific gene expression shifts in the sex steroid pathway, including synthesizing enzymes as the aromatase cyp19a1 and estrogen and androgen receptors. PMID:25364805

  18. Contextual chemosensory urine signaling in an African cichlid fish

    PubMed Central

    Maruska, Karen P.; Fernald, Russell D.

    2012-01-01

    SUMMARY Chemosensory signaling is crucial for communication in many fish species, but little is known about how signalers modulate chemical output in response to sensory information and social context. Here, we tested the hypothesis that dominant male African cichlid fish (Astatotilapia burtoni) use urine signals during social interactions, and demonstrate that this signaling depends on social context (reproductive; territorial) and on available sensory information (visual cues; full interaction). We injected males with dye to visualize urine pulses and exposed them to full sensory information or visual cues alone of four types: (1) dominant male; (2) gravid (reproductively receptive) females; (3) mouth-brooding (non-receptive) females; or (4) control (no fish). We found that males released urine sooner and increased their urination frequency when visually exposed to gravid females as compared with mouth-brooding females and or no-fish controls. While males could distinguish female reproductive states using visual cues alone, courtship behavior rates were ∼10-fold higher when they fully interacted with gravid females compared with receiving visual cues alone. Males also increased their urination and territorial behaviors when exposed to another male, suggesting that chemical signals may convey information on dominance status. These data support the hypothesis that dominant males use urine as a chemical signal and adjust the frequency of their urine output based on contextual information. PMID:22162854

  19. Gut Microbiota Dynamics during Dietary Shift in Eastern African Cichlid Fishes

    PubMed Central

    Baldo, Laura; Riera, Joan Lluís; Tooming-Klunderud, Ave; Albà, M. Mar; Salzburger, Walter

    2015-01-01

    The gut microbiota structure reflects both a host phylogenetic history and a signature of adaptation to the host ecological, mainly trophic niches. African cichlid fishes, with their array of closely related species that underwent a rapid dietary niche radiation, offer a particularly interesting system to explore the relative contribution of these two factors in nature. Here we surveyed the host intra- and interspecific natural variation of the gut microbiota of five cichlid species from the monophyletic tribe Perissodini of lake Tanganyika, whose members transitioned from being zooplanktivorous to feeding primarily on fish scales. The outgroup riverine species Astatotilapia burtoni, largely omnivorous, was also included in the study. Fusobacteria, Firmicutes and Proteobacteria represented the dominant components in the gut microbiota of all 30 specimens analysed according to two distinct 16S rRNA markers. All members of the Perissodini tribe showed a homogenous pattern of microbial alpha and beta diversities, with no significant qualitative differences, despite changes in diet. The recent diet shift between zooplantkon- and scale-eaters simply reflects on a significant enrichment of Clostridium taxa in scale-eaters where they might be involved in the scale metabolism. Comparison with the omnivorous species A. burtoni suggests that, with increased host phylogenetic distance and/or increasing herbivory, the gut microbiota begins differentiating also at qualitative level. The cichlids show presence of a large conserved core of taxa and a small set of core OTUs (average 13–15%), remarkably stable also in captivity, and putatively favoured by both restricted microbial transmission among related hosts (putatively enhanced by mouthbrooding behavior) and common host constraints. This study sets the basis for a future large-scale investigation of the gut microbiota of cichlids and its adaptation in the process of the host adaptive radiation. PMID:25978452

  20. The diversity of male nuptial coloration leads to species diversity in Lake Victoria cichlids.

    PubMed

    Miyagi, Ryutaro; Terai, Yohey

    2013-01-01

    The amazing coloration shown by diverse cichlid fish not only fascinates aquarium keepers, but also receives great attention from biologists interested in speciation because of its recently-revealed role in their adaptive radiation in an African lake. We review the important role of coloration in the speciation and adaptive evolution of Lake Victoria cichlids, which have experienced adaptive radiation during a very short evolutionary period. Mature male cichlids display their colors during mate choice. The color of their skin reflects light, and the reflected light forms a color signal that is received by the visual system of females. The adaptive divergence of visual perceptions shapes and diverges colorations, to match the adapted visual perceptions. The divergence of visual perception and coloration indicates that the divergence of color signals causes reproductive isolation between species, and this process leads to speciation. Differences in color signals among coexisting species act to maintain reproductive isolation by preventing hybridization. Thus, the diversity of coloration has caused speciation and has maintained species diversity in Lake Victoria cichlids.

  1. Lake level fluctuations synchronize genetic divergences of cichlid fishes in African lakes.

    PubMed

    Sturmbauer, C; Baric, S; Salzburger, W; Rüber, L; Verheyen, E

    2001-02-01

    Water level fluctuations are important modulators of speciation processes in tropical lakes, in that they temporarily form or break down barriers to gene flow among adjacent populations and/or incipient species. Time estimates of the most recent major lowstands of the three African Great Lakes are thus crucial to infer the relative timescales of explosive speciation events in cichlid species flocks. Our approach combines geological evidence with genetic divergence data of cichlid fishes from the three Great East African Lakes derived from the fastest-evolving mtDNA segment. Thereby, we show for each of the three lakes that individuals sampled from several populations which are currently isolated by long geographic distances and/or deep water form clusters of equally closely related haplotypes. The distribution of identical or equally closely related haplotypes in a lake basin allows delineation of the extent of lake level fluctuations. Our data suggest that the same climatic phenomenon synchronized the onset of genetic divergence of lineages in all three species flocks, such that their most recent evolutionary history seems to be linked to the same external modulators of adaptive radiation. A calibration of the molecular clock of the control region was elaborated by gauging the age of the Lake Malawi species flock through the divergence among the utaka-cichlid and the mbuna-cichlid lineages to minimally 570,000 years and maximally 1 Myr. This suggests that the low-lake-level period which established the observed patterns of genetic relatedness dates back less than 57,000 years, probably even to 17,000-12,400 years ago, when Lake Victoria dried up and Lakes Malawi and Tanganyika were also low. A rapid rise of all three lakes about 11,000 years ago established the large-scale population subdivisions observed today. Over that period of time, a multitude of species originated in Lakes Malawi and Victoria with an impressive degree of morphological and ecological

  2. Species-specific differences in adaptive phenotypic plasticity in an ecologically relevant trophic trait: hypertrophic lips in Midas cichlid fishes.

    PubMed

    Machado-Schiaffino, Gonzalo; Henning, Frederico; Meyer, Axel

    2014-07-01

    The spectacular species richness of cichlids and their diversity in morphology, coloration, and behavior have made them an ideal model for the study of speciation and adaptive evolution. Hypertrophic lips evolved repeatedly and independently in African and Neotropical cichlid radiations. Cichlids with hypertrophic lips forage predominantly in rocky crevices and it has been hypothesized that mechanical stress caused by friction could result in larger lips through phenotypic plasticity. To test the influence of the environment on the size and development of lips, we conducted a series of breeding and feeding experiments on Midas cichlids. Full-sibs of Amphilophus labiatus (thick-lipped) and Amphilophus citrinellus (thin-lipped) each were split into a control group which was fed food from the water column and a treatment group whose food was fixed to substrates. We found strong evidence for phenotypic plasticity on lip area in the thick-lipped species, but not in the thin-lipped species. Intermediate phenotypic values were observed in hybrids from thick- and thin-lipped species reared under "control" conditions. Thus, both a genetic, but also a phenotypic plastic component is involved in the development of hypertrophic lips in Neotropical cichlids. Moreover, species-specific adaptive phenotypic plasticity was found, suggesting that plasticity is selected for in recent thick-lipped species.

  3. Aromatase regulates aggression in the African cichlid fish Astatotilapia burtoni.

    PubMed

    Huffman, Lin S; O'Connell, Lauren A; Hofmann, Hans A

    2013-03-15

    The roles of estrogen and androgens in male social behavior are well studied, but little is known about how these hormones contribute to behavior in a social hierarchy. Here we test the role of aromatase, the enzyme that converts testosterone into estradiol, in mediating aggression and reproductive behavior in male Astatotilapia burtoni, an African cichlid fish that displays remarkable plasticity in social behavior. We first measured aromatase expression in subordinate and dominant males in brain regions that regulate social behavior and found that subordinate males have higher aromatase expression than dominant males in the magnocellular and gigantocellular regions of the preoptic area. Next, we functionally tested the role of aromatase in regulating behavior by intraperitoneally injecting dominant males with either saline or fadrozole (FAD), an aromatase inhibitor, and found that FAD treatment decreases aggressive, but not reproductive, behaviors compared to saline controls. To determine the underlying physiological and molecular consequences of FAD treatment, we measured estradiol and testosterone levels from plasma and brain aromatase expression in FAD and saline treated dominant males. We found that estradiol levels decreased and testosterone levels increased in response to FAD treatment. Moreover, FAD treated males had increased aromatase expression in the gigantocellular portion of the POA, possibly a compensatory response. Overall, our results suggest aromatase is a key enzyme that promotes aggression in A. burtoni males through actions in the preoptic area.

  4. Twelve-Day Reinforcement-Based Memory Retention in African Cichlids (Labidochromis caeruleus)

    PubMed Central

    Ingraham, Erica; Anderson, Nicole D.; Hurd, Peter L.; Hamilton, Trevor J.

    2016-01-01

    The formation of long-term memories for food sources is essential for the survival of most animals. Long-term memory formation in mammalian species has been demonstrated through a variety of conditioning tasks, however, the nature of long-term memory in fish is less known. In the current study, we explored whether African cichlids (Labidochromis caeruleus) could form memories for food-reinforced stimuli that last for 12 days. During the training sessions, fish were reinforced for approaching an upward drifting line grating. After a rest period of 12 days, fish demonstrated a significant preference for the upward drifting grating. To determine whether this preference could also be reversed, fish were then reinforced for approaching a downward drifting line grating after a 20-day rest period. When tested 12 days later, there were no significant differences in preference for either stimulus; however, following a second training period for the downward stimulus, there was a significant preference for the downward drifting grating. This suggests that cichlids are able to form reversible discrimination-based memories for food-reinforced stimuli that remain consolidated for at least 12 days. PMID:27582695

  5. Expression and Sequence Evolution of Aromatase cyp19a1 and Other Sexual Development Genes in East African Cichlid Fishes

    PubMed Central

    Böhne, Astrid; Heule, Corina; Boileau, Nicolas; Salzburger, Walter

    2013-01-01

    Sex determination mechanisms are highly variable across teleost fishes and sexual development is often plastic. Nevertheless, downstream factors establishing the two sexes are presumably conserved. Here, we study sequence evolution and gene expression of core genes of sexual development in a prime model system in evolutionary biology, the East African cichlid fishes. Using the available five cichlid genomes, we test for signs of positive selection in 28 genes including duplicates from the teleost whole-genome duplication, and examine the expression of these candidate genes in three cichlid species. We then focus on a particularly striking case, the A- and B-copies of the aromatase cyp19a1, and detect different evolutionary trajectories: cyp19a1A evolved under strong positive selection, whereas cyp19a1B remained conserved at the protein level, yet is subject to regulatory changes at its transcription start sites. Importantly, we find shifts in gene expression in both copies. Cyp19a1 is considered the most conserved ovary-factor in vertebrates, and in all teleosts investigated so far, cyp19a1A and cyp19a1B are expressed in ovaries and the brain, respectively. This is not the case in cichlids, where we find new expression patterns in two derived lineages: the A-copy gained a novel testis-function in the Ectodine lineage, whereas the B-copy is overexpressed in the testis of the speciest-richest cichlid group, the Haplochromini. This suggests that even key factors of sexual development, including the sex steroid pathway, are not conserved in fish, supporting the idea that flexibility in sexual determination and differentiation may be a driving force of speciation. PMID:23883521

  6. Continental monophyly of cichlid fishes and the phylogenetic position of Heterochromis multidens.

    PubMed

    Keck, Benjamin P; Hulsey, C Darrin

    2014-04-01

    The incredibly species-rich cichlid fish faunas of both the Neotropics and Africa are generally thought to be reciprocally monophyletic. However, the phylogenetic affinity of the African cichlid Heterochromis multidens is ambiguous, and this distinct lineage could make African cichlids paraphyletic. In past studies, Heterochromis has been variously suggested to be one of the earliest diverging lineages within either the Neotropical or the African cichlid radiations, and it has even been hypothesized to be the sister lineage to a clade containing all Neotropical and African cichlids. We examined the phylogenetic relationships among a representative sample of cichlids with a dataset of 29 nuclear loci to assess the support for the different hypotheses of the phylogenetic position of Heterochromis. Although individual gene trees in some instances supported alternative relationships, a majority of gene trees, integration of genes into species trees, and hypothesis testing of putative topologies all supported Heterochromis as belonging to the clade of African cichlids.

  7. The African cichlid fish Astatotilapia burtoni uses acoustic communication for reproduction: sound production, hearing, and behavioral significance.

    PubMed

    Maruska, Karen P; Ung, Uyhun S; Fernald, Russell D

    2012-01-01

    Sexual reproduction in all animals depends on effective communication between signalers and receivers. Many fish species, especially the African cichlids, are well known for their bright coloration and the importance of visual signaling during courtship and mate choice, but little is known about what role acoustic communication plays during mating and how it contributes to sexual selection in this phenotypically diverse group of vertebrates. Here we examined acoustic communication during reproduction in the social cichlid fish, Astatotilapia burtoni. We characterized the sounds and associated behaviors produced by dominant males during courtship, tested for differences in hearing ability associated with female reproductive state and male social status, and then tested the hypothesis that female mate preference is influenced by male sound production. We show that dominant males produce intentional courtship sounds in close proximity to females, and that sounds are spectrally similar to their hearing abilities. Females were 2-5-fold more sensitive to low frequency sounds in the spectral range of male courtship sounds when they were sexually-receptive compared to during the mouthbrooding parental phase. Hearing thresholds were also negatively correlated with circulating sex-steroid levels in females but positively correlated in males, suggesting a potential role for steroids in reproductive-state auditory plasticity. Behavioral experiments showed that receptive females preferred to affiliate with males that were associated with playback of courtship sounds compared to noise controls, indicating that acoustic information is likely important for female mate choice. These data show for the first time in a Tanganyikan cichlid that acoustic communication is important during reproduction as part of a multimodal signaling repertoire, and that perception of auditory information changes depending on the animal's internal physiological state. Our results highlight the

  8. Ancestral and derived attributes of the dlx gene repertoire, cluster structure and expression patterns in an African cichlid fish

    PubMed Central

    2011-01-01

    Background Cichlid fishes have undergone rapid, expansive evolutionary radiations that are manifested in the diversification of their trophic morphologies, tooth patterning and coloration. Understanding the molecular mechanisms that underlie the cichlids' unique patterns of evolution requires a thorough examination of genes that pattern the neural crest, from which these diverse phenotypes are derived. Among those genes, the homeobox-containing Dlx gene family is of particular interest since it is involved in the patterning of the brain, jaws and teeth. Results In this study, we characterized the dlx genes of an African cichlid fish, Astatotilapia burtoni, to provide a baseline to later allow cross-species comparison within Cichlidae. We identified seven dlx paralogs (dlx1a, -2a, -4a, -3b, -4b, -5a and -6a), whose orthologies were validated with molecular phylogenetic trees. The intergenic regions of three dlx gene clusters (dlx1a-2a, dlx3b-4b, and dlx5a-6a) were amplified with long PCR. Intensive cross-species comparison revealed a number of conserved non-coding elements (CNEs) that are shared with other percomorph fishes. This analysis highlighted additional lineage-specific gains/losses of CNEs in different teleost fish lineages and a novel CNE that had previously not been identified. Our gene expression analyses revealed overlapping but distinct expression of dlx orthologs in the developing brain and pharyngeal arches. Notably, four of the seven A. burtoni dlx genes, dlx2a, dlx3b, dlx4a and dlx5a, were expressed in the developing pharyngeal teeth. Conclusion This comparative study of the dlx genes of A. burtoni has deepened our knowledge of the diversity of the Dlx gene family, in terms of gene repertoire, expression patterns and non-coding elements. We have identified possible cichlid lineage-specific changes, including losses of a subset of dlx expression domains in the pharyngeal teeth, which will be the targets of future functional studies. PMID:21205289

  9. Biogeographical implications of Zambezian Cichlidogyrus species (Platyhelminthes: Monogenea: Ancyrocephalidae) parasitizing Congolian cichlids.

    PubMed

    Vanhove, Maarten P M; Van Steenberge, Maarten; Dessein, Steven; Volckaert, Filip A M; Snoeks, Jos; Huyse, Tine; Pariselle, Antoine

    2013-01-22

    Fishes normally restricted to inland waters are valuable model systems for historical biogeography, inter alia, because of their limited dispersal abilities and concordance with the distribution patterns of other freshwater taxa (Zogaris et al. 2009). The comparison of fish species assemblages has been the major biogeographical tool for delineating African aquatic ecoregions as the fossil record is often meagre and merely offers complementary information. This is, for example, the case for the Zambezian and Congolian ichthyofaunal provinces, which display substantial contemporary fish diversity (Stewart 2001). Between both regions lies the Bangweulu-Mweru ecoregion (sensu Scott 2005), known for its high percentage of endemicity. Although hydrographically belonging to the Congo Basin, the Bangweulu-Mweru ecoregion has a high affinity with the Zambezi province (Scott 2005), due to historical river connections (Tweddle 2010). Studies comparing the Zambezi and Congo ichthyofaunal provinces are rare and hampered by lack of data from the Congo Basin. The latter harbours more than 1250 fish species (Snoeks et al. 2011) while in the Zambezi, only 120 freshwater fishes are found (Tweddle 2010). Indeed, species richness declines in all major African teleost families from the Congo Basin southwards, riverine haplochromine cichlids forming a notable exception to this rule (Joyce et al. 2005). Although it was hypothesized by Tweddle (2010) that the origin of many Zambezian fish species is in the Congo Basin, the haplochromines Serranochromis Regan, Sargochromis Regan, Pharyngochromis Greenwood and Chetia Trewavas, together forming the serranochromines, have their centre of diversity in the rivers of the Zambezian ichthyofaunal province (Joyce et al. 2005). Therefore, the biogeographical history of Cichlidae across the Zambezi- Congo watershed is not only key to cichlid biogeography on an African scale, but also complementary to biogeography of all other teleosts in the region

  10. Ecological and Lineage-Specific Factors Drive the Molecular Evolution of Rhodopsin in Cichlid Fishes.

    PubMed

    Torres-Dowdall, Julián; Henning, Frederico; Elmer, Kathryn R; Meyer, Axel

    2015-11-01

    The visual system in the colorful cichlid fishes from the African great lakes is believed to be important for their adaptive radiations. However, few studies have attempted to compare the visual system of radiating cichlid lineages with that of cichlids that have not undergone recent radiations. One such study published in this journal (Schott RK, Refvik SP, Hauser FE, López-Fernández H, Chang BSW. 2014. Divergent positive selection in rhodopsin from lake and riverine cichlid fishes. Mol Biol Evol. 31:1149-1165) found divergent selection on rhodopsin between African lacustrine and riverine cichlid species and riverine Neotropical cichlids, concluding that ecology drives the molecular evolution of this opsin. Here, we expand this analysis by incorporating rhodopsin sequences from Neotropical lacustrine cichlids and show that both ecology and phylogeny are important drivers of the molecular evolution of rhodopsin in cichlids. We found little overlap of sites under selection between African and Neotropical lineages and a faster rate of molecular evolution in African compared with Neotropical cichlids. These results support the notion that genetic or population genetic features particular to African cichlids contributed to their radiations.

  11. The genetic and developmental basis of an exaggerated craniofacial trait in East African cichlids.

    PubMed

    Concannon, Moira R; Albertson, R Craig

    2015-12-01

    The evolution of an exaggerated trait can lead to a novel morphology that allows organisms to exploit new niches. The molecular bases of such phenotypes can reveal insights into the evolution of unique traits. Here, we investigate a rare morphological innovation in modern haplochromine cichlids, a flap of fibrous tissue that causes a pronounced projection of the snout, which is limited to a single genus (Labeotropheus) of Lake Malawi cichlids. We compare flap size in our focal species L. fuelleborni (LF) to homologous landmarks in other closely related cichlid species that show a range of ecological overlap with LF, and demonstrate that variation in flap size is discontinuous among Malawi cichlid species. We demonstrate further that flap development in LF begins at early juvenile stages, and scales allometrically with body size. We then used an F2 hybrid mapping population, derived via crossing LF to a close ecological competitor that lacks this trait, Tropheops "red cheek" (TRC), to identify quantitative trait loci (QTL) that underlie flap development. In all, we identified four loci associated with variation in flap size, and for each the LF allele contributed to a larger flap. We next cross-referenced our QTL map with population genomic data, comparing natural populations of LF and TRC, to identify divergent polymorphisms within each QTL interval. Candidate genes for flap development are discussed. Together, these data indicate a relatively simple and tractable genetic basis for this morphological innovation, which is consistent with its apparently sudden and saltatory evolutionary history. J. Exp. Zool. (Mol. Dev. Evol.) 324B: 662-670, 2015. © 2015 Wiley Periodicals, Inc.

  12. No Experimental Evidence for Sneaking in a West African Cichlid Fish with Extremely Long Sperm

    PubMed Central

    Langen, Kathrin; Thünken, Timo; Bakker, Theo C. M.

    2013-01-01

    Alternative reproductive tactics are widespread in fishes, increasing the potential for sperm competition. Sperm competition has enormous impact on both variation in sperm numbers and sperm size. In cichlids, the sperm competition risk is very divergent and longer sperm are usually interpreted as adaptation to sperm competition. Here we examined whether sneaking tactics exist in Pelvicachromis taeniatus, a socially monogamous cichlid with biparental brood care from West Africa. The small testis indicates low gonadal investment which is typical for genetically monogamous species. In contrast, sperm length with up to 85 μm is extraordinarily long. We examined the reproductive behaviour of ten groups with a male-biased sex ratio under semi-natural conditions via continuous video recording. We recorded spawning site preferences and correlates of reproductive success and conducted paternity tests using microsatellites. Safe breeding sites that could be successfully defended were preferred. All offspring could be assigned to their parents and no multiple paternities were detected. Body size of spawning pairs predicted their spawning probability and offspring hatching rate suggesting benefits from mating with large individuals. Our study suggests low risk of sperm competition under the given conditions in P. taeniatus and thus first evidence for genetic monogamy in a substrate breeding cichlid. PMID:24386589

  13. Species of Gyrodactylus von Nordmann, 1832 (Platyhelminthes: Monogenea) from cichlids from Zambezi and Limpopo river basins in Zimbabwe and South Africa: evidence for unexplored species richness.

    PubMed

    Zahradníčková, Petra; Barson, Maxwell; Luus-Powell, Wilmien J; Přikrylová, Iva

    2016-09-01

    New findings on Gyrodactylus spp. parasitising African cichlids in southern Africa are presented, comprising data from Zimbabwe and South Africa. Morphometry of opisthaptoral hard parts in combination with nuclear ribosomal DNA sequences confirmed the presence of six species of Gyrodactylus von Nordmann, 1832. Three new species are described from fishes in Zimbabwe: Gyrodactylus chitandiri n. sp. from the gill arches of Coptodon rendalli (Boulenger) and Pseudocrenilabrus philander (Weber); Gyrodactylus occupatus n. sp. from the fins of Oreochromis niloticus (L.), Pharyngochromis acuticeps (Steindachner) and P. philander; and Gyrodactylus parisellei n. sp. from the fins of O. niloticus, P. philander and Tilapia sp. Gyrodactylus nyanzae Paperna, 1973 was also identified from the gills of O. niloticus and C. rendalli collected from two localities in Zimbabwe; these findings represent new host and locality records for this parasite. Gyrodactylus sturmbaueri Vanhove, Snoeks, Volckaert & Huyse, 2011 was identified from P. philander collected in South Africa and Zimbabwe thereby providing new host and locality records for this parasite. Finally, Gyrodactylus yacatli García-Vásquez, Hansen, Christison, Bron & Shinn, 2011 was collected from the fins of O. niloticus and P. philander studied in Zimbabwe; this represents the first record of this species from the continent of Africa. Notably, this study improves upon the knowledge of Gyrodactylus spp. parasitising cichlids from these southern African regions. All species studied were recorded from at least two different cichlid host species indicating trend for a wide range of Gyrodactylus hosts in Africa. Accordingly, this supports the idea of intensive host switching in the course of their evolution.

  14. Developmental effects of visual environment on species-assortative mating preferences in Lake Victoria cichlid fish.

    PubMed

    Wright, D S; Demandt, N; Alkema, J T; Seehausen, O; Groothuis, T G G; Maan, M E

    2017-02-01

    Local adaptation can be a potent force in speciation, with environmental heterogeneity leading to niche specialization and population divergence. However, local adaption often requires nonrandom mating to generate reproductive isolation. Population divergence in sensory properties can be particularly consequential in speciation, affecting both ecological adaptation and sexual communication. Pundamilia pundamila and Pundamilia nyererei are two closely related African cichlid species that differ in male coloration, blue vs. red. They co-occur at rocky islands in southern Lake Victoria, but inhabit different depth ranges with different light environments. The species differ in colour vision properties, and females exert species-specific preferences for blue vs. red males. Here, we investigated the mechanistic link between colour vision and preference, which could provide a rapid route to reproductive isolation. We tested the behavioural components of this link by experimentally manipulating colour perception - we raised both species and their hybrids under light conditions mimicking shallow and deep habitats - and tested female preference for blue and red males under both conditions. We found that rearing light significantly affected female preference: shallow-reared females responded more strongly to P. pundamilia males and deep-reared females favoured P. nyererei males - implying that visual development causally affects mate choice. These results are consistent with sensory drive predictions, suggesting that the visual environment is key to behavioural isolation of these species. However, the observed plasticity could also make the species barrier vulnerable to environmental change: species-assortative preferences were weaker in females that were reared in the other species' light condition.

  15. Testing the stages model in the adaptive radiation of cichlid fishes in East African Lake Tanganyika

    PubMed Central

    Muschick, Moritz; Nosil, Patrik; Roesti, Marius; Dittmann, Marie Theres; Harmon, Luke; Salzburger, Walter

    2014-01-01

    Adaptive radiation (AR) is a key process in the origin of organismal diversity. However, the evolution of trait disparity in connection with ecological specialization is still poorly understood. Available models for vertebrate ARs predict that diversification occurs in the form of temporal stages driven by different selective forces. Here, we investigate the AR of cichlid fishes in East African Lake Tanganyika and use macroevolutionary model fitting to evaluate whether diversification happened in temporal stages. Six trait complexes, for which we also provide evidence of their adaptiveness, are analysed with comparative methods: body shape, pharyngeal jaw shape, gill raker traits, gut length, brain weight and body coloration. Overall, we do not find strong evidence for the ‘stages model’ of AR. However, our results suggest that trophic traits diversify earlier than traits implicated in macrohabitat adaptation and that sexual communication traits (i.e. coloration) diversify late in the radiation. PMID:25274371

  16. Chromosome differentiation patterns during cichlid fish evolution

    PubMed Central

    2010-01-01

    Background Cichlid fishes have been the subject of increasing scientific interest because of their rapid adaptive radiation which has led to an extensive ecological diversity and their enormous importance to tropical and subtropical aquaculture. To increase our understanding of chromosome evolution among cichlid species, karyotypes of one Asian, 22 African, and 30 South American cichlid species were investigated, and chromosomal data of the family was reviewed. Results Although there is extensive variation in the karyotypes of cichlid fishes (from 2n = 32 to 2n = 60 chromosomes), the modal chromosome number for South American species was 2n = 48 and the modal number for the African ones was 2n = 44. The only Asian species analyzed, Etroplus maculatus, was observed to have 46 chromosomes. The presence of one or two macro B chromosomes was detected in two African species. The cytogenetic mapping of 18S ribosomal RNA (18S rRNA) gene revealed a variable number of clusters among species varying from two to six. Conclusions The karyotype diversification of cichlids seems to have occurred through several chromosomal rearrangements involving fissions, fusions and inversions. It was possible to identify karyotype markers for the subfamilies Pseudocrenilabrinae (African) and Cichlinae (American). The karyotype analyses did not clarify the phylogenetic relationship among the Cichlinae tribes. On the other hand, the two major groups of Pseudocrenilabrinae (tilapiine and haplochromine) were clearly discriminated based on the characteristics of their karyotypes. The cytogenetic mapping of 18S ribosomal RNA (18S rRNA) gene did not follow the chromosome diversification in the family. The dynamic evolution of the repeated units of rRNA genes generates patterns of chromosomal distribution that do not help follows the phylogenetic relationships among taxa. The presence of B chromosomes in cichlids is of particular interest because they may not be represented in the reference genome

  17. Adaptive divergence between lake and stream populations of an East African cichlid fish.

    PubMed

    Theis, Anya; Ronco, Fabrizia; Indermaur, Adrian; Salzburger, Walter; Egger, Bernd

    2014-11-01

    Divergent natural selection acting in different habitats may build up barriers to gene flow and initiate speciation. This speciation continuum can range from weak or no divergence to strong genetic differentiation between populations. Here, we focus on the early phases of adaptive divergence in the East African cichlid fish Astatotilapia burtoni, which occurs in both Lake Tanganyika (LT) and inflowing rivers. We first assessed the population structure and morphological differences in A. burtoni from southern LT. We then focused on four lake-stream systems and quantified body shape, ecologically relevant traits (gill raker and lower pharyngeal jaw) as well as stomach contents. Our study revealed the presence of several divergent lake-stream populations that rest at different stages of the speciation continuum, but show the same morphological and ecological trajectories along the lake-stream gradient. Lake fish have higher bodies, a more superior mouth position, longer gill rakers and more slender pharyngeal jaws, and they show a plant/algae and zooplankton-biased diet, whereas stream fish feed more on snails, insects and plant seeds. A test for reproductive isolation between closely related lake and stream populations did not detect population-assortative mating. Analyses of F1 offspring reared under common garden conditions indicate that the detected differences in body shape and gill raker length do not constitute pure plastic responses to different environmental conditions, but also have a genetic basis. Taken together, the A. burtoni lake-stream system constitutes a new model to study the factors that enhance and constrain progress towards speciation in cichlid fishes.

  18. Expression of arginine vasotocin in distinct preoptic regions is associated with dominant and subordinate behaviour in an African cichlid fish

    PubMed Central

    Greenwood, Anna K; Wark, Abigail R; Fernald, Russell D; Hofmann, Hans A

    2008-01-01

    Neuropeptides have widespread modulatory effects on behaviour and physiology and are associated with phenotypic transitions in a variety of animals. Arginine vasotocin (AVT) is implicated in mediating alternative male phenotypes in teleost fish, but the direction of the association differs among species, with either higher or lower AVT related to more territorial behaviour in different fishes. To clarify the complex relationship between AVT and alternative phenotype, we evaluated AVT expression in an African cichlid in which social status is associated with divergent behaviour and physiology. We compared AVT mRNA expression between territorial and non-territorial (NT) males in both whole brains and microdissected anterior preoptic areas using transcription profiling, and in individual preoptic nuclei using in situ hybridization. These complementary methods revealed that in the posterior preoptic area (gigantocellular nucleus), territorial males exhibit higher levels of AVT expression than NT males. Conversely, in the anterior preoptic area (parvocellular nucleus), AVT expression is lower in territorial males than NT males. We further correlated AVT expression with behavioural and physiological characteristics of social status to gain insight into the divergent functions of individual AVT nuclei. Overall, our findings highlight a complex association between AVT and social behaviour. PMID:18628117

  19. Local variation and parallel evolution: morphological and genetic diversity across a species complex of neotropical crater lake cichlid fishes

    PubMed Central

    Elmer, Kathryn R.; Kusche, Henrik; Lehtonen, Topi K.; Meyer, Axel

    2010-01-01

    The polychromatic and trophically polymorphic Midas cichlid fish species complex (Amphilophus cf. citrinellus) is an excellent model system for studying the mechanisms of speciation and patterns of phenotypic diversification in allopatry and in sympatry. Here, we first review research to date on the species complex and the geological history of its habitat. We analyse body shape variation from all currently described species in the complex, sampled from six crater lakes (maximally 1.2–23.9 kyr old) and both great lakes in Nicaragua. We find that Midas cichlid populations in each lake have their own characteristic body shape. In lakes with multiple sympatric species of Midas cichlid, each species has a distinct body shape. Across the species complex, most body shape change relates to body depth, head, snout and mouth shape and caudal peduncle length. There is independent parallel evolution of an elongate limnetic species in at least two crater lakes. Mitochondrial genetic diversity is higher in crater lakes with multiple species. Midas cichlid species richness increases with the size and age of the crater lakes, though no such relationship exists for the other syntopic fishes. We suggest that crater lake Midas cichlids follow the predicted pattern of an adaptive radiation, with early divergence of each crater lake colonization, followed by intralacustrine diversification and speciation by ecological adaptation and sexual selection. PMID:20439280

  20. Female preference for males depends on reproductive physiology in the African cichlid fish Astatotilapia burtoni.

    PubMed

    Kidd, Michael R; O'Connell, Lauren A; Kidd, Celeste E; Chen, Christine W; Fontenot, Miles R; Williams, Sidney J; Hofmann, Hans A

    2013-01-01

    Mate choice is fundamental to sexual selection, yet little is known about underlying physiological mechanisms that influence female mating decisions. We investigated the endocrine underpinnings of female mate choice in the African cichlid Astatotilapia burtoni, a non-seasonal breeder. In addition to profiling behavioral and hormonal changes across the female reproductive cycle, we tested two hypotheses regarding possible factors influencing female mate choice. We first asked whether female mate choice is influenced by male visual and/or chemical cues. A. burtoni females were housed for one full reproductive cycle in the center of a dichotomous choice apparatus with a large (attractive) or small (unattractive) conspecific male on either side. Females associated mostly with small, less attractive males, but on the day of spawning reversed their preference to large, attractive males, with whom they mated almost exclusively, although this choice depended on the relative amount of androgens released into the water by small males. We next asked whether male behavior or androgen levels change in relation to the stimulus females' reproductive state. We found that stimulus male aggression decreased and reproductive displays increased as the day of spawning approached. Moreover male testosterone levels changed throughout the females' reproductive cycle, with larger males releasing more testosterone into the water than small males. Our data suggest that female association in a dichotomous choice assay is only indicative of the actual mate choice on the day of spawning. Furthermore, we show that male behavior and hormone levels are dependent on the reproductive state of conspecific females.

  1. Major-histocompatibility-complex variation in two species of cichlid fishes from Lake Malawi.

    PubMed

    Ono, H; O'hUigin, C; Tichy, H; Klein, J

    1993-09-01

    Lake Malawi in eastern Africa harbors > 500 endemic species of cichlid fishes, all of which are believed to have emerged from a single founding population in the past 2 Myr. Molecular characterization of differences among the species could provide important information about the nature of speciation in the period of adaptive radiation. Because of the close relationship, however, molecular variation among the species has been difficult to ascertain. In this communication, we provide evidence for extensive differences, in major-histocompatibility-complex (Mhc) class II genes, between two related species, Pseudotropheus zebra and Melanochromis auratus. We used specific primers to amplify and sequence intron 1 and exon 2 of the class II genes from 18 individuals. Although we found 20 different sequences among the 42 that we produced, there was not a single sequence shared by the two species. Thus the study suggests that different cichlid species of Lake Malawi have different profiles of class II alleles, presumably because the polymorphism present in the ancestral founding population segregated differentially into the various species. These results make Mhc genes an important tool for elucidating speciation.

  2. Hybrid Breakdown in Cichlid Fish

    PubMed Central

    Stelkens, Rike Bahati; Schmid, Corinne; Seehausen, Ole

    2015-01-01

    Studies from a wide diversity of taxa have shown a negative relationship between genetic compatibility and the divergence time of hybridizing genomes. Theory predicts the main breakdown of fitness to happen after the F1 hybrid generation, when heterosis subsides and recessive allelic (Dobzhansky-Muller) incompatibilities are increasingly unmasked. We measured the fitness of F2 hybrids of African haplochromine cichlid fish bred from species pairs spanning several thousand to several million years divergence time. F2 hybrids consistently showed the lowest viability compared to F1 hybrids and non-hybrid crosses (crosses within the grandparental species), in agreement with hybrid breakdown. Especially the short- and long-term survival (2 weeks to 6 months) of F2 hybrids was significantly reduced. Overall, F2 hybrids showed a fitness reduction of 21% compared to F1 hybrids, and a reduction of 43% compared to the grandparental, non-hybrid crosses. We further observed a decrease of F2 hybrid viability with the genetic distance between grandparental lineages, suggesting an important role for negative epistatic interactions in cichlid fish postzygotic isolation. The estimated time window for successful production of F2 hybrids resulting from our data is consistent with the estimated divergence time between the multiple ancestral lineages that presumably hybridized in three major adaptive radiations of African cichlids. PMID:25996870

  3. Social regulation of male reproductive plasticity in an African cichlid fish.

    PubMed

    Maruska, Karen P; Fernald, Russell D

    2013-12-01

    Social interactions with the outcome of a position in a dominance hierarchy can have profound effects on reproductive behavior and physiology, requiring animals to integrate environmental information with their internal physiological state; but how is salient information from the animal's dynamic social environment transformed into adaptive behavioral, physiological, and molecular-level changes? The African cichlid fish, Astatotilapia burtoni, is ideally suited to understand socially controlled reproductive plasticity because activity of the male reproductive (brain-pituitary-gonad) axis is tightly linked to social status. Males form hierarchies in which a small percentage of brightly colored dominant individuals have an active reproductive axis, defend territories, and spawn with females, while the remaining males are subordinate, drably colored, do not hold a territory, and have a suppressed reproductive system with minimal opportunities for spawning. These social phenotypes are plastic and quickly reversible, meaning that individual males may switch between dominant and subordinate status multiple times within a lifetime. Here, we review the rapid and remarkable plasticity that occurs along the entire reproductive axis when males rise in social rank, a transition that has important implications for the operational sex ratio of the population. When males rise in rank, transformations occur in the brain, pituitary, circulation, and testes over short time-scales (minutes to days). Changes are evident in overt behavior, as well as modifications at the physiological, cellular, and molecular levels that regulate reproductive capacity. Widespread changes triggered by a switch in rank highlight the significance of external social information in shaping internal physiology and reproductive competence.

  4. Behavioral and Physiological Plasticity: Rapid Changes during Social Ascent in an African Cichlid Fish

    PubMed Central

    Fernald, Russell D.

    2010-01-01

    In many vertebrates, reproduction is regulated by social interactions in which dominant males control access to females and food. Subordinate males that displace dominant individuals must rapidly adopt behavioral and physiological traits of the higher rank to gain reproductive success. To understand the process of phenotypic plasticity during social ascent, we analyzed the temporal expression pattern of dominance behaviors and circulating androgen levels when socially-suppressed males of an African cichlid fish Astatotilapia burtoni ascended in status. These experiments tested a prediction of the ‘challenge hypothesis’ that, during periods of social instability, male androgen levels are higher than during socially stable times. We found that socially and reproductively suppressed males perform territorial and reproductive behaviors within minutes of an opportunity to ascend in status, and that animals switch from initial expression of territorial behaviors to more reproductive behaviors during territory establishment. Following this rapid response, social stability may be achieved within 1–3 days of social ascent. Consistent with predictions of the ‘challenge hypothesis’, circulating 11-ketotestosterone (11-KT) levels were elevated within 30 min following social opportunity, coincident with increased aggressive behavior. However, territorial behaviors and serum 11-KT levels were then dissociated by 72 hrs after social ascent, suggesting either rapid social stability and/or increased physiological potential for androgen production. This behavioral and physiological plasticity in male A. burtoni suggests that perception of social opportunity triggers a suite of quick changes to facilitate rapid transition towards reproductive success, and reveals important features of social ascent not previously recognized. PMID:20303357

  5. Replicated divergence in cichlid radiations mirrors a major vertebrate innovation.

    PubMed

    McGee, Matthew D; Faircloth, Brant C; Borstein, Samuel R; Zheng, Jimmy; Darrin Hulsey, C; Wainwright, Peter C; Alfaro, Michael E

    2016-01-13

    Decoupling of the upper jaw bones--jaw kinesis--is a distinctive feature of the ray-finned fishes, but it is not clear how the innovation is related to the extraordinary diversity of feeding behaviours and feeding ecology in this group. We address this issue in a lineage of ray-finned fishes that is well known for its ecological and functional diversity--African rift lake cichlids. We sequenced ultraconserved elements to generate a phylogenomic tree of the Lake Tanganyika and Lake Malawi cichlid radiations. We filmed a diverse array of over 50 cichlid species capturing live prey and quantified the extent of jaw kinesis in the premaxillary and maxillary bones. Our combination of phylogenomic and kinematic data reveals a strong association between biting modes of feeding and reduced jaw kinesis, suggesting that the contrasting demands of biting and suction feeding have strongly influenced cranial evolution in both cichlid radiations.

  6. Replicated divergence in cichlid radiations mirrors a major vertebrate innovation

    PubMed Central

    McGee, Matthew D.; Faircloth, Brant C.; Borstein, Samuel R.; Zheng, Jimmy; Darrin Hulsey, C.; Wainwright, Peter C.; Alfaro, Michael E.

    2016-01-01

    Decoupling of the upper jaw bones—jaw kinesis—is a distinctive feature of the ray-finned fishes, but it is not clear how the innovation is related to the extraordinary diversity of feeding behaviours and feeding ecology in this group. We address this issue in a lineage of ray-finned fishes that is well known for its ecological and functional diversity—African rift lake cichlids. We sequenced ultraconserved elements to generate a phylogenomic tree of the Lake Tanganyika and Lake Malawi cichlid radiations. We filmed a diverse array of over 50 cichlid species capturing live prey and quantified the extent of jaw kinesis in the premaxillary and maxillary bones. Our combination of phylogenomic and kinematic data reveals a strong association between biting modes of feeding and reduced jaw kinesis, suggesting that the contrasting demands of biting and suction feeding have strongly influenced cranial evolution in both cichlid radiations. PMID:26763694

  7. Modularity of the Oral Jaws Is Linked to Repeated Changes in the Craniofacial Shape of African Cichlids

    PubMed Central

    Parsons, Kevin J.; Cooper, W. James; Albertson, R. Craig

    2011-01-01

    The African cichlids of the East-African rift-lakes provide one of the most dramatic examples of adaptive radiation known. It has long been thought that functional decoupling of the oral and pharyngeal jaws in cichlids has facilitated their explosive evolution. Recent research has also shown that craniofacial evolution from radiations in lakes Victoria, Malawi, and Tanganyika has occurred along a shared primary axis of shape divergence, whereby the preorbital region of the skull changes in a manner that is, relatively independent from other head regions. We predicted that the preorbital region would comprise a variational module and used an extensive dataset from each lake that allowed us to test this prediction using a model selection approach. Our findings supported the presence of a preorbital module across all lakes, within each lake, and for Malawi, within sand and rock-dwelling clades. However, while a preorbital module was consistently present, notable differences were also observed among groups. Of particular interest, a negative association between patterns of variational modularity was observed between the sand and rock-dwelling clades, a patter consistent with character displacement. These findings provide the basis for further experimental research involving the determination of the developmental and genetic bases of these patterns of modularity. PMID:21716745

  8. The Gut Microbial Community of Midas Cichlid Fish in Repeatedly Evolved Limnetic-Benthic Species Pairs

    PubMed Central

    Frickey, Tancred; Jones, Julia C.; Meyer, Axel

    2014-01-01

    Gut bacterial communities are now known to influence a range of fitness related aspects of organisms. But how different the microbial community is in closely related species, and if these differences can be interpreted as adaptive is still unclear. In this study we compared microbial communities in two sets of closely related sympatric crater lake cichlid fish species pairs that show similar adaptations along the limnetic-benthic axis. The gut microbial community composition differs in the species pair inhabiting the older of two crater lakes. One major difference, relative to other fish, is that in these cichlids that live in hypersaline crater lakes, the microbial community is largely made up of Oceanospirillales (52.28%) which are halotolerant or halophilic bacteria. This analysis opens up further avenues to identify candidate symbiotic or co-evolved bacteria playing a role in adaptation to similar diets and life-styles or even have a role in speciation. Future functional and phylosymbiotic analyses might help to address these issues. PMID:24733403

  9. First description of monogenean parasites in Lake Tanganyika: the cichlid Simochromis diagramma (Teleostei, Cichlidae) harbours a high diversity of Gyrodactylus species (Platyhelminthes, Monogenea).

    PubMed

    Vanhove, Maarten P M; Snoeks, Jos; Volckaert, Filip A M; Huyse, Tine

    2011-03-01

    Lake Tanganyika harbours the most diverse endemic cichlid fish assemblage of Africa, but its monogenean fish parasites have not been investigated. Here we report, for the first time, on the Gyrodactylus parasites in this hotspot of fish biodiversity. Haptor morphometrics and nuclear ribosomal DNA sequences revealed 3 new species on Zambian Simochromis diagramma: Gyrodactylus sturmbaueri n. sp., G. thysi n. sp. and G. zimbae n. sp. Their distinct morphology and strong genetic differentiation suggest that they belong to distant lineages within the genus Gyrodactylus, and phylogenetic reconstructions suggest affinities with other genera of gyrodactylids. Additional U-shaped haptoral plates in G. thysi n. sp. and a second large spine-like structure in the male copulatory organ of G. zimbae seem to represent new features for the genus. Such large diversity on a single host species can probably be explained by host-switching events during the course of evolution, in agreement with the generally accepted concept that ecological transfer is an important aspect of gyrodactylid speciation. Additional parasitological surveys on other host species, covering a broader phylogenetic and geographical range, should clarify the evolutionary history of Gyrodactylidae on cichlids in the African Great Lake and other parts of Africa.

  10. Phylogenetic analysis of cichlid fishes using nuclear DNA markers.

    PubMed

    Sültmann, H; Mayer, W E; Figueroa, F; Tichy, H; Klein, J

    1995-11-01

    The recent explosive adaptive radiation of cichlids in the great lakes of Africa has attracted the attention of both morphologists and molecular biologists. To decipher the phylogenetic relationships among the various taxa within the family Cichlidae is a prerequisite for answering some fundamental questions about the nature of the speciation process. In the present study, we used the random amplification of polymorphic DNA (RAPD) technique to obtain sequence differences between selected cichlid species. We then designed specific primers based on these sequences and used them to amplify template DNA from a large number of species by the polymerase chain reaction (PCR). We sequenced the amplified products and searched the sequences for indels and shared substitutions. We identified a number of such characters at three loci--DXTU1, DXTU2, and DXTU3--and used them for phylogenetic and cladistic analysis of the relationships among the various cichlid groups. Our studies assign an outgroup position to Neotropical cichlids in relation to African cichlids, provide evidence for a sister-group relationship of tilapiines to the haplochromines, group Cyphotilapia frontosa with the lamprologines of Lake Tanganyika, place Astatoreochromis alluaudi to an outgroup position with respect to other haplochromines of Lakes Victoria and Malawi, and provide additional support for the monophyly of the remaining Lake Victoria haplochromines and the Lake Malawi haplochromines. The described approach holds great promise for further resolution of cichlid phylogeny.

  11. Comparative cytogenetics of ten species of cichlid fishes (Teleostei, Cichlidae) from the Araguaia River system, Brazil, by conventional cytogenetic methods.

    PubMed

    Valente, G Targino; Vitorino, C de Andrade; Cabral-de-Mello, D C; Oliveira, C; Souza, I Lima; Martins, C; Venere, P C

    2012-01-01

    Cichlids represent one of the most species-rich families of fishes and have attracted the attention of evolutionary biologists due to the rapid radiation occurring in some groups and the importance of some species in the world aquaculture. Cytogenetic analysis was conducted in 10 cichlid species from the Araguaia River, Amazon Basin, Brazil. The chromosome number was 2n=48 for all analyzed species except for Laetacara araguaiae Ottoni et Costa, 2009 (2n=44). Chromosomal polymorphism was detected only in Geophagus proximus (Castelnau, 1855), which exhibits an extra large submetacentric and and a dot-like chromosomes. Moreover, the C-banding revealed a general pericentromeric heterochromatic pattern and some additional blocks for some species. The heterochromatic blocks corresponding to AgNOR bearing regions were observed in all species and also corresponded to CMA3 positive blocks, which were observed in terminal regions. Besides the general conserved chromosomal and heterochromatin patterns for South American cichlids, the presence of GC-rich heterochromatin was quite different in the species Biotodoma cupido (Heckel, 1840), Geophagus proximus, Retroculus lapidifer (Castelnau, 1855), Crenicichla strigata Günther, 1862 and Heros efasciatus Heckel, 1840. The results suggest that independent events of heterochromatin modification occurred during chromosome evolution in the group, regardless of the conservation of macro-chromosomal structure.

  12. Water pH during early development influences sex ratio and male morph in a West African cichlid fish, Pelvicachromis pulcher.

    PubMed

    Reddon, Adam R; Hurd, Peter L

    2013-06-01

    Environmental sex determination (ESD) is one of the most striking examples of phenotypic plasticity. Individuals from species that exhibit ESD can develop as either males or females depending on the particular environmental conditions they experience during early development. In fish, ESD species often show a relatively subtle effect of environment, resulting in a substantial number of both sexes being produced in both male- and female-biasing conditions, rather than the unisex clutches that are typical of many reptiles. This less dramatic form of ESD allows the opportunity to study the effects of sexual differentiation on within-sex variation in behavior and morphology by comparing same-sex individuals produced in male- and female-biasing conditions. Here, we confirm that sex determination in the West African cichlid, Pelvicachromis pulcher, is influenced by pH during early development. We show that pH also affects the ratio of two alternative male reproductive types with the polygynous morph being overproduced in male-biasing conditions and the monogamous male morph being overproduced in female-biasing conditions. Our results suggest that the sexual differentiation process may be an important force in maintaining individual variation in behavior and reproductive tactics.

  13. Females of an African cichlid fish display male-typical social dominance behavior and elevated androgens in the absence of males.

    PubMed

    Renn, Suzy C P; Fraser, Eleanor J; Aubin-Horth, Nadia; Trainor, Brian C; Hofmann, Hans A

    2012-04-01

    Social environment can affect the expression of sex-typical behavior in both males and females. Males of the African cichlid species Astatotilapia burtoni have long served as a model system to study the neural, endocrine, and molecular basis of socially plastic dominance behavior. Here we show that in all-female communities of A. burtoni, some individuals acquire a male-typical dominance phenotype, including aggressive territorial defense, distinctive color patterns, and courtship behavior. Furthermore, dominant females have higher levels of circulating androgens than either subordinate females or females in mixed-sex communities. These male-typical traits do not involve sex change, nor do the social phenotypes in all-female communities differ in relative ovarian size, suggesting that factors other than gonadal physiology underlie much of the observed variation. In contrast to the well-studied situation in males, dominant and subordinate females do not differ in the rate of somatic growth. Dominant females are not any more likely than subordinates to spawn with an introduced male, although they do so sooner. These results extend the well known extraordinary behavioral plasticity of A. burtoni to the females of this species and provide a foundation for uncovering the neural and molecular basis of social dominance behavior while controlling for factors such as sex, gonadal state and growth.

  14. Phylogeography, colonization and population history of the Midas cichlid species complex (Amphilophus spp.) in the Nicaraguan crater lakes

    PubMed Central

    2010-01-01

    Background Elucidation of the mechanisms driving speciation requires detailed knowledge about the phylogenetic relationships and phylogeography of the incipient species within their entire ranges as well as their colonization history. The Midas cichlid species complex Amphilophus spp. has been proven to be a powerful model system for the study of ecological specialization, sexual selection and the mechanisms of sympatric speciation. Here we present a comprehensive and integrative phylogeographic analysis of the complete Midas Cichlid species complex in Nicaragua (> 2000 individuals) covering the entire distributional range, using two types of molecular markers (the mitochondrial DNA control region and 15 microsatellites). We investigated the majority of known lake populations of this species complex and reconstructed their colonization history in order to distinguish between alternative speciation scenarios. Results We found that the large lakes contain older and more diverse Midas Cichlid populations, while all crater lakes hold younger and genetically less variable species assemblages. The large lakes appear to have repeatedly acted as source populations for all crater lakes, and our data indicate that faunal exchange among crater lakes is extremely unlikely. Despite their very recent (often only a few thousand years old) and common origin from the two large Nicaraguan lakes, all crater lake Midas Cichlid radiations underwent independent, but parallel, evolution, and comprise distinct genetic units. Indeed several of these crater lakes contain multiple genetically distinct incipient species that most likely arose through sympatric speciation. Several crater lake radiations can be traced back to a single ancestral line, but some appear to have more than one founding lineage. The timing of the colonization(s) of each crater lake differs, although most of them occurred more (probably much more) recently than 20,000 years ago. Conclusion The genetic differentiation

  15. The genetics of mate preferences in hybrids between two young and sympatric Lake Victoria cichlid species.

    PubMed

    Svensson, Ola; Woodhouse, Katie; van Oosterhout, Cock; Smith, Alan; Turner, George F; Seehausen, Ole

    2017-02-22

    The genetic architecture of mate preferences is likely to affect significant evolutionary processes, including speciation and hybridization. Here, we investigate laboratory hybrids between a pair of sympatric Lake Victoria cichlid fish species that appear to have recently evolved from a hybrid population between similar predecessor species. The species demonstrate strong assortative mating in the laboratory, associated with divergent male breeding coloration (red dorsum versus blue). We show in a common garden experiment, using DNA-based paternity testing, that the strong female mate preferences among males of the two species are fully recovered in a large fraction of their F2 hybrid generation. Individual hybrid females often demonstrated consistent preferences in multiple mate choice trials (more than or equal to five) across a year or more. This result suggests that female mate preference is influenced by relatively few major genes or genomic regions. These preferences were not changed by experience of a successful spawning event with a male of the non-preferred species in a no-choice single-male trial. We found no evidence for imprinting in the F2 hybrids, although the F1 hybrid females may have been imprinted on their mothers. We discuss this nearly Mendelian inheritance of consistent innate mate preferences in the context of speciation theory.

  16. Two new species of zooplanktivorous haplochromine cichlids from Lake Victoria, Tanzania

    PubMed Central

    de Zeeuw, Marnix P.; Westbroek, Irene; van Oijen, Martien J.P.; Witte, Frans

    2013-01-01

    Abstract Two new species of zooplanktivorous haplochromine cichlids from Lake Victoria, Tanzania, are described and illustrated. These species closely resemble each other. Their affinities to other zooplanktivorous haplochromines from Lake Victoria are discussed. Haplochromis argens sp. n., which featured under nicknames (mainly Haplochromis “argens”) in more than 50 papers, was caught both in the Mwanza Gulf and the Emin Pasha Gulf, whereas Haplochromis goldschmidti sp. n. was only found in the Emin Pasha Gulf. Of the latter species only males are available, but it seems unlikely that it represents a case of male colour polymorphism as several presumably unrelated characters differ in sympatry between the two species, suggesting that there is no gene flow. Statistical analysis revealed that the overall difference between the two species is greater than that between the populations from the two locations. Body depth of the two species in sympatry in the Emin Pasha Gulf was more similar than that of Haplochromis goldschmidti sp. n. and the allopatric population of Haplochromis argens sp. n. from the Mwanza Gulf,which mayindicate an overall environmental effect. However, several measurements related to the width of snout and mouth differed more between the populations of the two species in sympatry than between the allopatric populations. In contrast to a group of zooplanktivorous species that recovered successfully after environmental changes in the lake, Haplochromis argens sp. n. is among a group that became extremely rare and probably is in danger of extinction; the conservation status of Haplochromis goldschmidti sp. n. is currently unknown. PMID:23717179

  17. Genomic islands of speciation separate cichlid ecomorphs in an East African crater lake*

    PubMed Central

    Tyers, Alexandra M.; Schiffels, Stephan; Terai, Yohey; Ngatunga, Benjamin P.; Miska, Eric A.; Durbin, Richard; Genner, Martin J.; Turner, George F.

    2015-01-01

    The genomic causes and effects of divergent ecological selection during speciation are still poorly understood. Here, we report the discovery and detailed characterization of early-stage adaptive divergence of two cichlid fish ecomorphs in a small (700m diameter) isolated crater lake in Tanzania. The ecomorphs differ in depth preference, male breeding color, body shape, diet and trophic morphology. With whole genome sequences of 146 fish, we identify 98 clearly demarcated genomic ‘islands’ of high differentiation and demonstrate association of genotypes across these islands to divergent mate preferences. The islands contain candidate adaptive genes enriched for functions in sensory perception (including rhodopsin and other twilight vision associated genes), hormone signaling and morphogenesis. Our study suggests mechanisms and genomic regions that may play a role in the closely related mega-radiation of Lake Malawi. PMID:26680190

  18. Sensory drive in cichlid speciation.

    PubMed

    Maan, Martine E; Hofker, Kees D; van Alphen, Jacques J M; Seehausen, Ole

    2006-06-01

    The role of selection in speciation is a central yet poorly understood problem in evolutionary biology. The rapid radiations of extremely colorful cichlid fish in African lakes have fueled the hypothesis that sexual selection can drive species divergence without geographical isolation. Here we present experimental evidence for a mechanism by which sexual selection becomes divergent: in two sibling species from Lake Victoria, female mating preferences for red and blue male nuptial coloration coincide with their context-independent sensitivities to red and blue light, which in turn correspond to a difference in ambient light in the natural habitat of the species. These results suggest that natural selection on visual performance, favoring different visual properties in different spectral environments, may lead to divergent sexual selection on male nuptial coloration. This interplay of ecological and sexual selection along a light gradient may provide a mechanism of rapid speciation through divergent sensory drive.

  19. A tribal level phylogeny of Lake Tanganyika cichlid fishes based on a genomic multi-marker approach.

    PubMed

    Meyer, Britta S; Matschiner, Michael; Salzburger, Walter

    2015-02-01

    The species-flocks of cichlid fishes in the East African Great Lakes Victoria, Malawi and Tanganyika constitute the most diverse extant adaptive radiations in vertebrates. Lake Tanganyika, the oldest of the lakes, harbors the morphologically and genetically most diverse assemblage of cichlids and contains the highest number of endemic cichlid genera of all African lakes. Based on morphological grounds, the Tanganyikan cichlid species have been grouped into 12-16 distinct lineages, so-called tribes. While the monophyly of most of the tribes is well established, the phylogenetic relationships among the tribes remain largely elusive. Here, we present a new tribal level phylogenetic hypothesis for the cichlid fishes of Lake Tanganyika that is based on the so far largest set of nuclear markers and a total alignment length of close to 18kb. Using next-generation amplicon sequencing with the 454 pyrosequencing technology, we compiled a dataset consisting of 42 nuclear loci in 45 East African cichlid species, which we subjected to maximum likelihood and Bayesian inference phylogenetic analyses. We analyzed the entire concatenated dataset and each marker individually, and performed a Bayesian concordance analysis and gene tree discordance tests. Overall, we find strong support for a position of the Oreochromini, Boulengerochromini, Bathybatini and Trematocarini outside of a clade combining the substrate spawning Lamprologini and the mouthbrooding tribes of the 'H-lineage', which are both strongly supported to be monophyletic. The Eretmodini are firmly placed within the 'H-lineage', as sister-group to the most species-rich tribe of cichlids, the Haplochromini. The phylogenetic relationships at the base of the 'H-lineage' received less support, which is likely due to high speciation rates in the early phase of the radiation. Discordance among gene trees and marker sets further suggests the occurrence of past hybridization and/or incomplete lineage sorting in the cichlid

  20. Species-Specific Relationships between Water Transparency and Male Coloration within and between Two Closely Related Lake Victoria Cichlid Species.

    PubMed

    Castillo Cajas, Ruth F; Selz, Oliver M; Ripmeester, Erwin A P; Seehausen, Ole; Maan, Martine E

    2012-01-01

    Environmental variation in signalling conditions affects animal communication traits, with possible consequences for sexual selection and reproductive isolation. Using spectrophotometry, we studied how male coloration within and between populations of two closely related Lake Victoria cichlid species (Pundamilia pundamilia and P. nyererei) covaries with water transparency. Focusing on coloration patches implicated in sexual selection, we predicted that in clear waters, with broad-spectrum light, (1) colours should become more saturated and (2) shift in hue away from the dominant ambient wavelengths, compared to more turbid waters. We found support for these predictions for the red and yellow coloration of P. nyererei but not the blue coloration of P. pundamilia. This may be explained by the species difference in depth distribution, which generates a steeper gradient in visual conditions for P. nyererei compared to P. pundamilia. Alternatively, the importance of male coloration in intraspecific sexual selection may differ between the species. We also found that anal fin spots, that is, the orange spots on male haplochromine anal fins that presumably mimic eggs, covaried with water transparency in a similar way for both species. This is in contrast to the other body regions studied and suggests that, while indeed functioning as signals, these spots may not play a role in species differentiation.

  1. Recent speciation between sympatric Tanganyikan cichlid colour morphs.

    PubMed

    Wagner, Catherine E; McCune, Amy R; Lovette, Irby J

    2012-07-01

    Lake Tanganyika, Africa's oldest lake, harbours an impressive diversity of cichlid fishes. Although diversification in its radiating groups is thought to have been initially rapid, cichlids from Lake Tanganyika show little evidence for ongoing speciation. In contrast, examples of recent divergence among sympatric colour morphs are well known in haplochromine cichlids from Lakes Malawi and Victoria. Here, we report genetic evidence for recent divergence between two sympatric Tanganyikan cichlid colour morphs. These Petrochromis morphs share mitochondrial haplotypes, yet microsatellite loci reveal that their sympatric populations form distinct genetic groups. Nuclear divergence between the two morphs is equivalent to that which arises geographically within one of the morphs over short distances and is substantially smaller than that among other sympatric species in this genus. These patterns suggest that these morphs diverged only recently, yet that barriers to gene flow exist which prevent extensive admixture despite their sympatric distribution. The morphs studied here provide an unusual example of active diversification in Lake Tanganyika's generally ancient cichlid fauna and enable comparisons of speciation processes between Lake Tanganyika and other African lakes.

  2. Genetic population structure indicates sympatric speciation of Lake Malawi pelagic cichlids.

    PubMed Central

    Shaw, P W; Turner, G F; Idid, M R; Robinson, R L; Carvalho, G R

    2000-01-01

    Allopatric processes of speciation have routinely been presented to explain the extraordinary radiation of the East African Great Lakes cichlid fish species flocks. The 21 or more species of pelagic cichlids within the Lake Malawi flock appear to have lake-wide distributions that challenge such a concept. Data from six microsatellite DNA loci indicate single, panmictic populations across the lake of three Diplotaxodon species. Levels of variability at these loci suggest that populations have been large and stable. Mitochondrial DNA sequence data (872 bp of control region + 981 bp of the NADH-2) from 90 species, representing all major clades within the Lake Malawi flock, indicate reciprocal monophyly of the pelagic clade. We suggest that these data support a hypothesis that speciation in sympatry is more plausible (and widespread) within the cichlid species flocks than previously thought. PMID:11413643

  3. Evolution of opercle shape in cichlid fishes from Lake Tanganyika - adaptive trait interactions in extant and extinct species flocks

    PubMed Central

    Wilson, Laura A. B.; Colombo, Marco; Sánchez-Villagra, Marcelo R.; Salzburger, Walter

    2015-01-01

    Phenotype-environment correlations and the evolution of trait interactions in adaptive radiations have been widely studied to gain insight into the dynamics underpinning rapid species diversification. In this study we explore the phenotype-environment correlation and evolution of operculum shape in cichlid fishes using an outline-based geometric morphometric approach combined with stable isotope indicators of macrohabitat and trophic niche. We then apply our method to a sample of extinct saurichthyid fishes, a highly diverse and near globally distributed group of actinopterygians occurring throughout the Triassic, to assess the utility of extant data to inform our understanding of ecomorphological evolution in extinct species flocks. A series of comparative methods were used to analyze shape data for 54 extant species of cichlids (N = 416), and 6 extinct species of saurichthyids (N = 44). Results provide evidence for a relationship between operculum shape and feeding ecology, a concentration in shape evolution towards present along with evidence for convergence in form, and significant correlation between the major axes of shape change and measures of gut length and body elongation. The operculum is one of few features that can be compared in extant and extinct groups, enabling reconstruction of phenotype-environment interactions and modes of evolutionary diversification in deep time. PMID:26584885

  4. At the edge of the thermal window: effects of elevated temperature on the resting metabolism, hypoxia tolerance and upper critical thermal limit of a widespread African cichlid

    PubMed Central

    McDonnell, Laura H.; Chapman, Lauren J.

    2015-01-01

    Tropical inland fishes are predicted to be especially vulnerable to thermal stress because they experience small temperature fluctuations that may select for narrow thermal windows. In this study, we measured resting metabolic rate (RMR), critical oxygen tension (Pcrit) and critical thermal maximum (CTMax) of the widespread African cichlid (Pseudocrenilabrus multicolor victoriae) in response to short-term acclimation to temperatures within and above their natural thermal range. Pseudocrenilabrus multicolor collected in Lake Kayanja, Uganda, a population living near the upper thermal range of the species, were acclimated to 23, 26, 29 and 32°C for 3 days directly after capture, and RMR and Pcrit were then quantified. In a second group of P. multicolor from the same population, CTMax and the thermal onset of agitation were determined for fish acclimated to 26, 29 and 32°C for 7 days. Both RMR and Pcrit were significantly higher in fish acclimated to 32°C, indicating decreased tolerance to hypoxia and increased metabolic requirements at temperatures only slightly (∼1°C) above their natural thermal range. The CTMax increased with acclimation temperature, indicating some degree of thermal compensation induced by short-term exposure to higher temperatures. However, agitation temperature (likely to represent an avoidance response to increased temperature during CTMax trials) showed no increase with acclimation temperature. Overall, the results of this study demonstrate that P. multicolor is able to maintain its RMR and Pcrit across the range of temperatures characteristic of its natural habitat, but incurs a higher cost of resting metabolism and reduced hypoxia tolerance at temperatures slightly above its present range. PMID:27293734

  5. Variable light environments induce plastic spectral tuning by regional opsin coexpression in the African cichlid fish, Metriaclima zebra

    PubMed Central

    Dalton, Brian E.; Lu, Jessica; Leips, Jeff; Cronin, Thomas W.; Carleton, Karen L.

    2015-01-01

    Critical behaviors such as predation and mate choice often depend on vision. Visual systems are sensitive to the spectrum of light in their environment, which can vary extensively both within and among habitats. Evolutionary changes in spectral sensitivity contribute to divergence and speciation. Spectral sensitivity of the retina is primarily determined by visual pigments, which are opsin proteins bound to a chromophore. We recently discovered that photoreceptors in different regions of the retina, which view objects against distinct environmental backgrounds, coexpress different pairs of opsins in an African cichlid fish, Metriaclima zebra. This coexpression tunes the sensitivity of the retinal regions to the corresponding backgrounds and may aid detection of dark objects, such as predators. Although intraretinal regionalization of spectral sensitivity in many animals correlates with their light environments, it is unknown whether variation in the light environment induces developmentally plastic alterations of intraretinal sensitivity regions. Here, we demonstrate with fluorescent in situ hybridization and qPCR that the spectrum and angle of environmental light both influence the development of spectral sensitivity regions by altering the distribution and level of opsins across the retina. Normally M. zebra coexpresses LWS opsin with RH2Aα opsin in double cones of the ventral but not the dorsal retina. However, when illuminated from below throughout development, adult M. zebra coexpressed LWS and RH2Aα in double cones both dorsally and ventrally. Thus, environmental background spectra alter the spectral sensitivity pattern that develops across the retina, potentially influencing behaviors and related evolutionary processes such as courtship and speciation. PMID:26175094

  6. Social opportunity causes rapid transcriptional changes in the social behaviour network of the brain in an African cichlid fish.

    PubMed

    Maruska, K P; Zhang, A; Neboori, A; Fernald, R D

    2013-02-01

    Animals constantly integrate external stimuli with their own internal physiological state to make appropriate behavioural decisions. Little is known, however, about where in the brain the salience of these signals is evaluated, or which neural and transcriptional mechanisms link this integration to adaptive behaviours. We used an African cichlid fish Astatotilapia burtoni to test the hypothesis that a new social opportunity activates the conserved 'social behaviour network' (SBN), a collection of brain nuclei known to regulate social behaviours across vertebrates. We measured mRNA levels of immediate early genes (IEGs) in microdissected brain regions as a proxy for neuronal activation, and discovered that IEGs were higher in all SBN nuclei in males that were given an opportunity to rise in social rank compared to control stable subordinate and dominant individuals. Furthermore, because the presence of sex-steroid receptors is one defining criteria of SBN nuclei, we also tested whether social opportunity or status influenced androgen and oestrogen receptor mRNA levels within these same regions. There were several rapid region-specific changes in receptor mRNA levels induced by social opportunity, most notably in oestrogen receptor subtypes in areas that regulate social aggression and reproduction, suggesting that oestrogenic signalling pathways play an important role in regulating male status. Several receptor mRNA changes occurred in regions with putative homologies to the mammalian septum and extended amygdala, two regions shared by SBN and reward circuits, suggesting an important role in the integration of social salience, stressors, hormonal state and adaptive behaviours. We also demonstrated increases in plasma sex- and stress-steroids at 30 min after a rise in social rank. This rapid endocrine and transcriptional response suggests that the SBN is involved in the integration of social inputs with internal hormonal state to facilitate the transition to dominant

  7. Water-level fluctuations and metapopulation dynamics as drivers of genetic diversity in populations of three Tanganyikan cichlid fish species

    PubMed Central

    Nevado, B; Mautner, S; Sturmbauer, C; Verheyen, E

    2013-01-01

    Understanding how genetic variation is generated and maintained in natural populations, and how this process unfolds in a changing environment, remains a central issue in biological research. In this work, we analysed patterns of genetic diversity from several populations of three cichlid species from Lake Tanganyika in parallel, using the mitochondrial DNA control region. We sampled populations inhabiting the littoral rocky habitats in both very deep and very shallow areas of the lake. We hypothesized that the former would constitute relatively older, more stable and genetically more diverse populations, because they should have been less severely affected by the well-documented episodes of dramatic water-level fluctuations. In agreement with our predictions, populations of all three species sampled in very shallow shorelines showed traces of stronger population growth than populations of the same species inhabiting deep shorelines. However, contrary to our working hypothesis, we found a significant trend towards increased genetic diversity in the younger, demographically less stable populations inhabiting shallow areas, in comparison with the older and more stable populations inhabiting the deep shorelines. We interpret this finding as the result of the establishment of metapopulation dynamics in the former shorelines, by the frequent perturbation and reshuffling of individuals between populations due to the lake-level fluctuations. The repeated succession of periods of allopatric separation and secondary contact is likely to have further increased the rapid pace of speciation in lacustrine cichlids. PMID:23837841

  8. Do constructional constraints influence cichlid craniofacial diversification?

    PubMed Central

    Hulsey, C.D; Mims, M.C; Streelman, J.T

    2007-01-01

    Constraints on form should determine how organisms diversify. Owing to competition for the limited space within the body, investment in adjacent structures may frequently represent an evolutionary compromise. For example, evolutionary trade-offs between eye size and jaw muscles in cichlid fish of the African great lakes are thought to represent a constructional constraint that influenced the diversification of these assemblages. To test the evolutionary independence of these structures in Lake Malawi cichlid fish, we measured the mass of the three major adductor mandibulae (AM) muscles and determined the eye volume in 41 species. Using both traditional and novel methodologies to control for resolved and unresolved phylogenetic relationships, we tested the evolutionary independence of these four structures. We found that evolutionary change in the AM muscles was positively correlated, suggesting that competition for space in the head has not influenced diversification among these jaw muscles. Furthermore, there was no negative relationship between change in total AM muscle mass and eye volume, indicating that there has been little effect of the evolution of eye size on AM evolution in Lake Malawi cichlids. The comparative approach used here should provide a robust method to test whether constructional constraints frequently limit phenotypic change in adaptive radiations. PMID:17519189

  9. Genome-wide RAD sequence data provide unprecedented resolution of species boundaries and relationships in the Lake Victoria cichlid adaptive radiation.

    PubMed

    Wagner, Catherine E; Keller, Irene; Wittwer, Samuel; Selz, Oliver M; Mwaiko, Salome; Greuter, Lucie; Sivasundar, Arjun; Seehausen, Ole

    2013-02-01

    Although population genomic studies using next generation sequencing (NGS) data are becoming increasingly common, studies focusing on phylogenetic inference using these data are in their infancy. Here, we use NGS data generated from reduced representation genomic libraries of restriction-site-associated DNA (RAD) markers to infer phylogenetic relationships among 16 species of cichlid fishes from a single rocky island community within Lake Victoria's cichlid adaptive radiation. Previous attempts at sequence-based phylogenetic analyses in Victoria cichlids have shown extensive sharing of genetic variation among species and no resolution of species or higher-level relationships. These patterns have generally been attributed to the very recent origin (<15,000 years) of the radiation, and ongoing hybridization between species. We show that as we increase the amount of sequence data used in phylogenetic analyses, we produce phylogenetic trees with unprecedented resolution for this group. In trees derived from our largest data supermatrices (3 to >5.8 million base pairs in width), species are reciprocally monophyletic with high bootstrap support, and the majority of internal branches on the tree have high support. Given the difficulty of the phylogenetic problem that the Lake Victoria cichlid adaptive radiation represents, these results are striking. The strict interpretation of the topologies we present here warrants caution because many questions remain about phylogenetic inference with very large genomic data set and because we can with the current analysis not distinguish between effects of shared ancestry and post-speciation gene flow. However, these results provide the first conclusive evidence for the monophyly of species in the Lake Victoria cichlid radiation and demonstrate the power that NGS data sets hold to resolve even the most difficult of phylogenetic challenges.

  10. Lake Tanganyika—A 'Melting Pot' of Ancient and Young Cichlid Lineages (Teleostei: Cichlidae)?

    PubMed Central

    Weiss, Juliane D.; Cotterill, Fenton P. D.; Schliewen, Ulrich K.

    2015-01-01

    A long history of research focused on the East Africa cichlid radiations (EAR) revealed discrepancies between mtDNA and nuclear phylogenies, suggesting that interspecific hybridisation may have been significant during the radiation of these fishes. The approximately 250 cichlid species of Lake Tanganyika have their roots in a monophyletic African cichlid assemblage, but controversies remain about the precise phylogenetic origin and placement of different lineages and consequently about L. Tanganyika colonization scenarios. 3312 AFLP loci and the mitochondrial ND2 gene were genotyped for 91 species representing almost all major lacustrine and riverine haplotilapiine east African cichlid lineages with a focus on L. Tanganyika endemics. Explicitly testing for the possibility of ancient hybridisation events, a comprehensive phylogenetic network hypothesis is proposed for the origin and diversification of L. Tanganyika cichlids. Inference of discordant phylogenetic signal strongly suggests that the genomes of two endemic L. Tanganyika tribes, Eretmodini and Tropheini, are composed of an ancient mixture of riverine and lacustrine lineages. For the first time a strong monophyly signal of all non-haplochromine mouthbrooding species endemic to L. Tanganyika (“ancient mouthbrooders”) was detected. Further, in the genomes of early diverging L. Tanganyika endemics Trematocarini, Bathybatini, Hemibatini and Boulengerochromis genetic components of other lineages belonging to the East African Radiation appear to be present. In combination with recent palaeo-geological results showing that tectonic activity in the L. Tanganyika region resulted in highly dynamic and heterogeneous landscape evolution over the Neogene and Pleistocene, the novel phylogenetic data render a single lacustrine basin as the geographical cradle of the endemic L. Tanganyika cichlid lineages unlikely. Instead a scenario of a pre-rift origin of several independent L. Tanganyika precursor lineages which

  11. Mix and match color vision: tuning spectral sensitivity by differential opsin gene expression in Lake Malawi cichlids.

    PubMed

    Parry, Juliet W L; Carleton, Karen L; Spady, Tyrone; Carboo, Aba; Hunt, David M; Bowmaker, James K

    2005-10-11

    Cichlid fish of the East African Rift Lakes are renowned for their diversity and offer a unique opportunity to study adaptive changes in the visual system in rapidly evolving species flocks. Since color plays a significant role in mate choice, differences in visual sensitivities could greatly influence and even drive speciation of cichlids. Lake Malawi cichlids inhabiting rock and sand habitats have significantly different cone spectral sensitivities. By combining microspectrophotometry (MSP) of isolated cones, sequencing of opsin genes, and spectral analysis of recombinant pigments, we have established the cone complements of four species of Malawi cichlids. MSP demonstrated that each of these species predominately expresses three cone pigments, although these differ between species to give three spectrally different cone complements. In addition, rare populations of spectrally distinct cones were found. In total, seven spectral classes were identified. This was confirmed by opsin gene sequencing, expression, and in vitro reconstitution. The genes represent the four major classes of cone opsin genes that diverged early in vertebrate evolution. All four species possess a long-wave-sensitive (LWS), three spectrally distinct green-sensitive (RH2), a blue-sensitive (SWS2A), a violet-sensitive (SWS2B), and an ultraviolet-sensitive (SWS1) opsin. However, African cichlids determine their spectral sensitivity by differential expression of primarily only three of the seven available cone opsin genes. Phylogenetic analysis suggests that all percomorph fish have similar potential.

  12. Simultaneous delimitation of species and quantification of interspecific hybridization in Amazonian peacock cichlids (genus cichla) using multi-locus data

    PubMed Central

    2012-01-01

    Background Introgression likely plays a significant role in evolution, but understanding the extent and consequences of this process requires a clear identification of species boundaries in each focal group. The delimitation of species, however, is a contentious endeavor. This is true not only because of the inadequacy of current tools to identify species lineages, but also because of the inherent ambiguity between natural populations and species paradigms. The result has been a debate about the supremacy of various species concepts and criteria. Here, we utilized multiple separate sources of molecular data, mtDNA, nuclear sequences, and microsatellites, to delimit species under a polytypic species concept (PTSC) and estimate the frequency and genomic extent of introgression in a Neotropical genus of cichlid fishes (Cichla). We compared our inferences of species boundaries and introgression under this paradigm to those when species are identified under a diagnostic species concept (DSC). Results We find that, based on extensive molecular data and an inclusive species concept, 8 separate biological entities should be recognized rather than the 15 described species of Cichla. Under the PTSC, fewer individuals are expected to exhibit hybrid ancestry than under the DSC (~2% vs. ~12%), but a similar number of the species exhibit introgression from at least one other species (75% vs. 60%). Under either species concept, the phylogenetic breadth of introgression in this group is notable, with both sister species and species from different major mtDNA clades exhibiting introgression. Conclusions Introgression was observed to be a widespread phenomenon for delimited species in this group. While several instances of introgressive hybridization were observed in anthropogenically altered habitats, most were found in undisturbed natural habitats, suggesting that introgression is a natural but ephemeral part of the evolution of many tropical species. Nevertheless, even transient

  13. Time and origin of cichlid colonization of the lower Congo rapids.

    PubMed

    Schwarzer, Julia; Misof, Bernhard; Ifuta, Seraphin N; Schliewen, Ulrich K

    2011-01-01

    Most freshwater diversity is arguably located in networks of rivers and streams, but, in contrast to lacustrine systems riverine radiations, are largely understudied. The extensive rapids of the lower Congo River is one of the few river stretches inhabited by a locally endemic cichlid species flock as well as several species pairs, for which we provide evidence that they have radiated in situ. We use more that 2,000 AFLP markers as well as multilocus sequence datasets to reconstruct their origin, phylogenetic history, as well as the timing of colonization and speciation of two Lower Congo cichlid genera, Steatocranus and Nanochromis. Based on a representative taxon sampling and well resolved phylogenetic hypotheses we demonstrate that a high level of riverine diversity originated in the lower Congo within about 5 mya, which is concordant with age estimates for the hydrological origin of the modern lower Congo River. A spatial genetic structure is present in all widely distributed lineages corresponding to a trisection of the lower Congo River into major biogeographic areas, each with locally endemic species assemblages. With the present study, we provide a phylogenetic framework for a complex system that may serve as a link between African riverine cichlid diversity and the megadiverse cichlid radiations of the East African lakes. Beyond this we give for the first time a biologically estimated age for the origin of the lower Congo River rapids, one of the most extreme freshwater habitats on earth.

  14. Correlation between nuptial colors and visual sensitivities tuned by opsins leads to species richness in sympatric Lake Victoria cichlid fishes.

    PubMed

    Miyagi, Ryutaro; Terai, Yohey; Aibara, Mitsuto; Sugawara, Tohru; Imai, Hiroo; Tachida, Hidenori; Mzighani, Semvua Isa; Okitsu, Takashi; Wada, Akimori; Okada, Norihiro

    2012-11-01

    Reproductive isolation that prevents interspecific hybridization between closely related coexisting species maintains sympatric species diversity. One of the reproductive isolations is mate choice based on color signals (breeding color perceived by color vision). This is well known in several animal taxa, yet little is known about its genetic and molecular mechanism. Lake Victoria cichlid fishes are thought to be an example of sympatric species diversity. In the species inhabiting different light environments in rocky shore, speciation by sensory drive through color signals has been proposed by analyses of the long wavelength-sensitive (LWS) opsin gene and the male nuptial coloration. However, the genetic and molecular mechanism of how diversity of sympatric species occurring in the same habitat is maintained remains unknown. To address this issue, we determined nucleotide sequences of eight opsins of six sympatric species collected from a sandy-muddy shore--an ideal model system for studying sympatric species. Among eight opsins, the LWS and RH1 alleles were diversified and one particular allele is dominant or fixed in each species, and we propose that this is due to natural selection. The functions of their LWS alleles were also diversified as shown by absorption measurements of reconstituted visual pigments. To analyze the relationship between nuptial coloration and the absorption of LWS pigments, we systematically evaluated and defined nuptial coloration. We showed that the coloration was species specific with respect to hue and significantly differentiated by the index values of hue (dominant wavelength: λ(d)). The λ(d) value of the male nuptial coloration correlated with the absorption of LWS pigments from all the species, suggesting that reproductive isolation through mate choice using color signals may prevent sympatric interspecific hybridization, thereby maintaining the species diversity in sympatric species in Lake Victoria.

  15. Complete Mitochondrial DNA Sequences of the Threadfin Cichlid (Petrochromis trewavasae) and the Blunthead Cichlid (Tropheus moorii) and Patterns of Mitochondrial Genome Evolution in Cichlid Fishes

    PubMed Central

    Fischer, Christoph; Koblmüller, Stephan; Gülly, Christian; Schlötterer, Christian; Sturmbauer, Christian; Thallinger, Gerhard G.

    2013-01-01

    The cichlid fishes of the East African Great Lakes represent a model especially suited to study adaptive radiation and speciation. With several African cichlid genome projects being in progress, a promising set of closely related genomes is emerging, which is expected to serve as a valuable data base to solve questions on genotype-phenotype relations. The mitochondrial (mt) genomes presented here are the first results of the assembly and annotation process for two closely related but eco-morphologically highly distinct Lake Tanganyika cichlids, Petrochromis trewavasae and Tropheus moorii. The genomic sequences comprise 16,588 bp (P. trewavasae) and 16,590 bp (T. moorii), and exhibit the typical mitochondrial structure, with 13 protein-coding genes, 2 rRNA genes, 22 tRNA genes, and a non-coding control region. Analyses confirmed that the two species are very closely related with an overall sequence similarity of 96%. We analyzed the newly generated sequences in the phylogenetic context of 21 published labroid fish mitochondrial genomes. Consistent with other vertebrates, the D-loop region was found to evolve faster than protein-coding genes, which in turn are followed by the rRNAs; the tRNAs vary greatly in the rate of sequence evolution, but on average evolve the slowest. Within the group of coding genes, ND6 evolves most rapidly. Codon usage is similar among examined cichlid tribes and labroid families; although a slight shift in usage patterns down the gene tree could be observed. Despite having a clearly different nucleotide composition, ND6 showed a similar codon usage. C-terminal ends of Cox1 exhibit variations, where the varying number of amino acids is related to the structure of the obtained phylogenetic tree. This variation may be of functional relevance for Cox1 synthesis. PMID:23826193

  16. Effects of a non-native cichlid fish (African jewelfish, Hemichromis letourneuxi Sauvage 1880) on a simulated Everglades aquatic community

    USGS Publications Warehouse

    Schofield, Pamela J.; Slone, Daniel H.; Gregoire, Denise R.; Loftus, William F.

    2014-01-01

    In an 8-month mesocosm experiment, we examined how a simulated Everglades aquatic community of small native fishes, snails, and shrimp changed with the addition of either a native predator (dollar sunfish Lepomis marginatus) or a non-native predator (African jewelfish Hemichromis letourneuxi) compared to a no-predator control. Two snail species (Planorbella duryi, Physella cubensis) and the shrimp (Palaemonetes paludosus) displayed the strongest predator-treatment effects, with significantly lower biomasses in tanks with Hemichromis. One small native fish (Heterandria formosa) was significantly less abundant in Hemichromis tanks, but there were no significant treatment effects for Gambusia holbrooki, Jordanella floridae, or Pomacea paludosa (applesnail). Overall, there were few treatment differences between native predator and no-predator control tanks. The results suggest that the potential of Hemichromis to affect basal food-web species that link primary producers with higher-level consumers in the aquatic food web, with unknown consequences for Florida waters.

  17. Big fish, little divergence: phylogeography of Lake Tanganyika’s giant cichlid, Boulengerochromis microlepis

    PubMed Central

    Koblmüller, Stephan; Odhiambo, Elizabeth A.; Sinyinza, Danny; Sturmbauer, Christian; Sefc, Kristina M.

    2014-01-01

    The largely endemic cichlid species flocks of the East African Great Lakes are among the prime examples for explosive speciation and adaptive radiation. Speciation rates differ among cichlid lineages, and the propensity to radiate has been linked to intrinsic and extrinsic factors such as sexual selection and ecological opportunity. Remarkably, only one cichlid tribe—the Boulengerochromini—comprises just a single species, Boulengerochromis microlepis, a predominantly piscivorous endemic of Lake Tanganyika and the world’s largest cichlid. While the lineage diverged from its closest relatives at the onset of the Lake Tanganyika radiation >8 MYA, mitochondrial control region sequences collected in this study dated the most recent common ancestor of B. microlepis to ~60–110 KYA. There was no evidence of phylogeographic structure in the lake-wide sample. Patterns of genetic diversity and demographic analyses were consistent with slow and steady population growth throughout the reconstructed timescale. Additionally, the shallow divergence within the species may be related to a possibly large variance in reproductive success in this highly fecund species. Trophic niche space restriction by sympatric piscivores, lack of geographic structure, low potential for sexual selection arising from the monogamous mating system and extinction may have contributed to keeping the lineage monotypic. PMID:25983338

  18. Big fish, little divergence: phylogeography of Lake Tanganyika's giant cichlid, Boulengerochromis microlepis.

    PubMed

    Koblmüller, Stephan; Odhiambo, Elizabeth A; Sinyinza, Danny; Sturmbauer, Christian; Sefc, Kristina M

    2015-04-01

    The largely endemic cichlid species flocks of the East African Great Lakes are among the prime examples for explosive speciation and adaptive radiation. Speciation rates differ among cichlid lineages, and the propensity to radiate has been linked to intrinsic and extrinsic factors such as sexual selection and ecological opportunity. Remarkably, only one cichlid tribe-the Boulengerochromini-comprises just a single species, Boulengerochromis microlepis, a predominantly piscivorous endemic of Lake Tanganyika and the world's largest cichlid. While the lineage diverged from its closest relatives at the onset of the Lake Tanganyika radiation >8 MYA, mitochondrial control region sequences collected in this study dated the most recent common ancestor of B. microlepis to ~60-110 KYA. There was no evidence of phylogeographic structure in the lake-wide sample. Patterns of genetic diversity and demographic analyses were consistent with slow and steady population growth throughout the reconstructed timescale. Additionally, the shallow divergence within the species may be related to a possibly large variance in reproductive success in this highly fecund species. Trophic niche space restriction by sympatric piscivores, lack of geographic structure, low potential for sexual selection arising from the monogamous mating system and extinction may have contributed to keeping the lineage monotypic.

  19. Salinity tolerance of the African Jewelfish Hemichromis letourneuxi, a non-native cichlid in South Florida (USA)

    USGS Publications Warehouse

    Langston, Jacqueline N.; Schofield, Pamela J.; Hill, Jeffrey E.; Loftus, William F.

    2010-01-01

    The African Jewelfish (Cichlidae: Hemichromis letourneuxi) is a predatory, non-native fish that has recently (since 2000) begun to expand its geographic range across south Florida. The salinity tolerance of H. letourneuxi was unknown, and thus it was unclear whether the species could use estuarine or coastal environments. The response of H. letourneuxi to chronic change in salinity was evaluated here by exposing fish to progressively increasing salinities (0–80 ppt). Fish were held at target salinities for a minimum of 30 days. The species showed excellent survival from 0–50 ppt. At 60 ppt, only 25% of the fish survived, and mean estimated survival time was 12 days. Above 60 ppt, mortality was 100%. Fish grew equally well from 0–50 ppt. In another experiment, fish were transferred directly from freshwater to various salinities from 5–35 ppt (seawater) and held for seven days, after which survivors were returned to freshwater. All fish transferred directly from freshwater to salinities up to 20 ppt survived; only 56% survived when transferred from freshwater to 25 ppt, and none survived transfer above 25 ppt. Experimental results indicated that H. letourneuxi can persist easily in salinities prevalent in coastal environments, even during periods of hypersalinity common in south Florida estuaries. Salinity will not restrict its dispersal by coastal pathways.

  20. Patterns in fish radiation are compatible with Pleistocene desiccation of Lake Victoria and 14,600 year history for its cichlid species flock.

    PubMed Central

    Seehausen, Ole

    2002-01-01

    Geophysical data are currently being interpreted as evidence for a late Pleistocene desiccation of Lake Victoria and its refilling 14,600 years ago. This implies that between 500 and 1000 endemic cichlid fish species must have evolved in 14,600 years, the fastest large-scale species radiation known. A recent review concludes that biological evidence clearly rejects the postulated Pleistocene desiccation of the lake: a 14,600 year history would imply exceptionally high speciation rates across a range of unrelated fish taxa. To test this suggestion, I calculated speciation rates for all 41 phylogenetic lineages of fish in the lake. Except for one cichlid lineage, accepting a 14 600 year history does not require any speciation rates that fall outside the range observed in fishes in other young lakes around the world. The exceptional taxon is a lineage of haplochromine cichlids that is also known for its rapid speciation elsewhere. Moreover, since it is unknown how many founding species it has, it is not certain that its speciation rates are really outside the range observed in fishes in other young lakes. Fish speciation rates are generally faster in younger than in older lakes, and those in Lake Victoria, by far the largest of the young lakes of the world, are no exception. From the speciation rates and from biogeographical observations that Lake Victoria endemics, which lack close relatives within the lake basin, have such relatives in adjacent drainage systems that may have had Holocene connections to Lake Victoria, I conclude that the composition of the fish assemblage does not provide biological evidence against Pleistocene desiccation. It supports a hypothesis of recent colonization from outside the lake basin rather than survival of a diverse assemblage within the basin. PMID:11886641

  1. Cichlid genomics and phenotypic diversity in a comparative context.

    PubMed

    Hulsey, C Darrin

    2009-12-01

    Cichlid fishes provide an excellent natural system for integrating studies of genomics and adaptive radiation. Cichlids are unique in comprising a substantial fraction of all vertebrate species, possessing unique jaw structures, displaying an exceptional range of breeding systems, and exhibiting rampant phenotypic convergence. The rate of divergence in cichlid jaws, teeth, color patterns, visual systems, reproductive biology, and mating behaviors is unparalleled among vertebrates. I discuss ways rapid divergence in cichlids and other adaptive radiations make understanding the genomic basis of adaptive divergence more tractable. Then, I briefly overview some major findings and insights into vertebrate adaptation that have been gained through cichlid genetic studies. Finally, I discuss the extensive evolutionary replication provided by cichlid adaptive radiations and their potential for studies of genotype-to-phenotype mapping.

  2. Sampling genetic diversity in the sympatrically and allopatrically speciating Midas cichlid species complex over a 16 year time series

    PubMed Central

    Bunje, Paul ME; Barluenga, Marta; Meyer, Axel

    2007-01-01

    Background Speciation often occurs in complex or uncertain temporal and spatial contexts. Processes such as reinforcement, allopatric divergence, and assortative mating can proceed at different rates and with different strengths as populations diverge. The Central American Midas cichlid fish species complex is an important case study for understanding the processes of speciation. Previous analyses have demonstrated that allopatric processes led to species formation among the lakes of Nicaragua as well as sympatric speciation that is occurring within at least one crater lake. However, since speciation is an ongoing process and sampling genetic diversity of such lineages can be biased by collection scheme or random factors, it is important to evaluate the robustness of conclusions drawn on individual time samples. Results In order to assess the validity and reliability of inferences based on different genetic samples, we have analyzed fish from several lakes in Nicaragua sampled at three different times over 16 years. In addition, this time series allows us to analyze the population genetic changes that have occurred between lakes, where allopatric speciation has operated, as well as between different species within lakes, some of which have originated by sympatric speciation. Focusing on commonly used genetic markers, we have analyzed both DNA sequences from the complete mitochondrial control region as well as nuclear DNA variation at ten microsatellite loci from these populations, sampled thrice in a 16 year time period, to develop a robust estimate of the population genetic history of these diversifying lineages. Conclusion The conclusions from previous work are well supported by our comprehensive analysis. In particular, we find that the genetic diversity of derived crater lake populations is lower than that of the source population regardless of when and how each population was sampled. Furthermore, changes in various estimates of genetic diversity within lakes

  3. A New Genus and Two New Species of Proteocephalidean Tapeworms (Cestoda) from Cichlid Fish (Perciformes: Cichlidae) in the Neotropics.

    PubMed

    de Chambrier, Alain; Pinacho-Pinacho, Carlos Daniel; Hernández-Orts, Jesus Servando; Scholz, Tomáš

    2017-02-01

    Cichlidocestus n. gen. is proposed to accommodate 2 new species of proteocephalidean cestodes, Cichlidocestus gillesi n. sp. from Cichlasoma amazonarum in Peru (type species) and Cichlidocestus janikae n. sp. from Hypsophrys nicaraguensis (all Perciformes: Cichlidae) in Costa Rica. The new genus is unique among all but 1 proteocephalidean genera in the position of the ovary that occupies the middle and posterior thirds of the median region of proglottids (vs. the ovary in the posterior third of proglottids near their posterior margin in all but 1 remaining taxa). In addition, Cichlidocestus is typified by the presence of a voluminous, spherical, internal seminal vesicle, several pairs of ventral excretory canals in the medulla, a pyramidal, quadrilobed scolex with an apical muscular sucker, and the posterior extent of the testes that may reach almost to the posterior margin of proglottids. The new genus shares the position of the ovary and its extension with Sciadocephalus (also a parasite of cichlids in the Neotropics as the new taxon); in all remaining proteocephalideans the ovary occupies the posterior third only. Sciadocephalus differs from Cichlidocestus by a different morphology of the scolex, which possesses an umbrella-like metascolex that is markedly wider than the strobila, the number of ventral osmoregulatory canals, and development of the uterus, which forms capsule-like formations filled with eggs in Sciadocephalus megalodiscus (vs. simple lateral diverticula in Cichlidocestus spp.). Both new species of Cichlidocestus can be easily distinguished from one another by the anterior extent of the poral vitelline follicles (anterior to the cirrus-sac, i.e., preporal, in C. gillesi vs. posterior, i.e., only postporal in C. janikae), size of the eggs (diameter of the external layer of the embryophore of C. gillesi 30-33 μm vs. 44-46 μm in C. janikae), and the number of uterine lateral diverticula (16-21 on 1 side in C. gillesi vs. only 8-12 in C. janikae

  4. Evolution of egg dummies in Tanganyikan cichlid fishes: the roles of parental care and sexual selection.

    PubMed

    Amcoff, M; Gonzalez-Voyer, A; Kolm, N

    2013-11-01

    Sexual selection has been suggested to be an important driver of speciation in cichlid fishes of the Great Lakes of Africa, and the presence of male egg dummies is proposed to have played a key role. Here, we investigate how mouthbrooding and egg dummies have evolved in Tanganyikan cichlids, the lineage which seeded the other African radiations, with a special emphasis on the egg dummies. Using modern phylogenetic comparative analyses and a phylogeny including 86% of the 200 described species, we provide formal evidence demonstrating correlated evolution between mouthbrooding and egg dummies in Tanganyikan cichlids. These results concur with existing evidence, suggesting that egg dummies have evolved through sensory exploitation. We also demonstrate that there is a strong evolutionary correlation between the presence of egg dummies and both pre- and post-copulatory sexual selection. Moreover, egg dummy evolution was contingent on the intensity of pre- and post-copulatory sexual selection in Tanganyikan cichlids. In sum, our results provide evidence supporting the hypothesis of egg dummies evolving through sensory exploitation and highlight the role of sexual selection in favouring the evolution and maintenance of this trait.

  5. Speciation within genomic networks: a case study based on Steatocranus cichlids of the lower Congo rapids.

    PubMed

    Schwarzer, Julia; Misof, B; Schliewen, U K

    2012-01-01

    Hybridization in animals is a much more common phenomenon as previously thought and may have profound implications for speciation research. The cichlid genus Steatocranus (Teleostei: Cichlidae), a close relative to members of the East African cichlid radiations, radiated under riverine conditions in the lower Congo rapids and produced a small species flock. Previous phylogenetic analyses suggested that hybridization occurred and contributed to speciation in this genus. A re-analysis of an already published 2000 loci-AFLP data set explicitly testing for patterns of ancient gene flow provided strong evidence for a highly reticulate phylogenetic history of the genus. We provide, to our knowledge, the first example of a complex reticulate network in vertebrates, including multiple closely related species connected through ancient as well as recent gene flow. In this context, the limited validity of strictly bifurcating tree hypotheses as a phylogenetic basis for hypothesis testing in evolutionary biology is discussed.

  6. Persistence of neutral polymorphisms in Lake Victoria cichlid fish

    PubMed Central

    Nagl, Sandra; Tichy, Herbert; Mayer, Werner E.; Takahata, Naoyuki; Klein, Jan

    1998-01-01

    Phylogenetic trees for groups of closely related species often have different topologies, depending on the genes used. One explanation for the discordant topologies is the persistence of polymorphisms through the speciation phase, followed by differential fixation of alleles in the resulting species. The existence of transspecies polymorphisms has been documented for alleles maintained by balancing selection but not for neutral alleles. In the present study, transspecific persistence of neutral polymorphisms was tested in the endemic haplochromine species flock of Lake Victoria cichlid fish. Putative noncoding region polymorphisms were identified at four randomly selected nuclear loci and tested on a collection of 12 Lake Victoria species and their putative riverine ancestors. At all loci, the same polymorphism was found to be present in nearly all the tested species, both lacustrine and riverine. Different polymorphisms at these loci were found in cichlids of other East African lakes (Malawi and Tanganyika). The Lake Victoria polymorphisms must have therefore arisen after the flocks now inhabiting the three great lakes diverged from one another, but before the riverine ancestors of the Lake Victoria flock colonized the Lake. Calculations based on the mtDNA clock suggest that the polymorphisms have persisted for about 1.4 million years. To maintain neutral polymorphisms for such a long time, the population size must have remained large throughout the entire period. PMID:9826684

  7. Persistence of neutral polymorphisms in Lake Victoria cichlid fish.

    PubMed

    Nagl, S; Tichy, H; Mayer, W E; Takahata, N; Klein, J

    1998-11-24

    Phylogenetic trees for groups of closely related species often have different topologies, depending on the genes used. One explanation for the discordant topologies is the persistence of polymorphisms through the speciation phase, followed by differential fixation of alleles in the resulting species. The existence of transspecies polymorphisms has been documented for alleles maintained by balancing selection but not for neutral alleles. In the present study, transspecific persistence of neutral polymorphisms was tested in the endemic haplochromine species flock of Lake Victoria cichlid fish. Putative noncoding region polymorphisms were identified at four randomly selected nuclear loci and tested on a collection of 12 Lake Victoria species and their putative riverine ancestors. At all loci, the same polymorphism was found to be present in nearly all the tested species, both lacustrine and riverine. Different polymorphisms at these loci were found in cichlids of other East African lakes (Malawi and Tanganyika). The Lake Victoria polymorphisms must have therefore arisen after the flocks now inhabiting the three great lakes diverged from one another, but before the riverine ancestors of the Lake Victoria flock colonized the Lake. Calculations based on the mtDNA clock suggest that the polymorphisms have persisted for about 1.4 million years. To maintain neutral polymorphisms for such a long time, the population size must have remained large throughout the entire period.

  8. Phylogeny and biogeography of 91 species of heroine cichlids (Teleostei: Cichlidae) based on sequences of the cytochrome b gene.

    PubMed

    Pérez, Gustavo A Concheiro; Rícan, Oldrich; Ortí, Guillermo; Bermingham, Eldredge; Doadrio, Ignacio; Zardoya, Rafael

    2007-04-01

    Heroini constitute the second largest tribe of Neotropical cichlids and show their greatest diversity in Mesoamerica. Although heroine species are morphologically and ecologically very diverse, they were all historically assigned to one single genus, Cichlasoma that was never formally revised from a phylogenetic point of view. Here, we present the most comprehensive molecular phylogeny of the tribe Heroini to date, based on the complete DNA sequence of the mitochondrial gene cytochrome b, and the analysis of 204 individuals representing 91 species. Phylogenetic analyses did not support the monophyly of heroines because the genus Pterophyllum was placed as the sister group of all remaining heroines plus cichlasomatines. However, the recovered relative position of Pterophyllum was without strong statistical support. Within the remaining heroines, Hyspelecara and Hoplarchus are recovered with low support in a basal position with respect to a clade that includes Heros, Uaru, Mesonauta, and Symphysodon, and the circumamazonian (CAM) heroines. The first clade is restricted to South America. The largest clade of heroines, the CAM heroines, include more than 85% of the species within the tribe. This clade is mostly Mesoamerican, but also contains four species found in the Greater Antilles (Nandopsis), and three genera found in South America (the 'Heros' festae group, Australoheros, and Caquetaia). Up to eight major lineages can be recovered within the CAM heroines, but the phylogenetic relationships among them remain unresolved. Two large suprageneric groups can be distinguished, the amphilophines and the herichthyines. The amphilophines include Amphilophus, Archocentrus, Hypsophrys, Neetroplus, Parachromis, Petenia, and five additional unnamed genera (the 'Heros' istlanus group, the 'Amphilophus' calobrensis group, the 'Heros' urophthalmus group, the 'Heros' wesseli group, and the 'Heros' sieboldii group). The herichthyines include the crown-group herichthyines

  9. Iranocichla persa, a new cichlid species from southern Iran (Teleostei, Cichlidae).

    PubMed

    Esmaeili, Hamid Reza; Sayyadzadeh, Golnaz; Seehausen, Ole

    2016-01-01

    Iranocichla persasp. n. is described from the Shur, Hasanlangi and Minab River drainages flowing into the Persian Gulf at the Strait of Hormuz in southern Iran. It is distinguished from Iranocichla hormuzensis, from the Mehran River drainage, by nuptial males having a bright orange breast and lower part of the head (vs. black), a poorly developed or invisible (vs. distinctive) "Tilapia-mark" in the dorsal fin and very clear white spots making almost wavy bars or stripes on the caudal fin (vs. without or with very few white spots). Mitochondrial DNA sequence characters suggest that both Iranocichla species are closely related but form two distinct clades, diagnosable by several fixed mutations in ND2, D-loop and partially by COI sequences. Populations from Kol River drainage, which is situated in-between the Mehran and the Shur River drainages, are more similar to Iranocichla hormuzensis in terms of their male nuptial coloration but to Iranocichla persasp. n. in their mitochondrial sequence characters. Their status requires further investigation.

  10. Iranocichla persa, a new cichlid species from southern Iran (Teleostei, Cichlidae)

    PubMed Central

    Esmaeili, Hamid Reza; Sayyadzadeh, Golnaz; Seehausen, Ole

    2016-01-01

    Abstract Iranocichla persa sp. n. is described from the Shur, Hasanlangi and Minab River drainages flowing into the Persian Gulf at the Strait of Hormuz in southern Iran. It is distinguished from Iranocichla hormuzensis, from the Mehran River drainage, by nuptial males having a bright orange breast and lower part of the head (vs. black), a poorly developed or invisible (vs. distinctive) “Tilapia-mark” in the dorsal fin and very clear white spots making almost wavy bars or stripes on the caudal fin (vs. without or with very few white spots). Mitochondrial DNA sequence characters suggest that both Iranocichla species are closely related but form two distinct clades, diagnosable by several fixed mutations in ND2, D-loop and partially by COI sequences. Populations from Kol River drainage, which is situated in-between the Mehran and the Shur River drainages, are more similar to Iranocichla hormuzensis in terms of their male nuptial coloration but to Iranocichla persa sp. n. in their mitochondrial sequence characters. Their status requires further investigation. PMID:27917068

  11. Food deprivation explains effects of mouthbrooding on ovaries and steroid hormones, but not brain neuropeptide and receptor mRNAs, in an African cichlid fish.

    PubMed

    Grone, Brian P; Carpenter, Russ E; Lee, Malinda; Maruska, Karen P; Fernald, Russell D

    2012-06-01

    Feeding behavior and reproduction are coordinately regulated by the brain via neurotransmitters, circulating hormones, and neuropeptides. Reduced feeding allows animals to engage in other behaviors important for fitness, including mating and parental care. Some fishes cease feeding for weeks at a time in order to provide care to their young by brooding them inside the male or female parent's mouth. Maternal mouthbrooding is known to impact circulating hormones and subsequent reproductive cycles, but neither the full effects of food deprivation nor the neural mechanisms are known. Here we ask what effects mouthbrooding has on several physiological processes including gonad and body mass, brain neuropeptide and receptor gene expression, and circulating steroid hormones in a mouthbrooding cichlid species, Astatotilapia burtoni. We ask whether any observed changes can be explained by food deprivation, and show that during mouthbrooding, ovary size and circulating levels of androgens and estrogens match those seen during food deprivation. Levels of gonadotropin-releasing hormone 1 (GnRH1) mRNA in the brain were low in food-deprived females compared to controls and in mouthbrooding females compared to gravid females. Levels of mRNA encoding two peptides involved in regulating feeding, hypocretin and cholecystokinin, were increased in the brains of food-deprived females. Brain mRNA levels of two receptors, GnRH receptor 2 and NPY receptor Y8c, were elevated in mouthbrooding females compared to the fed condition, but NPY receptor Y8b mRNA was differently regulated by mouthbrooding. These results suggest that many, but not all, of the characteristic physiological changes that occur during mouthbrooding are consequences of food deprivation.

  12. Intraspecific cone opsin expression variation in the cichlids of Lake Malawi.

    PubMed

    Smith, Adam R; D'Annunzio, Lindsay; Smith, Abbi E; Sharma, Anit; Hofmann, Christopher M; Marshall, N J; Carleton, Karen L

    2011-01-01

    The expression of cone opsin genes is a primary determinant of the characteristics of colour vision. Interspecific variation in opsin expression is common in African cichlids. It is correlated with foraging among cichlids from Lake Malawi, and with ambient light environment among cichlids from Lake Victoria. In this study, we tested whether gene expression varied within species such that it might be important in contributing to divergence. We hypothesized that light attenuation with depth would be correlated with predictable changes in gene expression in Lake Malawi, and that this variation would tune visual sensitivities to match the ambient light environment. We observed significant differences in cone opsin expression in three different comparisons among populations of the same species. Higher LWS expression was found in shallow versus deep Copadichromis eucinostomus. In Metriaclima zebra, individuals from Zimbawe Rock expressed significantly more SWS2B than those from Thumbi West Island, although these locales have similar ambient light environments. Finally, Tropheops gracilior from deeper water had significantly more variation in expression than their shallow counterparts. These results support that gene expression varies significantly between populations of the same species. Surprisingly, these results could not be explained by predicted visual performance as models predicted that differential expression patterns did not confer sensitivity advantages at different depths. This suggested that expression variation did not confer a local sensitivity advantage. Therefore, our findings were contrary to a primary requirement of the sensory bias hypothesis. As such, other explanations for intraspecific gene expression variation need to be tested.

  13. Transvalued species in an African forest.

    PubMed

    Remis, Melissa J; Hardin, Rebecca

    2009-12-01

    We combined ethnographic investigations with repeated ecological transect surveys in the Dzanga-Sangha Dense Forest Reserve (RDS), Central African Republic, to elucidate consequences of intensifying mixed use of forests. We devised a framework for transvaluation of wildlife species, which means the valuing of species on the basis of their ecological, economic, and symbolic roles in human lives. We measured responses to hunting, tourism, and conservation of two transvalued species in RDS: elephants (Loxodonta cyclotis) and gorillas (Gorilla gorilla). Our methods included collecting data on encounter rates and habitat use on line transects. We recorded cross-cultural variation in ideas about and interactions with these species during participant observation of hunting and tourism encounters and ethnographic interviews with hunters, conservation staff, researchers, and tourists. Ecologically, gorillas used human-modified landscapes successfully, and elephants were more vulnerable than gorillas to hunting. Economically, tourism and encounters with elephants and gorillas generated revenues and other benefits for local participants. Symbolically, transvaluation of species seemed to undergird competing institutions of forest management that could prove unsustainable. Nevertheless, transvaluation may also offer alternatives to existing social hierarchies, thereby integrating local and transnational support for conservation measures. The study of transvaluation requires attention to transnational flows of ideas and resources because they influence transspecies interactions. Cross-disciplinary in nature, transvalution of species addresses the political and economic challenges to conservation because it recognizes the varied human communities that shape the survival of wildlife in a given site. Transvaluation of species could foster more socially inclusive management and monitoring approaches attuned to competing economic demands, specific species behaviors, and human

  14. Same school, different conduct: rates of multiple paternity vary within a mixed-species breeding school of semi-pelagic cichlid fish (Cyprichromis spp.).

    PubMed

    Anderson, Caleb; Werdenig, Alexandra; Koblmüller, Stephan; Sefc, Kristina M

    2016-01-01

    Mating system variability is known to exist between and within species, often due to environmental influences. An open question is whether, vice versa, similar environmental conditions entail congruent mating behavior, for example in terms of multiple paternity, in species or populations sharing largely comparable breeding modes. This study employed microsatellite markers to investigate the incidence of multiple paternity in Cyprichromis coloratus and Cyprichromis leptosoma, two sympatric, closely related, mouthbrooding Lake Tanganyika cichlids with similar ecological and behavioral characteristics including the formation of open-water schools. Mouthbrooding females of both species were collected from the same mixed-species breeding school at the same time, minimizing environmental variation during courtship and mating. In C. coloratus, four of 12 broods had more than one sire, with a mean of 1.33 reconstructed sires per brood. C. leptosoma exhibited multiple paternity in 18 of 22 broods, with a mean of 2.59 or 2.86 reconstructed sires per brood according to the programs gerud and colony, respectively. In addition, two broods were found to contain offspring transplanted from another brood. There was no significant difference in brood size between species, but mean sire number did differ significantly. Hence, substantial similarity in reproductive behavior along with shared environmental conditions during courtship and spawning did not lead to equal rates of polyandry or sneaking in the two species.

  15. Tol2-Mediated Generation of a Transgenic Haplochromine Cichlid, Astatotilapia burtoni

    PubMed Central

    Fernald, Russell D.

    2013-01-01

    Cichlid fishes represent one of the most species-rich and rapid radiations of a vertebrate family. These ∼2200 species, predominantly found in the East African Great Lakes, exhibit dramatic differences in anatomy, physiology, and behavior. However, the genetic bases for this radiation, and for the control of their divergent traits, are unknown. A flood of genomic and transcriptomic data promises to suggest mechanisms underlying the diversity, but transgenic technology will be needed to rigorously test the hypotheses generated. Here we demonstrate the successful use of the Tol2 transposon system to generate transgenic Astatotilapia burtoni, a haplochromine cichlid from Lake Tanganyika, carrying the GFP transgene under the control of the ubiquitous EF1α promoter. The transgene integrates into the genome, is successfully passed through the germline, and the widespread GFP expression pattern is stable across siblings and multiple generations. The stable inheritance and expression patterns indicate that the Tol2 system can be applied to generate A. burtoni transgenic lines. Transgenesis has proven to be a powerful technology for manipulating genes and cells in other model organisms and we anticipate that transgenic A. burtoni and other cichlids will be used to test the mechanisms underlying behavior and speciation. PMID:24204902

  16. Mitochondrial phylogeny and phylogeography of East African squeaker catfishes (Siluriformes: Synodontis)

    PubMed Central

    Koblmüller, Stephan; Sturmbauer, Christian; Verheyen, Erik; Meyer, Axel; Salzburger, Walter

    2006-01-01

    Background Squeaker catfishes (Pisces, Mochokidae, Synodontis) are widely distributed throughout Africa and inhabit a biogeographic range similar to that of the exceptionally diverse cichlid fishes, including the three East African Great Lakes and their surrounding rivers. Since squeaker catfishes also prefer the same types of habitats as many of the cichlid species, we hypothesized that the East African Synodontis species provide an excellent model group for comparative evolutionary and phylogeographic analyses. Results Our analyses reveal the existence of six major lineages of Synodontis in East Africa that diversified about 20 MYA from a Central and/or West African ancestor. The six lineages show a clear geographic patterning. Two lineages are endemic to Lake Tanganyika (plus one non-endemic representative), and these are the only two Synodontis lineages that diversified further into a small array of species. One of these species is the cuckoo catfish (S. multipunctatus), a unique brood parasite of mouthbrooding haplochromine cichlids, which seems to have evolved in parallel with the radiation of its cichlid host lineage, the Tropheini. We also detect an accelerated rate of molecular evolution in S. multipunctatus, which might be the consequence of co-evolutionary dynamics. Conclusion We conclude that the ancestral lineage of today's East African squeaker catfish fauna has colonized the area before the Great Lakes have formed. This ancestor diversified rapidly into at least six lineages that inhabit lakes and rivers in East Africa. Lake Tanganyika is the only lake harboring a small species flock of squeaker catfishes. PMID:16784525

  17. Redescription of Neoechinorhynchus (Neoechinorhynchus) golvani Salgado-Maldonado, 1978 (Acanthocephala: Neoechinorhynchidae) and description of a new species from freshwater cichlids (Teleostei: Cichlidae) in Mexico.

    PubMed

    Salgado-Maldonado, Guillermo

    2013-05-01

    A redescription of Neoechinorhynchus (Neoechinorhynchus) golvani Salgado-Maldonado (An Inst Biol Univ Nal Autón Méx, Ser Zool 49:35-47, 1978) is presented, based on adult specimens collected from the type host Paraneetroplus fenestratus from the type location, the Lago de Catemaco lake, Veracruz state, Mexico, and its presence is recorded in other cichlids. Detailed studies of N. (N.) golvani using light microscopy revealed some taxonomically important, previously unreported features, such as the size and shape of fully developed adult males and females, and the structure of the eggs. Morphological variability in N. (N.) golvani is described. Based on these data, the geographic distribution of this species is documented. Neoechinorhynchus (Neoechinorhynchus) panucensis n. sp. is described from Herichthys labridens (Pellegrin), Amatitlania nigrofasciata (Günther), and Herichthys cyanoguttatus Baird and Girard (all of them Cichlidae), collected in the Río Atlapexco, a tributary to the upper Río Panuco basin, Hidalgo State, Mexico. This new species stand up alone because of its minute proboscis (♂ 50 × 60, ♀ 42-55 (48.5) × 48-63 (57.7)) and anterior hooks (♂ 27-30 (28.8) × 3-5 (4), ♀ 28-32 (30) × 5 (5)). A key to the species of Neoechinorhynchus recorded from freshwater fishes in Central and South America is included.

  18. Untangling the evolutionary history of a highly polymorphic species: introgressive hybridization and high genetic structure in the desert cichlid fish Herichtys minckleyi.

    PubMed

    Magalhaes, Isabel S; Ornelas-Garcıa, Claudia Patricia; Leal-Cardin, Mariana; Ramírez, Tania; Barluenga, Marta

    2015-09-01

    Understanding the origin of biodiversity requires knowledge on the evolutionary processes that drive divergence and speciation, as well as on the processes constraining it. Intraspecific polymorphisms can provide insight into the mechanisms that generate and maintain phenotypic, behavioural and life history diversification, and can help us understand not only the processes that lead to speciation but also the processes that prevent local fixation of morphs. The 'desert cichlid' Herichtys minckleyi is a highly polymorphic species endemic to a biodiversity hotspot in northern Mexico, the Cuatro Ciénegas valley. This species is polymorphic in body shape and trophic apparatus, and eco-morphotypes coexist in small spring-fed lagoons across the valley. We investigated the genetic structure of these polymorphisms and their phylogeographic history by analysing the entire control region of the mitochondrial DNA and 10 nuclear microsatellite markers in several populations from different sites and morphs. We found two very divergent mitochondrial lineages that most likely predate the closing of the valley and are not associated with morphotypes or sites. One of these lineages is also found in the sister species Herichthys cyanoguttatus. Data from neutral microsatellite markers suggest that most lagoons or drainages constitute their own genetic cluster with sympatric eco-morphotypes forming panmictic populations. Alternative mechanisms such as phenotypic plasticity and a few loci controlled traits provide possible explanations for the sympatric coexistence of discrete nonoverlapping eco-morphotypes with apparent lack of barriers to gene flow within multiple lagoons and drainages.

  19. Eggspot Number and Sexual Selection in the Cichlid Fish Astatotilapia burtoni

    PubMed Central

    Henning, Frederico; Meyer, Axel

    2012-01-01

    Sexual selection on male coloration is one of the main mechanisms proposed to explain the explosive speciation rates in East African cichlid fish. True eggspots are color patterns characteristic of the most species-rich lineage of cichlids, the Haplochromini, and have been suggested to be causally related to the speciation processes. Eggspots are thought to have originated by sensory exploitation and subsequently gained several roles in sexual advertisement. However, for most of these functions the evidence is equivocal. In addition, the genetic architecture of this trait still is largely unknown. We conducted bidirectional selective breeding experiments for eggspot numbers in the model cichlid, Astatotilapia burtoni. After two generations, low lines responded significantly, whereas the high lines did not. Body size was both phenotypically and genotypically correlated with eggspot number and showed correlated response to selection. Males with higher numbers of eggspots were found to sire larger offspring. Despite the potential to act as honest indicators of fitness, the behavioral experiments showed no evidence of a role in either intra- or inter-sexual selection. Visual-based female preference was instead explained by courtship intensity. The evolution of this trait has been interpreted in light of adaptive theories of sexual selection, however the present and published results suggest the influence of non-adaptive factors such as sensory exploitation, environmental constraints and sexual antagonism. PMID:22937082

  20. Regulatory gene networks that shape the development of adaptive phenotypic plasticity in a cichlid fish.

    PubMed

    Schneider, Ralf F; Li, Yuanhao; Meyer, Axel; Gunter, Helen M

    2014-09-01

    Phenotypic plasticity is the ability of organisms with a given genotype to develop different phenotypes according to environmental stimuli, resulting in individuals that are better adapted to local conditions. In spite of their ecological importance, the developmental regulatory networks underlying plastic phenotypes often remain uncharacterized. We examined the regulatory basis of diet-induced plasticity in the lower pharyngeal jaw (LPJ) of the cichlid fish Astatoreochromis alluaudi, a model species in the study of adaptive plasticity. Through raising juvenile A. alluaudi on either a hard or soft diet (hard-shelled or pulverized snails) for between 1 and 8 months, we gained insight into the temporal regulation of 19 previously identified candidate genes during the early stages of plasticity development. Plasticity in LPJ morphology was first detected between 3 and 5 months of diet treatment. The candidate genes, belonging to various functional categories, displayed dynamic expression patterns that consistently preceded the onset of morphological divergence and putatively contribute to the initiation of the plastic phenotypes. Within functional categories, we observed striking co-expression, and transcription factor binding site analysis was used to examine the prospective basis of their coregulation. We propose a regulatory network of LPJ plasticity in cichlids, presenting evidence for regulatory crosstalk between bone and muscle tissues, which putatively facilitates the development of this highly integrated trait. Through incorporating a developmental time-course into a phenotypic plasticity study, we have identified an interconnected, environmentally responsive regulatory network that shapes the development of plasticity in a key innovation of East African cichlids.

  1. Gyrodactylus species (Monogenea: Gyrodactylidae) on the cichlid fishes of Senegal, with the description of Gyrodactylus ergensi n. sp. from Mango tilapia, Sarotherodon galilaeus L. (Teleostei: Cichilidae).

    PubMed

    Prikrylová, Iva; Matejusová, Iveta; Musilová, Nad'a; Gelnar, Milan

    2009-12-01

    The first record of Gyrodactylus species Nordmann, 1832 on the cichlid fish from Senegal is reported. Gyrodactylus parasites were found on four host species studied, Hemichromis fasciatus, Hemichromis letournaeuxi, Oreochromis niloticus, and Sarotherodon galilaeus. Gyrodactylus cichlidarum Paperna (Bamidgeh 13:14-29, 1968) were collected from H. fasciatus, and its identity was confirmed based on the morphometrical comparison with the holotype specimens of G. cichlidarum. Only one specimen of Gyrodactylus sp. was noted on H. letournaeuxi. The gyrodactylid specimens on O. niloticus and S. galilaeus were described as Gyrodactylus ergensi n. sp. based on the detailed morphometrical analysis supported by sequencing. The haptoral sclerites of G. ergensi n. sp., which closely resemble those of Gyrodactylus nyanzae Paperna, 1973, are compared with the type material and discussed. A partial sequence of the internal transcribed spacer recombinant DNA (ITS rDNA) was obtained from two specimens of G. ergensi, and a close relationship between G. ergensi n. sp. and G. cichlidarum is suggested based on 92% similarity in ITS rDNA region.

  2. Monophyletic origin of Lake Victoria cichlid fishes suggested by mitochondrial DNA sequences.

    PubMed

    Meyer, A; Kocher, T D; Basasibwaki, P; Wilson, A C

    1990-10-11

    Lake Victoria, together with its satellite lakes, harbours roughly 200 endemic forms of cichlid fishes that are classified as 'haplochromines' and yet the lake system is less than a million years old. This 'flock' has attracted attention because of the possibility that it evolved within the lake from one ancestral species and that biologists are thus presented with a case of explosive evolution. Within the past decade, however, morphology has increasingly emphasized the view that the flock may be polyphyletic. We sequenced up to 803 base pairs of mitochondrial DNA from 14 representative Victorian species and 23 additional African species. The flock seems to be monophyletic, and is more akin to that from Lake Malawi than to species from Lake Tanganyika; in addition, it contains less genetic variation than does the human species, and there is virtually no sharing of mitochondrial DNA types among species. These results confirm that the founding event was recent.

  3. Function of a key morphological innovation: fusion of the cichlid pharyngeal jaw

    PubMed Central

    Darrin Hulsey, C

    2005-01-01

    The pharyngeal jaw of cichlids may represent a key innovation that facilitated their unparalleled trophic divergence. In cichlids, ‘fusion’ of the lower pharyngeal jaw (LPJ) results from suturing between the two lower ceratobranchials. To examine, what novel abilities a more extensively fused pharyngeal jaw may confer, the function of LPJ suturing was examined in Heroine cichlids. Greater LPJ suturing, pharyngeal jaw splitting under compression and the forces used to crush molluscs in the wild suggest increased LPJ fusion in the trophically polymorphic Herichthys minckleyi operates to strengthen the pharyngeal jaw. Among Heroine cichlid species, the presence of an external LPJ suture and feeding specialization on molluscs was evolutionarily quite variable, but greater LPJ fusion estimated from the amount of external suturing was highly correlated with molluscivory. Throughout cichlid diversification, increased pharyngeal jaw fusion via suturing has likely helped to reinforce the LPJ during pharyngeal processing thereby facilitating the ability of cichlids to exploit durable prey. PMID:16608685

  4. Parallelism of amino acid changes at the RH1 affecting spectral sensitivity among deep-water cichlids from Lakes Tanganyika and Malawi.

    PubMed

    Sugawara, Tohru; Terai, Yohey; Imai, Hiroo; Turner, George F; Koblmüller, Stephan; Sturmbauer, Christian; Shichida, Yoshinori; Okada, Norihiro

    2005-04-12

    Many examples of the appearance of similar traits in different lineages are known during the evolution of organisms. However, the underlying genetic mechanisms have been elucidated in very few cases. Here, we provide a clear example of evolutionary parallelism, involving changes in the same genetic pathway, providing functional adaptation of RH1 pigments to deep-water habitats during the adaptive radiation of East African cichlid fishes. We determined the RH1 sequences from 233 individual cichlids. The reconstruction of cichlid RH1 pigments with 11-cis-retinal from 28 sequences showed that the absorption spectra of the pigments of nine species were shifted toward blue, tuned by two particular amino acid replacements. These blue-shifted RH1 pigments might have evolved as adaptations to the deep-water photic environment. Phylogenetic evidence indicates that one of the replacements, A292S, has evolved several times independently, inducing similar functional change. The parallel evolution of the same mutation at the same amino acid position suggests that the number of genetic changes underlying the appearance of similar traits in cichlid diversification may be fewer than previously expected.

  5. Colour-assortative mating among populations of Tropheus moorii, a cichlid fish from Lake Tanganyika, East Africa.

    PubMed

    Salzburger, Walter; Niederstätter, Harald; Brandstätter, Anita; Berger, Burkhard; Parson, Walther; Snoeks, Jos; Sturmbauer, Christian

    2006-02-07

    The species flocks of cichlid fishes in the East African Lakes Tanganyika, Malawi and Victoria are prime examples of adaptive radiation and explosive speciation. Several hundreds of endemic species have evolved in each of the lakes over the past several thousands to a few millions years. Sexual selection via colour-assortative mating has often been proposed as a probable causal factor for initiating and maintaining reproductive isolation. Here, we report the consequences of human-mediated admixis among differentially coloured populations of the endemic cichlid fish Tropheus moorii from several localities that have accidentally been put in sympatry in a small harbour bay in the very south of Lake Tanganyika. We analysed the phenotypes (coloration) and genotypes (mitochondrial control region and five microsatellite loci) of almost 500 individuals, sampled over 3 consecutive years. Maximum-likelihood-based parenthood analyses and Bayesian inference of population structure revealed that significantly more juveniles are the product of within-colour-morph matings than could be expected under the assumption of random mating. Our results clearly indicate a marked degree of assortative mating with respect to the different colour morphs. Therefore, we postulate that sexual selection based on social interactions and female mate choice has played an important role in the formation and maintenance of the different colour morphs in Tropheus, and is probably common in other maternally mouthbrooding cichlids as well.

  6. The Adaptive Radiation of Cichlid Fish in Lake Tanganyika: A Morphological Perspective

    PubMed Central

    Takahashi, Tetsumi; Koblmüller, Stephan

    2011-01-01

    Lake Tanganyika is the oldest of the Great Ancient Lakes in the East Africa. This lake harbours about 250 species of cichlid fish, which are highly diverse in terms of morphology, behaviour, and ecology. Lake Tanganyika's cichlid diversity has evolved through explosive speciation and is treated as a textbook example of adaptive radiation, the rapid differentiation of a single ancestor into an array of species that differ in traits used to exploit their environments and resources. To elucidate the processes and mechanisms underlying the rapid speciation and adaptive radiation of Lake Tanganyika's cichlid species assemblage it is important to integrate evidence from several lines of research. Great efforts have been, are, and certainly will be taken to solve the mystery of how so many cichlid species evolved in so little time. In the present review, we summarize morphological studies that relate to the adaptive radiation of Lake Tanganyika's cichlids and highlight their importance for understanding the process of adaptive radiation. PMID:21716857

  7. The fish eye view: are cichlids conspicuous?

    PubMed

    Dalton, Brian E; Cronin, Thomas W; Marshall, N Justin; Carleton, Karen L

    2010-07-01

    The extent of animal colouration is determined by an interplay between natural and sexual selection. Both forces probably shape colouration in the speciose, rock-dwelling cichlids of Lake Malawi. Sexual selection is thought to drive male colouration, overcoming natural selection to create conspicuous colour patterns via female mate choice and male-male competition. However, natural selection should make female cichlids cryptic because they mouthbrood their young. We hypothesize that as a result of both sexual and natural selection, males will have colours that are more conspicuous than female colours. Cichlid spectral sensitivity, especially in the ultraviolet, probably influences how colours appear to them. Here we use simple models of the trichromatic colour space of cichlid visual systems to compare the conspicuousness of male and female nuptial colours of nine species. Conspicuousness of colours was evaluated as their Euclidian distance in colour space from environmental backgrounds and from other colours on the same fish. We find in six of the nine species that breeding males have colours that are statistically more conspicuous than female colours. These colours contrast strongly with each other or with the backgrounds, and they fall within a range of spectra best transmitted in the habitat. Female colour distances were sometimes smaller, suggesting that females of some species are more cryptic than males. Therefore, selection can differentially act to generate male colours that are more conspicuous than those in females. However, in two species, females had colours that were more conspicuous than male colours, suggesting that other selective forces and possibly sexual conflicts are acting in this system.

  8. Molecular phylogeny of monogeneans parasitizing African freshwater Cichlidae inferred from LSU rDNA sequences.

    PubMed

    Mendlová, Monika; Pariselle, Antoine; Vyskočilová, Martina; Simková, Andrea

    2010-11-01

    The African freshwater fish of Cichlidae are parasitized by five genera of monogeneans belonging to Dactylogyridea. Ectoparasitic Scutogyrus, Onchobdella, and the highly diversified Cichlidogyrus represent three genera located on the gills, while the endoparasitic Enterogyrus and Urogyrus are located in the stomach and the urinary bladder, respectively. Representatives of four dactylogyridean genera (except for Urogyrus) were collected from seven cichlid species in West Africa. The aim of this study was to investigate the phylogenetic relationships between ectoparasitic and endoparasitic dactylogyridaen monogeneans specific to African freshwater Cichlidae and other representatives of Dactylogyridae, including a wide range of species from both freshwater and marine environments. All phylogenetic analyses point to the polyphyletic origin of the subfamily Ancyrocephalinae. Both Enterogyrus and Onchobdella were found to be monophyletic. The phylogenetic position of Scutogyrus longicornis was placed within the Cichlidogyrus species, which suggests the non-monophyly of Cichlidogyrus. Therefore, we have proposed a taxonomical revision of the species recently considered to be Scutogyrus. However, these four dactylogyridean genera-specific to cichlids do not form a monophyletic group. Using LSU rDNA analyses, we found that Enterogyrus and Onchobdella form a clade with Protogyrodactylus, i.e., the parasite species does not live in cichlids, which suggests that endoparasitism in cichlid monogeneans is not an ancestral feature.

  9. Construction of chromosome markers from the Lake Victoria cichlid Paralabidochromis chilotes and their application to comparative mapping.

    PubMed

    Kuroiwa, A; Terai, Y; Kobayashi, N; Yoshida, K; Suzuki, M; Nakanishi, A; Matsuda, Y; Watanabe, M; Okada, N

    2014-01-01

    Cichlid fishes in the African Great Lakes are known as a spectacular example of adaptive radiation in vertebrates. Four linkage maps have been constructed to identify the genes responsible for adaptation and speciation, and the genetic linkages of those genes are assumed to play an important role during adaptive evolution. However, it is difficult to analyze such linkages because the linkage groups of one species do not match well with those of the other species. Chromosome markers are a powerful tool for the direct identification of linkage homology between different species. We used information about the linkage map of the Lake Malawi cichlid (Labeotropheus fuelleborni/Metriaclima zebra) to isolate bacterial artificial chromosome (BAC) clones from the BAC library of Paralabidochromis chilotes, Lake Victoria. We identified 18 of 22 P. chilotes chromosomes by single- and multi-color BAC fluorescence in situ hybridization using 19 BAC clones. Comparative mapping with the chromosome markers of P. chilotes in Astatotilapia burtoni (2n = 40) from Lake Tanganyika revealed the chromosome rearrangements that have occurred in this lineage. These chromosome markers will be useful for delineating the process of genome and chromosome evolution in African species.

  10. A sensory bias has triggered the evolution of egg-spots in cichlid fishes.

    PubMed

    Egger, Bernd; Klaefiger, Yuri; Theis, Anya; Salzburger, Walter

    2011-01-01

    Although, generally, the origin of sex-limited traits remains elusive, the sensory exploitation hypothesis provides an explanation for the evolution of male sexual signals. Anal fin egg-spots are such a male sexual signal and a key characteristic of the most species-rich group of cichlid fishes, the haplochromines. Males of about 1500 mouth-brooding species utilize these conspicuous egg-dummies during courtship--apparently to attract females and to maximize fertilization success. Here we test the hypothesis that the evolution of haplochromine egg-spots was triggered by a pre-existing bias for eggs or egg-like coloration. To this end, we performed mate-choice experiments in the basal haplochromine Pseudocrenilabrus multicolor, which manifests the plesiomorphic character-state of an egg-spot-less anal fin. Experiments using computer-animated photographs of males indeed revealed that females prefer images of males with virtual ('in-silico') egg-spots over images showing unaltered males. In addition, we tested for color preferences (outside a mating context) in a phylogenetically representative set of East African cichlids. We uncovered a strong preference for yellow, orange or reddish spots in all haplochromines tested and, importantly, also in most other species representing more basal lines. This pre-existing female sensory bias points towards high-quality (carotenoids-enriched) food suggesting that it is adaptive.

  11. Mating and Parental Care in Lake Tanganyika's Cichlids.

    PubMed

    Sefc, Kristina M

    2011-01-01

    Cichlid fishes of Lake Tanganyika display a variety of mating and parental care behaviors, including polygamous and monogamous mouthbrooding and substrate breeding, cooperative breeding, as well as various alternative reproductive tactics such as sneaking and piracy. Moreover, reproductive behaviors sometimes vary within species both in space and in time. Here, I survey reports on mating and parenting behaviors of Lake Tanganyika cichlid species and address the evolution of mating and parental care patterns and sexual dimorphism. Notes on measures of sexual selection intensity and the difficulties of defining mating systems and estimating selection intensities at species level conclude the essay.

  12. Climatic variability in combination with eutrophication drives adaptive responses in the gills of Lake Victoria cichlids.

    PubMed

    van Rijssel, Jacco C; Hecky, Robert E; Kishe-Machumu, Mary A; Meijer, Saskia E; Pols, Johan; van Tienderen, Kaj M; Ververs, Jan D; Wanink, Jan H; Witte, Frans

    2016-12-01

    Textbook examples of adaptive radiation often show rapid morphological changes in response to environmental perturbations. East Africa's Lake Victoria, famous for its stunning adaptive radiation of cichlids, has suffered from human-induced eutrophication over the past decades. This cultural eutrophication is thought to be partly responsible for the dramatically reduced cichlid biodiversity, but climatic variability in itself might also have contributed to the eutrophication which resulted in low oxygen levels and decreased water transparency. To determine how recent environmental changes have influenced the lake and its cichlids over the past 50 years, we gathered environmental and meteorological variables and compared these with gill surface area of four cichlid species. We found that during the period of severe eutrophication and temperature increase (1980s), reduced wind speeds coincided with a reduction in oxygen levels and a decrease in both water temperature and transparency. The gill surface area in three out of the four cichlid species increased during this period which is consistent with adaptive change in response to increased hypoxia. During the 2000s, wind speeds, oxygen levels, water transparency and water temperature increased again, while cichlid gill surface area decreased. Our results imply that climatic changes and especially wind speed and direction might play a crucial role in tropical lake dynamics. The changes in Lake Victoria's water quality coincide with fluctuations in cichlid gill surface area, suggesting that these fish can respond rapidly to environmental perturbations, but also that climatic variability, together with continued eutrophication, might be detrimental to the lake's cichlid biodiversity.

  13. Evolution of the ribosomal RNA internal transcribed spacer one (ITS-1) in cichlid fishes of the Lake Victoria region.

    PubMed

    Booton, G C; Kaufman, L; Chandler, M; Oguto-Ohwayo, R; Duan, W; Fuerst, P A

    1999-03-01

    The nucleotide sequences of the first internal transcribed spacer (ITS-1) of the ribosomal RNA gene cluster have been determined for 11 species of closely related endemic cichlid fishes of the Lake Victoria region (LVR) and 6 related East African cichlids. The ITS-1 sequences confirmed independently derived basal phylogenies, but provide limited insight within this species flock. The line leading to Pseudocrenilabrus multicolor arose early, close to the divergence event that separated the tilapiine and haplochromine tribes of the "African Group" of the family Cichlidae. In this phylogeny, Astatoreochromis alluaudi and the riverine Astatotilapia burtoni are sister taxa, which together are a sister group to a monophyletic assemblage including both Lake Victoria and Lake Edward taxa. The ITS-1 data support the monophyly of haplochromine genera across lakes. Since Lake Victoria is believed to have been dry between 14, 500 and 12,400 BPE, the modern assemblage must have been derived from reinvasion by the products of earlier cladogenesis events. Thus, although the regional superflock is monophyletic, the haplochromines of Lake Victoria itself did not evolve in situ from a single ancestor.

  14. Microsatellite support for active inbreeding in a cichlid fish.

    PubMed

    Langen, Kathrin; Schwarzer, Julia; Kullmann, Harald; Bakker, Theo C M; Thünken, Timo

    2011-01-01

    In wild animal populations, the degree of inbreeding differs between species and within species between populations. Because mating with kin often results in inbreeding depression, observed inbreeding is usually regarded to be caused by limited outbreeding opportunities due to demographic factors like small population size or population substructuring. However, theory predicts inclusive benefits from mating with kin, and thus part of the observed variation in inbreeding might be due to active inbreeding preferences. Although some recent studies indeed report kin mating preferences, the evidence is still highly ambiguous. Here, we investigate inbreeding in a natural population of the West African cichlid fish Pelvicachromis taeniatus which showed clear kin mating preferences in standardized laboratory experiments but no inbreeding depression. The presented microsatellite analysis reveals that the natural population has, in comparison to two reference populations, a reduced allelic diversity (A = 3) resulting in a low heterozygosity (H(o) = 0.167) pointing to a highly inbred population. Furthermore, we found a significant heterozygote deficit not only at population (F(is) = 0.116) but also at subpopulation level (F(is) = 0.081) suggesting that inbreeding is not only a by-product of population substructuring but possibly a consequence of behavioral kin preferences.

  15. Mitochondrial phylogeography of rock-dwelling cichlid fishes reveals evolutionary influence of historical lake level fluctuations of Lake Tanganyika, Africa.

    PubMed

    Verheyen, E; Rüber, L; Snoeks, J; Meyer, A

    1996-06-29

    The East African Lakes Tanganyika, Malawi and Victoria each harbour hundreds of endemic invertebrate and vertebrate species. Inferences about the ecological and evolutionary processes responsible for the origin of these species flocks will only be possible when they are made within historical and comparative frameworks. Specifically, the relative importance of intrinsic characteristics and extrinsic factors may offer information about the processes that drive diversification and speciation in these species. We investigated the sequence variation of a segment of the mitochondrial DNA control region of 32 populations representing all four nominal species in the three genera of eretmodine cichlids from Lake Tanganyika. Based on a phylogenetic analysis of these data we attempted to evaluate the importance of major lake level fluctuations on patterns of intralacustrine speciation. The geography of genetic variation reveals a high degree of within-lake endemism among genetically well-separated lineages distributed along the inferred shore lines of three historically intermittent lake basins. Seismic data indicate that extreme lowering of water levels in the Pleistocene caused the single Lake Tanganyika basin to split into three isolated ones. The strong phylogeographic structure of the Eretmodini, and the observation that some closely related populations occur on opposite shores of the lake, agree with this geological scenario. The three-clade-three-basin phylogeographic pattern was repeated twice within this tribe of cichlids. The phylogeographic pattern of eretmodine cichlids suggests that major fluctuations in the level of the lake have been important in shaping their adaptive radiation and speciation. The mitochondrially defined clades are in conflict with the current taxonomy of the group and suggest that there has been convergent evolution in trophic morphology, particularly in the shapes of oral teeth, taxonomically the most diagnostic characters of the three

  16. The effect of light intensity on prey detection behavior in two Lake Malawi cichlids, Aulonocara stuartgranti and Tramitichromis sp.

    PubMed

    Schwalbe, Margot A B; Webb, Jacqueline F

    2015-04-01

    Two sand-dwelling cichlids from Lake Malawi (Aulonocara stuartgranti, Tramitichromis sp.) that feed on benthic invertebrates, but have different lateral line phenotypes, use lateral line and/or visual cues to detect prey under light versus dark conditions. The current study examined how ecologically relevant variation in light intensity [0-800 lux (lx)] influences detection of prey (mobile, immobile) in each species by analyzing six behavioral parameters. Both species fed at light intensities ≥1 lx and trends in behavior among light intensities were informative. However, prey type and/or time of day (but not light intensity) predicted all four parameters analyzed with generalized linear mixed models in A. stuartgranti, whereas the interaction of light intensity and time of day predicted three of these parameters in Tramitichromis sp. Data suggest that the critical light intensity is 1-12 lx for both species, that the integration of visual and lateral line input explains differences in detection of mobile and immobile prey and behavioral changes at the transition from 1 to 0 lx in A. stuartgranti, and that Tramitichromis sp. likely uses binocular vision to locate prey. Differences in the sensory biology of species that exploit similar prey will have important implications for the trophic ecology of African cichlid fishes.

  17. A three-dimensional stereotaxic MRI brain atlas of the cichlid fish Oreochromis mossambicus.

    PubMed

    Simões, José M; Teles, Magda C; Oliveira, Rui F; Van der Linden, Annemie; Verhoye, Marleen

    2012-01-01

    The African cichlid Oreochromis mossambicus (Mozambique tilapia) has been used as a model system in a wide range of behavioural and neurobiological studies. The increasing number of genetic tools available for this species, together with the emerging interest in its use for neurobiological studies, increased the need for an accurate hodological mapping of the tilapia brain to supplement the available histological data. The goal of our study was to elaborate a three-dimensional, high-resolution digital atlas using magnetic resonance imaging, supported by Nissl staining. Resulting images were viewed and analysed in all orientations (transverse, sagittal, and horizontal) and manually labelled to reveal structures in the olfactory bulb, telencephalon, diencephalon, optic tectum, and cerebellum. This high resolution tilapia brain atlas is expected to become a very useful tool for neuroscientists using this fish model and will certainly expand their use in future studies regarding the central nervous system.

  18. Nuclear markers reveal that inter-lake cichlids' similar morphologies do not reflect similar genealogy.

    PubMed

    Kassam, Daud; Seki, Shingo; Horic, Michio; Yamaoka, Kosaku

    2006-08-01

    The apparent inter-lake morphological similarity among East African Great Lakes' cichlid species/genera has left evolutionary biologists asking whether such similarity is due to sharing of common ancestor or mere convergent evolution. In order to answer such question, we first used Geometric Morphometrics, GM, to quantify morphological similarity and then subsequently used Amplified Fragment Length Polymorphism, AFLP, to determine if similar morphologies imply shared ancestry or convergent evolution. GM revealed that not all presumed morphological similar pairs were indeed similar, and the dendrogram generated from AFLP data indicated distinct clusters corresponding to each lake and not inter-lake morphological similar pairs. Such results imply that the morphological similarity is due to convergent evolution and not shared ancestry. The congruency of GM and AFLP generated dendrograms imply that GM is capable of picking up phylogenetic signal, and thus GM can be potential tool in phylogenetic systematics.

  19. A Three-Dimensional Stereotaxic MRI Brain Atlas of the Cichlid Fish Oreochromis mossambicus

    PubMed Central

    Simões, José M.; Teles, Magda C.; Oliveira, Rui F.; Van der Linden, Annemie; Verhoye, Marleen

    2012-01-01

    The African cichlid Oreochromis mossambicus (Mozambique tilapia) has been used as a model system in a wide range of behavioural and neurobiological studies. The increasing number of genetic tools available for this species, together with the emerging interest in its use for neurobiological studies, increased the need for an accurate hodological mapping of the tilapia brain to supplement the available histological data. The goal of our study was to elaborate a three-dimensional, high-resolution digital atlas using magnetic resonance imaging, supported by Nissl staining. Resulting images were viewed and analysed in all orientations (transverse, sagittal, and horizontal) and manually labelled to reveal structures in the olfactory bulb, telencephalon, diencephalon, optic tectum, and cerebellum. This high resolution tilapia brain atlas is expected to become a very useful tool for neuroscientists using this fish model and will certainly expand their use in future studies regarding the central nervous system. PMID:22984463

  20. Separated by sand, fused by dropping water: habitat barriers and fluctuating water levels steer the evolution of rock-dwelling cichlid populations in Lake Tanganyika.

    PubMed

    Koblmüller, Stephan; Salzburger, Walter; Obermüller, Beate; Eigner, Eva; Sturmbauer, Christian; Sefc, Kristina M

    2011-06-01

    The conditions of phenotypic and genetic population differentiation allow inferences about the evolution, preservation and loss of biological diversity. In Lake Tanganyika, water level fluctuations are assumed to have had a major impact on the evolution of stenotopic littoral species, though this hypothesis has not been specifically examined so far. The present study investigates whether subtly differentiated colour patterns of adjacent Tropheus moorii populations are maintained in isolation or in the face of continuous gene flow, and whether the presumed influence of water level fluctuations on lacustrine cichlids can be demonstrated in the small-scale population structure of the strictly stenotopic, littoral Tropheus. Distinct population differentiation was found even across short geographic distances and minor habitat barriers. Population splitting chronology and demographic histories comply with our expectation of old and rather stable populations on steeper sloping shore, and more recently established populations in a shallower region. Moreover, population expansions seem to coincide with lake level rises in the wake of Late Pleistocene megadroughts ~100 KYA. The imprint of hydrologic events on current population structure in the absence of ongoing gene flow suggests that phenotypic differentiation among proximate Tropheus populations evolves and persists in genetic isolation. Sporadic gene flow is effected by lake level fluctuations following climate changes and controlled by the persistence of habitat barriers during lake level changes. Since similar demographic patterns were previously reported for Lake Malawi cichlids, our data furthermore strengthen the hypothesis that major climatic events synchronized facets of cichlid evolution across the East African Great Lakes.

  1. Colour variation in cichlid fish: Developmental mechanisms, selective pressures and evolutionary consequences☆

    PubMed Central

    Maan, Martine E.; Sefc, Kristina M.

    2013-01-01

    Cichlid fishes constitute one of the most species-rich families of vertebrates. In addition to complex social behaviour and morphological versatility, they are characterised by extensive diversity in colouration, both within and between species. Here, we review the cellular and molecular mechanisms underlying colour variation in this group and the selective pressures responsible for the observed variation. We specifically address the evidence for the hypothesis that divergence in colouration is associated with the evolution of reproductive isolation between lineages. While we conclude that cichlid colours are excellent models for understanding the role of animal communication in species divergence, we also identify taxonomic and methodological biases in the current research effort. We suggest that the integration of genomic approaches with ecological and behavioural studies, across the entire cichlid family and beyond it, will contribute to the utility of the cichlid model system for understanding the evolution of biological diversity. PMID:23665150

  2. Drug cytotoxicity assay for African trypanosomes and Leishmania species.

    PubMed

    Bodley, A L; McGarry, M W; Shapiro, T A

    1995-10-01

    The trypanosomes and Leishmania species are parasitic protozoa that afflict millions of people throughout the world. If not treated, African trypanosomiasis and visceral leishmaniasis are fatal. The available drugs are severely limited by toxicity, marginal efficacy, the requirement for parenteral administration, and spreading drug resistance. In this study, a spectrophotometric assay was developed and validated for measuring the cytotoxicity of test compounds against axenically cultured bloodstream-form Trypanosoma brucei (African trypanosomes) and promastigotes of Leishmania donovani. Enzymatic hydrolysis of p-nitrophenyl phosphate, monitored by a microtiter plate reader, is a reliable surrogate for parasite cell counts. The assay is simple, inexpensive, and highly reproducible. The coefficient of variation for EC50 values is < 10% for determinations obtained over several months. This method permits the rapid screening of candidates for much-needed new drugs against these parasites.

  3. A microsatellite-based genetic linkage map and putative sex-determining genomic regions in Lake Victoria cichlids.

    PubMed

    Kudo, Yu; Nikaido, Masato; Kondo, Azusa; Suzuki, Hikoyu; Yoshida, Kohta; Kikuchi, Kiyoshi; Okada, Norihiro

    2015-04-15

    Cichlid fishes in East Africa have undergone extensive adaptive radiation, which has led to spectacular diversity in their morphology and ecology. To date, genetic linkage maps have been constructed for several tilapias (riverine), Astatotilapia burtoni (Lake Tanganyika), and hybrid lines of Lake Malawi cichlids to facilitate genome-wide comparative analyses. In the present study, we constructed a genetic linkage map of the hybrid line of Lake Victoria cichlids, so that maps of cichlids from all the major areas of East Africa will be available. The genetic linkage map shown here is derived from the F2 progeny of an interspecific cross between Haplochromis chilotes and Haplochromis sauvagei and is based on 184 microsatellite and two single-nucleotide polymorphism (SNP) markers. Most of the microsatellite markers used in the present study were originally designed for other genetic linkage maps, allowing us to directly compare each linkage group (LG) among different cichlid groups. We found 25 LGs, the total length of which was 1133.2cM with an average marker spacing of about 6.09cM. Our subsequent linkage mapping analysis identified two putative sex-determining loci in cichlids. Interestingly, one of these two loci is located on cichlid LG5, on which the female heterogametic ZW locus and several quantitative trait loci (QTLs) related to adaptive evolution have been reported in Lake Malawi cichlids. We also found that V1R1 and V1R2, candidate genes for the fish pheromone receptor, are located very close to the recently detected sex-determining locus on cichlid LG5. The genetic linkage map study presented here may provide a valuable foundation for studying the chromosomal evolution of East African cichlids and the possible role of sex chromosomes in generating their genomic diversity.

  4. Introgressive hybridization in a trophically polymorphic cichlid

    PubMed Central

    Hulsey, C Darrin; García-de-León, Francisco J

    2013-01-01

    Trophically polymorphic species could represent lineages that are rapidly diverging along an ecological axis or could phenotypically mark the collapse of species through introgressive hybridization. We investigated patterns of introgression between the trophically polymorphic cichlid fish Herichthys minckleyi and its relative H. cyanoguttatus using a combination of population genetics and species tree analyses. We first examined the distribution of mitochondrial haplotypes within the alternative H. minckleyi pharyngeal jaw morphotypes that are endemic to the small desert valley of Cuatro Ciénegas. We recovered two clusters of mitochondrial haplotypes. The first contained a number of slightly differentiated cytochrome b (cytb) haplotypes that showed some phylogeographic signal and were present in both jaw morphotypes. The other haplotype was monomorphic, highly differentiated from the other cluster, present in equal frequencies in the morphotypes, and identical to H. cyanoguttatus haplotypes found outside Cuatro Ciénegas. Then, we investigated whether H. minckleyi individuals with the H. cyanoguttatus cytb were more evolutionarily similar to H. cyanoguttatus or other H. minckleyi using a species tree analysis of 84 nuclear loci. Both H. minckleyi pharyngeal morphotypes, regardless of their cytb haplotype, were quite distinct from H. cyanoguttatus. However, hybridization could be blurring subdivision within H. minckleyi as the alternative jaw morphotypes were not genetically distinct from one another. Accounting for introgression from H. cyanoguttatus will be essential to understand the evolution of the trophically polymorphic cichlid H. minckleyi. PMID:24340193

  5. The introduced Asian parasitic copepod Neoergasilus japonicus (Harada) (Cyclopoida: Ergasilidae) from endangered cichlid teleosts in Mexico.

    PubMed

    Suárez-Morales, Eduardo; Paredes-Trujillo, Amelia; González-Solís, David

    2010-11-01

    The cyclopoid copepod Neoergasilus japonicus ( Harada, 1930 ) is recorded from three endangered or threatened fish species from southeast Mexico: the tailbar cichlid Vieja hartwegi (Taylor and Miller, 1980); the Angostura cichlid V. breidohri (Werner and Stawikowski, 1987); and the sieve cichlid C. grammodes (Taylor and Miller, 1980). This ectoparasitic copepod is considered, together with most other members of Neoergasilus, an Eastern Asian form. N. japonicus is one of the most widespread parasitic Asian copepods, as it has rapidly invaded Europe and North America, including Mexico. We estimated the prevalence, mean abundance, and intensity of infection of N. japonicus in these cichlid teleosts; our data agree with previous works stating the high prevalence of this ectoparasite. This copepod has a wide range of hosts among freshwater fish taxa, but this is only the second published report from cichlids in the Neotropical region. The three cichlids surveyed, V. hartwegi, V. breidohri, and C. grammodes, are new hosts of this copepod. Its occurrence in Mexico is attributed to different events of introduction by human agency. This is the southernmost record of N. japonicus in continental America. It is a matter of concern that this copepod is parasitizing endangered or threatened endemic cichlids in the Neotropical region. Because its high infective efficiency and ability to shift hosts, this Asian parasite is expected to spread farther southwards into Central and South America.

  6. Functional Diversification within a Predatory Species Flock

    PubMed Central

    Burress, Edward D.; Duarte, Alejandro; Serra, Wilson S.; Loueiro, Marcelo; Gangloff, Michael M.; Siefferman, Lynn

    2013-01-01

    Ecological speciation is well-known from adaptive radiations in cichlid fishes inhabiting lentic ecosystems throughout the African rift valley and Central America. Here, we investigate the ecological and morphological diversification of a recently discovered lotic predatory Neotropical cichlid species flock in subtropical South America. We document morphological and functional diversification using geometric morphometrics, stable C and N isotopes, stomach contents and character evolution. This species flock displays species-specific diets and skull and pharyngeal jaw morphology. Moreover, this lineage appears to have independently evolved away from piscivory multiple times and derived forms are highly specialized morphologically and functionally relative to ancestral states. Ecological speciation played a fundamental role in this radiation and our data reveal novel conditions of ecological speciation including a species flock that evolved: 1) in a piscivorous lineage, 2) under lotic conditions and 3) with pronounced morphological novelties, including hypertrophied lips that appear to have evolved rapidly. PMID:24278349

  7. Evolutionary dynamics of rRNA gene clusters in cichlid fish

    PubMed Central

    2012-01-01

    Background Among multigene families, ribosomal RNA (rRNA) genes are the most frequently studied and have been explored as cytogenetic markers to study the evolutionary history of karyotypes among animals and plants. In this report, we applied cytogenetic and genomic methods to investigate the organization of rRNA genes among cichlid fishes. Cichlids are a group of fishes that are of increasing scientific interest due to their rapid and convergent adaptive radiation, which has led to extensive ecological diversity. Results The present paper reports the cytogenetic mapping of the 5S rRNA genes from 18 South American, 22 African and one Asian species and the 18S rRNA genes from 3 African species. The data obtained were comparatively analyzed with previously published information related to the mapping of rRNA genes in cichlids. The number of 5S rRNA clusters per diploid genome ranged from 2 to 15, with the most common pattern being the presence of 2 chromosomes bearing a 5S rDNA cluster. Regarding 18S rDNA mapping, the number of sites ranged from 2 to 6, with the most common pattern being the presence of 2 sites per diploid genome. Furthermore, searching the Oreochromis niloticus genome database led to the identification of a total of 59 copies of 5S rRNA and 38 copies of 18S rRNA genes that were distributed in several genomic scaffolds. The rRNA genes were frequently flanked by transposable elements (TEs) and spread throughout the genome, complementing the FISH analysis that detect only clustered copies of rRNA genes. Conclusions The organization of rRNA gene clusters seems to reflect their intense and particular evolutionary pathway and not the evolutionary history of the associated taxa. The possible role of TEs as one source of rRNA gene movement, that could generates the spreading of ribosomal clusters/copies, is discussed. The present paper reinforces the notion that the integration of cytogenetic data and genomic analysis provides a more complete picture for

  8. Sexually dimorphic levels of color trait integration and the resolution of sexual conflict in Lake Malawi cichlids.

    PubMed

    Brzozowski, Frances; Roscoe, Jennifer; Parsons, Kevin; Albertson, Craig

    2012-06-01

    East African cichlids are renowned for their propensity to radiate, and variation in color patterns accounts for much of endemic cichlid diversity. Sexual dimorphism in color among cichlid species likely represents the outcome of different selective regimes acting on each sex, and is a classic example of sexual conflict. It is generally assumed that this conflict has been mitigated through the evolution of sex-linked color polymorphisms. Here, we propose that the evolution of sex-specific differences in levels of color trait integration may represent an additional mechanism through which sexual conflict has been resolved in this group. Specifically, we predict: (1) that general patterns of integration are influenced by early developmental events and thus conserved across sexes and (2) that male color is less integrated than females, and thus more evolvable in terms of producing an elaborate palette (i.e., in response to sexual selection), whereas female color is more integrated, facilitating wholesale shifts in color for background matching (i.e., in response to natural selection for crypsis). We tested these hypotheses using an F(2) design to compare the segregation of male and female color patterns. Both exploratory methods and hypothesis-driven analyses of integration demonstrate that the covariance structure of color traits in males and females is distinct, and that males are significantly less integrated than females. We suggest that the ability of species to promote different levels, and to a lesser extent patterns, of phenotypic integration between males and females may have contributed to the evolutionary success of this group.

  9. Late Pleistocene Desiccation of Lake Victoria and Rapid Evolution of Cichlid Fishes

    NASA Astrophysics Data System (ADS)

    Johnson, Thomas C.; Scholz, Christopher A.; Talbot, Michael R.; Kelts, Kerry; Ricketts, R. D.; Ngobi, Gideon; Beuning, Kristina; Ssemmanda, Immacculate; McGill, J. W.

    1996-08-01

    Lake Victoria is the largest lake in Africa and harbors more than 300 endemic species of haplochromine cichlid fish. Seismic reflection profiles and piston cores show that the lake not only was at a low stand but dried up completely during the Late Pleistocene, before 12,400 carbon-14 years before the present. These results imply that the rate of speciation of cichlid fish in this tropical lake has been extremely rapid.

  10. Linkage relationships and haplotype polymorphism among cichlid Mhc class II B loci.

    PubMed Central

    Málaga-Trillo, E; Zaleska-Rutczynska, Z; McAndrew, B; Vincek, V; Figueroa, F; Sültmann, H; Klein, J

    1998-01-01

    The species flocks of cichlid fishes in the Great East African Lakes are paradigms of adaptive radiation and hence, of great interest to evolutionary biologists. Phylogenetic studies of these fishes have, however, been hampered by the lack of suitable polymorphic markers. The genes of the major histocompatibility complex hold the promise to provide, through their extensive polymorphism, a large number of such markers, but their use has been hampered by the complexity of the genetic system and the lack of definition of the individual loci. In this study we take the first substantial step to alleviate this problem. Using a combination of methods, including the typing of single sperm cells, gyno- or androgenetic individuals, and haploid embryos, as well as sequencing of class II B restriction fragments isolated from gels for Southern blots, we identify the previously characterized homology groups as distinct loci. At least 17 polymorphic class II B loci, all of which are presumably transcribed, have been found among the different species studied. Most of these loci are shared across the various cichlid species and genera. The number of loci per haplotype varies from individual to individual, ranging from 1 to 13. A total of 21 distinct haplotypes differing in the number of loci they carry has thus far been identified. All the polymorphic loci are part of the same cluster in which, however, distances between at least some of the loci (as indicated by recombination frequencies) are relatively large. Both the individual loci and the haplotypes can now be used to study phylogenetic relationships among the members of the species flocks and the mode in which speciation occurs during adaptive radiation. PMID:9649539

  11. Social Status and Arginine Vasotocin Neuronal Phenotypes in a Cichlid Fish.

    PubMed

    Almeida, Olinda; Oliveira, Rui F

    2015-01-01

    The nonapeptide arginine vasotocin (AVT) and its mammalian homologue arginine vasopressin play a key role in the regulation of social behaviour across vertebrates. In teleost fishes, three AVT neuronal populations have been described in the preoptic area (POA): the parvocellular (pPOA), the magnocellular (mPOA) and the gigantocellular (gPOA). Neurons from each of these areas project both to the pituitary and to other brain regions, where AVT is supposed to regulate neural circuits underlying social behaviour. However, in the fish species studied so far, there is considerable variation in which AVT neuronal populations are involved in behavioural modulation and in the direction of the effect. In this study, the association between AVT neuronal phenotypes and social status was investigated in the Mozambique tilapia (Oreochromis mossambicus). This species is an African female mouth-brooding cichlid fish in which males form breeding aggregations in which dominant males establish territories and subordinate males to act as floaters. With respect to sex differences in AVT neuronal phenotypes, females have a larger number of AVT neurons in the pPOA and mPOA. Within males, AVT appeared associated with social subordination, as indicated by the larger cell body areas of AVT neurons in mPOA and gPOA nuclei of non-territorial males. There were also positive correlations between submissive behaviour and the soma size of AVT cells in all three nuclei and AVT cell number in the mPOA. In summary, the results provide evidence for an involvement of AVT in the modulation of social behaviour in tilapia, but it was not possible to identify specific roles for specific AVT neuronal populations. The results presented here also contrast with those previously published for another cichlid species with a similar mating system, which highlights the species-specific nature of the pattern of association between AVT and social behaviour even within the same taxonomic family.

  12. Molecular characterization of Theileria species associated with mortality in four species of African antelopes.

    PubMed

    Nijhof, A M; Pillay, V; Steyl, J; Prozesky, L; Stoltsz, W H; Lawrence, J A; Penzhorn, B L; Jongejan, F

    2005-12-01

    Pathogen DNA was isolated from roan antelope (Hippotragus equinus), sable antelope (Hippotragus niger), greater kudu (Tragelaphus strepsiceros), and common gray duiker (Sylvicapra grimmia) in South Africa whose deaths were attributed to either theileriosis or cytauxzoonosis. We developed Theileria species-specific probes used in combination with reverse line blot hybridization assays and identified three different species of Theileria in four African antelope species. The close phylogenetic relationship between members of the genera Theileria and Cytauxzoon, similarities in the morphologies of developmental stages, and confusion in the literature regarding theileriosis or cytauxzoonosis are discussed.

  13. Comparative phylogenomic analyses of teleost fish Hox gene clusters: lessons from the cichlid fish Astatotilapia burtoni

    PubMed Central

    Hoegg, Simone; Boore, Jeffrey L; Kuehl, Jennifer V; Meyer, Axel

    2007-01-01

    Background Teleost fish have seven paralogous clusters of Hox genes stemming from two complete genome duplications early in vertebrate evolution, and an additional genome duplication during the evolution of ray-finned fish, followed by the secondary loss of one cluster. Gene duplications on the one hand, and the evolution of regulatory sequences on the other, are thought to be among the most important mechanisms for the evolution of new gene functions. Cichlid fish, the largest family of vertebrates with about 2500 species, are famous examples of speciation and morphological diversity. Since this diversity could be based on regulatory changes, we chose to study the coding as well as putative regulatory regions of their Hox clusters within a comparative genomic framework. Results We sequenced and characterized all seven Hox clusters of Astatotilapia burtoni, a haplochromine cichlid fish. Comparative analyses with data from other teleost fish such as zebrafish, two species of pufferfish, stickleback and medaka were performed. We traced losses of genes and microRNAs of Hox clusters, the medaka lineage seems to have lost more microRNAs than the other fish lineages. We found that each teleost genome studied so far has a unique set of Hox genes. The hoxb7a gene was lost independently several times during teleost evolution, the most recent event being within the radiation of East African cichlid fish. The conserved non-coding sequences (CNS) encompass a surprisingly large part of the clusters, especially in the HoxAa, HoxCa, and HoxDa clusters. Across all clusters, we observe a trend towards an increased content of CNS towards the anterior end. Conclusion The gene content of Hox clusters in teleost fishes is more variable than expected, with each species studied so far having a different set. Although the highest loss rate of Hox genes occurred immediately after whole genome duplications, our analyses showed that gene loss continued and is still ongoing in all teleost

  14. Chronology of the extant African elephant species and case study of the species identification of the small African elephant with the molecular phylogenetic method.

    PubMed

    Murata, Yumie; Yonezawa, Takahiro; Kihara, Ichiro; Kashiwamura, Toshihide; Sugihara, Yuji; Nikaido, Masato; Okada, Norihiro; Endo, Hideki; Hasegawa, Masami

    2009-07-15

    Despite vigorous genetic studies of African elephants (Loxodonta africana and L. cyclotis) during the last decade, their evolutionary history is still obscure. Phylogenetic studies and coalescence time estimation using longer nucleotide sequence data from denser samplings are necessary to better understand the natural history of African elephants. Further, species identification among African elephants is sometimes very difficult using only the external morphological characteristics. This is a serious problem for making an adequate breeding plan in zoological gardens. In this paper, we investigated the continent-wide phylogeographical pattern of the African elephants and estimated the coalescence times among them. From these molecular data and geological evidence, we proposed an evolutionary scenario for the African elephants. We further demonstrated the effectiveness of molecular phylogenetic methods in species identification.

  15. Eco-morphological differentiation in Lake Magadi tilapia, an extremophile cichlid fish living in hot, alkaline and hypersaline lakes in East Africa.

    PubMed

    Kavembe, Geraldine D; Kautt, Andreas F; Machado-Schiaffino, Gonzalo; Meyer, Axel

    2016-04-01

    Ecological diversification through divergent selection is thought to be a major force during the process of adaptive radiations. However, the large sizes and complexity of most radiations such as those of the cichlids in the African Great Lakes make it impossible to infer the exact evolutionary history of any population divergence event. The genus Alcolapia, a small cichlid lineage endemic to Lakes Magadi and Natron in East Africa, exhibits phenotypes similar to some of those found in cichlids of the radiations of the African Great Lakes. The simplicity within Alcolapia makes it an excellent model system to investigate ecological diversification and speciation. We used an integrated approach including population genomics based on RAD-seq data, geometric morphometrics and stable isotope analyses to investigate the eco-morphological diversification of tilapia in Lake Magadi and its satellite lake Little Magadi. Additionally, we reconstructed the demographic history of the species using coalescent simulations based on the joint site frequency spectrum. The population in Little Magadi has a characteristically upturned mouth--possibly an adaptation to feeding on prey from the water surface. Eco-morphological differences between populations within Lake Magadi are more subtle, but are consistent with known ecological differences between its lagoons such as high concentrations of nitrogen attributable to extensive guano deposits in Rest of Magadi relative to Fish Springs Lagoon. All populations diverged simultaneously only about 1100 generations ago. Differences in levels of gene flow between populations and the effective population sizes have likely resulted in the inferred heterogeneous patterns of genome-wide differentiation.

  16. Prey vulnerability to peacock cichlids and largemouth bass based on predator gape and prey body depth

    USGS Publications Warehouse

    Hill, Jeffrey E.; Nico, Leo G.; Cichra, Charles E.; Gilbert, Carter R.

    2005-01-01

    The interaction of prey fish body depth and predator gape size may produce prey assemblages dominated by invulnerable prey and excessive prey-to-predator biomass ratios. Peacock cichlids (Cichla ocellaris) were stocked into southeast Florida canals to consume excess prey fish biomass, particularly spotted tilapia (Tilapia mariae). The ecomorphologically similar largemouth bass (Micropterus salmoides) was already present in the canals. We present relations of length-specific gape size for peacock cichlids and largemouth bass. Both predators have broadly overlapping gape size, but largemouth bass ?126 mm total length have slightly larger gape sizes than peacock cichlids of the same length. Also, we experimentally tested the predictions of maximum prey size for peacock cichlids and determined that a simple method of measuring gape size used for largemouth bass also is appropriate for peacock cichlids. Lastly, we determined relations of body depth and length of prey species to investigate relative vulnerability. Using a simple predator-prey model and length frequencies of predators and bluegill (Lepomis macrochirus), redear sunfish (Lepomis microlophus), and spotted tilapia prey, we documented that much of the prey biomass in southeast Florida canals is unavailable for largemouth bass and peacock cichlid predation.

  17. A complex mode of aggressive mimicry in a scale-eating cichlid fish.

    PubMed

    Boileau, Nicolas; Cortesi, Fabio; Egger, Bernd; Muschick, Moritz; Indermaur, Adrian; Theis, Anya; Büscher, Heinz H; Salzburger, Walter

    2015-09-01

    Aggressive mimicry is an adaptive tactic of parasitic or predatory species that closely resemble inoffensive models in order to increase fitness via predatory gains. Although similarity of distantly related species is often intuitively implicated with mimicry, the exact mechanisms and evolutionary causes remain elusive in many cases. Here, we report a complex aggressive mimicry strategy in Plecodus straeleni, a scale-eating cichlid fish from Lake Tanganyika, which imitates two other cichlid species. Employing targeted sequencing on ingested scales, we show that P. straeleni does not preferentially parasitize its models but—contrary to prevailing assumptions—targets a variety of co-occurring dissimilar looking fish species. Combined with tests for visual resemblance and visual modelling from a prey perspective, our results suggest that complex interactions among different cichlid species are involved in this mimicry system.

  18. A complex mode of aggressive mimicry in a scale-eating cichlid fish

    PubMed Central

    Boileau, Nicolas; Cortesi, Fabio; Egger, Bernd; Muschick, Moritz; Indermaur, Adrian; Theis, Anya; Büscher, Heinz H.; Salzburger, Walter

    2015-01-01

    Aggressive mimicry is an adaptive tactic of parasitic or predatory species that closely resemble inoffensive models in order to increase fitness via predatory gains. Although similarity of distantly related species is often intuitively implicated with mimicry, the exact mechanisms and evolutionary causes remain elusive in many cases. Here, we report a complex aggressive mimicry strategy in Plecodus straeleni, a scale-eating cichlid fish from Lake Tanganyika, which imitates two other cichlid species. Employing targeted sequencing on ingested scales, we show that P. straeleni does not preferentially parasitize its models but—contrary to prevailing assumptions—targets a variety of co-occurring dissimilar looking fish species. Combined with tests for visual resemblance and visual modelling from a prey perspective, our results suggest that complex interactions among different cichlid species are involved in this mimicry system. PMID:26399975

  19. Chromosome comparison of 17 species / sub-species of African Goliathini (Coleoptera, Scarabaeidae, Cetoniinae)

    PubMed Central

    Dutrillaux, Anne-Marie; Dutrillaux, Bernard

    2016-01-01

    Abstract The mitotic karyotypes of 17 species of African Goliathini (Cetoniinae) are described using various chromosome banding techniques. All but one are composed of 20 chromosomes, mostly metacentric, forming a karyotype assumed to be close to that of the Polyphaga ancestor. The most derived karyotypes are those of Goliathus goliatus Drury, 1770, with eight pairs of acrocentrics and Chlorocana africana Drury, 1773, with only14 chromosomes. In species of the genera Cyprolais Burmeister, 1842, Megalorhina Westwood, 1847, Stephanocrates Kolbe, 1894 and Stephanorrhina Burmeister, 1842, large additions of variable heterochromatin are observed on both some particular autosomes and the X chromosome. Species of the genera Eudicella White, 1839 and Dicronorrhina Burmeister, 1842 share the same sub-metacentric X. Although each species possesses its own karyotype, it remains impossible to propose robust phylogenetic relationships on the basis of chromosome data only. PMID:27551348

  20. Population genomic signatures of divergent adaptation, gene flow and hybrid speciation in the rapid radiation of Lake Victoria cichlid fishes.

    PubMed

    Keller, I; Wagner, C E; Greuter, L; Mwaiko, S; Selz, O M; Sivasundar, A; Wittwer, S; Seehausen, O

    2013-06-01

    Adaptive radiations are an important source of biodiversity and are often characterized by many speciation events in very short succession. It has been proposed that the high speciation rates in these radiations may be fuelled by novel genetic combinations produced in episodes of hybridization among the young species. The role of such hybridization events in the evolutionary history of a group can be investigated by comparing the genealogical relationships inferred from different subsets of loci, but such studies have thus far often been hampered by shallow genetic divergences, especially in young adaptive radiations, and the lack of genome-scale molecular data. Here, we use a genome-wide sampling of SNPs identified within restriction site-associated DNA (RAD) tags to investigate the genomic consistency of patterns of shared ancestry and adaptive divergence among five sympatric cichlid species of two genera, Pundamilia and Mbipia, which form part of the massive adaptive radiation of cichlids in the East African Lake Victoria. Species pairs differ along several axes: male nuptial colouration, feeding ecology, depth distribution, as well as the morphological traits that distinguish the two genera and more subtle morphological differences. Using outlier scan approaches, we identify signals of divergent selection between all species pairs with a number of loci showing parallel patterns in replicated contrasts either between genera or between male colour types. We then create SNP subsets that we expect to be characterized to different extents by selection history and neutral processes and describe phylogenetic and population genetic patterns across these subsets. These analyses reveal very different evolutionary histories for different regions of the genome. To explain these results, we propose at least two intergeneric hybridization events (between Mbipia spp. and Pundamilia spp.) in the evolutionary history of these five species that would have lead to the evolution

  1. Are accessory hearing structures linked to inner ear morphology? Insights from 3D orientation patterns of ciliary bundles in three cichlid species

    PubMed Central

    2014-01-01

    Background Cichlid fishes show considerable diversity in swim bladder morphology. In members of the subfamily Etroplinae, the connection between anterior swim bladder extensions and the inner ears enhances sound transmission and translates into an improved hearing ability. We tested the hypothesis that those swim bladder modifications coincide with differences in inner ear morphology and thus compared Steatocranus tinanti (vestigial swim bladder), Hemichromis guttatus (large swim bladder without extensions), and Etroplus maculatus (intimate connection between swim bladder and inner ears). Methodology and results We applied immunostaining together with confocal imaging and scanning electron microscopy for the investigation of sensory epithelia, and high-resolution, contrast-enhanced microCT imaging for characterizing inner ears in 3D, and evaluated otolith dimensions. Compared to S. tinanti and H. guttatus, inner ears of E. maculatus showed an enlargement of all three maculae, and a particularly large lacinia of the macula utriculi. While our analysis of orientation patterns of ciliary bundles on the three macula types using artificially flattened maculae uncovered rather similar orientation patterns of ciliary bundles, interspecific differences became apparent when illustrating the orientation patterns on the 3D models of the maculae: differences in the shape and curvature of the lacinia of the macula utriculi, and the anterior arm of the macula lagenae resulted in an altered arrangement of ciliary bundles. Conclusions Our results imply that improved audition in E. maculatus is associated not only with swim bladder modifications but also with altered inner ear morphology. However, not all modifications in E. maculatus could be connected to enhanced auditory abilities, and so a potential improvement of the vestibular sense, among others, also needs to be considered. Our study highlights the value of analyzing orientation patterns of ciliary bundles in their intact 3

  2. Cytogenetic mapping of the retroelements Rex1, Rex3 and Rex6 among cichlid fish: new insights on the chromosomal distribution of transposable elements.

    PubMed

    Valente, G T; Mazzuchelli, J; Ferreira, I A; Poletto, A B; Fantinatti, B E A; Martins, C

    2011-01-01

    To enhance our understanding of the organization of the genome and chromosome evolution of cichlid fish species, we have isolated and physically mapped onto the chromosomes the transposable elements (TEs) Rex1, Rex3 and Rex6, which are conserved in teleost fish, in the chromosomes of African and South American cichlid species. The physical mapping of different Rex elements showed that they are primarily compartmentalized in the pericentromeric heterochromatic regions, although dispersed or clustered signals in euchromatic regions were also observed. The presence of TEs in heterochromatin can be correlated with their role in the structure and organization of heterochromatic areas (such as centromeres) or with the lower selective pressure that act on these gene-poor regions. The Rex elements were also concentrated in the largest chromosome pair of the Nile tilapia, Oreochromis niloticus. This chromosome pair is supposed to have originated by fusions, demonstrating the possible involvement of TEs with chromosome rearrangements. Besides general patterns of chromosomal distribution, comparative analysis suggests that Rex elements could differ in their chromosomal distribution among different fish groups or species and that intrinsic aspects of the genomes could influence the spread, accumulation or elimination of TEs.

  3. Mitochondrial phylogeny of the endemic mouthbrooding lineages of cichlid fishes from Lake Tanganyika in eastern Africa.

    PubMed

    Sturmbauer, C; Meyer, A

    1993-07-01

    Of the three cichlid species flocks in eastern Africa, Lake Tanganyika harbors the oldest species assemblage, which is also the most diverse morphologically and behaviorally. For 12 species (20 individuals) of 12 genera of the tribe Ectodini, 852 bp from two segments (cytochrome b and control region) of the mitochondrial genome were sequenced. In addition, orthologous sequences were obtained from eight species (11 individuals) representing other mouthbrooding lineages from Lake Tanganyika. Comparisons of sequence divergences revealed that the single Tanganyikan tribe Ectodini appears to be approximately five times older than the whole Lake Malawi cichlid species flock, suggesting that the radiation of the Tanganyikan mouthbrooding lineages took place long before the species flocks of Lakes Malawi and Victoria evolved. Seven of nine surveyed tribes of Tanganyikan cichlids appear to be approximately equally divergent, and this seems to corroborate the hypothesis of a rapid simultaneous formation of lineages at an early stage in the history of the Lake Tanganyika species flock. The close genetic relationship between the endemic Tropheus lineage and a nonendemic "Haplochromine," Astatotilapia burtoni, indicates that members of the tribe Tropheini may be the sister group of the cichlid flocks of Lakes Malawi and Victoria. The phylogenetic analyses demonstrate the monophyly of the Ectodini and identify the Cyprichromini as their sister group among the Tanganyikan cichlids. Within the tribe Ectodini the molecular data suggest both a branching pattern different than that previously proposed and a subdivision of the Ectodini into four clades, instead of the two originally described. The previously postulated model of morphological transformations believed to be responsible for the drastically different types of ecological specialization found among the Ectodini might therefore be in need of reinterpretation. Characters immediately related to foraging and nutrition seem to

  4. Using Cichlids for Illustrating Mendel's Laws

    ERIC Educational Resources Information Center

    Gennaro, Eugene D.; Winters, Charlotte M.

    1978-01-01

    A classroom experiment is proposed in which students can mate a banded or spotted convict cichlid with a pink convict cichlid and observe the markings of their "children" and "grandchildren" as a way of illustrating Mendel's Laws of Dominance and Segregation. (MN)

  5. Depth and substratum differentiations among coexisting herbivorous cichlids in Lake Tanganyika

    PubMed Central

    Ochi, Haruki

    2016-01-01

    Cichlid fish in Lake Tanganyika represent a system of adaptive radiation in which eight ancestral lineages have diversified into hundreds of species through adaptation to various niches. However, Tanganyikan cichlids have been thought to be oversaturated, that is, the species number exceeds the number of niches and ecologically equivalent and competitively even species coexist. However, recent studies have shed light on niche segregation on a finer scale among apparently equivalent species. We observed depth and substratum preferences of 15 herbivorous cichlids from four ecomorphs (i.e. grazer, browser, scraper and scooper) on a rocky littoral slope for 14 years. Depth differentiation was detected among grazers that defended feeding territories and among browsers with feeding territories. Cichlid species having no feeding territory also showed specificity on depth and substratum, resulting in habitat segregation among species that belong to the same ecomorph. Phylogenetically close species did not occupy adjacent depths, nor the opposite depth zones. Our findings suggest that apparently equivalent species of the same ecomorph coexist parapatrically along depth on a few-metre scale, or coexist with different substratum preferences on the rocky shore, and this niche segregation may have been acquired by competition between encountering equivalent species through repetitive lake-level fluctuations. PMID:28018609

  6. Cichlid fishes in the Angolan headwaters region: molecular evidence of the ichthyofaunal contact between the Cuanza and Okavango-Zambezi systems.

    PubMed

    Musilová, Zuzana; Kalous, Lukáš; Petrtýl, Miloslav; Chaloupková, Petra

    2013-01-01

    The headwaters of five large African river basins flow through the Bié Plateau in Angola and still remain faunistically largely unexplored. We investigated fish fauna from the Cuanza and Okavango-Zambezi river systems from central Angola. We reconstructed molecular phylogenies of the most common cichlid species from the region, Tilapia sparrmanii and Serranochromis macrocephalus, using both mitochondrial and nuclear markers. We found evidence for ichthyofaunal contact and gene flow between the Cuanza and Okavango-Zambezi watersheds in the Bié Plateau in central Angola. Waterfalls and rapids also appeared to restrict genetic exchange among populations within the Cuanza basin. Further, we found that the Angolan Serranochromis cichlid fishes represent a monophyletic lineage with respect to other haplochromines, including the serranochromines from the Congo and Zambezi rivers. This study represents an important initial step in a biodiversity survey of this extremely poorly explored region, as well as giving further understanding to species distributions and gene flow both between and within river basins.

  7. Genetic architecture sets limits on transgressive segregation in hybrid cichlid fishes.

    PubMed

    Albertson, R Craig; Kocher, Thomas D

    2005-03-01

    The role of hybridization in the evolution of animal species is poorly understood. Transgressive segregation is a mechanism through which hybridization can generate diversity and ultimately lead to speciation. In this report we investigated the capacity of hybridization to generate novel (transgressive) phenotypes in the taxonomically diverse cichlid fishes. We generated a large F2 hybrid population by crossing two closely related cichlid species from Lake Malawi in Africa with differently shaped heads. Our morphometric analysis focused on two traits with different selective histories. The cichlid lower jaw (mandible) has evolved in response to strong directional selection, and does not segregate beyond the parental phenotype. The cichlid neurocranium (skull) has likely diverged in response to forces other than consistent directional selection (e.g., stabilizing selection), and exhibits marked transgressive segregation in our F2 population. We show that the genetic architecture of the cichlid jaw limits transgression, whereas the genetic basis of skull shape is permissive of transgressive segregation. These data suggest that natural selection, acting through the genome, will limit the degree of diversity that may be achieved via hybridization. Results are discussed in the context of the broader question of how phenotypic diversity may be achieved in rapidly evolving systems.

  8. Adaptive phenotypic plasticity in the Midas cichlid fish pharyngeal jaw and its relevance in adaptive radiation

    PubMed Central

    2011-01-01

    Background Phenotypic evolution and its role in the diversification of organisms is a central topic in evolutionary biology. A neglected factor during the modern evolutionary synthesis, adaptive phenotypic plasticity, more recently attracted the attention of many evolutionary biologists and is now recognized as an important ingredient in both population persistence and diversification. The traits and directions in which an ancestral source population displays phenotypic plasticity might partly determine the trajectories in morphospace, which are accessible for an adaptive radiation, starting from the colonization of a novel environment. In the case of repeated colonizations of similar environments from the same source population this "flexible stem" hypothesis predicts similar phenotypes to arise in repeated subsequent radiations. The Midas Cichlid (Amphilophus spp.) in Nicaragua has radiated in parallel in several crater-lakes seeded by populations originating from the Nicaraguan Great Lakes. Here, we tested phenotypic plasticity in the pharyngeal jaw of Midas Cichlids. The pharyngeal jaw apparatus of cichlids, a second set of jaws functionally decoupled from the oral ones, is known to mediate ecological specialization and often differs strongly between sister-species. Results We performed a common garden experiment raising three groups of Midas cichlids on food differing in hardness and calcium content. Analyzing the lower pharyngeal jaw-bones we find significant differences between diet groups qualitatively resembling the differences found between specialized species. Observed differences in pharyngeal jaw expression between groups were attributable to the diet's mechanical resistance, whereas surplus calcium in the diet was not found to be of importance. Conclusions The pharyngeal jaw apparatus of Midas Cichlids can be expressed plastically if stimulated mechanically during feeding. Since this trait is commonly differentiated - among other traits - between

  9. Distribution of baboon endogenous virus among species of African monkeys suggests multiple ancient cross-species transmissions in shared habitats.

    PubMed Central

    van der Kuyl, A C; Dekker, J T; Goudsmit, J

    1995-01-01

    PCR amplification of baboon endogenous virus (BaEV) long terminal repeat, reverse transcriptase gene, and env fragments from 24 different species of African monkeys indicates that BaEV is less widespread than was formerly thought. Instead of being present in every species of African primates, BaEV can be found only in baboons, geladas, and mangabeys (all belonging to the Papionini tribe) and in African green monkey (Cercopithecus aethiops)subspecies. BaEV, which can be activated from baboon and gelada tissues, was most likely introduced in the germ line only recently (less than a few million years ago) and has not been inherited from a common ancestor of all extant African monkeys. Neighbor-joining and maximum-likelihood analyses of the sequences obtained showed that two distinct virus clusters can be distinguished: the first containing baboon, gelada, and African green monkey BaEV sequences and the second consisting of mandrill and mangabey BaEV sequences. This viral evolutionary tree does not follow host phylogeny, indicating the cross-species transmissions and multiple germ line fixations of the virus must have occurred in the past. BaEV sequences are found in monkeys inhabiting savannas (baboons, geladas, and African green monkeys) as well as forests (managabeys and mandrills) and cluster according to the habitats of their hosts, providing evidence for cross-species transmission in shared habitats. PMID:7494300

  10. Hearing in Cichlid Fishes under Noise Conditions

    PubMed Central

    Ladich, Friedrich; Schulz-Mirbach, Tanja

    2013-01-01

    Background Hearing thresholds of fishes are typically acquired under laboratory conditions. This does not reflect the situation in natural habitats, where ambient noise may mask their hearing sensitivities. In the current study we investigate hearing in terms of sound pressure (SPL) and particle acceleration levels (PAL) of two cichlid species within the naturally occurring range of noise levels. This enabled us to determine whether species with and without hearing specializations are differently affected by noise. Methodology/Principal Findings We investigated auditory sensitivities in the orange chromide Etroplus maculatus, which possesses anterior swim bladder extensions, and the slender lionhead cichlid Steatocranus tinanti, in which the swim bladder is much smaller and lacks extensions. E. maculatus was tested between 0.2 and 3kHz and S. tinanti between 0.1 and 0.5 kHz using the auditory evoked potential (AEP) recording technique. In both species, SPL and PAL audiograms were determined in the presence of quiet laboratory conditions (baseline) and continuous white noise of 110 and 130 dB RMS. Baseline thresholds showed greatest hearing sensitivity around 0.5 kHz (SPL) and 0.2 kHz (PAL) in E. maculatus and 0.2 kHz in S. tinanti. White noise of 110 dB elevated the thresholds by 0–11 dB (SPL) and 7–11 dB (PAL) in E. maculatus and by 1–2 dB (SPL) and by 1–4 dB (PAL) in S. tinanti. White noise of 130 dB elevated hearing thresholds by 13–29 dB (SPL) and 26–32 dB (PAL) in E. maculatus and 6–16 dB (SPL) and 6–19 dB (PAL) in S. tinanti. Conclusions Our data showed for the first time for SPL and PAL thresholds that the specialized species was masked by different noise regimes at almost all frequencies, whereas the non-specialized species was much less affected. This indicates that noise can limit sound detection and acoustic orientation differently within a single fish family. PMID:23469032

  11. The Role of microRNAs in the Repeated Parallel Diversification of Lineages of Midas Cichlid Fish from Nicaragua

    PubMed Central

    Franchini, Paolo; Xiong, Peiwen; Fruciano, Carmelo; Meyer, Axel

    2016-01-01

    Cichlid fishes are an ideal model system for studying biological diversification because they provide textbook examples of rapid speciation. To date, there has been little focus on the role of gene regulation during cichlid speciation. However, in recent years, gene regulation has been recognized as a powerful force linking diversification in gene function to speciation. Here, we investigated the potential role of miRNA regulation in the diversification of six cichlid species of the Midas cichlid lineage (Amphilophus spp.) inhabiting the Nicaraguan crater lakes. Using several genomic resources, we inferred 236 Midas miRNA genes that were used to predict the miRNA target sites on 8,232 Midas 3′-UTRs. Using population genomic calculations of SNP diversity, we found the miRNA genes to be more conserved than protein coding genes. In contrast to what has been observed in other cichlid fish, but similar to what has been typically found in other groups, we observed genomic signatures of purifying selection on the miRNA targets by comparing these sites with the less conserved nontarget portion of the 3′-UTRs. However, in one species pair that has putatively speciated sympatrically in crater Lake Apoyo, we recovered a different pattern of relaxed purifying selection and high genetic divergence at miRNA targets. Our results suggest that sequence evolution at miRNA binding sites could be a critical genomic mechanism contributing to the rapid phenotypic evolution of Midas cichlids. PMID:27189980

  12. Duration of memory of dominance relationships in a group living cichlid

    NASA Astrophysics Data System (ADS)

    Hotta, Takashi; Takeyama, Tomohiro; Jordan, Lyndon Alexander; Kohda, Masanori

    2014-09-01

    Animal contests are costly and tend to escalate when rivals have similar competitive abilities. Individuals that remember dominance relationships with rivals may avoid repeated agonistic interactions and hence avoid the costs of repeated escalation of contests. However, it can be difficult to experimentally disentangle the effects of memory from those of loser effects (losers behaving subordinately due to prior defeats). Here, we test whether loser effects or individual memory mediate contest behaviour in the African cichlid, Julidochromis transcriptus. We find that on days 3 and 5 after initial contests, losers display subordinate behaviour to contest winners but not to novel contestants. However, this effect disappears after 7 days, at which time losers do not display subordinate behaviour to either rival. These results show that (1) this fish can recall a previously dominant contestant for up to 5 days and (2) as no subordinate displays were shown to the novel contestant, there are no evidences for loser effects in this species. Such short-term memory of past interactions may have broad significance in social species with repeated interactions.

  13. Genome-wide Evidence Reveals that African and Eurasian Golden Jackals Are Distinct Species.

    PubMed

    Koepfli, Klaus-Peter; Pollinger, John; Godinho, Raquel; Robinson, Jacqueline; Lea, Amanda; Hendricks, Sarah; Schweizer, Rena M; Thalmann, Olaf; Silva, Pedro; Fan, Zhenxin; Yurchenko, Andrey A; Dobrynin, Pavel; Makunin, Alexey; Cahill, James A; Shapiro, Beth; Álvares, Francisco; Brito, José C; Geffen, Eli; Leonard, Jennifer A; Helgen, Kristofer M; Johnson, Warren E; O'Brien, Stephen J; Van Valkenburgh, Blaire; Wayne, Robert K

    2015-08-17

    The golden jackal of Africa (Canis aureus) has long been considered a conspecific of jackals distributed throughout Eurasia, with the nearest source populations in the Middle East. However, two recent reports found that mitochondrial haplotypes of some African golden jackals aligned more closely to gray wolves (Canis lupus), which is surprising given the absence of gray wolves in Africa and the phenotypic divergence between the two species. Moreover, these results imply the existence of a previously unrecognized phylogenetically distinct species despite a long history of taxonomic work on African canids. To test the distinct-species hypothesis and understand the evolutionary history that would account for this puzzling result, we analyzed extensive genomic data including mitochondrial genome sequences, sequences from 20 autosomal loci (17 introns and 3 exon segments), microsatellite loci, X- and Y-linked zinc-finger protein gene (ZFX and ZFY) sequences, and whole-genome nuclear sequences in African and Eurasian golden jackals and gray wolves. Our results provide consistent and robust evidence that populations of golden jackals from Africa and Eurasia represent distinct monophyletic lineages separated for more than one million years, sufficient to merit formal recognition as different species: C. anthus (African golden wolf) and C. aureus (Eurasian golden jackal). Using morphologic data, we demonstrate a striking morphologic similarity between East African and Eurasian golden jackals, suggesting parallelism, which may have misled taxonomists and likely reflects uniquely intense interspecific competition in the East African carnivore guild. Our study shows how ecology can confound taxonomy if interspecific competition constrains size diversification.

  14. A pharyngeal jaw evolutionary innovation facilitated extinction in Lake Victoria cichlids.

    PubMed

    McGee, Matthew D; Borstein, Samuel R; Neches, Russell Y; Buescher, Heinz H; Seehausen, Ole; Wainwright, Peter C

    2015-11-27

    Evolutionary innovations, traits that give species access to previously unoccupied niches, may promote speciation and adaptive radiation. Here, we show that such innovations can also result in competitive inferiority and extinction. We present evidence that the modified pharyngeal jaws of cichlid fishes and several marine fish lineages, a classic example of evolutionary innovation, are not universally beneficial. A large-scale analysis of dietary evolution across marine fish lineages reveals that the innovation compromises access to energy-rich predator niches. We show that this competitive inferiority shaped the adaptive radiation of cichlids in Lake Tanganyika and played a pivotal and previously unrecognized role in the mass extinction of cichlid fishes in Lake Victoria after Nile perch invasion.

  15. Evolutionary dynamics of retrotransposable elements Rex1, Rex3 and Rex6 in neotropical cichlid genomes

    PubMed Central

    2013-01-01

    Background Transposable elements (TEs) have the potential to produce broad changes in the genomes of their hosts, acting as a type of evolutionary toolbox and generating a collection of new regulatory and coding sequences. Several TE classes have been studied in Neotropical cichlids; however, the information gained from these studies is restricted to the physical chromosome mapping, whereas the genetic diversity of the TEs remains unknown. Therefore, the genomic organization of the non-LTR retrotransposons Rex1, Rex3, and Rex6 in five Amazonian cichlid species was evaluated using physical chromosome mapping and DNA sequencing to provide information about the role of TEs in the evolution of cichlid genomes. Results Physical mapping revealed abundant TE clusters dispersed throughout the chromosomes. Furthermore, several species showed conspicuous clusters accumulation in the centromeric and terminal portions of the chromosomes. These TE chromosomal sites are associated with both heterochromatic and euchromatic regions. A higher number of Rex1 clusters were observed among the derived species. The Rex1 and Rex3 nucleotide sequences were more conserved in the basal species than in the derived species; however, this pattern was not observed in Rex6. In addition, it was possible to observe conserved blocks corresponding to the reverse transcriptase fragment of the Rex1 and Rex3 clones and to the endonuclease of Rex6. Conclusion Our data showed no congruence between the Bayesian trees generated for Rex1, Rex3 and Rex6 of cichlid species and phylogenetic hypothesis described for the group. Rex1 and Rex3 nucleotide sequences were more conserved in the basal species whereas Rex6 exhibited high substitution rates in both basal and derived species. The distribution of Rex elements in cichlid genomes suggests that such elements are under the action of evolutionary mechanisms that lead to their accumulation in particular chromosome regions, mostly in heterochromatins. PMID

  16. Body Size Diversity and Frequency Distributions of Neotropical Cichlid Fishes (Cichliformes: Cichlidae: Cichlinae)

    PubMed Central

    Steele, Sarah E.; López-Fernández, Hernán

    2014-01-01

    Body size is an important correlate of life history, ecology and distribution of species. Despite this, very little is known about body size evolution in fishes, particularly freshwater fishes of the Neotropics where species and body size diversity are relatively high. Phylogenetic history and body size data were used to explore body size frequency distributions in Neotropical cichlids, a broadly distributed and ecologically diverse group of fishes that is highly representative of body size diversity in Neotropical freshwater fishes. We test for divergence, phylogenetic autocorrelation and among-clade partitioning of body size space. Neotropical cichlids show low phylogenetic autocorrelation and divergence within and among taxonomic levels. Three distinct regions of body size space were identified from body size frequency distributions at various taxonomic levels corresponding to subclades of the most diverse tribe, Geophagini. These regions suggest that lineages may be evolving towards particular size optima that may be tied to specific ecological roles. The diversification of Geophagini appears to constrain the evolution of body size among other Neotropical cichlid lineages; non-Geophagini clades show lower species-richness in body size regions shared with Geophagini. Neotropical cichlid genera show less divergence and extreme body size than expected within and among tribes. Body size divergence among species may instead be present or linked to ecology at the community assembly scale. PMID:25180970

  17. Hybridization generates a hopeful monster: a hermaphroditic selfing cichlid

    PubMed Central

    Smith, Alan; García-Alonso, Javier; van Oosterhout, Cock

    2016-01-01

    Compared with other phylogenetic groups, self-fertilization (selfing) is exceedingly rare in vertebrates and is known to occur only in one small clade of fishes. Here we report observing one F1-hybrid individual that developed into a functional hermaphrodite after crossing two closely-related sexually reproducing species of cichlids. Microsatellite alleles segregated consistent with selfing and Mendelian inheritance and we could rule out different modes of parthenogenesis including automixis. We discuss why selfing is not more commonly observed in vertebrates in nature, and the role of hybridization in the evolution of novel traits. PMID:27069660

  18. Cyto-nuclear genomic dissociation and the African elephant species question.

    PubMed

    Roca, Alfred L; Georgiadis, Nicholas; O'Brien, Stephen J

    2007-07-01

    Studies of skull morphology and of nuclear DNA have strongly concluded that African elephants comprise two species. Nonetheless, Debruyne (2005) has suggested a single-species model for Loxodonta based on the polyphyly of a single genetic locus, mitochondrial DNA (mtDNA). Discordant patterns between mitochondrial and nuclear DNA markers were subsequently reported in some African savanna elephant populations, further supporting a two-species model, and prompting us to re-examine here the geographic distribution of different elephant morphotypes and their relationship to nuclear and mtDNA phylogeographic patterns. We used exact tests to compare the distribution of forest elephant-typical and savanna elephant-typical characteristics across eight published datasets containing morphological, mtDNA or nuclear DNA data for African elephants. Among the elephants examined by Debruyne (2005), we found that patterns of forest vs. savanna characteristics were significantly different (p < 10(-5)) between mtDNA and morphology, suggesting the presence of cyto-nuclear genomic dissociation. We show that the eight African elephant continent-wide datasets compared, including that of Debruyne (2005), together support a two-species model with cyto-nuclear genomic dissociation rather than a one-species model, and together indicate that Africa harbors two species of elephant.

  19. Ancient hybridization fuels rapid cichlid fish adaptive radiations

    PubMed Central

    Meier, Joana I.; Marques, David A.; Mwaiko, Salome; Wagner, Catherine E.; Excoffier, Laurent; Seehausen, Ole

    2017-01-01

    Understanding why some evolutionary lineages generate exceptionally high species diversity is an important goal in evolutionary biology. Haplochromine cichlid fishes of Africa's Lake Victoria region encompass >700 diverse species that all evolved in the last 150,000 years. How this ‘Lake Victoria Region Superflock' could evolve on such rapid timescales is an enduring question. Here, we demonstrate that hybridization between two divergent lineages facilitated this process by providing genetic variation that subsequently became recombined and sorted into many new species. Notably, the hybridization event generated exceptional allelic variation at an opsin gene known to be involved in adaptation and speciation. More generally, differentiation between new species is accentuated around variants that were fixed differences between the parental lineages, and that now appear in many new combinations in the radiation species. We conclude that hybridization between divergent lineages, when coincident with ecological opportunity, may facilitate rapid and extensive adaptive radiation. PMID:28186104

  20. Antimicrobial rubrolides from a South African species of Synoicum tunicate.

    PubMed

    Sikorska, Justyna; Parker-Nance, Shirley; Davies-Coleman, Michael T; Vining, Oliver B; Sikora, Aleksandra E; McPhail, Kerry L

    2012-10-26

    The CH₂Cl₂-MeOH extract of a South African tunicate described as the new Synoicum globosum Parker-Nance sp. nov. (Ascidiacea, Aplousobranchia) was subjected to ¹H NMR-guided fractionation. This resulted in the identification of new 3″-bromorubrolide F (1), 3'-bromorubrolide E (2), 3'-bromorubrolide F (3), and 3',3″-dibromorubrolide E (4) and reisolation of known rubrolides E (5) and F (6), based on NMR spectroscopic and mass spectrometric data. Biological testing of both new and known members of this reported antimicrobial family of halogenated, aryl-substituted furanones indicated moderate antibacterial properties for 3'-bromorubrolide E (2), 3',3″-dibromorubrolide E (4), and rubrolide F (6) against methicillin-resistant Staphylococcus aureus (MRSA) and S. epidermidis.

  1. Antimicrobial Rubrolides from a South African Species of Synoicum Tunicate

    PubMed Central

    Sikorska, Justyna; Parker-Nance, Shirley; Davies-Coleman, Michael T.; Vining, Oliver B.; Sikora, Aleksandra E.; McPhail, Kerry L.

    2012-01-01

    The CH2Cl2-MeOH extract of a South African tunicate described as the new Synoicum globosum Parker-Nance sp. nov. (Ascidiacea, Aplousobranchia) was subjected to 1H NMR-guided fractionation. This resulted in the identification of new 3″-bromorubrolide F (1), 3′-bromorubrolide E (2), 3′-bromorubrolide F (3) and 3′, 3″-dibromorubrolide E (4), and reisolation of known rubrolides E (5) and F (6), based on NMR spectroscopic and mass spectrometric data. Biological testing of both new and known members of this reported antimicrobial family of halogenated, aryl-substituted furanones indicated moderate antibacterial properties for 3′-bromorubrolide E (2), 3′, 3″-dibromorubrolide E (4), and rubrolide F (6) against methicillin-resistant Staphylococcus aureus (MRSA) and S. epidermidis. PMID:23030848

  2. Vector Competence of Selected African Mosquito (Diptera: Culicidae) Species for Rift Valley Fever Virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Outbreaks of Rift Valley fever (RVF) in Egypt, Yemen, and Saudi Arabia have indicated the potential for this disease to spread from its enzootic areas in sub-Saharan Africa. Because little is known about the potential for most African mosquito species to transmit RVF virus (RVFV), we conducted stud...

  3. A new species of trichostrongyloid in African buffalo (Syncerus caffer) (Artiodactyla: Bovinae) from Uganda

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Africanastrongylus giganticus n. sp. is described based on large ostertagiine nematodes occurring in the abomasum of African buffalo, Syncerus caffer, from Uganda; this represents the second species recognized in the genus. Specimens of A. giganticus are characterized by large size (15-19 mm in tot...

  4. A new brachypterous scarab species, Orphnus longicornis (Coleoptera: Scarabaeidae: Orphninae), from the East African Rift.

    PubMed

    Frolov, Andrey; Akhmetova, Lilia

    2015-11-05

    The Afrotropical Region is the center of the diversity of the scarab beetle genus Orphnus MacLeay, 1819 (Coleoptera: Scarabaeidae: Orphninae), with 94 species occurring from Sahel in the north to Little Karoo in the south (Paulian, 1948; Petrovitz, 1971; Frolov, 2008). The East African Rift is one of the richest regions of the Afrotropics housing more than 20 species of Orphnus (Paulian, 1948; Frolov, 2013), most of which are endemic to this region. Yet the scarab beetle fauna of the East African Rift, and especially the Eastern Arc Mountains, is still inadequately studied. Examination of the material housed in the Museum of Natural History of Humboldt-Universität, Berlin, Germany (ZMHUB), revealed a series of brachypterous Orphnus beetles belonging to an undescribed species. The new species is described and illustrated below.

  5. Characterization of Serum Phospholipase A2 Activity in Three Diverse Species of West African Crocodiles

    PubMed Central

    Merchant, Mark; Juneau, Kate; Gemillion, Jared; Falconi, Rodolfo; Doucet, Aaron; Shirley, Matthew H.

    2011-01-01

    Secretory phospholipase A2, an enzyme that exhibits substantial immunological activity, was measured in the serum of three species of diverse West African crocodiles. Incubation of different volumes of crocodile serum with bacteria labeled with a fluorescent fatty acid in the sn-2 position of membrane lipids resulted in a volume-dependent liberation of fluorescent probe. Serum from the Nile crocodile (Crocodylus niloticus) exhibited slightly higher activity than that of the slender-snouted crocodile (Mecistops cataphractus) and the African dwarf crocodile (Osteolaemus tetraspis). Product formation was inhibited by BPB, a specific PLA2 inhibitor, confirming that the activity was a direct result of the presence of serum PLA2. Kinetic analysis showed that C. niloticus serum produced product more rapidly than M. cataphractus or O. tetraspis. Serum from all three species exhibited temperature-dependent PLA2 activities but with slightly different thermal profiles. All three crocodilian species showed high levels of activity against eight different species of bacteria. PMID:22110960

  6. B chromosomes have a functional effect on female sex determination in Lake Victoria cichlid fishes.

    PubMed

    Yoshida, Kohta; Terai, Yohey; Mizoiri, Shinji; Aibara, Mitsuto; Nishihara, Hidenori; Watanabe, Masakatsu; Kuroiwa, Asato; Hirai, Hirohisa; Hirai, Yuriko; Matsuda, Yoichi; Okada, Norihiro

    2011-08-01

    The endemic cichlid fishes in Lake Victoria are a model system for speciation through adaptive radiation. Although the evolution of the sex-determination system may also play a role in speciation, little is known about the sex-determination system of Lake Victoria cichlids. To understand the evolution of the sex-determination system in these fish, we performed cytogenetic analysis in 11 cichlid species from Lake Victoria. B chromosomes, which are present in addition to standard chromosomes, were found at a high prevalence rate (85%) in these cichlids. In one species, B chromosomes were female-specific. Cross-breeding using females with and without the B chromosomes demonstrated that the presence of the B chromosomes leads to a female-biased sex ratio in this species. Although B chromosomes were believed to be selfish genetic elements with little effect on phenotype and to lack protein-coding genes, the present study provides evidence that B chromosomes have a functional effect on female sex determination. FISH analysis using a BAC clone containing B chromosome DNA suggested that the B chromosomes are derived from sex chromosomes. Determination of the nucleotide sequences of this clone (104.5 kb) revealed the presence of several protein-coding genes in the B chromosome, suggesting that B chromosomes have the potential to contain functional genes. Because some sex chromosomes in amphibians and arthropods are thought to be derived from B chromosomes, the B chromosomes in Lake Victoria cichlids may represent an evolutionary transition toward the generation of sex chromosomes.

  7. Range expansion of the Mayan cichlid, cichlasoma urophthalmus (pisces, cichlidae), above 28°N in Florida

    USGS Publications Warehouse

    Paperno, R.; Ruiz-Carus, R.; Krebs, J.M.; McIvor, C.C.

    2008-01-01

    Introduced exotic species are a well-recognized problem in Florida's subtropical ecosystems. The presence of the exotic Mayan cichlid (Cichlasoma urophthalmus) was first confirmed in Florida in 1983, when numerous individuals were found in the northeastern Florida Bay. Since then, this species has continued to expand its range northward. The capture, beginning in October 2004 to present, of large numbers of Mayan cichlids from central Florida's east- and west-coast mangrove systems north of 28°N latitude is documented here. Mayan cichlids in a wide range of sizes (estimated ages 0-7 years) at both east- and west-coast sites were collected. In addition, macroscopic examination of gonads showed the presence of developing eggs. The occurrence of multiple age-classes, maturing individuals, cichlid nests, and juveniles, plus repeated collections over a four-year period, indicates that the Mayan cichlid is successfully reproducing and surviving the average winter temperatures in some estuarine waters in central Florida.

  8. Two new Phytophthora species from South African Eucalyptus plantations.

    PubMed

    Maseko, Bongani; Burgess, Treena I; Coutinho, Teresa A; Wingfield, Michael J

    2007-11-01

    A recent study to determine the cause of collar and root rot disease outbreaks of cold tolerant Eucalyptus species in South Africa resulted in the isolation of two putative new Phytophthora species. Based on phylogenetic comparisons using the ITS and beta-tubulin gene regions, these species were shown to be distinct from known species. These differences were also supported by robust morphological characteristics. The names, Phytophthora frigida sp. nov. and Phytophthora alticola sp. nov. are thus provided for these taxa, which are phylogenetically closely related to species within the ITS clade 2 (P. citricola, P. tropicali and P.multivesiculata) and 4 (P. arecae and P. megakarya), respectively. Phytophthora frigida is heterothallic, and produces stellate to rosaceous growth patterns on growth medium, corraloid hyphae, sporangia with a variety of distorted shapes and has the ability to grow at low temperatures. Phytophthora alticola is homothallic and has a slower growth rate in culture. Both P. frigida and P. alticola are pathogenic to Eucalyptus dunnii. In pathogenicity tests, they were, however, less pathogenic than P. cinnamomi, which is a well-known pathogen of Eucalyptus in South Africa.

  9. Alternative Reproductive Tactics in the Shell-Brooding Lake Tanganyika Cichlid Neolamprologus brevis

    PubMed Central

    Ota, Kazutaka; Aibara, Mitsuto; Morita, Masaya; Awata, Satoshi; Hori, Michio; Kohda, Masanori

    2012-01-01

    Alternative reproductive tactics (ARTs) are found in several Lake Tanganyika shell-brooding cichlids. Field studies were conducted in the Wonzye population to examine reproductive ecology and ARTs in the Lake Tanganyika shell-brooding cichlid Neolamprologus brevis. We discovered that this fish occurred in both rocky- and sandy-bottom habitats, but in rocky habitats, brood-caring females exclusively occurred in shell-patches that another cichlid species created. All N. brevis of both sexes in the patches were sexually mature, whereas immature males and females with unripe eggs were found frequently in sandy-bottom habitats. Males in sandy-bottom habitats were smaller, but fed more frequently and were in better somatic condition than males in the patches. Similar tendency was found in females. This indicates that N. brevis uses different habitats depending on the stage of its life history, with migration from sandy-bottom habitats to the shell-patches for reproduction. Males in the patches exhibited different behavior patterns: floating above the patches and lying in the patches. The former was larger, more aggressive, and invested less in gonads (relative to body size) than the latter. These results accord with those of other shell-brooding Lake Tanganyika cichlids with ARTs, and they therefore suggest the presence of ARTs in N. brevis. PMID:22888463

  10. An evaluation of the role of sensory drive in the evolution of lake Malawi cichlid fishes.

    PubMed

    Smith, Adam R; van Staaden, Moira J; Carleton, Karen L

    2012-01-01

    Although the cichlids of Lake Malawi are an important model system for the study of sensory evolution and sexual selection, the evolutionary processes linking these two phenomena remain unclear. Prior works have proposed that evolutionary divergence is driven by sensory drive, particularly as it applies to the visual system. While evidence suggests that sensory drive has played a role in the speciation of Lake Victoria cichlids, the findings from several lines of research on cichlids of Lake Malawi are not consistent with the primary tenets of this hypothesis. More specifically, three observations make the sensory drive model implausible in Malawi: (i) a lack of environmental constraint due to a broad and intense ambient light spectrum in species rich littoral habitats, (ii) pronounced variation in receiver sensory characteristics, and (iii) pronounced variability in male courtship signal characteristics. In the following work, we synthesize the results from recent studies to draw attention to the importance of sensory variation in cichlid evolution and speciation, and we suggest possible avenues of future research.

  11. Species delimitation and digit number in a North African skink

    PubMed Central

    Brown, R P; Tejangkura, T; El Mouden, E H; Ait Baamrane, M A; Znari, M

    2012-01-01

    Delimitation of species is an important and controversial area within evolutionary biology. Many species boundaries have been defined using morphological data. New genetic approaches now offer more objective evaluation and assessment of the reliability of morphological variation as an indicator that speciation has occurred. We examined geographic variation in morphology of the continuously distributed skink Chalcides mionecton from Morocco and used Bayesian analyses of nuclear and mitochondrial DNA (mtDNA) loci to examine: (i) their concordance with morphological patterns, (ii) support for species delimitation, (iii) timing of speciation, and (iv) levels of gene flow between species. Four digit individuals were found at sites between Cap Rhir (in the south) and the northern extreme of the range, whereas five-digit individuals were found in two disjunct areas: (i) south of Cap Rhir and (ii) the north of the range where they were often syntopic with four-digit individuals. The pattern of variation in generalized body dimensions was largely concordant with that in digit number, suggesting two general morphotypes. Bayesian analyses of population structure showed that individuals from sites south of Cap Rhir formed one genetic cluster, but that northern four- and five-digit individuals clustered together. Statistical support for delimitation of these genetic clusters into two species was provided by a recent Bayesian method. Phylogenetic–coalescent dating with external time calibrations indicates that speciation was relatively recent, with a 95% posterior interval of 0.46–2.66 mya. This postdates equivalent phylogenetic dating estimates of sequence divergence by approximately 1 Ma. Statistical analyses of a small number of independent loci provide important insights into the history of the speciation process in C. mionecton and support delimitation of populations into two species with distributions that are spatially discordant with patterns of morphological

  12. Micro- and macroevolutionary decoupling of cichlid jaws: a test of Liem's key innovation hypothesis.

    PubMed

    Hulsey, C D; García de León, F J; Rodiles-Hernández, R

    2006-10-01

    The extent to which elements of functional systems can change independently (modularity) likely influences the diversification of lineages. Major innovations in organismal design, like the pharyngeal jaw in cichlid fishes, may be key to a group's success when they relax constraints on diversification by increasing phenotypic modularity. In cichlid fishes, pharyngeal jaw modifications that enhanced the ability to breakdown prey may have freed their oral jaws from serving their ancestral dual role as a site of both prey capture and prey processing. This functional decoupling that allowed the oral jaws to become devoted solely to prey capture has been hypothesized to have permitted the two sets of cichlid jaws to evolve independently. We tested the hypothesis that oral and pharyngeal jaw mechanics are evolutionarily decoupled both within and among Neotropical Heroine cichlids. In the trophically polymorphic species Herichthys minckleyi, molariforms that exhibit enlarged molarlike pharyngeal jaw teeth were found to have approximately 400% greater lower jaw mass compared to H. minckleyi with the alternative papilliform pharyngeal morphology. However, oral jaw gape, lower jaw velocity ratios, anterior jaw linkage mechanics, and jaw protrusion did not differ between the morphotypes. In 40 other Heroine species, there was a weak correlation between oral jaw mechanics and pharyngeal jaw mass when phylogenetic history was ignored. Yet, after expansion of the cytochrome b phylogeny for Heroines, change in oral jaw mechanics was found to be independent of evolutionary change in pharyngeal jaw mass based on independent contrasts. Evolutionary decoupling of oral and pharyngeal jaw mechanics has likely played a critical role in the unparalleled trophic diversification of cichlid fishes.

  13. Characterization and cross-species amplification of microsatellite markers in African Silverbill (Lonchura cantans).

    PubMed

    Parine, N R; Kumar, D; Pathan, A A K; Elrobh, M S; Khan, W; Alanazi, M

    2013-11-18

    We tested the cross-amplification of eight microsatellites developed for Bengalese finch in African Silverbill (Lonchura cantans). In order to develop resources for conservation genetic studies in the species L. cantans, we tested the amplification success and polymorphism in eight previously developed microsatellite loci, in L. cantans. All eight microsatellite markers were successfully amplified, of which all were polymorphic, with 3 to 9 alleles and an expected heterozygosity (HE) ranging from 0.606 to 0.718. On average, there were 5.25 alleles/locus and a mean HE of 0.6456. These eight polymorphic markers could be of potential use in studies of genetic variability, population structure, and reproductive strategy of African Silverbills. The markers tested should be useful for population and conservation genetic studies in this genus, and, in particular, for species closely related to the source species, L. cantans.

  14. Morphology, Molecules, and Monogenean Parasites: An Example of an Integrative Approach to Cichlid Biodiversity

    PubMed Central

    Van Steenberge, Maarten; Pariselle, Antoine; Huyse, Tine; Volckaert, Filip A. M.; Snoeks, Jos; Vanhove, Maarten P. M.

    2015-01-01

    The unparalleled biodiversity of Lake Tanganyika (Africa) has fascinated biologists for over a century; its unique cichlid communities are a preferred model for evolutionary research. Although species delineation is, in most cases, relatively straightforward, higher-order classifications were shown not to agree with monophyletic groups. Here, traditional morphological methods meet their limitations. A typical example are the tropheine cichlids currently belonging to Simochromis and Pseudosimochromis. The affiliations of these widespread and abundant cichlids are poorly understood. Molecular work suggested that genus and species boundaries should be revised. Moreover, previous morphological results indicated that intraspecific variation should be considered to delineate species in Lake Tanganyika cichlids. We review the genera Simochromis and Pseudosimochromis using an integrative approach. Besides a morphometric study and a barcoding approach, monogenean Cichlidogyrus (Platyhelminthes: Ancyrocephalidae) gill parasites, often highly species-specific, are used as complementary markers. Six new species are described. Cichlidogyrus raeymaekersi sp. nov., C. muterezii sp. nov. and C. banyankimbonai sp. nov. infect S. diagramma. Cichlidogyrus georgesmertensi sp. nov. was found on S. babaulti and S. pleurospilus, C. franswittei sp. nov. on both S. marginatus and P. curvifrons and C. frankwillemsi sp. nov. only on P. curvifrons. As relatedness between Cichlidogyrus species usually reflects relatedness between hosts, we considered Simochromis monotypic because the three Cichlidogyrus species found on S. diagramma belonged to a different morphotype than those found on the other Simochromis. The transfer of S. babaulti, S. marginatus, S. pleurospilus and S. margaretae to Pseudosimochromis was justified by the similarity of their Cichlidogyrus fauna and the intermediate morphology of S. margaretae. Finally parasite data also supported the synonymy between S. pleurospilus and S

  15. Molecular characterization of Babesia and Cytauxzoon species in wild South-African meerkats.

    PubMed

    Leclaire, Sarah; Menard, Sandie; Berry, Antoine

    2015-04-01

    Piroplasms, including Babesia, Cytauxzoon and Theileria species, frequently infect domestic and wild mammals. At present, there is no information on the occurrence and molecular identity of these tick-borne blood parasites in the meerkat, one of South Africa's most endearing wildlife celebrities. Meerkats live in territorial groups, which may occur on ranchland in close proximity to humans, pets and livestock. Blood collected from 46 healthy meerkats living in the South-African Kalahari desert was screened by microscopy and molecular methods, using PCR and DNA sequencing of 18S rRNA and ITS1 genes. We found that meerkats were infected by 2 species: one species related to Babesia sp. and one species related to Cytauxzoon sp. Ninety one percent of the meerkats were infected by the Cytauxzoon and/or the Babesia species. Co-infection occurred in 46% of meerkats. The pathogenicity and vectors of these two piroplasm species remains to be determined.

  16. Carotenoid-based coloration in cichlid fishes

    PubMed Central

    Sefc, Kristina M.; Brown, Alexandria C.; Clotfelter, Ethan D.

    2014-01-01

    Animal colors play important roles in communication, ecological interactions and speciation. Carotenoid pigments are responsible for many yellow, orange and red hues in animals. Whereas extensive knowledge on the proximate mechanisms underlying carotenoid coloration in birds has led to testable hypotheses on avian color evolution and signaling, much less is known about the expression of carotenoid coloration in fishes. Here, we promote cichlid fishes (Perciformes: Cichlidae) as a system in which to study the physiological and evolutionary significance of carotenoids. Cichlids include some of the best examples of adaptive radiation and color pattern diversification in vertebrates. In this paper, we examine fitness correlates of carotenoid pigmentation in cichlids and review hypotheses regarding the signal content of carotenoid-based ornaments. Carotenoid-based coloration is influenced by diet and body condition and is positively related to mating success and social dominance. Gaps in our knowledge are discussed in the last part of this review, particularly in the understanding of carotenoid metabolism pathways and the genetics of carotenoid coloration. We suggest that carotenoid metabolism and transport are important proximate mechanisms responsible for individual and population-differences in cichlid coloration that may ultimately contribute to diversification and speciation. PMID:24667558

  17. A novel molecular marker for the study of Neotropical cichlid phylogeny.

    PubMed

    Fabrin, T M C; Gasques, L S; Prioli, S M A P; Prioli, A J

    2015-12-22

    The use of molecular markers has contributed to phylogeny and to the reconstruction of species' evolutionary history. Each region of the genome has different evolution rates, which may or may not identify phylogenetic signal at different levels. Therefore, it is important to assess new molecular markers that can be used for phylogenetic reconstruction. Regions that may be associated with species characteristics and are subject to selective pressure, such as opsin genes, which encode proteins related to the visual system and are widely expressed by Cichlidae family members, are interesting. Our aim was to identify a new nuclear molecular marker that could establish the phylogeny of Neotropical cichlids and is potentially correlated with the visual system. We used Bayesian inference and maximum likelihood analysis to support the use of the nuclear opsin LWS gene in the phylogeny of eight Neotropical cichlid species. Their use concatenated to the mitochondrial gene COI was also tested. The LWS gene fragment comprised the exon 2-4 region, including the introns. The LWS gene provided good support for both analyses up to the genus level, distinguishing the studied species, and when concatenated to the COI gene, there was a good support up to the species level. Another benefit of utilizing this region, is that some polymorphisms are associated with changes in spectral properties of the LWS opsin protein, which constitutes the visual pigment that absorbs red light. Thus, utilization of this gene as a molecular marker to study the phylogeny of Neotropical cichlids is promising.

  18. Population-structure and genetic diversity in a haplochromine cichlid fish [corrected] of a satellite lake of Lake Victoria.

    PubMed

    Abila, Romulus; Barluenga, Marta; Engelken, Johannes; Meyer, Axel; Salzburger, Walter

    2004-09-01

    The approximately 500 species of the cichlid fish species flock of Lake Victoria, East Africa, have evolved in a record-setting 100,000 years and represent one of the largest adaptive radiations. We examined the population structure of the endangered cichlid species Xystichromis phytophagus from Lake Kanyaboli, a satellite lake to Lake Victoria in the Kenyan Yala wetlands. Two sets of molecular markers were analysed--sequences of the mitochondrial control region as well as six microsatellite loci--and revealed surprisingly high levels of genetic variability in this species. Mitochondrial DNA sequences failed to detect population structuring among the three sample populations. A model-based population assignment test based on microsatellite data revealed that the three populations most probably aggregate into a larger panmictic population. However, values of population pairwise FST indicated moderate levels of genetic differentiation for one population. Eleven distinct mitochondrial haplotypes were found among 205 specimens of X. phytophagus, a relatively high number compared to the total number of 54 haplotypes that were recovered from hundreds of specimens of the entire cichlid species flock of Lake Victoria. Most of the X. phytophagus mitochondrial DNA haplotypes were absent from the main Lake Victoria, corroborating the putative importance of satellite lakes as refugia for haplochromine cichlids that went extinct from the main lake in the last decades and possibly during the Late Pleistocene desiccation of Lake Victoria.

  19. Male-Male Competition as a Force in Evolutionary Diversification: Evidence in Haplochromine Cichlid Fish

    PubMed Central

    Dijkstra, Peter D.; Groothuis, Ton G. G.

    2011-01-01

    It has been suggested that intrasexual competition can be a source of negative frequency-dependent selection, causing agonistic character displacement and facilitating speciation and coexistence of (sibling) species. In this paper we synthesise the evidence that male-male and female-female competition contributes to cichlid diversification, showing that competition is stronger among same-coloured individuals than those with different colours. We argue that intrasexual selection is more complex because there are several examples where males do not bias aggression towards their own type. In addition, sibling species or colour morphs often show asymmetric dominance relationships. We briefly discuss potential mechanisms that might promote the maintenance of covariance between colour and aggression-related traits even in the face of gene-flow. We close by proposing several avenues for future studies that might shed more light on the role of intrasexual competition in cichlid diversification. PMID:21785710

  20. Antipredator responses by native mosquitofish to non-native cichlids: An examination of the role of prey naiveté

    USGS Publications Warehouse

    Rehage, Jennifer S.; Dunlop, Katherine L.; Loftus, William F.

    2009-01-01

    The strong impact of non-native predators in aquatic systems is thought to relate to the evolutionary naiveté of prey. Due to isolation and limited dispersal, this naiveté may be relatively high in freshwater systems. In this study, we tested this notion by examining the antipredator response of native mosquitofish, Gambusia holbrooki, to two non-native predators found in the Everglades, the African jewelfish,Hemichromis letourneuxi, and the Mayan cichlid, Cichlasoma urophthalmus. We manipulated prey naiveté by using two mosquitofish populations that varied in their experience with the recent invader, the African jewelfish, but had similar levels of experience with the longer-established Mayan cichlid. Specifically, we tested these predictions: (1) predator hunting modes differed between the two predators, (2) predation rates would be higher by the novel jewelfish predator, (3) particularly on the naive population living where jewelfish have not invaded yet, (4) antipredator responses would be stronger to Mayan cichlids due to greater experience and weaker and/or ineffective to jewelfish, and (5) especially weakest by the naive population. We assayed prey and predator behavior, and prey mortality in lab aquaria where both predators and prey were free-ranging. Predator hunting modes and habitat domains differed, with jewelfish being more active search predators that used slightly higher parts of the water column and less of the habitat structure relative to Mayan cichlids. In disagreement with our predictions, predation rates were similar between the two predators, antipredator responses were stronger to African jewelfish (except for predator inspections), and there was no difference in response between jewelfish-savvy and jewelfish-naive populations. These results suggest that despite the novelty of introduced predators, prey may be able to respond appropriately if non-native predator archetypes are similar enough to those of native predators, if prey rely

  1. Molecular characterisation of Anaplasma species from African buffalo (Syncerus caffer) in Kruger National Park, South Africa.

    PubMed

    Sisson, Danielle; Hufschmid, Jasmin; Jolles, Anna; Beechler, Brianna; Jabbar, Abdul

    2017-03-01

    Bovine anaplasmosis is a tick-borne disease, mainly caused by Anaplasma marginale and A. centrale and is distributed in tropical and sub-tropical areas. This study aimed to characterise A. marginale and A. centrale from African buffaloes in Kruger National Park (KNP), South Africa, using the DNA sequences of the genes coding for major surface protein (msp1β) and heat shock protein (groEL), respectively. A total of 747 blood samples were collected from February 2014 to August 2016 from African buffaloes kept in KNP, and DNAs were tested using a molecular-phylogenetic approach. Out of 747 samples tested, 129 (17.3%) and 98 (13.1%) were positive for single infection with A. marginale and A. centrale, respectively; whereas 113 (15.1%) were positive for both Anaplasma spp. Pairwise difference of 1.6-8.5% was observed in msp1β sequences of A. marginale whereas that was only 0.3-2.4% for groEL sequences of A. centrale. Separate phylogenetic analyses of msp1β and groEL sequences of A. marginale and A. centrale, respectively, revealed that sequences of Anaplasma spp. from African buffaloes were unique and they grouped separately when compared with previously published sequences of both species. This is the first study to characterise A. marginale and A. centrale from African buffalo using species specific molecular markers. This study will pave the way for future studies to assess genetic variation among Anaplasma spp. from wild ruminants using molecular markers that are better at differentiating between species and strains than the more commonly used 16S rRNA gene, and help to undertake health and fitness studies and host-parasite dynamics using quantitative molecular tools.

  2. A new species of Eurytoma (Hymenoptera: Eurytomidae) attacking, Quadrastichus spp. (Hymenoptera: Eulophidae) galling Erythrina spp. (Fabaceae) with a summary of African Eurytoma spp. biology and species checklist

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Eurytoma erythrinae Gates and Delvare, new species, is described and illustrated. This species was reared from field-collected galls induced on Erythrina spp. by Quadrastichus spp. (Hymenoptera: Eulophidae), in Tanzania, Ghana, and South Africa. It is compared to a closely related African species. W...

  3. Seasonal Patterns of Mixed Species Groups in Large East African Mammals

    PubMed Central

    Kiffner, Christian; Kioko, John; Leweri, Cecilia; Krause, Stefan

    2014-01-01

    Mixed mammal species groups are common in East African savannah ecosystems. Yet, it is largely unknown if co-occurrences of large mammals result from random processes or social preferences and if interspecific associations are consistent across ecosystems and seasons. Because species may exchange important information and services, understanding patterns and drivers of heterospecific interactions is crucial for advancing animal and community ecology. We recorded 5403 single and multi-species clusters in the Serengeti-Ngorongoro and Tarangire-Manyara ecosystems during dry and wet seasons and used social network analyses to detect patterns of species associations. We found statistically significant associations between multiple species and association patterns differed spatially and seasonally. Consistently, wildebeest and zebras preferred being associated with other species, whereas carnivores, African elephants, Maasai giraffes and Kirk's dik-diks avoided being in mixed groups. During the dry season, we found that the betweenness (a measure of importance in the flow of information or disease) of species did not differ from a random expectation based on species abundance. In contrast, in the wet season, we found that these patterns were not simply explained by variations in abundances, suggesting that heterospecific associations were actively formed. These seasonal differences in observed patterns suggest that interspecific associations may be driven by resource overlap when resources are limited and by resource partitioning or anti-predator advantages when resources are abundant. We discuss potential mechanisms that could drive seasonal variation in the cost-benefit tradeoffs that underpin the formation of mixed-species groups. PMID:25470495

  4. Morphology and Efficiency of a Specialized Foraging Behavior, Sediment Sifting, in Neotropical Cichlid Fishes

    PubMed Central

    Willis, Stuart; Watkins, Crystal; Honeycutt, Rodney L.; Winemiller, Kirk O.

    2014-01-01

    Understanding of relationships between morphology and ecological performance can help to reveal how natural selection drives biological diversification. We investigate relationships between feeding behavior, foraging performance and morphology within a diverse group of teleost fishes, and examine the extent to which associations can be explained by evolutionary relatedness. Morphological adaptation associated with sediment sifting was examined using a phylogenetic linear discriminant analysis on a set of ecomorphological traits from 27 species of Neotropical cichlids. For most sifting taxa, feeding behavior could be effectively predicted by a linear discriminant function of ecomorphology across multiple clades of sediment sifters, and this pattern could not be explained by shared evolutionary history alone. Additionally, we tested foraging efficiency in seven Neotropical cichlid species, five of which are specialized benthic feeders with differing head morphology. Efficiency was evaluated based on the degree to which invertebrate prey could be retrieved at different depths of sediment. Feeding performance was compared both with respect to feeding mode and species using a phylogenetic ANCOVA, with substrate depth as a covariate. Benthic foraging performance was constant across sediment depths in non-sifters but declined with depth in sifters. The non-sifting Hypsophrys used sweeping motions of the body and fins to excavate large pits to uncover prey; this tactic was more efficient for consuming deeply buried invertebrates than observed among sediment sifters. Findings indicate that similar feeding performance among sediment-sifting cichlids extracting invertebrate prey from shallow sediment layers reflects constraints associated with functional morphology and, to a lesser extent, phylogeny. PMID:24603485

  5. Desertification and a shift of forest species in the West African Sahel

    USGS Publications Warehouse

    Gonzalez, Patrick

    2001-01-01

    Original field data show that forest species richness and tree density in the West African Sahel declined in the last half of the 20th century. Average forest species richness of areas of 4 km2 in Northwest Senegal fell from 64 ?? 2 species ca 1945 to 43 ?? 2 species in 1993, a decrease significant at p < 0.001. Densities of trees of height ???3 m declined from 10 ?? 0.3 trees ha-1 in 1954 to 7.8 ?? 0.3 trees ha-1 in 1989, also significant at p < 0.001. Standing wood biomass fell 2.1 t ha-1 in the period 1956-1993, releasing CO2 at a rate of 60 kgC person-1 yr-1. These changes have shifted vegetation zones toward areas of higher rainfall at an average rate of 500 to 600 m yr-1. Arid Sahel species have expanded in the north, tracking a concomitant retraction of mesic Sudan and Guinean species to the south. Multivariate analyses identify latitude and longitude, proxies for rainfall and temperature, as the most significant factors explaining tree and shrub distribution. The changes also decreased human carrying capacity to below actual population densities. The rural population of 45 people km-2 exceeded the 1993 carrying capacity, for firewood from shrubs, of 13 people km-2 (range 1 to 21 people km-2). As an adaptation strategy, ecological and socioeconomic factors favor the natural regeneration of local species over the massive plantation of exotic species. Natural regeneration is a traditional practice in which farmers select small field trees that they wish to raise to maturity, protect them, and prune them to promote rapid growth of the apical meristem. The results of this research provide evidence for desertification in the West African Sahel. These documented impacts of desertification foreshadow possible future effects of climate change.

  6. Kinship reinforces cooperative predator inspection in a cichlid fish.

    PubMed

    Hesse, Saskia; Anaya-Rojas, Jaime M; Frommen, Joachim G; Thünken, Timo

    2015-11-01

    Kin selection theory predicts that cooperation is facilitated between genetic relatives, as by cooperating with kin an individual might increase its inclusive fitness. Although numerous theoretical papers support Hamilton's inclusive fitness theory, experimental evidence is still underrepresented, in particular in noncooperative breeders. Cooperative predator inspection is one of the most intriguing antipredator strategies, as it implies high costs on inspectors. During an inspection event, one or more individuals leave the safety of a group and approach a potential predator to gather information about the current predation risk. We investigated the effect of genetic relatedness on cooperative predator inspection in juveniles of the cichlid fish Pelvicachromis taeniatus, a species in which juveniles live in shoals under natural conditions. We show that relatedness significantly influenced predator inspection behaviour with kin dyads being significantly more cooperative. Thus, our results indicate a higher disposition for cooperative antipredator behaviour among kin as predicted by kin selection theory.

  7. Dietary carotenoids do not improve motility or antioxidant capacity in cichlid fish sperm.

    PubMed

    Sullivan, Melissa; Brown, Alexandria C; Clotfelter, Ethan D

    2014-10-01

    Carotenoids may act as antioxidants under many circumstances. We examined the importance of carotenoids as antioxidants in the gonads of male convict cichlids (Amatitlania nigrofasciata), a species in which males lack the carotenoid-based breeding coloration that characterizes females. Male fish were fed one of four diets that included different combinations of xanthophyll and carotene carotenoids, and then we measured carotenoid concentration of the gonads, gonadosomatic index (GSI), sperm motility, and the antioxidant capacity of the gonads. Significant differences were found in gonadal carotenoid content among treatment groups, suggesting that dietary carotenoids were indeed sequestered in the gonads. There were no differences among diet groups, however, in GSI, sperm motility, or gonadal antioxidant capacity. These findings suggest that carotenoids are required only in small amounts in the testes of male convict cichlids or that they play a limited role in protecting sperm from oxidative damage.

  8. ITS2 secondary structure for species circumscription: case study in southern African Strychnos L. (Loganiaceae).

    PubMed

    Adebowale, Adekunle; Lamb, Jennifer; Nicholas, Ashley; Naidoo, Yougasphree

    2016-12-01

    Recently developed computational tools in ITS2 sequence-structure phylogenetics are improving tree robustness by exploitation of the added information content of the secondary structure. Despite this strength, however, their adoption for species-level clarifications in angiosperms has been slow. We investigate the utility of combining ITS2 sequence and secondary structure to separate species of southern African Strychnos, and assess correlation between compensatory base changes (CBCs) and currently recognised species boundaries. Combined phylogenetic analysis of sequence and secondary structure datasets performed better, in terms of robustness and species resolution, than analysis involving primary sequences only, achieving 100 and 88.2 % taxa discriminations respectively. Further, the Strychnos madagascariensis complex is well-resolved by sequence-structure phylogenetic analysis. The 17 Strychnos species corresponded to 14 ITS2 CBC clades. Four of the five taxa in section Densiflorae belong to a single CBC clade, whose members tend to form natural hybrids. Our finding supports the application of ITS2 as a complementary barcoding marker for species identification. It also highlights the potential of comparative studies of ITS2 CBC features among prospective parental pairs in breeding experiments as a rapid proxy for cross compatibility assessment. This could save valuable time in crop improvement. Patterns of CBC evolution and species boundaries in Strychnos suggests a positive correlation. We conclude that the CBC pattern coupled with observed ITS2 sequence paraphyly in section Densiflorae points to a speciation work-in-progress.

  9. Genetic structure of pelagic and littoral cichlid fishes from Lake Victoria.

    PubMed

    Takeda, Miyuki; Kusumi, Junko; Mizoiri, Shinji; Aibara, Mitsuto; Mzighani, Semvua Isa; Sato, Tetsu; Terai, Yohey; Okada, Norihiro; Tachida, Hidenori

    2013-01-01

    The approximately 700 species of cichlids found in Lake Victoria in East Africa are thought to have evolved over a short period of time, and they represent one of the largest known examples of adaptive radiation. To understand the processes that are driving this spectacular radiation, we must determine the present genetic structure of these species and elucidate how this structure relates to the ecological conditions that caused their adaptation. We analyzed the genetic structure of two pelagic and seven littoral species sampled from the southeast area of Lake Victoria using sequences from the mtDNA control region and 12 microsatellite loci as markers. Using a Bayesian model-based clustering method to analyze the microsatellite data, we separated these nine species into four groups: one group composed of pelagic species and another three groups composed mainly of rocky-shore species. Furthermore, we found significant levels of genetic variation between species within each group at both marker loci using analysis of molecular variance (AMOVA), although the nine species often shared mtDNA haplotypes. We also found significant levels of genetic variation between populations within species. These results suggest that initial groupings, some of which appear to have been related to habitat differences, as well as divergence between species within groups took place among the cichlid species of Lake Victoria.

  10. A comparative study of an innate immune response in Lamprologine cichlid fishes

    NASA Astrophysics Data System (ADS)

    O'Connor, Constance M.; Reddon, Adam R.; Marsh-Rollo, Susan E.; Hellmann, Jennifer K.; Ligocki, Isaac Y.; Hamilton, Ian M.; Balshine, Sigal

    2014-10-01

    Social interactions facilitate pathogen transmission and increase virulence. Therefore, species that live in social groups are predicted to suffer a higher pathogen burden, to invest more heavily in immune defence against pathogens, or both. However, there are few empirical tests of whether social species indeed invest more heavily in immune defence than non-social species. In the current study, we conducted a phylogenetically controlled comparison of innate immune response in Lamprologine cichlid fishes. We focused on three species of highly social cichlids that live in permanent groups and exhibit cooperative breeding ( Julidochromis ornatus, Neolamprologus pulcher and Neolamprologus savoryi) and three species of non-social cichlids that exhibit neither grouping nor cooperative behaviour ( Telmatochromis temporalis, Neolamprologus tetracanthus and Neolamprologus modestus). We quantified the innate immune response by injecting wild fishes with phytohaemagglutinin (PHA), a lectin that causes a cell-mediated immune response. We predicted that the three highly social species would show a greater immune reaction to the PHA treatment, indicating higher investment in immune defence against parasites relative to the three non-social species. We found significant species-level variation in immune response, but contrary to our prediction, this variation did not correspond to social system. However, we found that immune response was correlated with territory size across the six species. Our results indicate that the common assumption of a positive relationship between social system and investment in immune function may be overly simplistic. We suggest that factors such as rates of both in-group and out-group social interactions are likely to be important mediators of the relationship between sociality and immune function.

  11. High level of mislabeling in Spanish and Greek hake markets suggests the fraudulent introduction of African species.

    PubMed

    Garcia-Vazquez, Eva; Perez, Juliana; Martinez, Jose L; Pardiñas, Antonio F; Lopez, Belen; Karaiskou, Nikoletta; Casa, Mary F; Machado-Schiaffino, Gonzalo; Triantafyllidis, Alexander

    2011-01-26

    DNA analysis of hake products commercialized in southern European (Spanish and Greek) market chains have demonstrated more than 30% mislabeling, on the basis of species substitution. Tails and fillets were more mislabeled than other products, such as slices and whole pieces. African species were substitute species for products labeled as American and European species, and we suggest it is a case of deliberate economically profitable mislabeling because real market prices of European and American hake products are higher than those of African in Spanish market chains. The presented results suggest fraud detection that disadvantages African producers. Government-mandated genetic surveys of commercial hakes and the use of subsequent statements of fair trade on labels of seafood products could help to reduce fraud levels in a global market of increasingly conscious consumers sensitive to ethical issues.

  12. Identification of naturally occurring hybrids between two overexploited sciaenid species along the South African coast.

    PubMed

    Mirimin, L; Kerwath, S E; Macey, B M; Bester-van der Merwe, A E; Lamberth, S J; Bloomer, P; Roodt-Wilding, R

    2014-07-01

    Hybridisation between fish species can play a significant role in evolutionary processes and can influence management and conservation planning, however, this phenomenon has been widely understudied, especially in marine organisms. The distribution limits of two sciaenid species (silver kob, Argyrosomus inodorus, and dusky kob, A. japonicus) partly overlap along the South African coast, where both species have undergone severe depletion due to overfishing. Following the identification of a number of possible cases of species misidentification or hybridisation (21 out of 422 individuals), nuclear and mitochondrial DNA data (12microsatellite loci and 562bp of the COI gene) were analysed to investigate the genetic composition of these individuals. Results indicated a field-based species misidentification rate of approximately 2.8% and a rate of natural hybridisation of 0.7%. Interestingly, all hybrid fish resulted from first-generation (F1) hybridisation events, which occurred exclusively between silver kob females and dusky kob males. Whether hybridisation is the result of natural events (such as secondary contact following a shift in distribution range), or anthropogenic activities (size-selective pressure due to overfishing), these findings have important implications for critical recovery and future management of these species in the wild.

  13. Species delimitation in the Central African herbs Haumania (Marantaceae) using georeferenced nuclear and chloroplastic DNA sequences.

    PubMed

    Ley, A C; Hardy, O J

    2010-11-01

    Species delimitation is a fundamental biological concept which is frequently discussed and altered to integrate new insights. These revealed that speciation is not a one step phenomenon but an ongoing process and morphological characters alone are not sufficient anymore to properly describe the results of this process. Here we want to assess the degree of speciation in two closely related lianescent taxa from the tropical African genus Haumania which display distinct vegetative traits despite a high similarity in reproductive traits and a partial overlap in distribution area which might facilitate gene flow. To this end, we combined phylogenetic and phylogeographic analyses using nuclear (nr) and chloroplast (cp) DNA sequences in comparison to morphological species descriptions. The nuclear dataset unambiguously supports the morphological species concept in Haumania. However, the main chloroplastic haplotypes are shared between species and, although a geographic analysis of cpDNA diversity confirms that individuals from the same taxon are more related than individuals from distinct taxa, cp-haplotypes display correlated geographic distributions between species. Hybridization is the most plausible reason for this pattern. A scenario involving speciation in geographic isolation followed by range expansion is outlined. The study highlights the gain of information on the speciation process in Haumania by adding georeferenced molecular data to the morphological characteristics. It also shows that nr and cp sequence data might provide different but complementary information, questioning the reliability of the unique use of chloroplast data for species recognition by DNA barcoding.

  14. Comparative cytogenetic mapping of Sox2 and Sox14 in cichlid fishes and inferences on the genomic organization of both genes in vertebrates

    PubMed Central

    Mazzuchelli, Juliana; Yang, Fengtang; Kocher, Thomas D.; Martins, Cesar

    2011-01-01

    To better understand the genomic organization and evolution of Sox genes in vertebrates, we cytogenetically mapped Sox2 and Sox14 genes in cichlid fishes and performed comparative analyses of their orthologs in several vertebrate species. The genomic regions neighbouring Sox2 and Sox14 have been conserved during vertebrate diversification. Although cichlids seem to have undergone high rates of genomic rearrangements, Sox2 and Sox14 are linked in the same chromosome in the Etroplinae Etroplus maculatus that represents the sister group of all remaining cichlids. However, this genes are located on different chromosomes in several species of the sister group Pseudocrenilabrinae. Similarly the ancestral synteny of Sox2 and Sox14 has been maintained in several vertebrates, but this synteny has been broken independently in all major groups as a consequence of karyotype rearrangements that took place during the vertebrate evolution. PMID:21691861

  15. Dealing with Food and Eggs in Mouthbrooding Cichlids: Structural and Functional Trade-Offs in Fitness Related Traits

    PubMed Central

    tkint, Tim; Verheyen, Erik; De Kegel, Barbara; Helsen, Philippe; Adriaens, Dominique

    2012-01-01

    Background As in any vertebrate, heads of fishes are densely packed with functions. These functions often impose conflicting mechanical demands resulting in trade-offs in the species-specific phenotype. When phenotypical traits are linked to gender-specific parental behavior, we expect sexual differences in these trade-offs. This study aims to use mouthbrooding cichlids as an example to test hypotheses on evolutionary trade-offs between intricately linked traits that affect different aspects of fitness. We focused on the oral apparatus, which is not only equipped with features used to feed and breathe, but is also used for the incubation of eggs. We used this approach to study mouthbrooding as part of an integrated functional system with diverging performance requirements and to explore gender-specific selective environments within a species. Methodology/Principal Findings Because cichlids are morphologically very diverse, we hypothesize that the implications of the added constraint of mouthbrooding will primarily depend on the dominant mode of feeding of the studied species. To test this, we compared the trade-off for two maternal mouthbrooding cichlid species: a “suction feeder” (Haplochromis piceatus) and a “biter” (H. fischeri). The comparison of morphology and performance of both species revealed clear interspecific and intersex differences. Our observation that females have larger heads was interpreted as a possible consequence of the fact that in both the studied species mouthbrooding is done by females only. As hypothesized, the observed sexual dimorphism in head shape is inferred as being suboptimal for some aspects of the feeding performance in each of the studied species. Our comparison also demonstrated that the suction feeding species had smaller egg clutches and more elongated eggs. Conclusions/Significance Our findings support the hypothesis that there is a trade-off between mouthbrooding and feeding performance in the two studied

  16. Replicated evolution of trophic specializations in an endemic cichlid fish lineage from Lake Tanganyika

    PubMed Central

    Rüber, Lukas; Verheyen, Erik; Meyer, Axel

    1999-01-01

    The current phylogenetic hypothesis for the endemic Lake Tanganyika cichlid fishes of the tribe Eretmodini is based solely on morphology and suggests that more complex trophic morphologies derived only once from a less specialized ancestral condition. A molecular phylogeny of eretmodine cichlids based on partial mitochondrial DNA cytochrome b and control-region sequences was used to reconstruct the evolutionary sequence of trophic adaptations and to test alternative models of morphological divergence. The six mitochondrial lineages found disagree with the current taxonomy and the morphology-based phylogeny. Mitochondrial lineages with similar trophic morphologies are not grouped monophyletically but are typically more closely related to lineages with different trophic phenotypes currently assigned to other genera. Our results indicate multiple independent origins of similar trophic specializations in these cichlids. A pattern of repeated divergent morphological evolution becomes apparent when the phylogeography of the mitochondrial haplotypes is analyzed in the context of the geological and paleoclimatological history of Lake Tanganyika. In more than one instance within Lake Tanganyika, similar morphological divergence of dentitional traits occurred in sympatric species pairs. Possibly, resource-based divergent selective regimes led to resource partitioning and brought about similar trophic morphologies independently and repeatedly. PMID:10468591

  17. Cichlid Fish Use Coloration as a Cue to Assess the Threat Status of Heterospecific Intruders.

    PubMed

    Lehtonen, Topi K; Sowersby, Will; Gagnon, Karine; Wong, Bob B M

    2015-10-01

    The ability to assess the threat posed by competitors, and to respond appropriately, is important for reducing the costs of aggression. In this respect, aggression directed toward heterospecifics is often just as significant as aggression among conspecifics. This is especially true for cichlid fish that share breeding grounds with heterospecifics. Indeed, cichlids are known to differentiate not only between conspecifics that pose different levels of threat but also between heterospecific territorial intruders by directing more aggression toward nonbreeding individuals. To assess whether the ability to make such distinctions could be based on color cues alone, we carried out a field study in which we experimentally presented Amphilophus sagittae cichlid pairs with model intruders of a sympatric congener, Amphilophus xiloaensis, in breeding versus nonbreeding coloration. Consistent with our prediction, we found that A. sagittae exhibited more aggression toward A. xiloaensis models of the latter color type. The results are, to our knowledge, the first to show that territory holders can, based on coloration alone, assess variation among individuals of a species other than their own in the threat posed to offspring survival.

  18. Effects of Saccharomyces cerevisiae on survival rate and growth performance of Convict Cichlid (Amatitlania nigrofasciata)

    PubMed Central

    Mohammadi, F; Mousavi, S. M.; Ahmadmoradi, E.; Zakeri, M.; Jahedi, A.

    2015-01-01

    Using probiotics can control pathogens by a variety of mechanisms. Probiotics can promote growth performance and have, therefore, become increasingly important in the aquaculture industry. Convict Cichlid belongs to the family of Cichlidae and is known for its rapid development in laboratory conditions and is suitable for behavioral examinations. The aim of this study was to evaluate the effects of Saccharomyces cerevisiae on growth performance, survival rate and body composition of Convict Cichlids (Amatitlania nigrofasciata). One hundred sixty eight Convict Cichlids (mean weight: 2.1 ± 0.12 g and mean length: 2.2 ± 0.05 cm) were fed by commercial diets with different concentrations of S. cerevisiae (0, 0.5%, 1%, 2%). At the end of the experiment, survival rate and growth indices were measured. Based on the results, growth performance significantly increased with probiotic, S. cerevisiae, specially, at the 2% probiotic level of concentration. In the present study, the best FCR (feed conversion rate), SGR (specific growth rate), CF (condition factor) and BWG (body weight gain) values were observed in a 2% concentration of S. cerevisiae. The results suggest that this yeast could improve feed utilization in this fish species. PMID:27175152

  19. Effects of Saccharomyces cerevisiae on survival rate and growth performance of Convict Cichlid (Amatitlania nigrofasciata).

    PubMed

    Mohammadi, F; Mousavi, S M; Ahmadmoradi, E; Zakeri, M; Jahedi, A

    2015-01-01

    Using probiotics can control pathogens by a variety of mechanisms. Probiotics can promote growth performance and have, therefore, become increasingly important in the aquaculture industry. Convict Cichlid belongs to the family of Cichlidae and is known for its rapid development in laboratory conditions and is suitable for behavioral examinations. The aim of this study was to evaluate the effects of Saccharomyces cerevisiae on growth performance, survival rate and body composition of Convict Cichlids (Amatitlania nigrofasciata). One hundred sixty eight Convict Cichlids (mean weight: 2.1 ± 0.12 g and mean length: 2.2 ± 0.05 cm) were fed by commercial diets with different concentrations of S. cerevisiae (0, 0.5%, 1%, 2%). At the end of the experiment, survival rate and growth indices were measured. Based on the results, growth performance significantly increased with probiotic, S. cerevisiae, specially, at the 2% probiotic level of concentration. In the present study, the best FCR (feed conversion rate), SGR (specific growth rate), CF (condition factor) and BWG (body weight gain) values were observed in a 2% concentration of S. cerevisiae. The results suggest that this yeast could improve feed utilization in this fish species.

  20. Social motivation and conflict resolution tactics as potential building blocks of sociality in cichlid fishes.

    PubMed

    Balshine, Sigal; Wong, Marian Y L; Reddon, Adam R

    2017-01-03

    Even closely related and ecologically similar cichlid species of Lake Tanganyika exhibit an impressive diversity of social systems, and therefore these fishes offer an excellent opportunity to examine the evolution of social behaviour. Sophisticated social relationships are thought to have evolved via a building block design where more fundamental social behaviours and cognitive processes have been combined, incrementally modified, and elaborated over time. Here, we studied two of these putative social building blocks in two closely related species of cichlids: Neolamprologus pulcher, a group-living species, and Telmatochromis temporalis, a non-grouping species. Otherwise well matched in ecology, this pair of species provide an excellent comparison point to understand how behavioural processes may have been modified in relation to the evolution of sociality. Using social assays in both the laboratory and in the field, we explored each species' motivation to interact with conspecifics, and each species' conflict resolution tactics. We found that individuals of the group living species, N. pulcher, displayed higher social motivation and were more likely to produce submission displays than were individuals of the non-grouping species, T. temporalis. We argue that the motivation to interact with conspecifics is a necessary prerequisite for the emergence of group living, and that the use of submission reduces the costs of conflict and facilitates the maintenance of close social proximity. These results suggest that social motivation and conflict resolution tactics are associated with social complexity, and that these behavioural traits may be functionally significant in the evolution and maintenance of sociality.

  1. Two new Trypanosoma species from African birds, with notes on the taxonomy of avian trypanosomes.

    PubMed

    Valkiūnas, Gediminas; Iezhova, Tatjana A; Carlson, Jenny S; Sehgal, Ravinder N M

    2011-10-01

    Trypanosoma anguiformis n. sp. and Trypanosoma polygranularis n. sp. are described from the African olive sunbird, Cyanomitra olivacea, and Latham's forest francolin, Francolinus lathami, respectively, based on the morphology of their hematozoic trypomastigotes and partial sequences of the small subunit ribosomal RNA gene. Both new species belong to the group of small non-striated avian trypanosomes (<30 µm in length on average) with the kinetoplast situated close to the posterior end of the body. Trypanosoma anguiformis can be readily distinguished from other small avian trypanosomes due to its markedly attenuated (snake-shaped) form of the hematozoic trypomastigotes and the dumbbell-shaped nucleus of the parasite. Trypanosoma polygranularis is readily distinguishable due to the markedly off-center (anteriorly) located nucleus, numerous azurophilic granules that are arranged in a line following the undulating membrane, and the large kinetoplast (with an area up to 1.7 µm(2) [1.1 µm(2) on average]). Illustrations of hematozoic trypomastigotes of the new species are given, and DNA lineages associated with these parasites are reported. The current situation in species taxonomy of avian trypanosomes is discussed. We call for the redescription of valid species of avian trypanosomes from their type vertebrate hosts and type localities by using morphological and polymerase chain reaction-based techniques as an initial essential step towards revising the species composition of avian trypanosomes and reconstructing the taxonomy of these organisms.

  2. Geological Substrates Shape Tree Species and Trait Distributions in African Moist Forests

    PubMed Central

    Fayolle, Adeline; Engelbrecht, Bettina; Freycon, Vincent; Mortier, Frédéric; Swaine, Michael; Réjou-Méchain, Maxime; Doucet, Jean-Louis; Fauvet, Nicolas; Cornu, Guillaume; Gourlet-Fleury, Sylvie

    2012-01-01

    Background Understanding the factors that shape the distribution of tropical tree species at large scales is a central issue in ecology, conservation and forest management. The aims of this study were to (i) assess the importance of environmental factors relative to historical factors for tree species distributions in the semi-evergreen forests of the northern Congo basin; and to (ii) identify potential mechanisms explaining distribution patterns through a trait-based approach. Methodology/Principal Findings We analyzed the distribution patterns of 31 common tree species in an area of more than 700,000 km2 spanning the borders of Cameroon, the Central African Republic, and the Republic of Congo using forest inventory data from 56,445 0.5-ha plots. Spatial variation of environmental (climate, topography and geology) and historical factors (human disturbance) were quantified from maps and satellite records. Four key functional traits (leaf phenology, shade tolerance, wood density, and maximum growth rate) were extracted from the literature. The geological substrate was of major importance for the distribution of the focal species, while climate and past human disturbances had a significant but lesser impact. Species distribution patterns were significantly related to functional traits. Species associated with sandy soils typical of sandstone and alluvium were characterized by slow growth rates, shade tolerance, evergreen leaves, and high wood density, traits allowing persistence on resource-poor soils. In contrast, fast-growing pioneer species rarely occurred on sandy soils, except for Lophira alata. Conclusions/Significance The results indicate strong environmental filtering due to differential soil resource availability across geological substrates. Additionally, long-term human disturbances in resource-rich areas may have accentuated the observed patterns of species and trait distributions. Trait differences across geological substrates imply pronounced

  3. Comparative evaluation of haemagglutination potential of haemolymph from two species of giant African land snails (Archachatina marginata and Achatina achatina).

    PubMed

    Abiona, John Adesanya; Akinduti, Paul Akinniyi; Oyekunle, Mufutao Atanda; Osinowo, Olusegun Ayodeji; Onagbesan, A Okanlawon Mohammed

    2014-05-01

    A comparative study was conducted to evaluate haemagglutination potential in the haemolymph of two species of giant African land snails (Archachatina marginata and Achatina achatina). Three liveweight groups of snails (<100 g, 101-150 g and >150 g) were used with 4 replicates per liveweight per species for haemagglutination assay (HA). The effect of aestivation on haemagglutination potential was also evaluated. Erythrocytes (2%) from cattle, sheep, goat and chicken were used for HA assay. Results showed that agglutinin-like substances that agglutinate erythrocytes of sheep, goat, cattle and chicken were present in the haemolymph of the two species of giant African land snails. Effect of species was found to be significant (P < 0.001) on haemagglutination titre. Haemolymph of A. marginata, had higher haemagglutination titre than that of A. achatina across the three liveweight groups used in this study. Snail liveweight had no significant effect (P > 0.05) on agglutinin content of the haemolymph in both species. Agglutination level depended on the source of erythrocyte used. Sheep erythrocyte recorded the highest haemagglutination titre, followed by goat, cattle, and chicken in that order. To our knowledge, this is the first evidence that Giant African land snails (GALS) haemolymph contain agglutinins as previously reported for Helix species. This evidence may be the basis for its survivability in the wild and thus establish the use of GALS for African herbal medicinal applications.

  4. Spatial variation of haemosporidian parasite infection in African rainforest bird species.

    PubMed

    Loiseau, Claire; Iezhova, Tatjana; Valkiūnas, Gediminas; Chasar, Anthony; Hutchinson, Anna; Buermann, Wolfgang; Smith, Thomas B; Sehgal, Ravinder N M

    2010-02-01

    Spatial heterogeneity influences the distribution, prevalence, and diversity of haemosporidian parasites. Previous studies have found complex patterns of prevalence with respect to habitat characteristics and parasite genotype, and their interactions, but there is little information regarding how parasitemia intensity and the prevalence of co-infections may vary in space. Here, using both molecular methods and microscopy, we report an analysis of the variation of parasitemia intensity and co-infections of avian haemosporidian parasites ( Plasmodium and Haemoproteus species) in 2 common African birds species, the yellow-whiskered greenbul ( Andropadus latirostris ) and the olive sunbird ( Cyanomitra olivacea ), at 3 sites with distinct habitat characteristics in Ghana. First, we found an interaction between the site and host species for the prevalence of Plasmodium spp. and Haemoproteus spp. For the olive sunbird, the prevalence of Plasmodium spp., as well as the number of individuals with co-infections, varied significantly among the sites, but these measures remained constant for the yellow-whiskered greenbul. In addition, yellow-whiskered greenbuls infected with Haemoproteus spp. were found only at 1 site. Furthermore, for both bird species, the parasitemia intensity of Plasmodium spp. varied significantly among the 3 sites, but with opposing trends. These results suggest that spatial heterogeneity differently affects haemosporidian infection parameters in these vertebrate-hosts. Environmental conditions here can either favor or reduce parasite infection. We discuss the implications of these discrepancies for conservation and ecological studies of infectious diseases in natural populations.

  5. African elephants show high levels of interest in the skulls and ivory of their own species.

    PubMed

    McComb, Karen; Baker, Lucy; Moss, Cynthia

    2006-03-22

    An important area of biology involves investigating the origins in animals of traits that are thought of as uniquely human. One way that humans appear unique is in the importance they attach to the dead bodies of other humans, particularly those of their close kin, and the rituals that they have developed for burying them. In contrast, most animals appear to show only limited interest in the carcasses or associated remains of dead individuals of their own species. African elephants (Loxodonta africana) are unusual in that they not only give dramatic reactions to the dead bodies of other elephants, but are also reported to systematically investigate elephant bones and tusks that they encounter, and it has sometimes been suggested that they visit the bones of relatives. Here, we use systematic presentations of object arrays to demonstrate that African elephants show higher levels of interest in elephant skulls and ivory than in natural objects or the skulls of other large terrestrial mammals. However, they do not appear to specifically select the skulls of their own relatives for investigation so that visits to dead relatives probably result from a more general attraction to elephant remains.

  6. Coxiella burnetii detected in three species of endangered North African gazelles that recently aborted.

    PubMed

    García, Elena; Espeso, Gerardo; Fernández, Rocío; Gómez-Martín, Ángel; Rodríguez-Linde, José María; De la Fe, Christian

    2017-01-15

    Coxiella (C.) burnetii is the etiological agent of the zoonotic disease known a Q fever. This agent can infect multiple hosts although its pathogenic potential in wild ruminants has been poorly studied. The polymerase chain reaction and the serological test detected the presence of C. burnetii in a population of North African gazelles (n = 355), comprising dorcas gazelle (Gazella dorcas neglecta), dama gazelle (Nanger dama mhorr) and Cuvier's gazelle (Gazella cuvieri) which, some of them, they recently aborted. Serological tests for Brucella spp., C. burnetii, Chlamydophila abortus, border disease pestivirus, and Toxoplasma spp. were performed together with specific cultures to detect Salmonella spp., Listeria spp., and Campylobacter spp. and a polymerase chain reaction for C. burnetii on serum and vaginal swabs samples collected from a representative number of animals (n = 65). These tests only detected the presence of C. burnetii in 18 specimens (27.3%). C. burnetii was the only pathogen detected, with eight animals testing positive on the polymerase chain reaction, 15 on the serological test, and five on both the tests. This article reveals the presence of C. burnetii during a medium and late-stage abortions occurred in a population of North African gazelles. The presence of C. burnetii as causal agent of abortions in Cuvier's gazelles has never been reported. The consequences of the findings are discussed here, showing the need to adopt urgent control measures to prevent the spread of C. burnetii in captive populations that are essential for the conservation of these endangered species.

  7. Shaping development through mechanical strain: the transcriptional basis of diet-induced phenotypic plasticity in a cichlid fish.

    PubMed

    Gunter, Helen M; Fan, Shaohua; Xiong, Fan; Franchini, Paolo; Fruciano, Carmelo; Meyer, Axel

    2013-09-01

    Adaptive phenotypic plasticity, the ability of an organism to change its phenotype to match local environments, is increasingly recognized for its contribution to evolution. However, few empirical studies have explored the molecular basis of plastic traits. The East African cichlid fish Astatoreochromis alluaudi displays adaptive phenotypic plasticity in its pharyngeal jaw apparatus, a structure that is widely seen as an evolutionary key innovation that has contributed to the remarkable diversity of cichlid fishes. It has previously been shown that in response to different diets, the pharyngeal jaws change their size, shape and dentition: hard diets induce an adaptive robust molariform tooth phenotype with short jaws and strong internal bone structures, while soft diets induce a gracile papilliform tooth phenotype with elongated jaws and slender internal bone structures. To gain insight into the molecular underpinnings of these adaptations and enable future investigations of the role that phenotypic plasticity plays during the formation of adaptive radiations, the transcriptomes of the two divergent jaw phenotypes were examined. Our study identified a total of 187 genes whose expression differs in response to hard and soft diets, including immediate early genes, extracellular matrix genes and inflammatory factors. Transcriptome results are interpreted in light of expression of candidate genes-markers for tooth size and shape, bone cells and mechanically sensitive pathways. This study opens up new avenues of research at new levels of biological organization into the roles of phenotypic plasticity during speciation and radiation of cichlid fishes.

  8. The evolutionary dynamics of ancient and recent polyploidy in the African semiaquatic species of the legume genus Aeschynomene.

    PubMed

    Chaintreuil, Clémence; Gully, Djamel; Hervouet, Catherine; Tittabutr, Panlada; Randriambanona, Herizo; Brown, Spencer C; Lewis, Gwilym P; Bourge, Mickaël; Cartieaux, Fabienne; Boursot, Marc; Ramanankierana, Heriniaina; D'Hont, Angélique; Teaumroong, Neung; Giraud, Eric; Arrighi, Jean-François

    2016-08-01

    The legume genus Aeschynomene is notable in the ability of certain semiaquatic species to develop nitrogen-fixing stem nodules. These species are distributed in two clades. In the first clade, all the species are characterized by the use of a unique Nod-independent symbiotic process. In the second clade, the species use a Nod-dependent symbiotic process and some of them display a profuse stem nodulation as exemplified in the African Aeschynomene afraspera. To facilitate the molecular analysis of the symbiotic characteristics of such legumes, we took an integrated molecular and cytogenetic approach to track occurrences of polyploidy events and to analyze their impact on the evolution of the African species of Aeschynomene. Our results revealed two rounds of polyploidy: a paleopolyploid event predating the African group and two neopolyploid speciations, along with significant chromosomal variations. Hence, we found that A. afraspera (8x) has inherited the contrasted genomic properties and the stem-nodulation habit of its parental lineages (4x). This study reveals a comprehensive picture of African Aeschynomene diversification. It notably evidences a history that is distinct from the diploid Nod-independent clade, providing clues for the identification of the specific determinants of the Nod-dependent and Nod-independent symbiotic processes, and for comparative analysis of stem nodulation.

  9. The African Crane Database (1978-2014): Records of three threatened crane species (Family: Gruidae) from southern and eastern Africa

    PubMed Central

    Smith, Tanya; Page-Nicholson, Samantha; Gibbons, Bradley; Jones, M. Genevieve W.; van Niekerk, Mark; Botha, Bronwyn; Oliver, Kirsten; McCann, Kevin

    2016-01-01

    Abstract Background The International Crane Foundation (ICF) / Endangered Wildlife Trust’s (EWT) African Crane Conservation Programme has recorded 26 403 crane sightings in its database from 1978 to 2014. This sightings collection is currently ongoing and records are continuously added to the database by the EWT field staff, ICF/EWT Partnership staff, various partner organizations and private individuals. The dataset has two peak collection periods: 1994-1996 and 2008-2012. The dataset collection spans five African countries: Kenya, Rwanda, South Africa, Uganda and Zambia; 98% of the data were collected in South Africa. Georeferencing of the dataset was verified before publication of the data. The dataset contains data on three African crane species: Blue Crane Anthropoides paradiseus, Grey Crowned Crane Balearica regulorum and Wattled Crane Bugeranus carunculatus. The Blue and Wattled Cranes are classified by the IUCN Red List of Threatened Species as Vulnerable and the Grey Crowned Crane as Endangered. New information This is the single most comprehensive dataset published on African Crane species that adds new information about the distribution of these three threatened species. We hope this will further aid conservation authorities to monitor and protect these species. The dataset continues to grow and especially to expand in geographic coverage into new countries in Africa and new sites within countries. The dataset can be freely accessed through the Global Biodiversity Information Facility data portal. PMID:27956850

  10. Hidden biodiversity in an ancient lake: phylogenetic congruence between Lake Tanganyika tropheine cichlids and their monogenean flatworm parasites.

    PubMed

    Vanhove, Maarten P M; Pariselle, Antoine; Van Steenberge, Maarten; Raeymaekers, Joost A M; Hablützel, Pascal I; Gillardin, Céline; Hellemans, Bart; Breman, Floris C; Koblmüller, Stephan; Sturmbauer, Christian; Snoeks, Jos; Volckaert, Filip A M; Huyse, Tine

    2015-09-03

    The stunning diversity of cichlid fishes has greatly enhanced our understanding of speciation and radiation. Little is known about the evolution of cichlid parasites. Parasites are abundant components of biodiversity, whose diversity typically exceeds that of their hosts. In the first comprehensive phylogenetic parasitological analysis of a vertebrate radiation, we study monogenean parasites infecting tropheine cichlids from Lake Tanganyika. Monogeneans are flatworms usually infecting the body surface and gills of fishes. In contrast to many other parasites, they depend only on a single host species to complete their lifecycle. Our spatially comprehensive combined nuclear-mitochondrial DNA dataset of the parasites covering almost all tropheine host species (N = 18), reveals species-rich parasite assemblages and shows consistent host-specificity. Statistical comparisons of host and parasite phylogenies based on distance and topology-based tests demonstrate significant congruence and suggest that host-switching is rare. Molecular rate evaluation indicates that species of Cichlidogyrus probably diverged synchronically with the initial radiation of the tropheines. They further diversified through within-host speciation into an overlooked species radiation. The unique life history and specialisation of certain parasite groups has profound evolutionary consequences. Hence, evolutionary parasitology adds a new dimension to the study of biodiversity hotspots like Lake Tanganyika.

  11. Hidden biodiversity in an ancient lake: phylogenetic congruence between Lake Tanganyika tropheine cichlids and their monogenean flatworm parasites

    PubMed Central

    Vanhove, Maarten P. M.; Pariselle, Antoine; Van Steenberge, Maarten; Raeymaekers, Joost A. M.; Hablützel, Pascal I.; Gillardin, Céline; Hellemans, Bart; Breman, Floris C.; Koblmüller, Stephan; Sturmbauer, Christian; Snoeks, Jos; Volckaert, Filip A. M.; Huyse, Tine

    2015-01-01

    The stunning diversity of cichlid fishes has greatly enhanced our understanding of speciation and radiation. Little is known about the evolution of cichlid parasites. Parasites are abundant components of biodiversity, whose diversity typically exceeds that of their hosts. In the first comprehensive phylogenetic parasitological analysis of a vertebrate radiation, we study monogenean parasites infecting tropheine cichlids from Lake Tanganyika. Monogeneans are flatworms usually infecting the body surface and gills of fishes. In contrast to many other parasites, they depend only on a single host species to complete their lifecycle. Our spatially comprehensive combined nuclear-mitochondrial DNA dataset of the parasites covering almost all tropheine host species (N = 18), reveals species-rich parasite assemblages and shows consistent host-specificity. Statistical comparisons of host and parasite phylogenies based on distance and topology-based tests demonstrate significant congruence and suggest that host-switching is rare. Molecular rate evaluation indicates that species of Cichlidogyrus probably diverged synchronically with the initial radiation of the tropheines. They further diversified through within-host speciation into an overlooked species radiation. The unique life history and specialisation of certain parasite groups has profound evolutionary consequences. Hence, evolutionary parasitology adds a new dimension to the study of biodiversity hotspots like Lake Tanganyika. PMID:26335652

  12. Species-level diversification of African dwarf crocodiles (Genus Osteolaemus): a geographic and phylogenetic perspective.

    PubMed

    Eaton, Mitchell J; Martin, Andrew; Thorbjarnarson, John; Amato, George

    2009-03-01

    The taxonomy of the African dwarf crocodile (genus Osteolaemus) has been disputed since a novel morphotype was discovered in the early 20th Century. Because this poorly-known reptile is widely hunted throughout the forests of Central and West Africa, resolving the existence and extent of taxonomic units has important management and conservation implications. Lack of molecular data from individuals of known origin and historical disagreement on diagnostic morphological characters have hindered attempts to settle one of the most important taxonomic questions in the Crocodylia. In an effort to clarify the evolutionary relationships among dwarf crocodiles, we sequenced three mitochondrial and two nuclear genes using a large sample of dwarf crocodiles from known localities across major drainage basins of forested Africa. Concordant results from Bayesian, maximum likelihood, maximum parsimony and population aggregation analytical methods support a previously recognized division of the dwarf crocodile into a Congo Basin form (O. osborni) and a West African form (Osteolaemus tetraspis), but also reveal a third diagnosable lineage from West Africa warranting recognition as an separate taxonomic unit. Corrected genetic distances between geographic regions ranged from 0.2% to 0.6% in nuclear fragments and 10.0 to 16.2% in mitochondrial COI. Population aggregation, using fixed and alternate character (nucleotide) states to cluster or divide populations, recovered 232 such molecular characters in 4286 bp of sequence data and unambiguously aggregated populations into their respective geographic clade. Several previously recognized morphological differences coincide with our molecular analysis to distinguish Congo Basin crocodiles from the Ogooué Basin and West Africa. Discrete morphological characters have not yet been documented between the latter two regions, suggesting further work is needed or molecular data may be required to recognize taxonomic divisions in cases where

  13. Rapid sympatric ecological differentiation of crater lake cichlid fishes within historic times

    PubMed Central

    2010-01-01

    .001). Conclusions This study provides empirical evidence of eco-morphological differentiation occurring very quickly after the colonization of a new and vacant habitat. Exceptionally low levels of neutral genetic diversity and inference from coalescence indicates that the Midas cichlid population in Apoyeque is much younger (ca. 100 years or generations old) than the crater itself (ca. 1 800 years old). This suggests either that the crater remained empty for many hundreds of years after its formation or that remnant volcanic activity prevented the establishment of a stable fish population during the early life of the crater lake. Based on our findings of eco-morphological variation in the Apoyeque Midas cichlids, and known patterns of adaptation in Midas cichlids in general, we suggest that this population may be in a very early stage of speciation (incipient species), promoted by disruptive selection and ecological diversification. PMID:20459869

  14. Analyses of volatiles produced by the African fruit fly species complex (Diptera, Tephritidae).

    PubMed

    Břízová, Radka; Vaníčková, Lucie; Faťarová, Mária; Ekesi, Sunday; Hoskovec, Michal; Kalinová, Blanka

    2015-01-01

    Ceratitis fasciventris, Ceratitis anonae and Ceratitis rosa are polyphagous agricultural pests originating from the African continent. The taxonomy of this group (the so-called Ceratitis FAR complex) is unclear. To clarify the taxonomic relationships, male and female-produced volatiles presumably involved in pre-mating communication were studied using comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry (GC×GC-TOFMS) followed by multivariate analysis, and gas chromatography combined with electroantennographic detection (GC-EAD). GC×GC-TOFMS analyses revealed sex specific differences in produced volatiles. Male volatiles are complex mixtures that differ both qualitatively and quantitatively but share some common compounds. GC-EAD analyses of male volatiles revealed that the antennal sensitivities of females significantly differ in the studied species. No female volatiles elicited antennal responses in males. The results show clear species-specific differences in volatile production and provide complementary information for the distinct delimitation of the putative species by chemotaxonomic markers.

  15. Analyses of volatiles produced by the African fruit fly species complex (Diptera, Tephritidae)

    PubMed Central

    Břízová, Radka; Vaníčková, Lucie; Faťarová, Mária; Ekesi, Sunday; Hoskovec, Michal; Kalinová, Blanka

    2015-01-01

    Abstract Ceratitis fasciventris, Ceratitis anonae and Ceratitis rosa are polyphagous agricultural pests originating from the African continent. The taxonomy of this group (the so-called Ceratitis FAR complex) is unclear. To clarify the taxonomic relationships, male and female-produced volatiles presumably involved in pre-mating communication were studied using comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry (GC×GC-TOFMS) followed by multivariate analysis, and gas chromatography combined with electroantennographic detection (GC-EAD). GC×GC-TOFMS analyses revealed sex specific differences in produced volatiles. Male volatiles are complex mixtures that differ both qualitatively and quantitatively but share some common compounds. GC-EAD analyses of male volatiles revealed that the antennal sensitivities of females significantly differ in the studied species. No female volatiles elicited antennal responses in males. The results show clear species-specific differences in volatile production and provide complementary information for the distinct delimitation of the putative species by chemotaxonomic markers. PMID:26798269

  16. Concordant genetic structure in two species of woodpecker distributed across the primary West African biogeographic barriers.

    PubMed

    Fuchs, Jérôme; Bowie, Rauri C K

    2015-07-01

    The lowland forests of western and central tropical Africa are separated by several potential biogeographic barriers to dispersal for forest adapted vertebrates. The two primary barriers are (1) the Dahomey Gap, a savanna corridor that reaches the coast of southern Ghana, Togo and Benin, and separates the West African rainforest into the Upper (Ghana west to Guinea) and Lower Guinea (Nigeria to Uganda and Angola) forest blocks, and (2) the Lower Niger River, a large delta that separates Western and Eastern Nigeria. Previous studies on terrestrial vertebrates (lizards, mammals and birds) have highlighted a genetic break in the Dahomey Gap/Lower Niger River area although the relative importance of each barrier has not been assessed due to limitations in geographic sampling. We compared the phylogeographic history of two co-distributed sister-species of woodpeckers (Campethera caroli and C. nivosa) using data from three loci representing all inheritance modes. Our analyses revealed that both the Dahomey Gap and possibly the Lower Niger River acted as strong biogeographic barriers for the two woodpecker species, with the Lower Niger River being the first barrier to have formed, leading to three distinct populations of C. nivosa. Our divergence time analyses revealed that both these biogeographic barriers formed during the Pleistocene, supporting the Pleistocene refuge hypothesis, with the Dahomey Gap likely appearing about 0.5 myr BP. No genetic structure was recovered among sampled populations in either the Upper or the Lower Guinea Forest Block for both species, despite the considerable geographic area covered.

  17. Sensory basis for detection of benthic prey in two Lake Malawi cichlids.

    PubMed

    Schwalbe, Margot A B; Webb, Jacqueline F

    2014-04-01

    The adaptive radiations of African cichlids resulted in a diversity of feeding morphologies and strategies, but the role of sensory biology in prey detection and feeding ecology remains largely unexplored. Two endemic Lake Malawi cichlid genera, Tramitichromis and Aulonocara, feed on benthic invertebrates, but differ in lateral line morphology (narrow and widened lateral line canals, respectively) and foraging strategy. The hypothesis that they use their lateral line systems differently was tested by looking at the relative contribution of the lateral line system and vision in prey detection by Tramitichromis sp. and comparing results to those from a complementary study using Aulonocara stuartgranti (Schwalbe et al., 2012). First, behavioral trials were used to assess the ability of Tramitichromis sp. to detect live (mobile) and dead (immobile) benthic prey under light and dark conditions. Second, trials were run before, immediately after, and several weeks after chemical ablation of the lateral line system to determine its role in feeding behavior. Results show that Tramitichromis sp. is a visual predator that neither locates prey in the dark nor depends on lateral line input for prey detection and is thus distinct from A. stuartgranti, which uses its lateral line or a combination of vision and lateral line to detect prey depending on light condition. Investigating how functionally distinctive differences in sensory morphology are correlated with feeding behavior in the laboratory and determining the role of sensory systems in feeding ecology will provide insights into how sensory capabilities may contribute to trophic niche segregation.

  18. Microsatellite cross-species amplification and utility in southern African elasmobranchs: A valuable resource for fisheries management and conservation

    PubMed Central

    2014-01-01

    Background Similarly to the rest of the world, southern Africa’s diverse chondrichthyan fauna is currently experiencing high fishing pressures from direct and non-direct fisheries to satisfy market demands for shark products such as fins and meat. In this study, the development of microsatellite markers through cross-species amplification of primer sets previously developed for closely related species is reported as an alternative approach to de novo marker development. This included the design of four microsatellite multiplex assays and their cross-species utility in genetic diversity analysis of southern African elasmobranchs. As this study forms part of a larger project on the development of genetic resources for commercially important and endemic southern African species, Mustelus mustelus was used as a candidate species for testing these multiplex assays in down-stream applications. Results Thirty five microsatellite primer sets previously developed for five elasmobranch species were selected from literature for testing cross-species amplification in 16 elasmobranch species occurring in southern Africa. Cross-species amplification success rates ranged from 28.6%-71.4%. From the successfully amplified microsatellites, 22 loci were selected and evaluated for levels of polymorphism, and four multiplex assays comprising of the 22 microsatellites were successfully constructed, optimised and characterised in a panel of 87 Mustelus mustelus individuals. A total of 125 alleles were observed across all loci, with the number of alleles ranging from 3–12 alleles. Cross-species amplification of the four optimised multiplex assays was further tested on 11 commercially important and endemic southern African elasmobranch species. Percentage of polymorphism ranged from 31.8%-95.5% in these species with polymorphic information content decreasing exponentially with evolutionary distance from the source species. Conclusions Cross-species amplification of the 35

  19. Secondary contact seeds phenotypic novelty in cichlid fishes.

    PubMed

    Nichols, Paul; Genner, Martin J; van Oosterhout, Cock; Smith, Alan; Parsons, Paul; Sungani, Harold; Swanstrom, Jennifer; Joyce, Domino A

    2015-01-07

    Theory proposes that genomic admixture between formerly reproductively isolated populations can generate phenotypic novelty for selection to act upon. Secondary contact may therefore be a significant promoter of phenotypic novelty that allows species to overcome environmental challenges and adapt to novel environments, including during adaptive radiation. To date, this has largely been considered from the perspective of interspecific hybridization at contact zones. However, it is also possible that this process occurs more commonly between natural populations of a single species, and thus its importance in adaptive evolution may have been underestimated. In this study, we tested the consequences of genomic introgression during apparent secondary contact between phenotypically similar lineages of the riverine cichlid fish Astatotilapia calliptera. We provide population genetic evidence of a secondary contact zone in the wild, and then demonstrate using mate-choice experiments that both lineages can reproduce together successfully in laboratory conditions. Finally, we show that genomically admixed individuals display extreme phenotypes not observed in the parental lineages. Collectively, the evidence shows that secondary contact can drive the evolution of phenotypic novelty, suggesting that pulses of secondary contact may repeatedly seed genetic novelty, which when coupled with ecological opportunity could promote rapid adaptive evolution in natural circumstances.

  20. Secondary contact seeds phenotypic novelty in cichlid fishes

    PubMed Central

    Nichols, Paul; Genner, Martin J.; van Oosterhout, Cock; Smith, Alan; Parsons, Paul; Sungani, Harold; Swanstrom, Jennifer; Joyce, Domino A.

    2015-01-01

    Theory proposes that genomic admixture between formerly reproductively isolated populations can generate phenotypic novelty for selection to act upon. Secondary contact may therefore be a significant promoter of phenotypic novelty that allows species to overcome environmental challenges and adapt to novel environments, including during adaptive radiation. To date, this has largely been considered from the perspective of interspecific hybridization at contact zones. However, it is also possible that this process occurs more commonly between natural populations of a single species, and thus its importance in adaptive evolution may have been underestimated. In this study, we tested the consequences of genomic introgression during apparent secondary contact between phenotypically similar lineages of the riverine cichlid fish Astatotilapia calliptera. We provide population genetic evidence of a secondary contact zone in the wild, and then demonstrate using mate-choice experiments that both lineages can reproduce together successfully in laboratory conditions. Finally, we show that genomically admixed individuals display extreme phenotypes not observed in the parental lineages. Collectively, the evidence shows that secondary contact can drive the evolution of phenotypic novelty, suggesting that pulses of secondary contact may repeatedly seed genetic novelty, which when coupled with ecological opportunity could promote rapid adaptive evolution in natural circumstances. PMID:25392475

  1. Phylogeography of SW Mediterranean firs: different European origins for the North African Abies species.

    PubMed

    Sánchez-Robles, Jose M; Balao, Francisco; Terrab, Anass; García-Castaño, Juan L; Ortiz, María A; Vela, Errol; Talavera, Salvador

    2014-10-01

    The current distribution of Western Mediterranean Abies species is a result of complex geodynamic processes and climatic oscillations that occurred in the past. Abies sect. Piceaster offers a good study model to explore how geo-climatic oscillations might have influenced its expansion and diversification on both sides of the W Mediterranean basin. We investigated the genetic variation within and among nine populations from five Abies species by molecular markers with high and low mutation rates and contrasting inheritance (AFLP and cpSSR). Analyses revealed the opening of the Strait of Gibraltar as an effective barrier against gene flow between the Southern Iberian (A. pinsapo) and North African (A. marocana and A. tazaotana) firs. The A. pinsapo populations in Spain and likewise those of the A. marocana - A. tazaotana population complex were not differentiated, and no evidence was found to distinguish A. tazaotana at the species level. Diversification of Abies across North Africa could occur by way of at least two vicariant events from Europe, in the west, giving rise to the A. marocana - A. tazaotana complex, and in the east, giving A. numidica. Secondary contacts among species from Abies sect. Piceaster (A. pinsapo and A. numidica), and with A. alba (Abies sect. Abies) are also indicated. However, there is a closer relationship between the Algerian fir (A. numidica) and the North Mediterranean widespread A. alba, than with the Moroccan firs (A. marocana and A. tazaotana) or the Southern Iberian (A. pinsapo). We also discuss the distribution range of these taxa in its paleogeological and paleoclimatic context, and propose that part of the modern geography of the South-Western Mediterranean firs might be traced back to the Tertiary.

  2. Biogeographical and phylogenetic origins of African fig species (Ficus section Galoglychia).

    PubMed

    Rønsted, Nina; Salvo, Gabriele; Savolainen, Vincent

    2007-04-01

    Ficus section Galoglychia (subgenus Urostigma; Moraceae) includes 72 species restricted to the African floristic region (a few extending to the Arabian Peninsula and Socotra). We present the first molecular phylogenetic analysis of the section including 56 ingroup (representing 44 species) and three outgroup taxa, to investigate its monophyly, classification and evolution. We used sequence data from the nuclear ribosomal internal and external transcribed spacers (ITS and ETS). Our results suggest that section Galoglychia is paraphyletic to the neotropical section Americana, although this is not supported by bootstrap analysis and only weakly supported by Bayesian posterior probabilities. Maximum parsimony analysis conflict with maximum likelihood and Bayesian analyses with respect to the closest relatives of section Americana in Africa. The subsections of section Galoglychia proposed by Berg [Berg, C.C., 1986. Subdivision of Ficus subg. Urostigma sect. Galoglychia (Moraceae). Proc. Kon. Ned. Akad. Wetensch., Ser. C, 89, 121-127] are generally supported. We find two major clades of section Galoglychia within Africa possibly corresponding to two main centres of diversity. One clade comprises members of subsections Platyphyllae and Chlamydodorae, which are more concentrated in Eastern Africa, and extend to Madagascar and neighbouring archipelagos (Comores, Mascarenes, Aldabra Islands and Seychelles). The other main clade includes members of subsections Caulocarpae, Cyathistipulae, Crassicostae and Galoglychia, which are concentrated in West and Central Africa.

  3. Water balance and renal function in two species of African lungfish Protopterus dolloi and Protopterus annectens.

    PubMed

    Patel, Monika; Iftikar, Fathima I; Smith, Richard W; Ip, Yuen K; Wood, Chris M

    2009-02-01

    The basic physiology of water balance and kidney function was characterized in two species of African lungfish, Protopterus dolloi and Protopterus annectens. Diffusive water efflux rate constants were low (0.13 h(-1)-0.38 h(-1) in various series) relative to values in freshwater teleost fish. Efflux rate constants increased approximately 3-fold after feeding in both species, and were greatly decreased after 8 months terrestrialization (P. dolloi only tested). Urine flow rates (UFR, 3.9-5.2 mL kg(-1) h(-1)) and glomerular filtration rates (GFR, 6.6-9.3 mL kg(-1) h(-1)) were quite high relative to values in most freshwater teleosts. However urinary ion excretion rates were low, with net re-absorption of >99% Na(+), >98% Cl(-), and >78% Ca(2+) from the primary filtrate, comparable to teleosts. Net water re-absorption was significantly greater in P. dolloi (56%) than in P. annectens (23%). We conclude that renal function in lungfish is similar to that in other primitive freshwater fish, but there is an interesting dichotomy between diffusive and osmotic permeabilities. Aquatic lungfish have low diffusive water permeability, an important pre-adaptation to life on land, and in accord with greatly reduced gill areas and low metabolic rates. However osmotic permeability is high, 4-12 times greater than diffusive permeability. A role for aquaporins in this dichotomy is speculated.

  4. Antigenic diversity is generated by distinct evolutionary mechanisms in African trypanosome species.

    PubMed

    Jackson, Andrew P; Berry, Andrew; Aslett, Martin; Allison, Harriet C; Burton, Peter; Vavrova-Anderson, Jana; Brown, Robert; Browne, Hilary; Corton, Nicola; Hauser, Heidi; Gamble, John; Gilderthorp, Ruth; Marcello, Lucio; McQuillan, Jacqueline; Otto, Thomas D; Quail, Michael A; Sanders, Mandy J; van Tonder, Andries; Ginger, Michael L; Field, Mark C; Barry, J David; Hertz-Fowler, Christiane; Berriman, Matthew

    2012-02-28

    Antigenic variation enables pathogens to avoid the host immune response by continual switching of surface proteins. The protozoan blood parasite Trypanosoma brucei causes human African trypanosomiasis ("sleeping sickness") across sub-Saharan Africa and is a model system for antigenic variation, surviving by periodically replacing a monolayer of variant surface glycoproteins (VSG) that covers its cell surface. We compared the genome of Trypanosoma brucei with two closely related parasites Trypanosoma congolense and Trypanosoma vivax, to reveal how the variant antigen repertoire has evolved and how it might affect contemporary antigenic diversity. We reconstruct VSG diversification showing that Trypanosoma congolense uses variant antigens derived from multiple ancestral VSG lineages, whereas in Trypanosoma brucei VSG have recent origins, and ancestral gene lineages have been repeatedly co-opted to novel functions. These historical differences are reflected in fundamental differences between species in the scale and mechanism of recombination. Using phylogenetic incompatibility as a metric for genetic exchange, we show that the frequency of recombination is comparable between Trypanosoma congolense and Trypanosoma brucei but is much lower in Trypanosoma vivax. Furthermore, in showing that the C-terminal domain of Trypanosoma brucei VSG plays a crucial role in facilitating exchange, we reveal substantial species differences in the mechanism of VSG diversification. Our results demonstrate how past VSG evolution indirectly determines the ability of contemporary parasites to generate novel variant antigens through recombination and suggest that the current model for antigenic variation in Trypanosoma brucei is only one means by which these parasites maintain chronic infections.

  5. Changes in the acoustic environment alter the foraging and sheltering behaviour of the cichlid Amititlania nigrofasciata.

    PubMed

    McLaughlin, Kirsty Elizabeth; Kunc, Hansjoerg P

    2015-07-01

    Anthropogenic noise can affect behaviour across a wide range of species in both terrestrial and aquatic environments. However, behaviours might not be affected in isolation. Therefore, a more holistic approach investigating how environmental stressors, such as noise pollution, affect different behaviours in concert is necessary. Using tank-based noise exposure experiments, we tested how changes in the acoustic environment affect the behaviour of the cichlid Amatitlania nigrofasciata. We found that exposure to anthropogenic noise affected a couple of behaviours: an increase in sheltering was accompanied by a decrease in foraging. Our results highlight the multiple negative effects of an environmental stressor on an individual's behaviour.

  6. Evolutionary history of the Lake Tanganyika cichlid tribe Lamprologini (Teleostei: Perciformes) derived from mitochondrial and nuclear DNA data

    PubMed Central

    Sturmbauer, Christian; Salzburger, Walter; Duftner, Nina; Schelly, Robert; Koblmüller, Stephan

    2010-01-01

    Lake Tanganyika comprises a cichlid species flock with substrate-breeding and mouthbrooding lineages. While sexual selection via mate choice on male mating color is thought to boost speciation rates in mouthbrooding cichlids, this is not the case in substrate-breeding lamprologines, which mostly form stable pairs and lack sexual dichromatism. We present a comprehensive reconstruction of the evolution of the cichlid tribe Lamprologini, based upon mtDNA sequences and multilocus nuclear DNA (AFLP) markers. Twelve mtDNA clades were identified, seven of which were corroborated by the AFLP tree. The radiation is likely to have started about 5.3 MYA, contemporarily with that of the mouthbrooding C-lineage, and probably triggered by the onset of deep-water conditions in Lake Tanganyika. Neither the Congo- nor the Malagarazi River species form the most ancestral branch. Several conflicts in the mtDNA phylogeny with taxonomic assignments based upon color, eco-morphology and behavior could be resolved and complemented by the AFLP analysis. Introgressive hybridization upon secondary contact seems to be the most likely cause for paraphyly of taxa due to mtDNA capture in species involving brood-care helpers, while accidental hybridization best explains the para- or polyphyly of several gastropod shell breeders. Taxonomic error or paraphyly due to the survival of ancestral lineages appear responsible for inconsistencies in the genera Lamprologus and Neolamprologus. PMID:20601006

  7. Evolutionary Fate of the Androgen Receptor−Signaling Pathway in Ray-Finned Fishes with a Special Focus on Cichlids

    PubMed Central

    Lorin, Thibault; Salzburger, Walter; Böhne, Astrid

    2015-01-01

    The emergence of the steroid system is coupled to the evolution of multicellular animals. In vertebrates in particular, the steroid receptor repertoire has been shaped by genome duplications characteristic to this lineage. Here, we investigate for the first time the composition of the androgen receptor–signaling pathway in ray-finned fish genomes by focusing in particular on duplicates that emerged from the teleost-specific whole-genome duplication. We trace lineage- and species-specific duplications and gene losses for the genomic and nongenomic pathway of androgen signaling and subsequently investigate the sequence evolution of these genes. In one particular fish lineage, the cichlids, we find evidence for differing selection pressures acting on teleost-specific whole-genome duplication paralogs at a derived evolutionary stage. We then look into the expression of these duplicated genes in four cichlid species from Lake Tanganyika indicating, once more, rapid changes in expression patterns in closely related fish species. We focus on a particular case, the cichlid specific duplication of the rac1 GTPase, which shows possible signs of a neofunctionalization event. PMID:26333839

  8. Male convict cichlid 11-ketotestosterone levels throughout the reproductive cycle: an exploratory profile study in laboratory and field populations

    PubMed Central

    Snekser, Jennifer L.; Itzkowitz, Murray

    2015-01-01

    The convict cichlid (Amatitlania nigrofasciata) has been extensively examined in relation to many behavioral topics, such as courtship, pair-bonding, bi-parental care, and territoriality. Recently, this model species has been utilized in studies on genetics, endocrinology, and neuroanatomy, with an ultimate goal of connecting behavior with its underlying mechanisms. The goal of this study was two-fold: (1) profile the circulating levels of plasma 11KT in the male convict cichlid at multiple points during the reproductive cycle and (2) generally compare the hormonal profiles of the widely used laboratory populations and those of a free-living population in the streams of Costa Rica. The results of the field experiment showed that male convict cichlids had higher levels of circulating 11KT during courtship and lower during the parental care and non-breeding phases. The profile of the laboratory population was similar to the profile of the free-living individuals, with significantly higher levels of 11KT occurring during courtship than during parental care, though the level of 11KT during non-breeding phase was elevated in the laboratory. The high levels of 11KT during courtship and low levels of 11KT during parental care found in both the field and the laboratory is similar to what has been reported in other species of teleosts, and may suggest an important function of 11KT in the expression of courtship behavior and the subsequent onset of parental behaviors in this model species. PMID:26020006

  9. Complex histories of repeated gene flow in Cameroon crater lake cichlids cast doubt on one of the clearest examples of sympatric speciation.

    PubMed

    Martin, Christopher H; Cutler, Joseph S; Friel, John P; Dening Touokong, Cyrille; Coop, Graham; Wainwright, Peter C

    2015-06-01

    One of the most celebrated examples of sympatric speciation in nature are monophyletic radiations of cichlid fishes endemic to Cameroon crater lakes. However, phylogenetic inference of monophyly may not detect complex colonization histories involving some allopatric isolation, such as double invasions obscured by genome-wide gene flow. Population genomic approaches are better suited to test hypotheses of sympatric speciation in these cases. Here, we use comprehensive sampling from all four sympatric crater lake cichlid radiations in Cameroon and outgroups across Africa combined with next-generation sequencing to genotype tens of thousands of SNPs. We find considerable evidence of gene flow between all four radiations and neighboring riverine populations after initial colonization. In a few cases, some sympatric species are more closely related to outgroups than others, consistent with secondary gene flow facilitating their speciation. Our results do not rule out sympatric speciation in Cameroon cichlids, but rather reveal a complex history of speciation with gene flow, including allopatric and sympatric phases, resulting in both reproductively isolated species and incipient species complexes. The best remaining non-cichlid examples of sympatric speciation all involve assortative mating within microhabitats. We speculate that this feature may be necessary to complete the process of sympatric speciation in nature.

  10. The in vitro pharmacological activities and a chemical investigation of three South African Salvia species.

    PubMed

    Kamatou, G P P; Viljoen, A M; Gono-Bwalya, A B; van Zyl, R L; van Vuuren, S F; Lourens, A C U; Başer, K H C; Demirci, B; Lindsey, K L; van Staden, J; Steenkamp, P

    2005-12-01

    Salvia species (sage) are well known in folk medicine throughout the world. In South Africa sage is used against fever and digestive disorders. Three closely related South African species (Salvia stenophylla, Salvia repens and Salvia runcinata) were investigated for their anti-oxidant (DPPH assay); anti-inflammatory (5-lipoxygenase and cyclo-oxygenase assays); antimalarial (tritiated hypoxanthine incorporation assay); antimicrobial (disc diffusion and micro-dilution assays) properties and toxicity profile (tetrazolium-based assay). The solvent extracts exhibited anti-oxidant, antimalarial and antibacterial and poor anti-inflammatory properties. The essential oils exhibited anti-inflammatory and antimalarial properties, but displayed poor anti-oxidant and antimicrobial activity. The extract of Salviastenophylla and the essential oil of Salvia runcinata displayed the highest toxicity profile. Overall, Salvia runcinata displayed the most favorable activity of all three taxa tested with an IC(50) value of 6.09 (anti-oxidant); 29.05 (antimalarial) and 22.82 microg/ml (anti-inflammatory). Analytical procedures (GC-MS and HPLC-UV) were employed to generate chromatographic profiles for the essential oils and solvent extracts respectively. The HPLC analysis revealed the presence of rosmarinic acid in all three taxa while carnosic acid was only present in Salvia repens and Salvia stenophylla. The GC-MS analysis showed that oils were qualitatively and quantitatively variable. beta-Caryophyllene was present in large amounts in all three taxa. Other components present include camphor, alpha-pinene and alpha-bisabolol. The results of the in vitro pharmacological activities provide a scientific basis to validate the use of these Salvia species in traditional medicine in South Africa.

  11. Genetic basis of continuous variation in the levels and modular inheritance of pigmentation in cichlid fishes.

    PubMed

    Albertson, R Craig; Powder, Kara E; Hu, Yinan; Coyle, Kaitlin P; Roberts, Reade B; Parsons, Kevin J

    2014-11-01

    Variation in pigmentation type and levels is a hallmark of myriad evolutionary radiations, and biologists have long been fascinated by the factors that promote and maintain variation in coloration across populations. Here, we provide insights into the genetic basis of complex and continuous patterns of colour variation in cichlid fishes, which offer a vast diversity of pigmentation patterns that have evolved in response to both natural and sexual selection. Specifically, we crossed two divergent cichlid species to generate an F2 mapping population that exhibited extensive variation in pigmentation levels and patterns. Our experimental design is robust in that it combines traditional quantitative trait locus (QTL) analysis with population genomics, which has allowed us to move efficiently from QTL interval to candidate gene. In total, we detected 41 QTL and 13 epistatic interactions that underlie melanocyte- and xanthophore-based coloration across the fins and flanks of these fishes. We also identified 2 QTL and 1 interaction for variation in the magnitude of integration among these colour traits. This finding in particular is notable as there are marked differences both within and between species with respect to the complexity of pigmentation patterns. While certain individuals are characterized by more uniform 'integrated' colour patterns, others exhibit many more degrees of freedom with respect to the distribution of colour 'modules' across the fins and flank. Our data reveal, for the first time, a genetic basis for this difference. Finally, we implicate pax3a as a mediator of continuous variation in the levels of xanthophore-based colour along the cichlid flank.

  12. Social familiarity modulates personality trait in a cichlid fish

    PubMed Central

    Galhardo, L.; Vitorino, A.; Oliveira, R. F.

    2012-01-01

    Personality traits, such as exploration–avoidance, are expected to be adaptive in a given context (e.g. low-risk environment) but to be maladaptive in others (e.g. high-risk environment). Therefore, it is expected that personality traits are flexible and respond to environmental fluctuations, given that consistency across different contexts is maintained, so that the relative individual responses in relation to others remains the same (i.e. although the magnitude of the response varies the differences between high and low responders are kept). Here, we tested the response of male cichlid fish (Oreochromis mossambicus) to a novel object (NO) in three different social contexts: (i) social isolation, (ii) in the presence of an unfamiliar conspecific, and (iii) in the presence of a familiar conspecific. Males in the familiar treatment exhibited more exploratory behaviour and less neophobia than males in either the unfamiliar or the social isolation treatments. However, there were no overall correlations in individual behaviour across the three treatments, suggesting a lack of consistency in exploration–avoidance as measured by the NO test in this species. Moreover, there were no differences in cortisol responsiveness to an acute stressor between the three treatments. Together, these results illustrate how behavioural traits usually taken as measures of personality may exhibit significant flexibility and lack the expected consistency across different social contexts. PMID:22859562

  13. Social familiarity modulates personality trait in a cichlid fish.

    PubMed

    Galhardo, L; Vitorino, A; Oliveira, R F

    2012-12-23

    Personality traits, such as exploration-avoidance, are expected to be adaptive in a given context (e.g. low-risk environment) but to be maladaptive in others (e.g. high-risk environment). Therefore, it is expected that personality traits are flexible and respond to environmental fluctuations, given that consistency across different contexts is maintained, so that the relative individual responses in relation to others remains the same (i.e. although the magnitude of the response varies the differences between high and low responders are kept). Here, we tested the response of male cichlid fish (Oreochromis mossambicus) to a novel object (NO) in three different social contexts: (i) social isolation, (ii) in the presence of an unfamiliar conspecific, and (iii) in the presence of a familiar conspecific. Males in the familiar treatment exhibited more exploratory behaviour and less neophobia than males in either the unfamiliar or the social isolation treatments. However, there were no overall correlations in individual behaviour across the three treatments, suggesting a lack of consistency in exploration-avoidance as measured by the NO test in this species. Moreover, there were no differences in cortisol responsiveness to an acute stressor between the three treatments. Together, these results illustrate how behavioural traits usually taken as measures of personality may exhibit significant flexibility and lack the expected consistency across different social contexts.

  14. Hydrodynamic drag constrains head enlargement for mouthbrooding in cichlids.

    PubMed

    Van Wassenbergh, Sam; Potes, Nuno Zavattieri; Adriaens, Dominique

    2015-08-06

    Presumably as an adaptation for mouthbrooding, many cichlid fish species have evolved a prominent sexual dimorphism in the adult head. Since the head of fishes serves as a bow during locomotion, an evolutionary increase in head volume to brood more eggs can trade-off with the hydrodynamic efficiency of swimming. Here, the differences between males and females in three-dimensional shape and size of the external head surfaces and the effect thereof on drag force during locomotion was analysed for the Nile tilapia (Oreochromis niloticus), a maternal mouthbrooder. To do so, three-dimensional body surface reconstructions from laser scans and computational fluid dynamics simulations were performed. After scaling the scanned specimens to post-cranial body volume, in order to theoretically equalize propulsive power, the external volume of the head of females was 27% larger than that of males (head length + 14%; head width + 9%). These differences resulted in an approximate 15% increase in drag force. Yet, hydrodynamics imposed important constraints on the adaptation for mouthbrooding as a much more drastic drop in swimming efficiency seems avoided by mainly enlarging the head along the swimming direction.

  15. Social deprivation affects cooperative predator inspection in a cichlid fish

    PubMed Central

    Hesse, Saskia; Anaya-Rojas, Jaime M.; Frommen, Joachim G.; Thünken, Timo

    2015-01-01

    The social environment individuals are exposed to during ontogeny shapes social skills and social competence in group-living animals. Consequently, social deprivation has serious effects on behaviour and development in animals but little is known about its impact on cooperation. In this study, we examined the effect of social environment on cooperative predator inspection. Predator inspection behaviour is a complex behaviour, which is present in a variety of shoaling fish species. Often, two fish leave the safety of the group and inspect a potentially dangerous predator in order to gather information about the current predation risk. As predator inspection is highly risky, it is prone to conflicts and cheating. However, cooperation among individuals may reduce the individual predation risk. We investigated this complex social behaviour in juveniles of the cichlid fish Pelvicachromis taeniatus that were reared in two different social environments throughout development. Fish reared in a group inspected more often than isolation-reared fish and were more likely to cooperate, i.e. they conducted conjoint inspection of a predator. By contrast, isolation-reared fish were more likely to perform a single inspection without a companion. These results suggest an impairment of cooperative behaviour in isolation-reared fish most probably due to lack of social experience and resulting in lowered social skills needed in coordinated behaviour. PMID:26064616

  16. Hormonal anticipation of territorial challenges in cichlid fish

    PubMed Central

    Antunes, Raquel A.; Oliveira, Rui F.

    2009-01-01

    In many territorial species androgens respond to social interactions. This response has been interpreted as a mechanism for adjusting aggressive motivation to a changing social environment. Therefore, it would be adaptive to anticipate social challenges and reacting to their clues with an anticipatory androgen response to adjust agonistic motivation to an imminent social challenge. Here we test the hypothesis of an anticipatory androgen response to territorial intrusions using classical conditioning to establish an association between a conditioned stimulus (CS = light) and an unconditioned stimulus (US = intruder male) in male cichlid fish (Oreochromis mossambicus). During the training phase conditioned males (CS−US paired presentations) showed a higher decrease in latency for agonistic response toward the intruder than unconditioned males (CS–US unpaired presentations). In the test trial, conditioned males showed an increase in androgen levels (i.e., testosterone and 11-ketotestosterone) relative to baseline, in response to the CS alone. This increase was similar to that of control males exposed to real intruders after CS, whereas unconditioned males showed a decrease in androgen levels in response to the CS. Furthermore, conditioned males were significantly more aggressive than unconditioned males during the post-CS period on test trial, even though the intruder male was not present during this period. These results reveal the occurrence of a conditioned androgen response that may give territorial males an advantage in mounting a defense to upcoming territorial intrusions, if the ability to readily elevate androgens does not co-vary with other traits that bear costs. PMID:19805238

  17. Diet-Morphology Correlations in the Radiation of South American Geophagine Cichlids (Perciformes: Cichlidae: Cichlinae)

    PubMed Central

    López-Fernández, Hernán; Winemiller, Kirk O.; Montaña, Carmen; Honeycutt, Rodney L.

    2012-01-01

    Genera within the South American cichlid tribe Geophagini display specialized feeding and reproductive strategies, with some taxa specialized for both substrate-sifting and mouth brooding. Several lineages within the clade also possess an epibranchial lobe (EBL), a unique pharyngeal structure that has been proposed to have a function in feeding and/or mouth brooding. A recently published genus-level phylogeny of Neotropical cichlids was used as the evolutionary framework for investigating the evolution of morphological features presumably correlated with diet and mouth brooding in the tribe Geophagini. We tested for possible associations between the geophagine epibranchial lobe and benthic feeding and mouth brooding. We also addressed whether the EBL may be associated with unique patterns of diversification in certain geophagine clades. Tests of binary character correlations revealed the EBL was significantly associated with mouth brooding. We also tested for a relationship between diet and morphology. We analyzed stomach contents and morphometric variation among 21 species, with data for two additional species obtained from the literature. Principal Components Analysis revealed axes of morphological variation significantly correlated with piscivory and benthivory, and both morphology and diet were significantly associated with phylogeny. These results suggest that the EBL could be an adaptation for either feeding or mouth brooding. The EBL, however, was not associated with species richness or accelerated rates of phyletic diversification. PMID:22485154

  18. Lineage-Specific Expansion of Vomeronasal Type 2 Receptor-Like (OlfC) Genes in Cichlids May Contribute to Diversification of Amino Acid Detection Systems

    PubMed Central

    Nikaido, Masato; Suzuki, Hikoyu; Toyoda, Atsushi; Fujiyama, Asao; Hagino-Yamagishi, Kimiko; Kocher, Thomas D.; Carleton, Karen; Okada, Norihiro

    2013-01-01

    Fish use olfaction to sense a variety of nonvolatile chemical signals in water. However, the evolutionary importance of olfaction in species-rich cichlids is controversial. Here, we determined an almost complete sequence of the vomeronasal type 2 receptor-like (OlfC: putative amino acids receptor in teleosts) gene cluster using the bacterial artificial chromosome library of the Lake Victoria cichlid, Haplochromis chilotes. In the cluster region, we found 61 intact OlfC genes, which is the largest number of OlfC genes identified among the seven teleost fish investigated to date. Data mining of the Oreochromis niloticus (Nile tilapia) draft genome sequence, and genomic Southern hybridization analysis revealed that the ancestor of all modern cichlids had already developed almost the same OlfC gene repertoire, which was accomplished by lineage-specific gene expansions. Furthermore, comparison of receptor sequences showed that recently duplicated paralogs are more variable than orthologs of different species at particular sites that were predicted to be involved in amino acid selectivity. Thus, the increase of paralogs through gene expansion may lead to functional diversification in detection of amino acids. This study implies that cichlids have developed a potent capacity to detect a variety of amino acids (and their derivatives) through OlfCs, which may have contributed to the extraordinary diversity of their feeding habitats. PMID:23501830

  19. Tree Density and Species Decline in the African Sahel Attributable to Climate

    NASA Technical Reports Server (NTRS)

    Gonzalez, Patrick; Tucker, Compton J.; Sy, H.

    2012-01-01

    Increased aridity and human population have reduced tree cover in parts of the African Sahel and degraded resources for local people. Yet, tree cover trends and the relative importance of climate and population remain unresolved. From field measurements, aerial photos, and Ikonos satellite images, we detected significant 1954-2002 tree density declines in the western Sahel of 18 +/- 14% (P = 0.014, n = 204) and 17 +/- 13% (P = 0.0009, n = 187). From field observations, we detected a significant 1960-2000 species richness decline of 21 +/- 11% (P = 0.0028, n = 14) across the Sahel and a southward shift of the Sahel, Sudan, and Guinea zones. Multivariate analyses of climate, soil, and population showed that temperature most significantly (P < 0.001) explained tree cover changes. Multivariate and bivariate tests and field observations indicated the dominance of temperature and precipitation, supporting attribution of tree cover changes to climate variability. Climate change forcing of Sahel climate variability, particularly the significant (P < 0.05) 1901-2002 temperature increases and precipitation decreases in the research areas, connects Sahel tree cover changes to global climate change. This suggests roles for global action and local adaptation to address ecological change in the Sahel.

  20. Peripheral Hearing Structures in Fishes: Diversity and Sensitivity of Catfishes and Cichlids.

    PubMed

    Ladich, Friedrich

    2016-01-01

    Fishes have evolved an astonishing diversity of peripheral (accessory/ancillary) auditory structures to improve hearing based on their ability to transmit oscillations of gas bladder walls to the inner ears. So far it is unclear to what degree the size of the bladder and the linkage to the ear affect hearing in fishes. An interfamilial study in catfishes revealed that families which possess large, single swim bladders and one to four Weberian ossicles were more sensitive at higher frequencies (≥1 kHz) than families which have small, paired, and encapsulated bladders and one to two ossicles. An intrafamilial investigation in thorny catfishes (family Doradidae) revealed that small differences in bladder morphology did not affect hearing similarly. Members of the cichlid family possess an even larger variation in peripheral auditory structures than catfishes. The linkage between the swim bladder and ear can either be present via anterior extensions of the bladder or be completely absent (in contrast to catfishes). Representatives having large bladders with extensions had the best sensitivities. Cichlids lacking extensions had lower sensitivities above 0.3 kHz. Species with a vestigial swim bladder exhibited a smaller hearing bandwidth than those with larger swim bladder (maximum frequency: 0.7 kHz vs. 3 kHz). Catfishes and cichlids reveal that larger gas bladders and more pronounced connections between the swim bladder and the inner ear result in improved hearing at higher frequencies. The lack of a connection between a large bladder and the inner ear does not necessarily result in a smaller detectable frequency range.

  1. Histochemical localisation of carbonic anhydrase in the inner ear of developing cichlid fish, Oreochromis mossambicus

    NASA Astrophysics Data System (ADS)

    Beier, M.; Hilbig, R.; Anken, R.

    2008-12-01

    Inner ear otolith growth in terms of mineralisation mainly depends on the enzyme carbonic anhydrase (CAH). CAH is located in specialised, mitochondria-rich macular cells (ionocytes), which are involved in the endolymphatic ion exchange, and the enzyme is responsible for the provision of the pH-value necessary for otolithic calcium carbonate deposition. In the present study, for the first time the localisation of histochemically demonstrated CAH was analysed during the early larval development of a teleost, the cichlid fish Oreochromis mossambicus. CAH-reactivity was observed already in stage 7 animals (onset of otocyst development; staging follows Anken et al. [Anken, R., Kappel, T., Slenzka, K., Rahmann, H. The early morphogenetic development of the cichlid fish, Oreochromis mossambicus (Perciformes, Teleostei). Zool. Anz. 231, 1-10, 1993]). Neuroblasts (from which sensory and supporting cells are derived) proved to be CAH-positive. Already at stage 12 (hatch), CAH-positive regions could be attributed to ionocyte containing regions both in the so-called meshwork and patches area of the macula (i.e., clearly before ionocytes can be identified on ultrastructural level or by employing immunocytochemistry). In contrast to the circumstances observed in mammalian species, sensory hair cells stained negative for CAH in the cichlid. With the onset of stage 16 (finray primordia in dorsal fin, yolk-sac being increasingly absorbed), CAH-reactivity was observed in the vestibular nerve. This indicates the onset of myelinisation and thus commencement of operation. The localisation of CAH in the inner ear of fish (especially the differences in comparison to mammals) is discussed on the basis of its role in otolith calcification. Since the vestibular system is a detector of acceleration and thus gravity, also aspects regarding effects of altered gravity on CAH and hence on the mineralisation of otoliths in an adaptive process are addressed.

  2. Ecomorphology of the African felid ensemble: the role of the skull and postcranium in determining species segregation and assembling history.

    PubMed

    Morales, M M; Giannini, N P

    2013-05-01

    Morphology of extant felids is regarded as highly conservative. Most previous studies have focussed on skull morphology, so a vacuum exists about morphofunctional variation in postcranium and its role in structuring ensembles of felids in different continents. The African felid ensemble is particularly rich in ecologically specialized felids. We studied the ecomorphology of this ensemble using 31 cranial and 93 postcranial morphometric variables measured in 49 specimens of all 10 African species. We took a multivariate approach controlling for phylogeny, with and without body size correction. Postcranial and skull + postcranial analyses (but not skull-only analyses) allowed for a complete segregation of species in morphospace. Morphofunctional factors segregating species included body size, bite force, zeugopodial lengths and osteological features related to parasagittal leg movement. A general gradient of bodily proportions was recovered: lightly built, long-legged felids with small heads and weak bite forces vs. the opposite. Three loose groups were recognized: small terrestrial felids, mid-to-large sized scansorial felids and specialized Acinonyx jubatus and Leptailurus serval. As predicted from a previous study, the assembling of the African felid ensemble during the Plio-Pleistocene occurred by the arrival of distinct felid lineages that occupied then vacant areas of morphospace, later diversifying in the continent.

  3. Taxonomy of Atlantic Central African orchids 5. A new species of Angraecum sect. Conchoglossum (Orchidaceae, Angraecinae) from Gabon and Cameroon

    PubMed Central

    Ječmenica, Vladimir; Droissart, Vincent; Noret, Nausicaa; Stévart, Tariq

    2016-01-01

    Abstract Recent field inventories and taxonomic research in Central Africa have resulted in the discovery of many new orchid species. Five specimens of an apparently new Angraecum species were collected in Gabon and Cameroon. They stand out for their hanging habit and short zig-zag stem. Morphology of leaves and habit is somewhat comparable to Angraecum cultriforme and Angraecum stolzii, two species from East Africa. Flowers of the novelty share the general morphology of Angraecum pyriforme from which the new species is distinguished by being smaller and with a different lip-spur ratio. Here we show that these five specimens represent a new species, described here as Angraecum lanceolatum. The distinguishing traits include thin lanceolate leaves, convolute distally, with a rhombic lip shape. Dichotomous key to four Central African species of sect. Conchoglossum and a table of the diagnostic characters of the seven related Continental African Angraecum taxa are included here. A preliminary assessment of the conservation status of Angraecum lanceolatum is provided, using the IUCN Red List Categories and Criteria. PMID:27081350

  4. Taxonomy of Atlantic Central African orchids 5. A new species of Angraecum sect. Conchoglossum (Orchidaceae, Angraecinae) from Gabon and Cameroon.

    PubMed

    Ječmenica, Vladimir; Droissart, Vincent; Noret, Nausicaa; Stévart, Tariq

    2016-01-01

    Recent field inventories and taxonomic research in Central Africa have resulted in the discovery of many new orchid species. Five specimens of an apparently new Angraecum species were collected in Gabon and Cameroon. They stand out for their hanging habit and short zig-zag stem. Morphology of leaves and habit is somewhat comparable to Angraecum cultriforme and Angraecum stolzii, two species from East Africa. Flowers of the novelty share the general morphology of Angraecum pyriforme from which the new species is distinguished by being smaller and with a different lip-spur ratio. Here we show that these five specimens represent a new species, described here as Angraecum lanceolatum. The distinguishing traits include thin lanceolate leaves, convolute distally, with a rhombic lip shape. Dichotomous key to four Central African species of sect. Conchoglossum and a table of the diagnostic characters of the seven related Continental African Angraecum taxa are included here. A preliminary assessment of the conservation status of Angraecum lanceolatum is provided, using the IUCN Red List Categories and Criteria.

  5. Similar morphologies of cichlid fish in Lakes Tanganyika and Malawi are due to convergence.

    PubMed

    Kocher, T D; Conroy, J A; McKaye, K R; Stauffer, J R

    1993-06-01

    The species flocks of cichlid fishes in the lakes of East Africa are the most spectacular example of adaptive radiation among living vertebrates. Similar highly derived morphologies are found among species in different lakes. These similarities have been variously interpreted either as evidence for migration of ancestral species between the lakes, or of striking convergence of morphology. To distinguish among these competing hypotheses we sequenced a portion of the mitochondrial DNA control region from six pairs of morphologically similar taxa from Lakes Malawi and Tanganyika. Our results clearly indicate a separate origin of these morphologies in the two lakes. They also suggest that the Tanganyikan radiation is relatively old, and that the species flocks in lakes Malawi and Victoria are derived from one of the ancient lineages found in Lake Tanganyika. These findings have important implications for understanding the pattern of morphological and behavioral evolution in these fish.

  6. Hedgehog signaling mediates adaptive variation in a dynamic functional system in the cichlid feeding apparatus

    PubMed Central

    Hu, Yinan; Albertson, R. Craig

    2014-01-01

    Adaptive variation in the craniofacial skeleton is a key component of resource specialization and habitat divergence in vertebrates, but the proximate genetic mechanisms that underlie complex patterns of craniofacial variation are largely unknown. Here we demonstrate that the Hedgehog (Hh) signaling pathway mediates widespread variation across a complex functional system that affects the kinematics of lower jaw depression—the opercular four-bar linkage apparatus—among Lake Malawi cichlids. By using a combined quantitative trait locus mapping and population genetics approach, we show that allelic variation in the Hh receptor, ptch1, affects the development of distinct bony elements in the head that represent two of three movable links in this functional system. The evolutionarily derived allele is found in species that feed from the water column, and is associated with shifts in anatomy that translate to a four-bar system capable of faster jaw rotation. Alternatively, the ancestral allele is found in species that feed on attached algae, and is associated with the development of a four-bar system that predicts slower jaw movement. Experimental manipulation of the Hh pathway during cichlid development recapitulates functionally salient natural variation in craniofacial geometry. In all, these results significantly extend our understanding of the mechanisms that fine-tune the craniofacial skeletal complex during adaptation to new foraging niches. PMID:24912175

  7. Hedgehog signaling mediates adaptive variation in a dynamic functional system in the cichlid feeding apparatus.

    PubMed

    Hu, Yinan; Albertson, R Craig

    2014-06-10

    Adaptive variation in the craniofacial skeleton is a key component of resource specialization and habitat divergence in vertebrates, but the proximate genetic mechanisms that underlie complex patterns of craniofacial variation are largely unknown. Here we demonstrate that the Hedgehog (Hh) signaling pathway mediates widespread variation across a complex functional system that affects the kinematics of lower jaw depression--the opercular four-bar linkage apparatus--among Lake Malawi cichlids. By using a combined quantitative trait locus mapping and population genetics approach, we show that allelic variation in the Hh receptor, ptch1, affects the development of distinct bony elements in the head that represent two of three movable links in this functional system. The evolutionarily derived allele is found in species that feed from the water column, and is associated with shifts in anatomy that translate to a four-bar system capable of faster jaw rotation. Alternatively, the ancestral allele is found in species that feed on attached algae, and is associated with the development of a four-bar system that predicts slower jaw movement. Experimental manipulation of the Hh pathway during cichlid development recapitulates functionally salient natural variation in craniofacial geometry. In all, these results significantly extend our understanding of the mechanisms that fine-tune the craniofacial skeletal complex during adaptation to new foraging niches.

  8. Pleistocene desiccation in East Africa bottlenecked but did not extirpate the adaptive radiation of Lake Victoria haplochromine cichlid fishes.

    PubMed

    Elmer, Kathryn R; Reggio, Chiara; Wirth, Thierry; Verheyen, Erik; Salzburger, Walter; Meyer, Axel

    2009-08-11

    The Great Lakes region of East Africa, including Lake Victoria, is the center of diversity of the mega-diverse cichlid fishes (Perciformes: Teleostei). Paleolimnological evidence indicates dramatic desiccation of this lake ca. 18,000-15,000 years ago. Consequently, the hundreds of extant endemic haplochromine species in the lake must have either evolved since then or refugia must have existed, within that lake basin or elsewhere, from which Lake Victoria was recolonized. We studied the population history of the Lake Victoria region superflock (LVRS) of haplochromine cichlids based on nuclear genetic analysis (12 microsatellite loci from 400 haplochomines) of populations from Lake Kivu, Lake Victoria, and the connected and surrounding rivers and lakes. Population genetic analyses confirmed that Lake Kivu haplochromines colonized Lake Victoria. Coalescent analyses show a 30- to 50-fold decline in the haplochromine populations of Lake Victoria, Lake Kivu, and the region ca. 18,000-15,000 years ago. We suggest that this coincides with drastic climatic and geological changes in the late Pleistocene. The most recent common ancestor of the Lake Victoria region haplochromines was estimated to have existed about 4.5 million years ago, which corresponds to the first radiation of cichlids in Lake Tanganyika and the origin of the tribe Haplochrominii. This relatively old evolutionary origin may explain the high levels of polymorphism still found in modern haplochromines. This degree of polymorphism might have acted as a "genetic reservoir" that permitted the explosive radiation of hundreds of haplochromines and their array of contemporary adaptive morphologies.

  9. Adaptive landscape and functional diversity of Neotropical cichlids: implications for the ecology and evolution of Cichlinae (Cichlidae; Cichliformes).

    PubMed

    Arbour, J H; López-Fernández, H

    2014-11-01

    Morphological, lineage and ecological diversity can vary substantially even among closely related lineages. Factors that influence morphological diversification, especially in functionally relevant traits, can help to explain the modern distribution of disparity across phylogenies and communities. Multivariate axes of feeding functional morphology from 75 species of Neotropical cichlid and a stepwise-AIC algorithm were used to estimate the adaptive landscape of functional morphospace in Cichlinae. Adaptive landscape complexity and convergence, as well as the functional diversity of Cichlinae, were compared with expectations under null evolutionary models. Neotropical cichlid feeding function varied primarily between traits associated with ram feeding vs. suction feeding/biting and secondarily with oral jaw muscle size and pharyngeal crushing capacity. The number of changes in selective regimes and the amount of convergence between lineages was higher than expected under a null model of evolution, but convergence was not higher than expected under a similarly complex adaptive landscape. Functional disparity was compatible with an adaptive landscape model, whereas the distribution of evolutionary change through morphospace corresponded with a process of evolution towards a single adaptive peak. The continentally distributed Neotropical cichlids have evolved relatively rapidly towards a number of adaptive peaks in functional trait space. Selection in Cichlinae functional morphospace is more complex than expected under null evolutionary models. The complexity of selective constraints in feeding morphology has likely been a significant contributor to the diversity of feeding ecology in this clade.

  10. Paralyzing action from a distance in an arboreal African ant species.

    PubMed

    Rifflet, Aline; Tene, Nathan; Orivel, Jerome; Treilhou, Michel; Dejean, Alain; Vetillard, Angelique

    2011-01-01

    Due to their prowess in interspecific competition and ability to catch a wide range of arthropod prey (mostly termites with which they are engaged in an evolutionary arms race), ants are recognized as a good model for studying the chemicals involved in defensive and predatory behaviors. Ants' wide diversity of nesting habits and relationships with plants and prey types implies that these chemicals are also very diverse. Using the African myrmicine ant Crematogaster striatula as our focal species, we adopted a three-pronged research approach. We studied the aggressive and predatory behaviors of the ant workers, conducted bioassays on the effect of their Dufour gland contents on termites, and analyzed these contents. (1) The workers defend themselves or eliminate termites by orienting their abdominal tip toward the opponent, stinger protruded. The chemicals emitted, apparently volatile, trigger the recruitment of nestmates situated in the vicinity and act without the stinger having to come into direct contact with the opponent. Whereas alien ants competing with C. striatula for sugary food sources are repelled by this behavior and retreat further and further away, termites defend their nest whatever the danger. They face down C. striatula workers and end up by rolling onto their backs, their legs batting the air. (2) The bioassays showed that the toxicity of the Dufour gland contents acts in a time-dependent manner, leading to the irreversible paralysis, and, ultimately, death of the termites. (3) Gas chromatography-mass spectrometry analyses showed that the Dufour gland contains a mixture of mono- or polyunsaturated long-chain derivatives, bearing functional groups like oxo-alcohols or oxo-acetates. Electrospray ionization-mass spectrometry showed the presence of a molecule of 1584 Da that might be a large, acetylated alkaloid capable of splitting into smaller molecules that could be responsible for the final degree of venom toxicity.

  11. Discovery of the invasive Mayan Cichlid fish "Cichlasoma" urophthalmus (Günther 1862) in Thailand, with comments on other introductions and potential impacts

    USGS Publications Warehouse

    Nico, Leo G.; Beamish, William H.; Musikasinthorn, Prachya

    2007-01-01

    We report on the occurrence and possible establishment of a non-native cichlid fish in a brackish-water system in the lower Chao Phraya River delta region, Thailand. Although, the possibility of some degree of introgressive hybridization can not be ruled out, Thailand specimens agree best with Mayan Cichlid “Cichlasoma” urophthalmus (Günther 1862). Our collections represent the first records of this New World, highly-invasive, euryhaline fish from Thailand and coincides with recent collections from Singapore. Positive identification of specimens as “C.” urophthalmus requires caution due to the diversity of the Cichlidae (>1,300 species), widespread introduction of many family members, variation within species, extensive interspecific overlap in characters, and proliferation of artificial cichlid hybrids (e.g., Flowerhorns). We first became aware of the Thailand population in 2005 when “C.” urophthalmus began appearing in the catches of local fishermen. We visited the site in November 2006 and obtained and examined voucher specimens. The abundance and wide size range of juveniles and adults in local ponds and an adjacent canal is evidence of natural reproduction. Because water bodies throughout the Chao Phraya delta are interconnected and subject to flooding, it is likely that “C.” urophthalmus is already established and is dispersing, but surveys and monitoring are needed to determine their exact geographic range. The Thailand population is compared to “C.” urophthalmus introduced into Florida (USA). Based on what is known about Florida “C.” urophthalmus, it is predicted that this cichlid will further invade coastal and inland waters in Thailand and elsewhere in Southeast Asia. This cichlid has a long history in the aquarium trade in Europe. However, there are no records from the wild in European waters and, because of the colder climate, the possibility of establishment in that region is relatively low.

  12. Odor discrimination in classical conditioning of proboscis extension in two stingless bee species in comparison to Africanized honeybees.

    PubMed

    Mc Cabe, S I; Hartfelder, K; Santana, W C; Farina, W M

    2007-11-01

    Learning in insects has been extensively studied using different experimental approaches. One of them, the proboscis extension response (PER) paradigm, is particularly well suited for quantitative studies of cognitive abilities of honeybees under controlled conditions. The goal of this study was to analyze the capability of three eusocial bee species to be olfactory conditioned in the PER paradigm. We worked with two Brazilian stingless bees species, Melipona quadrifasciata and Scaptotrigona aff. depilis, and with the invasive Africanized honeybee, Apis mellifera. These three species present very different recruitment strategies, which could be related with different odor-learning abilities. We evaluated their gustatory responsiveness and learning capability to discriminate floral odors. Gustatory responsiveness was similar for the three species, although S. aff. depilis workers showed fluctuations along the experimental period. Results for the learning assays revealed that M. quadrifasciata workers can be conditioned to discriminate floral odors in a classical differential conditioning protocol and that this discrimination is maintained 15 min after training. During conditioning, Africanized honeybees presented the highest discrimination, for M. quadrifasciata it was intermediate, and S. aff. depilis bees presented no discrimination. The differences found are discussed considering the putative different learning abilities and procedure effect for each species.

  13. Divergence between C. melo and African Cucumis Species Identified by Chromosome Painting and rDNA Distribution Pattern.

    PubMed

    Li, Kunpeng; Wang, Huaisong; Wang, Jiming; Sun, Jianying; Li, Zongyun; Han, Yonghua

    2016-01-01

    The 5S and 45S rDNA sites are useful chromosome landmarks and can provide valuable information about karyotype evolution and species interrelationships. In this study, we employed fluorescence in situ hybridization (FISH) to determine the number and chromosomal location of 5S and 45S rDNA loci in 8 diploid Cucumis species. Two oligonucleotide painting probes specific for the rDNA-bearing chromosomes in C. melo were hybridized to other Cucumis species in order to investigate the homeologies among the rDNA-carrying chromosomes in Cucumis species. The analyzed diploid species showed 3 types of rDNA distribution patterns, which provided clear cytogenetic evidence on the divergence between C. melo and wild diploid African Cucumis species. The present results not only show species interrelationships in the genus Cucumis, but the rDNA FISH patterns can also be used as cytological markers for the discrimination of closely related species. The data will be helpful for breeders to choose the most suitable species from various wild species for improvement of cultivated melon.

  14. Crater lake cichlids individually specialize along the benthic–limnetic axis

    PubMed Central

    Kusche, Henrik; Recknagel, Hans; Elmer, Kathryn Rebecca; Meyer, Axel

    2014-01-01

    A common pattern of adaptive diversification in freshwater fishes is the repeated evolution of elongated open water (limnetic) species and high-bodied shore (benthic) species from generalist ancestors. Studies on phenotype-diet correlations have suggested that population-wide individual specialization occurs at an early evolutionary and ecological stage of divergence and niche partitioning. This variable restricted niche use across individuals can provide the raw material for earliest stages of sympatric divergence. We investigated variation in morphology and diet as well as their correlations along the benthic-limnetic axis in an extremely young Midas cichlid species, Amphilophus tolteca, endemic to the Nicaraguan crater lake Asososca Managua. We found that A. tolteca varied continuously in ecologically relevant traits such as body shape and lower pharyngeal jaw morphology. The correlation of these phenotypes with niche suggested that individuals are specialized along the benthic-limnetic axis. No genetic differentiation within the crater lake was detected based on genotypes from 13 microsatellite loci. Overall, we found that individual specialization in this young crater lake species encompasses the limnetic-as well as the benthic macro-habitat. Yet there is no evidence for any diversification within the species, making this a candidate system for studying what might be the early stages preceding sympatric divergence. A common pattern of adaptive diversification in freshwater fishes is the repeated evolution of open water (limnetic) species and of shore (benthic) species. Individual specialization can reflect earliest stages of evolutionary and ecological divergence. We here demonstrate individual specialization along the benthic–limnetic axis in a young adaptive radiation of crater lake cichlid fishes. PMID:24772288

  15. Genetic linkage of distinct adaptive traits in sympatrically speciating crater lake cichlid fish

    PubMed Central

    Fruciano, Carmelo; Franchini, Paolo; Kovacova, Viera; Elmer, Kathryn R.; Henning, Frederico; Meyer, Axel

    2016-01-01

    Our understanding of how biological diversity arises is limited, especially in the case of speciation in the face of gene flow. Here we investigate the genomic basis of adaptive traits, focusing on a sympatrically diverging species pair of crater lake cichlid fishes. We identify the main quantitative trait loci (QTL) for two eco-morphological traits: body shape and pharyngeal jaw morphology. These traits diverge in parallel between benthic and limnetic species in the repeated adaptive radiations of this and other fish lineages. Remarkably, a single chromosomal region contains the highest effect size QTL for both traits. Transcriptomic data show that the QTL regions contain genes putatively under selection. Independent population genomic data corroborate QTL regions as areas of high differentiation between the sympatric sister species. Our results provide empirical support for current theoretical models that emphasize the importance of genetic linkage and pleiotropy in facilitating rapid divergence in sympatry. PMID:27597183

  16. Drivers of extinction risk in African mammals: the interplay of distribution state, human pressure, conservation response and species biology

    PubMed Central

    Di Marco, Moreno; Buchanan, Graeme M.; Szantoi, Zoltan; Holmgren, Milena; Grottolo Marasini, Gabriele; Gross, Dorit; Tranquilli, Sandra; Boitani, Luigi; Rondinini, Carlo

    2014-01-01

    Although conservation intervention has reversed the decline of some species, our success is outweighed by a much larger number of species moving towards extinction. Extinction risk modelling can identify correlates of risk and species not yet recognized to be threatened. Here, we use machine learning models to identify correlates of extinction risk in African terrestrial mammals using a set of variables belonging to four classes: species distribution state, human pressures, conservation response and species biology. We derived information on distribution state and human pressure from satellite-borne imagery. Variables in all four classes were identified as important predictors of extinction risk, and interactions were observed among variables in different classes (e.g. level of protection, human threats, species distribution ranges). Species biology had a key role in mediating the effect of external variables. The model was 90% accurate in classifying extinction risk status of species, but in a few cases the observed and modelled extinction risk mismatched. Species in this condition might suffer from an incorrect classification of extinction risk (hence require reassessment). An increased availability of satellite imagery combined with improved resolution and classification accuracy of the resulting maps will play a progressively greater role in conservation monitoring. PMID:24733953

  17. Quantitative analysis of neocortical gyrencephaly in African elephants (Loxodonta africana) and six species of cetaceans: comparison with other mammals.

    PubMed

    Manger, Paul R; Prowse, Michelle; Haagensen, Mark; Hemingway, Jason

    2012-08-01

    This study provides quantitative data on the extent of gyrencephaly in the large-brained African elephant and several species of cetaceans (from smaller to larger brained) in comparison with other mammals. Across three mammalian orders (primates, carnivores, and artiodactyls), the species with the larger brains are more gyrencephalic with each order, exhibiting a specific negative allometry. The African elephant, with a 5-kg brain, has a gyrencephalic index (GI) of 3.89, which, though highly gyrencephalic, is not more so than would be predicted for a mammal with a 5-kg brain. The cetaceans had an average GI of 5.43, are the most gyrencephalic mammals studied to date, and are more gyrencephalic than one would predict based on comparison with other mammals. No relationship between brain mass and GI was evident in the cetaceans as seen in other mammals, with all cetaceans showing similar GIs irrespective of brain mass (range of GI 5.23-5.70, range of brain mass 577-5617 g). This is yet another parameter indicating cetaceans to be neuroanatomical outliers. Two species of pinnipeds studied had GIs that were well above those seen for terrestrial carnivores, and the aquatic manatee was close to lissencephalic. Thus, all three groups of marine mammals showed unusual extents of cortical gyrencephaly, indicating a morphological alteration of the telencephalon associated with the return to the marine environment. The analysis suggests that cortical thickness and neuronal density are important factors in determining the extent of gyrencephaly across mammalian species.

  18. The Utility of Geometric Morphometrics to Elucidate Pathways of Cichlid Fish Evolution

    PubMed Central

    Kerschbaumer, Michaela; Sturmbauer, Christian

    2011-01-01

    Fishes of the family Cichlidae are famous for their spectacular species flocks and therefore constitute a model system for the study of the pathways of adaptive radiation. Their radiation is connected to trophic specialization, manifested in dentition, head morphology, and body shape. Geometric morphometric methods have been established as efficient tools to quantify such differences in overall body shape or in particular morphological structures and meanwhile found wide application in evolutionary biology. As a common feature, these approaches define and analyze coordinates of anatomical landmarks, rather than traditional counts or measurements. Geometric morphometric methods have several merits compared to traditional morphometrics, particularly for the distinction and analysis of closely related entities. Cichlid evolutionary research benefits from the efficiency of data acquisition, the manifold opportunities of analyses, and the potential to visualize shape changes of those landmark-based methods. This paper briefly introduces to the concepts and methods of geometric morphometrics and presents a selection of publications where those techniques have been successfully applied to various aspects of cichlid fish diversification. PMID:21716723

  19. Male mate preference and size-assortative mating in convict cichlids: A role for female aggression?

    PubMed

    Bloch, A N; Estela, V J; Leese, J M; Itzkowitz, M

    2016-09-01

    Many monogamous species demonstrate size-assortative mating patterns within natural populations. To better understand the role of intersexual selection in this process, we examined the effect of male preference for female body size in the convict cichlid (Amatitlania siquia). We provided males with a choice between females that differed in size, relative to each other and in relation to the focal male. Based on previous work, we expected males to prefer the largest available female mates across all treatments. Surprisingly, males spent more time near the smaller of two available females, but only when the other female was larger than the male. Additionally, males spent little time with either of two potential female mates when both females were larger than the male. We hypothesized that while males might prefer the largest of available females, female behavior might limit males from acting on this preference. To test this, males were force paired with a smaller or larger female. Pair formation only occurred when the female was smaller than the male, and females that were larger than their male counterparts showed significantly more aggression when compared to smaller females. Together, these data suggest that in the absence of intrasexual competition, male mate preference for large females in convict cichlids might be limited by female aggression.

  20. The evolution of cichlid fish egg-spots is linked with a cis-regulatory change.

    PubMed

    Santos, M Emília; Braasch, Ingo; Boileau, Nicolas; Meyer, Britta S; Sauteur, Loïc; Böhne, Astrid; Belting, Heinz-Georg; Affolter, Markus; Salzburger, Walter

    2014-10-09

    The origin of novel phenotypic characters is a key component in organismal diversification; yet, the mechanisms underlying the emergence of such evolutionary novelties are largely unknown. Here we examine the origin of egg-spots, an evolutionary innovation of the most species-rich group of cichlids, the haplochromines, where these conspicuous male fin colour markings are involved in mating. Applying a combination of RNAseq, comparative genomics and functional experiments, we identify two novel pigmentation genes, fhl2a and fhl2b, and show that especially the more rapidly evolving b-paralog is associated with egg-spot formation. We further find that egg-spot bearing haplochromines, but not other cichlids, feature a transposable element in the cis-regulatory region of fhl2b. Using transgenic zebrafish, we finally demonstrate that this region shows specific enhancer activities in iridophores, a type of pigment cells found in egg-spots, suggesting that a cis-regulatory change is causally linked to the gain of expression in egg-spot bearing haplochromines.

  1. Lateralized Kinematics of Predation Behavior in a Lake Tanganyika Scale-Eating Cichlid Fish

    PubMed Central

    Takeuchi, Yuichi; Hori, Michio; Oda, Yoichi

    2012-01-01

    Behavioral lateralization has been documented in many vertebrates. The scale-eating cichlid fish Perissodus microlepis is well known for exhibiting lateral dimorphism in its mouth morphology and lateralized behavior in robbing scales from prey fish. A previous field study indicated that this mouth asymmetry closely correlates with the side on which prey is attacked, but details of this species' predation behavior have not been previously analyzed because of the rapidity of the movements. Here, we studied scale-eating behavior in cichlids in a tank through high-speed video monitoring and quantitative assessment of behavioral laterality and kinematics. The fish observed showed a clear bias toward striking on one side, which closely correlated with their asymmetric mouth morphologies. Furthermore, the maximum angular velocity and amplitude of body flexion were significantly larger during attacks on the preferred side compared to those on the nonpreferred side, permitting increased predation success. In contrast, no such lateral difference in movement elements was observed in acoustically evoked flexion during the escape response, which is similar to flexion during scale eating and suggests that they share a common motor control pathway. Thus the neuronal circuits controlling body flexion during scale eating may be functionally lateralized upstream of this common motor pathway. PMID:22238598

  2. The comparative anatomy of the abdominal gastrointestinal tract of six species of African mole-rats (Rodentia, Bathyergidae).

    PubMed

    Kotzé, Sanet H; Van Der Merwe, Elizabeth L; Bennett, Nigel C; O'Riain, M Justin

    2010-01-01

    The gastrointestinal tracts (GITs) of six species of African mole-rats (Bathyergidae) were compared. The aim was to provide a comprehensive anatomical comparison between the different species. The relative shape, length, and surface areas were taken into account to determine whether the GITs are phylogenetically constrained or exhibit anatomical adaptations in response to diets. In all six species the stomach was simple and glandular. With the exception of Heterocephalus glaber, the caecum was coiled in a flat spiral, the ascending colon was arranged in a loop of varying lengths, and a mucosal colonic papillary-lined groove was present in the ascending colon in all species. By contrast, the caecum in H. glaber was uncoiled, the ascending colon was not looped, and the groove was not papillated. A caeco-appendix was observed only in Bathyergus suillus and Georychus capensis. Hierarchical multivariate cluster analysis on the presence/absence of nine anatomical structures associated with the GIT of mole-rats revealed that H. glaber was anatomically the least similar of the six species (77.6% similarity) with respect to the nine GIT variables included. All Cryptomys species were the same (100% similarity), and two species B. suillus and G. capensis grouped together and were more similar to the Cryptomys genus (95% similarity) than they were to H. glaber. These findings support previous phylogenetic classifications. The voluminous caeco-colon in B. suillus may be explained by its ingestion of grasses in addition to below-ground storage organs of plants. We conclude that phylogeny and diet affect the GIT anatomy of the African mole rats studied here.

  3. Multispecies Outcomes of Sympatric Speciation after Admixture with the Source Population in Two Radiations of Nicaraguan Crater Lake Cichlids.

    PubMed

    Kautt, Andreas F; Machado-Schiaffino, Gonzalo; Meyer, Axel

    2016-06-01

    The formation of species in the absence of geographic barriers (i.e. sympatric speciation) remains one of the most controversial topics in evolutionary biology. While theoretical models have shown that this most extreme case of primary divergence-with-gene-flow is possible, only a handful of accepted empirical examples exist. And even for the most convincing examples uncertainties remain; complex histories of isolation and secondary contact can make species falsely appear to have originated by sympatric speciation. This alternative scenario is notoriously difficult to rule out. Midas cichlids inhabiting small and remote crater lakes in Nicaragua are traditionally considered to be one of the best examples of sympatric speciation and lend themselves to test the different evolutionary scenarios that could lead to apparent sympatric speciation since the system is relatively small and the source populations known. Here we reconstruct the evolutionary history of two small-scale radiations of Midas cichlids inhabiting crater lakes Apoyo and Xiloá through a comprehensive genomic data set. We find no signs of differential admixture of any of the sympatric species in the respective radiations. Together with coalescent simulations of different demographic models our results support a scenario of speciation that was initiated in sympatry and does not result from secondary contact of already partly diverged populations. Furthermore, several species seem to have diverged simultaneously, making Midas cichlids an empirical example of multispecies outcomes of sympatric speciation. Importantly, however, the demographic models strongly support an admixture event from the source population into both crater lakes shortly before the onset of the radiations within the lakes. This opens the possibility that the formation of reproductive barriers involved in sympatric speciation was facilitated by genetic variants that evolved in a period of isolation between the initial founding

  4. Multispecies Outcomes of Sympatric Speciation after Admixture with the Source Population in Two Radiations of Nicaraguan Crater Lake Cichlids

    PubMed Central

    Kautt, Andreas F.; Machado-Schiaffino, Gonzalo; Meyer, Axel

    2016-01-01

    The formation of species in the absence of geographic barriers (i.e. sympatric speciation) remains one of the most controversial topics in evolutionary biology. While theoretical models have shown that this most extreme case of primary divergence-with-gene-flow is possible, only a handful of accepted empirical examples exist. And even for the most convincing examples uncertainties remain; complex histories of isolation and secondary contact can make species falsely appear to have originated by sympatric speciation. This alternative scenario is notoriously difficult to rule out. Midas cichlids inhabiting small and remote crater lakes in Nicaragua are traditionally considered to be one of the best examples of sympatric speciation and lend themselves to test the different evolutionary scenarios that could lead to apparent sympatric speciation since the system is relatively small and the source populations known. Here we reconstruct the evolutionary history of two small-scale radiations of Midas cichlids inhabiting crater lakes Apoyo and Xiloá through a comprehensive genomic data set. We find no signs of differential admixture of any of the sympatric species in the respective radiations. Together with coalescent simulations of different demographic models our results support a scenario of speciation that was initiated in sympatry and does not result from secondary contact of already partly diverged populations. Furthermore, several species seem to have diverged simultaneously, making Midas cichlids an empirical example of multispecies outcomes of sympatric speciation. Importantly, however, the demographic models strongly support an admixture event from the source population into both crater lakes shortly before the onset of the radiations within the lakes. This opens the possibility that the formation of reproductive barriers involved in sympatric speciation was facilitated by genetic variants that evolved in a period of isolation between the initial founding

  5. Demography of woody species in a semi-arid African savanna reserve following the re-introduction of elephants

    NASA Astrophysics Data System (ADS)

    O'Connor, Timothy G.

    2017-01-01

    The hypothesis that African elephants may cause the local extirpation of selected woody species was evaluated in a medium-sized, semi-arid reserve following their reintroduction at low density. Mortality, state-change, and regeneration of 25 tree and 17 shrub species were studied between 1997 and 2010. Annual mortality of shrub species ranged from 0.2 to 8.0%, with six species experiencing 6-8%. Eight shrub species lost more than half their adult population (range 10-94%). Annual tree mortality ranged from 0.2 to 10.5%. The two dominant dryland tree species experienced <1% annual mortality, 18 species lost more than half their tree population, and one was eliminated. Elephants accounted for >63% and stress-related agents >20% of tree deaths. The manner in which elephants induced tree death depended on species. The proportion of individuals of a species killed by pollarding or uprooting ranged from 0 to 74%, and by debarking from 0 to 100%. Complete uprooting was a common cause of death for three shrub species. Regeneration ranged from zero for six tree and one shrub species to a seedling every 7 m2 for Colophospermum mopane and 23 m2 for Dichrostachys cinerea in riparian habitat. Three shrub and eight tree species were identified as vulnerable to local extirpation owing to a combination of high mortality and poor regeneration that is likely to result in a considerably simplified system. Reintroduction of elephants into medium-sized reserves without regulation of their numbers may not be a desirable action.

  6. Contrasting patterns of gene flow between sister plant species in the understorey of African moist forests - the case of sympatric and parapatric Marantaceae species.

    PubMed

    Ley, A C; Hardy, O J

    2014-08-01

    Gene flow within and between species is a fundamental process shaping the evolutionary history of taxa. However, the extent of hybridization and reinforcement is little documented in the tropics. Here we explore the pattern of gene flow between three sister species from the herbaceous genus Marantochloa (Marantaceae), sympatrically distributed in the understorey of the African rainforest, using data from the chloroplast and nuclear genomes (DNA sequences and AFLP). We found highly contrasting patterns: while there was no evidence of gene flow between M. congensis and M. monophylla, species identity between M. monophylla and M. incertifolia was maintained despite considerable gene flow. We hypothesize that M. incertifolia originated from an ancient hybridization event between M. congensis and M. monophylla, considering the current absence of hybridization between the two assumed parent species, the rare presence of shared haplotypes between all three species and the high percentage of haplotypes shared by M. incertifolia with each of the two parent species. This example is contrasted with two parapatrically distributed species from the same family in the genus Haumania forming a hybrid zone restricted to the area of overlap. This work illustrates the diversity of speciation/introgression patterns that can potentially occur in the flora of tropical Africa.

  7. An overview of the Gyrodactylus (Monogenea: Gyrodactylidae) species parasitizing African catfishes, and their morphological and molecular diversity.

    PubMed

    Přikrylová, Iva; Blažek, Radim; Vanhove, Maarten P M

    2012-03-01

    An overview of Gyrodactylus infecting catfishes from the African continent is provided, including new data from Sudan, Senegal, Kenya and Mozambique. Haptoral sclerite morphometry and nuclear ribosomal DNA sequences revealed the presence of eight Gyrodactylus species. On Senegalese Synodontis nigrita, Gyrodactylus synodonti n. sp. and Gyrodactylus nigritae n. sp. are described. These are the first reports of gyrodactylid parasites from mochokid hosts. From the fins of North African catfish Clarias gariepinus collected in Mozambique, Gyrodactylus alekosi n. sp. and Gyrodactylus rysavyi were identified. G. rysavyi was also reported from Kenyan C. gariepinus and Senegalese Clarias anguillaris. From the fins of C. anguillaris studied in Senegal, two more species, Gyrodactylus transvaalensis and Gyrodactylus gelnari n. sp. were recognised. In addition, Gyrodactylus turkanaensis n. sp. from the gills of Kenyan C. gariepinus was described and an undescribed Gyrodactylus sp. was recorded from Sudanese representatives of the same host. Detailed morphometrical and molecular comparisons of the species are presented and discussed. The study highlights the hitherto understudied diversity of viviparous monogenean parasites throughout Africa.

  8. Pharmacokinetics of Amitriptyline HCl and Its Metabolites in Healthy African Grey Parrots ( Psittacus erithacus ) and Cockatoos (Cacatua Species).

    PubMed

    Visser, Marike; Ragsdale, Michelle M; Boothe, Dawn M

    2015-12-01

    Amitriptyline, a tricyclic antidepressant, is used clinically to treat feather-destructive behavior in psittacine birds at a recommended dosage of 1-5 mg/kg PO q12-24h, which has been extrapolated from human medicine and based on anecdotal reports. The purpose of this pilot study was to describe the individual and population pharmacokinetic parameters of amitriptyline after a single oral dose at 1.5 mg/kg, 4.5 mg/kg, and 9 mg/kg in healthy African grey parrots ( Psittacus erithacus , n = 3) and cockatoos (Cacatua species, n = 3). Three birds received an initial 1.5 mg/kg oral dose, and blood samples were collected for 24 hours at fixed time intervals. Serum concentrations of amitriptyline and its metabolites were determined by polarized immunofluorescence. After determining the initial parameters and a 14-day washout period, 2 African grey parrots and 1 cockatoo received a single oral dose at 4.5 mg/kg, and 3 cockatoos and 1 African grey parrot received a single oral dose at 9 mg/kg. Concentrations reached the minimum therapeutic range reported in people (60 ng/mL) in 4 of 10 birds (4.5 and 9.0 mg/kg). Concentrations were within the toxic range in 1 African grey parrot (9 mg/kg), with regurgitation, ataxia, and dullness noted. Serum concentrations were nondetectable in 3 birds (1.5 and 4.5 mg/kg) and detectable but below the human therapeutic range in 3 birds (1.5 mg/kg and 9 mg/kg). Drug concentrations were continuing to increase at the end of the study (24 hours) in 1 bird. Elimination half-life varied from 1.6 to 91.2 hours. Population pharmacokinetics indicated significantly varied absorption, and elimination constants varied between species. Although amitriptyline appeared to be tolerated in most birds, disposition varies markedly among and within species, between the 2 genera, and within individual birds. The current recommended dosage of 1-5 mg/kg q12h in psittacine birds appears insufficient to achieve serum concentrations within the human therapeutic range

  9. Heritability and adaptive significance of the number of egg-dummies in the cichlid fish Astatotilapia burtoni.

    PubMed

    Lehtonen, Topi K; Meyer, Axel

    2011-08-07

    Cichlid fishes are a textbook example of rapid speciation and exuberant diversity--this applies especially to haplochromines, a lineage with approximately 1800 species. Haplochromine males uniquely possess oval, bright spots on their anal fin, called 'egg-spots' or 'egg-dummies'. These are presumed to be an evolutionary key innovation that contributed to the tribe's evolutionary success. Egg-spots have been proposed to mimic the ova of the mouthbrooding females of the corresponding species, contribute to fertilization success and even facilitate species recognition. Interestingly, egg-spot number varies extensively not only between species, but also within some populations. This high degree of intraspecific variation may appear to be counterintuitive since selection might be expected to act to stabilize traits that are correlated with fitness measures. We addressed this 'paradox' experimentally, and found that in the haplochromine cichlid Astatotilapia burtoni, the number of egg-spots was related to male age, body condition and dominance status. Intriguingly, the egg-spot number also had a high heritable component (narrow sense heritability of 0.5). These results suggest that the function of egg-spots might have less to do with fertilization success or species recognition, but rather relate to mate choice and/or male-male competition, helping to explain the high variability in this important trait.

  10. Large Spatial Scale of the Phenotype-Environment Color Matching in Two Cryptic Species of African Desert Jerboas (Dipodidae: Jaculus)

    PubMed Central

    Boratyński, Zbyszek; Brito, José Carlos; Campos, João Carlos; Karala, Maija; Mappes, Tapio

    2014-01-01

    We tested the camouflage hypothesis, or the linkage between animal (Saharan rodent) and habitat coloration, on the largest geographical scale yet conducted. We aimed to determine whether phenotypic variation is explained by micro-habitat variation and/or genetic polymorphism to determine 1) the strength of linkage between fur color and local substrate color, and 2) the divergence in fur coloration between two genetic clades, representing cryptic species, throughout the complete range of the African desert jerboas (Jaculus jaculus). We used a combination of museum and field-collected specimens, remote sensing tools, satellite and digital photography and molecular genetic and phylogenetic methods to investigate the above hypotheses. Along with showing that the two divergent genetic clades of jerboas occur sympatrically throughout their African distribution, we showed significant covariation between dorsal fur coloration of the animals and the color of their habitat. We also described significant phenotypic divergence in fur color, consistent with genetic divergence between the sympatric clades. The linkage between environment and phenotype supports the idea that the selection promoting cryptic coloration is persistent in contemporary populations of jerboas, however the phenotypic divergence indicates that it has different strengths (or optima) in the two clades. The mosaic distribution of micro-habitats occupied by geographically sympatric clades suggests that it may influence both ecological and evolutionary dynamics between these two cryptic species. PMID:24714509

  11. The genome of African yam (Dioscorea cayenensis-rotundata complex) hosts endogenous sequences from four distinct Badnavirus species.

    PubMed

    Umber, Marie; Filloux, Denis; Muller, Emmanuelle; Laboureau, Nathalie; Galzi, Serge; Roumagnac, Philippe; Iskra-Caruana, Marie-Line; Pavis, Claudie; Teycheney, Pierre-Yves; Seal, Susan E

    2014-10-01

    Several endogenous viral elements (EVEs) have been identified in plant genomes, including endogenous pararetroviruses (EPRVs). Here, we report the first characterization of EPRV sequences in the genome of African yam of the Dioscorea cayenensis-rotundata complex. We propose that these sequences should be termed 'endogenous Dioscorea bacilliform viruses' (eDBVs). Molecular characterization of eDBVs shows that they constitute sequences originating from various parts of badnavirus genomes, resulting in a mosaic structure that is typical of most EPRVs characterized to date. Using complementary molecular approaches, we show that eDBVs belong to at least four distinct Badnavirus species, indicating multiple, independent, endogenization events. Phylogenetic analyses of eDBVs support and enrich the current taxonomy of yam badnaviruses and lead to the characterization of a new Badnavirus species in yam. The impact of eDBVs on diagnosis, yam germplasm conservation and movement, and breeding is discussed.

  12. The function of anal fin egg-spots in the cichlid fish Astatotilapia burtoni.

    PubMed

    Theis, Anya; Salzburger, Walter; Egger, Bernd

    2012-01-01

    Color and pigmentation patterns of animals are often targets of sexual selection because of their role in communication. Although conspicuous male traits are typically implicated with intersexual selection, there are examples where sex-specific displays play a role in an intrasexual context, e.g. when they serve as signals for aggression level and/or status. Here, we focus on the function of a conspicuous male ornament in the most species-rich tribe of cichlid fishes, the haplochromines. A characteristic feature of these ca. 1500 species are so-called egg-spots in form of ovoid markings on the anal fins of males, which are made up of carotenoid based pigment cells. It has long been assumed that these yellow, orange or reddish egg-spots play an important role in the courtship and spawning behavior of these maternal mouth-brooding fishes by mimicking the eggs of a conspecific female. The exact function of egg-spots remains unknown, however, and there are several hypotheses about their mode of action. To uncover the function of this cichlid-specific male ornament, we used female mate choice experiments and a male aggression test in the haplochromine species Astatotilapia burtoni. We manipulated the number and arrangement of egg-spots on the anal fins of males, or removed them entirely, and tested (1) female preference with visual contact only using egg-traps, (2) female preference with free contact using paternity testing with microsatellites and (3) male aggression. We found that females did not prefer males with many egg-spots over males with fewer egg-spots and that females tended to prefer males without egg-spots over males with egg-spots. Importantly, males without egg-spots sired clutches with the same fertilization rate as males with egg-spots. In male aggression trials, however, males with fewer egg-spots received significantly more attacks, suggesting that egg-spots are an important signal in intrasexual communication.

  13. The African buffalo: a villain for inter-species spread of infectious diseases in southern Africa.

    PubMed

    Michel, Anita L; Bengis, Roy G

    2012-06-20

    The African buffalo (Syncerus caffer) is a large wild bovid which until recently ranged across all but the driest parts of sub-Saharan Africa, and their local range being limited to about 20 km from surface water. They are of high ecological value due to their important role as bulk feeders in the grazing hierarchy. They also have high economic value, because they are one of the sought after 'Big Five' in the eco-tourism industry. In Africa, buffaloes have been recognised for some time as an important role player in the maintenance and transmission of a variety of economically important livestock diseases at the wildlife and/or livestock interface. These include African strains of foot-and-mouth disease (FMD), Corridor disease (theileriosis), bovine tuberculosis and bovine brucellosis. For a number of other diseases of veterinary importance, African buffaloes may also serve as amplifier or incidental host, whereby infection with the causative pathogens may cause severe clinical signs such as death or abortion as in the case of anthrax and Rift Valley fever, or remain mild or subclinical for example heartwater. The long term health implications of most of those infections on the buffalo at a population level is usually limited, and they do not pose a threat on the population's survival. Because of their ability to harbour and transmit important diseases to livestock, their sustainable future in ecotourism, trade and transfrontier conservation projects become complex and costly and reliable diagnostic tools are required to monitor these infections in buffalo populations.

  14. Hierarchical Multi-Species Modeling of Carnivore Responses to Hunting, Habitat and Prey in a West African Protected Area

    PubMed Central

    Burton, A. Cole; Sam, Moses K.; Balangtaa, Cletus; Brashares, Justin S.

    2012-01-01

    Protected areas (PAs) are a cornerstone of global efforts to shield wildlife from anthropogenic impacts, yet their effectiveness at protecting wide-ranging species prone to human conflict – notably mammalian carnivores – is increasingly in question. An understanding of carnivore responses to human-induced and natural changes in and around PAs is critical not only to the conservation of threatened carnivore populations, but also to the effective protection of ecosystems in which they play key functional roles. However, an important challenge to assessing carnivore communities is the often infrequent and imperfect nature of survey detections. We applied a novel hierarchical multi-species occupancy model that accounted for detectability and spatial autocorrelation to data from 224 camera trap stations (sampled between October 2006 and January 2009) in order to test hypotheses about extrinsic influences on carnivore community dynamics in a West African protected area (Mole National Park, Ghana). We developed spatially explicit indices of illegal hunting activity, law enforcement patrol effort, prey biomass, and habitat productivity across the park, and used a Bayesian model selection framework to identify predictors of site occurrence for individual species and the entire carnivore community. Contrary to our expectation, hunting pressure and edge proximity did not have consistent, negative effects on occurrence across the nine carnivore species detected. Occurrence patterns for most species were positively associated with small prey biomass, and several species had either positive or negative associations with riverine forest (but not with other habitat descriptors). Influences of sampling design on carnivore detectability were also identified and addressed within our modeling framework (e.g., road and observer effects), and the multi-species approach facilitated inference on even the rarest carnivore species in the park. Our study provides insight for the

  15. Wild Termitomyces Species Collected from Ondo and Ekiti States Are More Related to African Species as Revealed by ITS Region of rDNA

    PubMed Central

    Oyetayo, Victor Olusegun

    2012-01-01

    Molecular identification of eighteen Termitomyces species collected from two states, Ondo and Ekiti in Nigeria was carried out using the internal transcribed spacer (ITS) region. The amplicons obtained from rDNA of Termitomyces species were compared with existing sequences in the NCBI GenBank. The results of the ITS sequence analysis discriminated between all the Termitomyces species (obtained from Ondo and Ekiti States) and Termitomyces sp. sequences obtained from NCBI GenBank. The degree of similarity of T1 to T18 to gene of Termitomyces sp. obtained from NCBI ranges between 82 and 99 percent. Termitomyces species from Garbon with ascension number AF321374 was the closest relative of T1 to T18 except T12 that has T. eurhizus and T. striatus as the closet relative. Phylogenetic tree generated with ITS sequences obtained from NCBI GenBank data revealed that T1 to T18 are more related to Termitomyces species indigenous to African countries such as Senegal, Congo, and Gabon. PMID:22649309

  16. Laboratory Investigations of African Pouched Rats (Cricetomys gambianus) as a Potential Reservoir Host Species for Monkeypox Virus.

    PubMed

    Hutson, Christina L; Nakazawa, Yoshinori J; Self, Joshua; Olson, Victoria A; Regnery, Russell L; Braden, Zachary; Weiss, Sonja; Malekani, Jean; Jackson, Eddie; Tate, Mallory; Karem, Kevin L; Rocke, Tonie E; Osorio, Jorge E; Damon, Inger K; Carroll, Darin S

    2015-01-01

    Monkeypox is a zoonotic disease endemic to central and western Africa, where it is a major public health concern. Although Monkeypox virus (MPXV) and monkeypox disease in humans have been well characterized, little is known about its natural history, or its maintenance in animal populations of sylvatic reservoir(s). In 2003, several species of rodents imported from Ghana were involved in a monkeypox outbreak in the United States with individuals of three African rodent genera (Cricetomys, Graphiurus, Funisciurus) shown to be infected with MPXV. Here, we examine the course of MPXV infection in Cricetomys gambianus (pouched Gambian rats) and this rodent species' competence as a host for the virus. We obtained ten Gambian rats from an introduced colony in Grassy Key, Florida and infected eight of these via scarification with a challenge dose of 4X104 plaque forming units (pfu) from either of the two primary clades of MPXV: Congo Basin (C-MPXV: n = 4) or West African (W-MPXV: n = 4); an additional 2 animals served as PBS controls. Viral shedding and the effect of infection on activity and physiological aspects of the animals were measured. MPXV challenged animals had significantly higher core body temperatures, reduced activity and increased weight loss than PBS controls. Viable virus was found in samples taken from animals in both experimental groups (C-MPXV and W-MPXV) between 3 and 27 days post infection (p.i.) (up to 1X108 pfu/ml), with viral DNA found until day 56 p.i. The results from this work show that Cricetomys gambianus (and by inference, probably the closely related species, Cricetomys emini) can be infected with MPXV and shed viable virus particles; thus suggesting that these animals may be involved in the maintenance of MPXV in wildlife mammalian populations. More research is needed to elucidate the epidemiology of MPXV and the role of Gambian rats and other species.

  17. Antimicrobial activity of two South African honeys produced from indigenous Leucospermum cordifolium and Erica species on selected micro-organisms

    PubMed Central

    Basson, Nicolaas J; Grobler, Sias R

    2008-01-01

    Background Honey has been shown to have wound healing properties which can be ascribed to its antimicrobial activity. The antimicrobial activity can be effective against a broad spectrum of bacterial species especially those of medical importance. It has also been shown that there is considerable variation in the antimicrobial potency of different types of honey, which is impossible to predict. With this in mind we tested the antimicrobial activity of honeys produced from plants grown in South Africa for their antibacterial properties on selected standard strains of oral micro-organisms. Methods The honeys used were produced from the blossoms of Eucalyptus cladocalyx (Bluegum) trees, an indigenous South African plant Leucospermum cordifolium (Pincushion), a mixture of wild heather shrubs, mainly Erica species (Fynbos) and a Leptospermum scoparium (Manuka) honey. Only pure honey which had not been heated was used. The honeys were tested for their antimicrobial properties with a broth dilution method. Results Although the honeys produced some inhibitory effect on the growth of the micro-organisms, no exceptionally high activity occurred in the South African honeys. The carbohydrate concentration plays a key role in the antimicrobial activity of the honeys above 25%. However, these honeys do contain other antimicrobial properties that are effective against certain bacterial species at concentrations well below the hypertonic sugar concentration. The yeast C. albicans was more resistant to the honeys than the bacteria. The species S. anginosus and S. oralis were more sensitive to the honeys than the other test bacteria. Conclusion The honeys produced from indigenous wild flowers from South Africa had no exceptionally high activity that could afford medical grade status. PMID:18627601

  18. Historical colonization and dispersal limitation supplement climate and topography in shaping species richness of African lizards (Reptilia: Agaminae).

    PubMed

    Kissling, W Daniel; Blach-Overgaard, Anne; Zwaan, Roelof E; Wagner, Philipp

    2016-09-27

    To what extent deep-time dispersal limitation shapes present-day biodiversity at broad spatial scales remains elusive. Here, we compiled a continental dataset on the distributions of African lizard species in the reptile subfamily Agaminae (a relatively young, Neogene radiation of agamid lizards which ancestors colonized Africa from the Arabian peninsula) and tested to what extent historical colonization and dispersal limitation (i.e. accessibility from areas of geographic origin) can explain present-day species richness relative to current climate, topography, and climate change since the late Miocene (~10 mya), the Pliocene (~3 mya), and the Last Glacial Maximum (LGM, 0.021 mya). Spatial and non-spatial multi-predictor regression models revealed that time-limited dispersal via arid corridors is a key predictor to explain macro-scale patterns of species richness. In addition, current precipitation seasonality, current temperature of the warmest month, paleo-temperature changes since the LGM and late Miocene, and topographic relief emerged as important drivers. These results suggest that deep-time dispersal constraints - in addition to climate and mountain building - strongly shape current species richness of Africa's arid-adapted taxa. Such historical dispersal limitation might indicate that natural movement rates of species are too slow to respond to rates of ongoing and projected future climate and land use change.

  19. Historical colonization and dispersal limitation supplement climate and topography in shaping species richness of African lizards (Reptilia: Agaminae)

    PubMed Central

    Kissling, W. Daniel; Blach-Overgaard, Anne; Zwaan, Roelof E.; Wagner, Philipp

    2016-01-01

    To what extent deep-time dispersal limitation shapes present-day biodiversity at broad spatial scales remains elusive. Here, we compiled a continental dataset on the distributions of African lizard species in the reptile subfamily Agaminae (a relatively young, Neogene radiation of agamid lizards which ancestors colonized Africa from the Arabian peninsula) and tested to what extent historical colonization and dispersal limitation (i.e. accessibility from areas of geographic origin) can explain present-day species richness relative to current climate, topography, and climate change since the late Miocene (~10 mya), the Pliocene (~3 mya), and the Last Glacial Maximum (LGM, 0.021 mya). Spatial and non-spatial multi-predictor regression models revealed that time-limited dispersal via arid corridors is a key predictor to explain macro-scale patterns of species richness. In addition, current precipitation seasonality, current temperature of the warmest month, paleo-temperature changes since the LGM and late Miocene, and topographic relief emerged as important drivers. These results suggest that deep-time dispersal constraints — in addition to climate and mountain building — strongly shape current species richness of Africa’s arid-adapted taxa. Such historical dispersal limitation might indicate that natural movement rates of species are too slow to respond to rates of ongoing and projected future climate and land use change. PMID:27671620

  20. Higher parasite richness, abundance and impact in native versus introduced cichlid fishes.

    PubMed

    Roche, Dominique G; Leung, Brian; Franco, Edgar F Mendoza; Torchin, Mark E

    2010-11-01

    Empirical studies suggest that most exotic species have fewer parasite species in their introduced range relative to their native range. However, it is less clear how, ecologically, the loss of parasite species translates into a measurable advantage for invaders relative to native species in the new community. We compared parasitism at three levels (species richness, abundance and impact) for a pair of native and introduced cichlid fishes which compete for resources in the Panama Canal watershed. The introduced Nile tilapia, Oreochromis niloticus, was infected by a single parasite species from its native range, but shared eight native parasite species with the native Vieja maculicauda. Despite acquiring new parasites in its introduced range, O. niloticus had both lower parasite species richness and lower parasite abundance compared with its native competitor. There was also a significant negative association between parasite load (abundance per individual fish) and host condition for the native fish, but no such association for the invader. The effects of parasites on the native fish varied across sites and types of parasites, suggesting that release from parasites may benefit the invader, but that the magnitude of release may depend upon interactions between the host, parasites and the environment.

  1. A Japanese view on speciation: "Sumiwake" explosive speciation of the cichlids in Lake Victoria.

    PubMed

    Kawamiya, Nobuo

    2003-01-01

    Imanishi's "mental" (cerebral) view of speciation is presented, in Mizuhata's revision. The key concept here is the "ethological partition" of the species. Members of each species=society (etho-species) share the same mental (brain) software, irrespective of their genetic structure. Cerebral animals perform active programmed selection, not to be confused with passive, non-programmed "natural selection" as in Neo-Darwinism. The program includes mating-choice of peculiar characters, distinct from the Neo-Darwinian sexual selection supposed due to the specific choosy genes. Speciation can occur, as a "partition of species=society", with bifurcation of mate-choosing program in the parent species. A main promoter for this bifurcation is species-specific "passion" for especially significant characters: long necks, ornamental antlers, ocelli feathers, bright nuptial colors etc. The cichlids in Lake Victoria achieved explosive speciation, while retaining their genetic homogeneity completely. Therefore it is illogical to attribute this divergence to extraordinary mutations in "action controlling genes". The origin of species=society (etho-species) can trace along to the Cambrian Period.

  2. Inheritance patterns of lateral dimorphism examined through breeding experiments in Tanganyikan cichlid (Julidochromis transcriptus) and Japanese Medaka (Oryzias latipes).

    PubMed

    Hata, Hiroki; Takahashi, Rieko; Ashiwa, Hiroshi; Awata, Satoshi; Takeyama, Tomohiro; Kohda, Masanori; Hori, Michio

    2012-01-01

    The asymmetry of mouth morphology, in which the mouth opens either leftward or rightward, is a unique example of antisymmetry that is widely found in fishes, such as Tanganyikan scale-eating cichlids, herbivorous cichlids, and the Japanese freshwater goby. This dimorphism is thought to be heritable in a Mendelian manner similar to that of the dominance of the lefty allele over righty, with homozygotes of lefty alleles being absent. This study aims to reveal whether this trait is inherited in the same Mendelian manner in fishes other than those examined to date, and whether the absence of the dominant homozygote is due to a lethal effect. We conducted F(1) and F(2) breeding experiments using the Tanganyikan cichlid Julidochromis transcriptus and Japanese medaka Oryzias latipes. For both J. transcriptus and O. latipes, the F(1) generations produced by incrossing lefty parents showed a lefty:righty ratio of 2:1, whereas incrosses of righties produced only righty offspring. Test crosses between lefty and righty produced a 1:1 ratio of lefty and righty offspring. These results are consistent with the inheritance model in which righty is homozygous for a recessive righty allele and lefty is heterozygous for dominant lefty and recessive righty alleles, in agreement with previous observations. The F(2) test cross also confirmed this pattern. Furthermore, no lethal effects on hatchability of O. latipes were detected, refuting the suggestion that the dominant homozygote is embryonic lethal. We conclude that mouth laterality is inherited in the same Mendelian manner in these two species, similar to that other fish species studied previously. However, the reason for absence of the dominant homozygote remains unclear.

  3. Laboratory Investigations of African Pouched Rats (Cricetomys gambianus) as a Potential Reservoir Host Species for Monkeypox Virus

    PubMed Central

    Hutson, Christina L.; Nakazawa, Yoshinori J.; Self, Joshua; Olson, Victoria A.; Regnery, Russell L.; Braden, Zachary; Weiss, Sonja; Malekani, Jean; Jackson, Eddie; Tate, Mallory; Karem, Kevin L.; Rocke, Tonie E.; Osorio, Jorge E.; Damon, Inger K.; Carroll, Darin S.

    2015-01-01

    Abstract Monkeypox is a zoonotic disease endemic to central and western Africa, where it is a major public health concern. Although Monkeypox virus (MPXV) and monkeypox disease in humans have been well characterized, little is known about its natural history, or its maintenance in animal populations of sylvatic reservoir(s). In 2003, several species of rodents imported from Ghana were involved in a monkeypox outbreak in the United States with individuals of three African rodent genera (Cricetomys, Graphiurus, Funisciurus) shown to be infected with MPXV. Here, we examine the course of MPXV infection in Cricetomys gambianus (pouched Gambian rats) and this rodent species’ competence as a host for the virus. We obtained ten Gambian rats from an introduced colony in Grassy Key, Florida and infected eight of these via scarification with a challenge dose of 4X104 plaque forming units (pfu) from either of the two primary clades of MPXV: Congo Basin (C-MPXV: n = 4) or West African (W-MPXV: n = 4); an additional 2 animals served as PBS controls. Viral shedding and the effect of infection on activity and physiological aspects of the animals were measured. MPXV challenged animals had significantly higher core body temperatures, reduced activity and increased weight loss than PBS controls. Viable virus was found in samples taken from animals in both experimental groups (C-MPXV and W-MPXV) between 3 and 27 days post infection (p.i.) (up to 1X108 pfu/ml), with viral DNA found until day 56 p.i. The results from this work show that Cricetomys gambianus (and by inference, probably the closely related species, Cricetomys emini) can be infected with MPXV and shed viable virus particles; thus suggesting that these animals may be involved in the maintenance of MPXV in wildlife mammalian populations. More research is needed to elucidate the epidemiology of MPXV and the role of Gambian rats and other species. PMID:26517724

  4. Hormonal and fitness consequences of behavioral assortative mating in the convict cichlid (Amatitlania siquia).

    PubMed

    Schweitzer, Cécile; Melot, Geoffrey; Laubu, Chloé; Teixeira, Maria; Motreuil, Sébastien; Dechaume-Moncharmont, François-Xavier

    2017-01-01

    In monogamous species, partner compatibility is a key factor influencing pairing and reproductive success. In pairs with biparental care, studies have mostly focused on behavioral compatibility because it is likely to encourage the coordination of parental care within pairs, leading to a better reproductive success. Behavior modulation, throughout the breeding season and as a function of the social context, is under the regulatory feedback control of endocrine mechanisms. From this link, the idea of hormonal partner compatibility as a key component of pair cohesion and maintenance has recently emerged. Here, we investigated the link between partner behavioral assortment and their hormonal response to the pairing context. We formed assortative and disassortative pairs of convict cichlids based on their behavioral type (proactive or reactive) and took hormone and fitness measurements. Testosterone, 11-ketotestosterone, 17β-estradiol and cortisol levels were measured from fish-holding water before and after pair formation. We found no relationship between the behavioral type of individuals and their pre-pairing hormone levels. Only the level of cortisol was affected by the partner but independently of its behavioral type. Reproductive success was not affected by the level of hormonal similarity within pairs, but we found that the variation in 11-ketotestosterone similarity between the isolated context and the pairing context was related to spawning size, and the variation in cortisol similarity to the number of fry. Behavioral compatibility does not reflect hormonal compatibility in the convict cichlid, but the relationship between reproductive success and the flexibility of hormonal similarity between partners suggests hormonal adjustment within pairs in this species.

  5. A new species of the rare African wool carder bee genus Anthidioma (Hymenoptera: Megachilidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A new species of the genus Anthidioma Pasteels (Megachilidae: Anthidiini) is described and figured from a female collected in the Obib Dunes in Namibia. Anthidioma obibense, new species, is differentieated from the only other species of the genus, A. chalicodomoides, on the basis of its integumenta...

  6. Solar drying and organoleptic characteristics of two tropical African fish species using improved low-cost solar driers.

    PubMed

    Mustapha, Moshood K; Ajibola, Taiye B; Salako, Abdulbashir F; Ademola, Sunmola K

    2014-05-01

    This study was done to evaluate the drying performance, efficiency, and effectiveness of five different types of improved low-cost solar driers in terms of moisture loss from two tropical African fish species Clarias gariepinus (African sharp tooth catfish) and Oreochromis niloticus (Nile tilapia) and testing the organoleptic characteristics of the dried samples. The driers used were made from plastic, aluminum, glass, glass with black igneous stone, and mosquito net, with traditional direct open-sun drying as a control. A significant (P < 0.05) decrease in weight resulting from moisture loss in the two fish species was observed in all the driers, with the highest reduction occurring in the glass drier containing black stone. The rate of weight loss was faster in the first 4 days of drying with black stone-inserted glass drier showing the fastest drying rate with a constant weight in C. gariepinus attained on the 11th day and in O. niloticus on the eighth day. The slowest drier was plastic where a constant weight of the species were recorded on and 13th day and 11th day, respectively. Volunteers were used to assess the organoleptic characteristics of the dried samples and they showed lowest acceptability for the open-sun drying, while samples from the glass drier containing black stone had the highest acceptability in terms of the taste, flavor, appearance, texture, odor, palatability, and shelf-life. The low-cost solar driers were effective found in removing water from the fish resulting in significant loss of weight and moisture. The highest drying time, efficient performance, drying effectiveness, and high acceptability of the organoleptic parameters of the dried products from the black stone-inserted glass drier were due to the ability of the glass and the black stone to retain, transmit, and radiate heat to the fish sample all the time (day and night). These low-cost driers are simple to construct, materials for its construction readily available, easy to

  7. Species-specific loss of sexual dimorphism in vocal effectors accompanies vocal simplification in African clawed frogs (Xenopus).

    PubMed

    Leininger, Elizabeth C; Kitayama, Ken; Kelley, Darcy B

    2015-03-01

    Phylogenetic studies can reveal patterns of evolutionary change, including the gain or loss of elaborate courtship traits in males. Male African clawed frogs generally produce complex and rapid courtship vocalizations, whereas female calls are simple and slow. In a few species, however, male vocalizations are also simple and slow, suggesting loss of male-typical traits. Here, we explore features of the male vocal organ that could contribute to loss in two species with simple, slow male calls. In Xenopus boumbaensis, laryngeal morphology is more robust in males than in females. Larynges are larger, have a more complex cartilaginous morphology and contain more muscle fibers. Laryngeal muscle fibers are exclusively fast-twitch in males but are both fast- and slow-twitch in females. The laryngeal electromyogram, a measure of neuromuscular synaptic strength, shows greater potentiation in males than in females. Male-specific physiological features are shared with X. laevis, as well as with a species of the sister clade, Silurana tropicalis, and thus are likely ancestral. In X. borealis, certain aspects of laryngeal morphology and physiology are sexually monomorphic rather than dimorphic. In both sexes, laryngeal muscle fibers are of mixed-twitch type, which limits the production of muscle contractions at rapid intervals. Muscle activity potentiation and discrete tension transients resemble female rather than male X. boumbaensis. The de-masculinization of these laryngeal features suggests an alteration in sensitivity to the gonadal hormones that are known to control the sexual differentiation of the larynx in other Xenopus and Silurana species.

  8. Do species populations really start small? New perspectives from the Late Neogene fossil record of African mammals.

    PubMed Central

    Vrba, E S; DeGusta, D

    2004-01-01

    This analysis of all known African larger mammals of the past 10 Myr offers new perspectives on the geographical circumstances of speciation. Our central question is: does the fossil evidence support the idea that most new species start as small populations and, if true, how long is the average growth interval until species are established at their mean later size? This simple question is important to unravelling the competing claims of rival models of speciation. We approached it by direct use of fossil data, which, to our knowledge, has not been done previously. We compared the numbers of fossil site records, as a proxy for magnitude of geographical spread, between survivorship intervals across all species. The results show that the average mammal species has indeed started its life in a relatively small population, and thereafter increased rapidly in geographical spread to reach its long-term equilibrium abundance by about 1 million years after origin. Some theoretical implications of these results are discussed. PMID:15101584

  9. The influence of interspecific competition and host preference on the phylogeography of two African ixodid tick species.

    PubMed

    Cangi, Nídia; Horak, Ivan G; Apanaskevich, Dmitry A; Matthee, Sonja; das Neves, Luís C B G; Estrada-Peña, Agustín; Matthee, Conrad A

    2013-01-01

    A comparative phylogeographic study on two economically important African tick species, Amblyomma hebraeum and Hyalomma rufipes was performed to test the influence of host specificity and host movement on dispersion. Pairwise AMOVA analyses of 277 mtDNA COI sequences supported significant population differentiation among the majority of sampling sites. The geographic mitochondrial structure was not supported by nuclear ITS-2 sequencing, probably attributed to a recent divergence. The three-host generalist, A. hebraeum, showed less mtDNA geographic structure, and a lower level of genetic diversity, while the more host-specific H. rufipes displayed higher levels of population differentiation and two distinct mtDNA assemblages (one predominantly confined to South Africa/Namibia and the other to Mozambique and East Africa). A zone of overlap is present in southern Mozambique. A mechanistic climate model suggests that climate alone cannot be responsible for the disruption in female gene flow. Our findings furthermore suggest that female gene dispersal of ticks is more dependent on the presence of juvenile hosts in the environment than on the ability of adult hosts to disperse across the landscape. Documented interspecific competition between the juvenile stages of H. rufipes and H. truncatum is implicated as a contributing factor towards disrupting gene flow between the two southern African H. rufipes genetic assemblages.

  10. Two decades of historical phenology observations of African tropical tree species: exploring the past to predict the futur

    NASA Astrophysics Data System (ADS)

    Hufkens, K.; Kosmala, M.; Ewango, C.; Richardson, A. D.; Beeckman, H.

    2015-12-01

    African tropical forests cover ~630 million ha, store up to 66 Pg of carbon and represent a significant carbon sink (0.34Pg C yr-1 ). As such African tropical forests provide an important negative feedback to the global carbon cycle. Unlike temperate forests, tropical forests lack sharp temperature and photoperiod cues to constrain phenology and growth. Therefore, events such as seasonal leaf abscission and reproductive life cycles are often driven by changes in water availability. With future climate predictions expecting a warmer, and especially drier tropical Africa, it is likely we will see concomitant changes in tree growth and phenology.As tropical trees show a high degree of phenological plasticity depending on the severity of the dry season, intermittent water stress or the location of an individual in the canopy structure. As such, frequent and long term observations are key to characterize tropical tree phenology. Here I use two long term historical phenology records of weekly observations, some digitized within the context of a citizen science project (http://junglerhythms.org/), to explore differences in tree phenology between two sites (Luki and Yangambi, DR Congo) with contrasting climate regimes within the Congo basin. I describe variation in leaf, flower and fruit phenology across similar species at both locations in relation to complementary historical climatological observations. I further discuss the potential implications of changing phenology under future climate conditions as phenological changes could alter both ecosystem demography and growing season length providing important feedbacks to the climate system.

  11. Computer animation as a tool to study preferences in the cichlid Pelvicachromis taeniatus.

    PubMed

    Baldauf, S A; Kullmann, H; Thünken, T; Winter, S; Bakker, T C M

    2009-08-01

    Four choice experiments were conducted with both sexes of the cichlid Pelvicachromis taeniatus using computer-manipulated stimuli of digital images differing in movement, body shape or colouration. The results show that computer animations can be useful and flexible tools in studying preferences of a cichlid with complex and variable preferences for different visual cues.

  12. Population genomic tests of models of adaptive radiation in Lake Victoria region cichlid fish.

    PubMed

    Bezault, Etienne; Mwaiko, Salome; Seehausen, Ole

    2011-12-01

    Adaptive radiation is usually thought to be associated with speciation, but the evolution of intraspecific polymorphisms without speciation is also possible. The radiation of cichlid fish in Lake Victoria (LV) is perhaps the most impressive example of a recent rapid adaptive radiation, with 600+ very young species. Key questions about its origin remain poorly characterized, such as the importance of speciation versus polymorphism, whether species persist on evolutionary time scales, and if speciation happens more commonly in small isolated or in large connected populations. We used 320 individuals from 105 putative species from Lakes Victoria, Edward, Kivu, Albert, Nabugabo and Saka, in a radiation-wide amplified fragment length polymorphism (AFLP) genome scan to address some of these questions. We demonstrate pervasive signatures of speciation supporting the classical model of adaptive radiation associated with speciation. A positive relationship between the age of lakes and the average genomic differentiation of their species, and a significant fraction of molecular variance explained by above-species level taxonomy suggest the persistence of species on evolutionary time scales, with radiation through sequential speciation rather than a single starburst. Finally the large gene diversity retained from colonization to individual species in every radiation suggests large effective population sizes and makes speciation in small geographical isolates unlikely.

  13. Rigorous approaches to species delimitation have significant implications for African crocodilian systematics and conservation.

    PubMed

    Shirley, Matthew H; Vliet, Kent A; Carr, Amanda N; Austin, James D

    2014-02-07

    Accurate species delimitation is a central assumption of biology that, in groups such as the Crocodylia, is often hindered by highly conserved morphology and frequent introgression. In Africa, crocodilian systematics has been hampered by complex regional biogeography and confounded taxonomic history. We used rigorous molecular and morphological species delimitation methods to test the hypothesis that the slender-snouted crocodile (Mecistops cataphractus) is composed of multiple species corresponding to the Congolian and Guinean biogeographic zones. Speciation probability was assessed by using 11 mitochondrial and nuclear genes, and cranial morphology for over 100 specimens, representing the full geographical extent of the species distribution. Molecular Bayesian and phylogenetic species delimitation showed unanimous support for two Mecistops species isolated to the Upper Guinean and Congo (including Lower Guinean) biomes that were supported by 13 cranial characters capable of unambiguously diagnosing each species. Fossil-calibrated phylogenetic reconstruction estimated that the species split ± 6.5-7.5 Ma, which is congruent with intraspecies divergence within the sympatric crocodile genus Osteolaemus and the formation of the Cameroon Volcanic Line. Our results underscore the necessity of comprehensive phylogeographic analyses within currently recognized taxa to detect cryptic species within the Crocodylia. We recommend that the community of crocodilian researchers reconsider the conceptualization of crocodilian species especially in the light of the conservation ramifications for this economically and ecologically important group.

  14. Rigorous approaches to species delimitation have significant implications for African crocodilian systematics and conservation

    PubMed Central

    Shirley, Matthew H.; Vliet, Kent A.; Carr, Amanda N.; Austin, James D.

    2014-01-01

    Accurate species delimitation is a central assumption of biology that, in groups such as the Crocodylia, is often hindered by highly conserved morphology and frequent introgression. In Africa, crocodilian systematics has been hampered by complex regional biogeography and confounded taxonomic history. We used rigorous molecular and morphological species delimitation methods to test the hypothesis that the slender-snouted crocodile (Mecistops cataphractus) is composed of multiple species corresponding to the Congolian and Guinean biogeographic zones. Speciation probability was assessed by using 11 mitochondrial and nuclear genes, and cranial morphology for over 100 specimens, representing the full geographical extent of the species distribution. Molecular Bayesian and phylogenetic species delimitation showed unanimous support for two Mecistops species isolated to the Upper Guinean and Congo (including Lower Guinean) biomes that were supported by 13 cranial characters capable of unambiguously diagnosing each species. Fossil-calibrated phylogenetic reconstruction estimated that the species split ± 6.5–7.5 Ma, which is congruent with intraspecies divergence within the sympatric crocodile genus Osteolaemus and the formation of the Cameroon Volcanic Line. Our results underscore the necessity of comprehensive phylogeographic analyses within currently recognized taxa to detect cryptic species within the Crocodylia. We recommend that the community of crocodilian researchers reconsider the conceptualization of crocodilian species especially in the light of the conservation ramifications for this economically and ecologically important group. PMID:24335982

  15. Virus recovery rates for wild-type and live-attenuated vaccine strains of African horse sickness virus serotype 7 in orally infected South African Culicoides species.

    PubMed

    Venter, G J; Paweska, J T

    2007-12-01

    Previously reported virus recovery rates from Culicoides (Avaritia) imicola Kieffer and Culicoides (Avaritia) bolitinos Meiswinkel (Diptera, Ceratopogonidae) orally infected with vaccine strain of African horse sickness virus serotype 7 (AHSV-7) were compared with results obtained from concurrently conducted oral infections with five recent AHSV-7 isolates from naturally infected horses from various localities in South Africa. Culicoides were fed sheep bloods spiked with 10(7.6) TCID(50)/mL of a live-attenuated vaccine strain AHSV-7, and with five field isolates in which virus titre in the bloodmeals ranged from 10(7.1) to 10(8.2) TCID(50)/mL). After an extrinsic incubation of 10 days at 23.5 degrees C, virus recovery rates were significantly higher in C. imicola (13.3%) and C. bolitinos (4.2%) infected with the live-attenuated virus than in midges infected with any of the field isolates. The virus recovery rates for the latter groups ranged from 0% to 9.5% for C. imicola and from 0% to 1.5% for C. bolitinos. The C. imicola population at Onderstepoort was significantly more susceptible to infection with AHSV-7 isolated at Onderstepoort than to the virus strains isolated from other localities. Results of this study suggest that tissue culture attenuation of AHSV-7 does not reduce its ability to orally infect competent Culicoides species and may even lead to enhanced replication in the vector. Furthermore, oral susceptibility in a midge population appears to vary for geographically distinct isolates of AHSV-7.

  16. An allelic series at pax7a is associated with colour polymorphism diversity in Lake Malawi cichlid fish.

    PubMed

    Roberts, Reade B; Moore, Emily C; Kocher, Thomas D

    2016-12-27

    Despite long-standing interest in the evolution and maintenance of discrete phenotypic polymorphisms, the molecular genetic basis of such polymorphism in the wild is largely unknown. Female sex-associated blotched colour polymorphisms found in cichlids of Lake Malawi, East Africa, represent a highly successful polymorphic phenotype, found and maintained in four genera across the geographic expanse of the lake. Previously, we identified an association with an allelic variant of the paired-box transcription factor gene pax7a and blotched colour morphs in Lake Malawi cichlid fishes. Although a diverse range of blotched phenotypes are present in Lake Malawi cichlid species, they all appeared to result from an allele of pax7a that produces increased levels of transcript. Here, we examine the developmental and genetic basis of variation among blotched morphs. First, we confirm that pax7a-associated blotch morphs result primarily from modulation of melanophore development and survival. From laboratory crosses and natural population studies, we identify at least three alleles of pax7a associated with discrete subtypes of blotched morphs, in addition to the ancestral pax7a allele. Genotypes at pax7a support initial evolution of a novel pax7a allele to produce the blotched class of morphs, followed by subsequent evolution of that pax7a blotched allele to produce additional alleles associated with discrete colour morphs. Variant alleles of pax7a produce different levels of pax7a transcript, correlating with pigmentation phenotype at the cellular level. This naturally selected allelic series should serve as a case study for understanding the molecular genetic control of pax7a expression and the evolution of sex-associated alleles.

  17. Impact of temperature on performance in two species of South African dwarf chameleon, Bradypodion pumilum and B. occidentale.

    PubMed

    Segall, Marion; Tolley, Krystal A; Vanhooydonck, Bieke; Measey, G John; Herrel, Anthony

    2013-10-15

    Temperature is an extrinsic factor that influences reptile behavior because of its impact on reptile physiology. Understanding the impact of temperature on performance traits is important as it may affect the ecology and fitness of ectothermic animals such as reptiles. Here, we examined the temperature dependence of performance in two species of South African dwarf chameleon (Bradypodion): one adapted to a semi-arid environment and one to a mesic environment. Ecologically relevant performance traits were tested at different temperatures to evaluate their thermal dependence, and temperature-performance breadths for 80% and 90% of each performance trait were calculated. Our results show distinct differences in the thermal dependence of speed- versus force-related performance traits. Moreover, our results show that the semi-arid species is better adapted to higher temperatures and as such has a better chance of coping with the predicted increases in environmental temperature. The mesic area-adapted species seems to be more sensitive to an increase in temperature and could therefore potentially be threatened by the predicted future climate change. However, further studies investigating the potential for acclimation in chameleons are needed to better understand how animals may respond to future climate change.

  18. Culicoides species abundance and potential over-wintering of African horse sickness virus in the Onderstepoort area, Gauteng, South Africa.

    PubMed

    Venter, Gert J; Labuschagne, Karien; Majatladi, Daphney; Boikanyo, Solomon N B; Lourens, Carina; Ebersohn, Karen; Venter, Estelle H

    2014-11-14

    In South Africa, outbreaks of African horse sickness (AHS) occur in summer; no cases are reported in winter, from July to September. The AHS virus (AHSV) is transmitted almost exclusively by Culicoides midges (Diptera: Ceratopogonidae), of which Culicoides imicola is considered to be the most important vector. The over-wintering mechanism of AHSV is unknown. In this study, more than 500 000 Culicoides midges belonging to at least 26 species were collected in 88 light traps at weekly intervals between July 2010 and September 2011 near horses in the Onderstepoort area of South Africa. The dominant species was C. imicola. Despite relatively low temperatures and frost, at least 17 species, including C. imicola, were collected throughout winter (June-August). Although the mean number of midges per night fell from > 50 000 (March) to < 100 (July and August), no midge-free periods were found. This study, using virus isolation on cell cultures and a reverse transcriptase polymerase chain reaction (RT-PCR) assay, confirmed low infection prevalence in field midges and that the detection of virus correlated to high numbers. Although no virus was detected during this winter period, continuous adult activity indicated that transmission can potentially occur. The absence of AHSV in the midges during winter can be ascribed to the relatively low numbers collected coupled to low infection prevalence, low virus replication rates and low virus titres in the potentially infected midges. Cases of AHS in susceptible animals are likely to start as soon as Culicoides populations reach a critical level.

  19. Assessing the potential of multi-seasonal WorldView-2 imagery for mapping West African agroforestry tree species

    NASA Astrophysics Data System (ADS)

    Karlson, Martin; Ostwald, Madelene; Reese, Heather; Bazié, Hugues Roméo; Tankoano, Boalidioa

    2016-08-01

    High resolution satellite systems enable efficient and detailed mapping of tree cover, with high potential to support both natural resource monitoring and ecological research. This study investigates the capability of multi-seasonal WorldView-2 imagery to map five dominant tree species at the individual tree crown level in a parkland landscape in central Burkina Faso. The Random Forest algorithm is used for object based tree species classification and for assessing the relative importance of WorldView-2 predictors. The classification accuracies from using wet season, dry season and multi-seasonal datasets are compared to gain insights about the optimal timing for image acquisition. The multi-seasonal dataset produced the most accurate classifications, with an overall accuracy (OA) of 83.4%. For classifications based on single date imagery, the dry season (OA = 78.4%) proved to be more suitable than the wet season (OA = 68.1%). The predictors that contributed most to the classification success were based on the red edge band and visible wavelengths, in particular green and yellow. It was therefore concluded that WorldView-2, with its unique band configuration, represents a suitable data source for tree species mapping in West African parklands. These results are particularly promising when considering the recently launched WorldView-3, which provides data both at higher spatial and spectral resolution, including shortwave infrared bands.

  20. Leucocytozoon (Apicomplexa: Leucocytozoidae) from West African birds, with descriptions of two species.

    PubMed

    Jones, Hugh I; Sehgal, Ravinder N M; Smith, Thomas B

    2005-04-01

    Five species of Leucocytozoon were recovered from 35/828 birds of 95 species examined from 6 sites in West Africa between May 1995 and June 2001. Leucocytozoon pogoniuli n. sp. is described from the tinker barbets Pogoniulus subsulphureus and Pogoniulus atroflavus. Leucocytozoon trachyphoni n. sp. is described from the barbet Trachyphonus purpureus. No leucocytozoids have been reported previously in species of Pogoniulus. Leucocytozoon nectariniae was identified from the sunbird Nectarinia olivacea, and Leucocytozoon brimonti was recovered from 4 species of Pycnonotidae (bulbuls), all of which are new host records. We also report the first Leucocytozoon to be recovered from the phylogenetically isolated bird, Picathartes sp. (Picathartidae). This parasite is similar in appearance to Leucocytozoon sakharoffi, and probably represents a previously undescribed species. In view of the intraspecific variability and, frequently, relatively minor interspecific differences within Leucocytozoidae, we suggest that the development and application of molecular techniques would greatly advance understanding of speciation and relationships within this family.

  1. Foraging environment determines the genetic architecture and evolutionary potential of trophic morphology in cichlid fishes.

    PubMed

    Parsons, Kevin J; Concannon, Moira; Navon, Dina; Wang, Jason; Ea, Ilene; Groveas, Kiran; Campbell, Calum; Albertson, R Craig

    2016-12-01

    Phenotypic plasticity allows organisms to change their phenotype in response to shifts in the environment. While a central topic in current discussions of evolutionary potential, a comprehensive understanding of the genetic underpinnings of plasticity is lacking in systems undergoing adaptive diversification. Here, we investigate the genetic basis of phenotypic plasticity in a textbook adaptive radiation, Lake Malawi cichlid fishes. Specifically, we crossed two divergent species to generate an F3 hybrid mapping population. At early juvenile stages, hybrid families were split and reared in alternate foraging environments that mimicked benthic/scraping or limnetic/sucking modes of feeding. These alternate treatments produced a variation in morphology that was broadly similar to the major axis of divergence among Malawi cichlids, providing support for the flexible stem theory of adaptive radiation. Next, we found that the genetic architecture of several morphological traits was highly sensitive to the environment. In particular, of 22 significant quantitative trait loci (QTL), only one was shared between the environments. In addition, we identified QTL acting across environments with alternate alleles being differentially sensitive to the environment. Thus, our data suggest that while plasticity is largely determined by loci specific to a given environment, it may also be influenced by loci operating across environments. Finally, our mapping data provide evidence for the evolution of plasticity via genetic assimilation at an important regulatory locus, ptch1. In all, our data address long-standing discussions about the genetic basis and evolution of plasticity. They also underscore the importance of the environment in affecting developmental outcomes, genetic architectures, morphological diversity and evolutionary potential.

  2. Helminth parasitism in two closely related South African rodents: abundance, prevalence, species richness and impinging factors.

    PubMed

    Spickett, Andrea; Junker, Kerstin; Krasnov, Boris R; Haukisalmi, Voitto; Matthee, Sonja

    2017-04-01

    We investigated patterns of helminth infection in two closely related rodents (social Rhabdomys pumilio occurring mainly in xeric habitats and solitary R. dilectus occurring mainly in mesic habitats) at 20 localities in different biomes of South Africa and asked if between-species differences were mainly caused by difference in sociality or difference in environmental conditions of their respective habitats. Helminths recovered from the gastrointestinal tract totalled 11 nematode and 5 cestode species from R. pumilio and 19 nematode and 7 cestode species from R. dilectus. In both hosts, mean abundance and prevalence of nematodes were higher compared to cestodes. Cestode infection as well as nematode abundance, species richness or prevalence did not differ between the two rodents. However, incidence of nematode infection was significantly higher in R. dilectus than in R. pumilio. Moreover, nematode numbers and species richness in infracommunities of R. pumilio inhabiting the relatively more xeric Karoo biome were significantly lower than in those inhabiting the relatively less xeric Fynbos biome. Although we could not unequivocally distinguish between effects of host sociality and environmental factors on the number of individuals and species of helminths in the two hosts, differences in the incidence of nematode infection between R. pumilio and R. dilectus as well as differences in the number of nematode individuals and species between R. pumilio from the Fynbos and the Karoo suggested the effect of environmental conditions on helminth infection to be more important than that of sociality.

  3. Dynamic Sequence Evolution of a Sex-Associated B Chromosome in Lake Malawi Cichlid Fish.

    PubMed

    Clark, Frances E; Conte, Matthew A; Ferreira-Bravo, Irani A; Poletto, Andreia B; Martins, Cesar; Kocher, Thomas D

    2017-01-01

    B chromosomes are extra chromosomes found in many species of plants, animals, and fungi. B chromosomes often manipulate common cellular processes to increase their frequency, sometimes to the detriment of organismal fitness. Here, we characterize B chromosomes in several species of Lake Malawi cichlid fish. Whole genome sequencing of Metriaclima zebra "Boadzulu" individuals revealed blocks of sequence with unusually high sequence coverage, indicative of increased copy number of those sequences. These regions of high sequence coverage were found only in females. SNPs unique to the high copy number sequences permitted the design of specific amplification primers. These primers amplified fragments only in Metriaclima lombardoi individuals that carried a cytologically identified B chromosome (B-carriers), indicating these extra copies are located on the B chromosome. These same primers were used to identify B-carrying individuals in additional species from Lake Malawi. Across 7 species, a total of 43 B-carriers were identified among 323 females. B-carriers were exclusively female; no B chromosomes were observed in the 317 males surveyed from these species. Quantitative analysis of the copy number variation of B-specific sequence blocks suggests that B-carriers possess a single B chromosome, consistent with previous karyotyping of M. lombardoi A single B chromosome in B-carriers is consistent with 2 potential drive mechanisms: one involving nondisjunction and preferential segregation in a mitotic division prior to the germ-line, and the other involving preferential segregation during meiosis I.

  4. Evolutionary associations between host traits and parasite load: insights from Lake Tanganyika cichlids.

    PubMed

    Hayward, A; Tsuboi, M; Owusu, C; Kotrschal, A; Buechel, S D; Zidar, J; Cornwallis, C K; Løvlie, H; Kolm, N

    2017-02-10

    Parasite diversity and abundance (parasite load) vary greatly among host species. However, the influence of host traits on variation in parasitism remains poorly understood. Comparative studies of parasite load have largely examined measures of parasite species richness and are predominantly based on records obtained from published data. Consequently, little is known about the relationships between host traits and other aspects of parasite load, such as parasite abundance, prevalence and aggregation. Meanwhile, understanding of parasite species richness may be clouded by limitations associated with data collation from multiple independent sources. We conducted a field study of Lake Tanganyika cichlid fishes and their helminth parasites. Using a Bayesian phylogenetic comparative framework, we tested evolutionary associations between five key host traits (body size, gut length, diet breadth, habitat complexity and number of sympatric hosts) predicted to influence parasitism, together with multiple measures of parasite load. We find that the number of host species that a particular host may encounter due to its habitat preferences emerges as a factor of general importance for parasite diversity, abundance and prevalence, but not parasite aggregation. In contrast, body size and gut size are positively related to aspects of parasite load within, but not between species. The influence of host phylogeny varies considerably among measures of parasite load, with the greatest influence exerted on parasite diversity. These results reveal that both host morphology and biotic interactions are key determinants of host-parasite associations and that consideration of multiple aspects of parasite load is required to fully understand patterns in parasitism.

  5. The relationship between satellite-derived indices and species diversity across African savanna ecosystems

    NASA Astrophysics Data System (ADS)

    Mapfumo, Ratidzo B.; Murwira, Amon; Masocha, Mhosisi; Andriani, R.

    2016-10-01

    The ability to use remotely sensed diversity is important for the management of ecosystems at large spatial extents. However, to achieve this, there is still need to develop robust methods and approaches that enable large-scale mapping of species diversity. In this study, we tested the relationship between species diversity measured in situ with the Normalized Difference Vegetation Index (NDVI) and the Coefficient of Variation in the NDVI (CVNDVI) derived from high and medium spatial resolution satellite data at dry, wet and coastal savanna woodlands. We further tested the effect of logging on NDVI along the transects and between transects as disturbance may be a mechanism driving the patterns observed. Overall, the results of this study suggest that high tree species diversity is associated with low and high NDVI and at intermediate levels is associated with low tree species diversity and NDVI. High tree species diversity is associated with high CVNDVI and vice versa and at intermediate levels is associated with high tree species diversity and CVNDVI.

  6. Effects of species and season on chemical composition and ruminal crude protein and organic matter degradability of some multi-purpose tree species by West African dwarf rams.

    PubMed

    Arigbede, O M; Anele, U Y; Südekum, K-H; Hummel, J; Oni, A O; Olanite, J A; Isah, A O

    2012-04-01

    Seasonal chemical composition and ruminal organic matter (OM) and crude protein (CP) degradabilities were determined in four tropical multi-purpose tree species (MPTS) namely; Pterocarpus santalinoides, Grewia pubescens, Enterolobium cyclocarpum and Leucaena leucocephala. Three West African dwarf (WAD) rams fitted with permanent rumen cannula were used for the degradability trials. Foliage samples were collected four times to represent seasonal variations as follows: January--mid dry; April--late dry; July--mid rainy and October--late rainy seasons. Leaf samples were randomly collected from the trees for estimation of dry matter (DM) and chemical composition. Ruminal in sacco OM and CP degradabilities were estimated from residues in nylon bags. All samples had high CP (161-259 g/kg DM) and moderate fibre concentrations [neutral detergent fibre (without residual ash], 300-501 g/kg DM; acid detergent fibre (without residual ash), 225-409 g/kg DM and acid detergent lignin, 87-179 g/kg DM across seasons. Interaction effects of species and season on chemical composition were highly significant (p = 0.001) except for trypsin inhibitor (p = 0.614). The MPTS recorded more than 60% OM and CP degradability at 24 h, which implied that they were all highly degradable in the rumen. Their incorporation into ruminant feeding systems as dry season forage supplements is therefore recommended.

  7. Species-specific loss of sexual dimorphism in vocal effectors accompanies vocal simplification in African clawed frogs (Xenopus)

    PubMed Central

    Leininger, Elizabeth C.; Kitayama, Ken; Kelley, Darcy B.

    2015-01-01

    ABSTRACT Phylogenetic studies can reveal patterns of evolutionary change, including the gain or loss of elaborate courtship traits in males. Male African clawed frogs generally produce complex and rapid courtship vocalizations, whereas female calls are simple and slow. In a few species, however, male vocalizations are also simple and slow, suggesting loss of male-typical traits. Here, we explore features of the male vocal organ that could contribute to loss in two species with simple, slow male calls. In Xenopus boumbaensis, laryngeal morphology is more robust in males than in females. Larynges are larger, have a more complex cartilaginous morphology and contain more muscle fibers. Laryngeal muscle fibers are exclusively fast-twitch in males but are both fast- and slow-twitch in females. The laryngeal electromyogram, a measure of neuromuscular synaptic strength, shows greater potentiation in males than in females. Male-specific physiological features are shared with X. laevis, as well as with a species of the sister clade, Silurana tropicalis, and thus are likely ancestral. In X. borealis, certain aspects of laryngeal morphology and physiology are sexually monomorphic rather than dimorphic. In both sexes, laryngeal muscle fibers are of mixed-twitch type, which limits the production of muscle contractions at rapid intervals. Muscle activity potentiation and discrete tension transients resemble female rather than male X. boumbaensis. The de-masculinization of these laryngeal features suggests an alteration in sensitivity to the gonadal hormones that are known to control the sexual differentiation of the larynx in other Xenopus and Silurana species. PMID:25788725

  8. Laboratory investigations of African Pouched Rats (Cricetomys gambianus) as a potential reservoir host species for Monkeypox Virus

    USGS Publications Warehouse

    Hutson, Christina L.; Nakazawa, Yoshinori J.; Self, Joshua; Olson, Victoria A.; Regnery, Russell L.; Braden, Zachary; Weiss, Sonja; Malekani, Jean; Jackson, Eddie; Tate, Mallory; Karem, Kevin L.; Rocke, Tonie E.; Osorio, Jorge E.; Damon, Inger K.; Carroll, Darin S.

    2015-01-01

    Monkeypox is a zoonotic disease endemic to central and western Africa, where it is a major public health concern. Although Monkeypox virus (MPXV) and monkeypox disease in humans have been well characterized, little is known about its natural history, or its maintenance in animal populations of sylvatic reservoir(s). In 2003, several species of rodents imported from Ghana were involved in a monkeypox outbreak in the United States with individuals of three African rodent genera (Cricetomys, Graphiurus, Funisciurus) shown to be infected with MPXV. Here, we examine the course of MPXV infection in Cricetomys gambianus (pouched Gambian rats) and this rodent species’ competence as a host for the virus. We obtained ten Gambian rats from an introduced colony in Grassy Key, Florida and infected eight of these via scarification with a challenge dose of 4X104 plaque forming units (pfu) from either of the two primary clades of MPXV: Congo Basin (C-MPXV: n = 4) or West African (W-MPXV: n = 4); an additional 2 animals served as PBS controls. Viral shedding and the effect of infection on activity and physiological aspects of the animals were measured. MPXV challenged animals had significantly higher core body temperatures, reduced activity and increased weight loss than PBS controls. Viable virus was found in samples taken from animals in both experimental groups (C-MPXV and W-MPXV) between 3 and 27 days post infection (p.i.) (up to 1X108pfu/ml), with viral DNA found until day 56 p.i. The results from this work show that Cricetomys gambianus (and by inference, probably the closely related species, Cricetomys emini) can be infected with MPXV and shed viable virus particles; thus suggesting that these animals may be involved in the maintenance of MPXV in wildlife mammalian populations. More research is needed to elucidate the epidemiology of MPXV and the role of Gambian rats and other species.

  9. African parasitoid fig wasp diversification is a function of Ficus species ranges.

    PubMed

    McLeish, Michael J; van Noort, Simon; Tolley, Krystal A

    2010-10-01

    Host specificity is a fundamental property implicit in obligate insect-plant associations. Rigid life history constraints exhibited by parasitoid fig wasps are believed to select for specialization directed at fig trees and this is supported by evidence of phenotypic adaptation to figs and partial co-speciation with the fig wasps they attack. Conversely, the ability to colonize such novel communities occurs under relaxed specificity, a behavior typified by more generalist groups such as parasitoids. The specificity directed towards Ficus species by Sycoryctinae parasitoid fig wasps is important in order to understand how this form of specialization influences their diversification and interactions with other fig wasp guilds. We use genetic distance analyses and reconstruct ancestral patterns of Ficus trait association with two genera of Sycoryctinae parasitoid fig wasps to identify evolutionary conservatism in Ficus species utilization. Ancestral state reconstructions of (i) affiliate Ficus subsection and (ii) syconia diameters of natal Ficus species indicate contrasting Ficus species ranges between Arachonia and Sycoryctes parasitoid genera. This work demonstrates that parasitoid speciation is not tightly constrained to Ficus speciation and rather a function of Ficus range limitations. Ficus evolution, ecology, and functional compatibility between parasitoid and Ficus traits appear to constrain parasitoid Ficus utilization. These results suggest that contrasting ecological settings and potential number of hosts available impose different ramifications for the evolution of parasitoid host specificity and so to the species interactions within the communities to which they belong.

  10. NASA and USGS invest in invasive species modeling to evaluate habitat for Africanized Honey Bees

    USGS Publications Warehouse

    2009-01-01

    Invasive non-native species, such as plants, animals, and pathogens, have long been an interest to the U.S. Geological Survey (USGS) and NASA. Invasive species cause harm to our economy (around $120 B/year), the environment (e.g., replacing native biodiversity, forest pathogens negatively affecting carbon storage), and human health (e.g., plague, West Nile virus). Five years ago, the USGS and NASA formed a partnership to improve ecological forecasting capabilities for the early detection and containment of the highest priority invasive species. Scientists from NASA Goddard Space Flight Center (GSFC) and the Fort Collins Science Center developed a longterm strategy to integrate remote sensing capabilities, high-performance computing capabilities and new spatial modeling techniques to advance the science of ecological invasions [Schnase et al., 2002].

  11. Climate and species richness predict the phylogenetic structure of African mammal communities.

    PubMed

    Kamilar, Jason M; Beaudrot, Lydia; Reed, Kaye E

    2015-01-01

    We have little knowledge of how climatic variation (and by proxy, habitat variation) influences the phylogenetic structure of tropical communities. Here, we quantified the phylogenetic structure of mammal communities in Africa to investigate how community structure varies with respect to climate and species richness variation across the continent. In addition, we investigated how phylogenetic patterns vary across carnivores, primates, and ungulates. We predicted that climate would differentially affect the structure of communities from different clades due to between-clade biological variation. We examined 203 communities using two metrics, the net relatedness (NRI) and nearest taxon (NTI) indices. We used simultaneous autoregressive models to predict community phylogenetic structure from climate variables and species richness. We found that most individual communities exhibited a phylogenetic structure consistent with a null model, but both climate and species richness significantly predicted variation in community phylogenetic metrics. Using NTI, species rich communities were composed of more distantly related taxa for all mammal communities, as well as for communities of carnivorans or ungulates. Temperature seasonality predicted the phylogenetic structure of mammal, carnivoran, and ungulate communities, and annual rainfall predicted primate community structure. Additional climate variables related to temperature and rainfall also predicted the phylogenetic structure of ungulate communities. We suggest that both past interspecific competition and habitat filtering have shaped variation in tropical mammal communities. The significant effect of climatic factors on community structure has important implications for the diversity of mammal communities given current models of future climate change.

  12. The relationship between growth, brain asymmetry and behavioural lateralization in a cichlid fish.

    PubMed

    Reddon, Adam R; Gutiérrez-Ibáñez, Cristián; Wylie, Douglas R; Hurd, Peter L

    2009-07-19

    Cerebral lateralization, the partitioning of cognitive tasks to one cerebral hemisphere, is a widespread phenomenon among vertebrates. Despite this diversity, every species studied to date shows substantial individual variation in the strength of lateralization. The neural basis of this trait is unclear, although asymmetries in cerebral structures have been investigated for over a century. The habenular nuclei, for example, have been shown to present striking neuroanatomical and/or neurochemical asymmetries in species ranging from jawless fish to mammals. In teleost fish, these nuclei are relatively symmetrical in most species. Those teleosts that do have asymmetrical habenular nuclei, show varying patterns of asymmetry in different species. Here we investigate the relationship between individual variation of asymmetry in the habenula of a South American cichlid fish, Geophagus brasiliensis, and behaviour in a commonly used test for visual laterality in fish, the detour task. We show that the strength of asymmetry in the habenula is correlated with strength of behavioural lateralization in the detour task. Both the strength and direction of habenular asymmetry are correlated with individual differences in growth rate. We suggest that this relationship results from processes linking growth rate and sexual differentiation to frequency-dependent variation in life-history strategies. To our knowledge, this is the first study to demonstrate a relationship at the individual level between neural asymmetry and lateralized behaviour in a fish.

  13. Three African antelope species with varying water dependencies exhibit similar selective brain cooling.

    PubMed

    Strauss, W Maartin; Hetem, Robyn S; Mitchell, Duncan; Maloney, Shane K; Meyer, Leith C R; Fuller, Andrea

    2016-05-01

    The use of selective brain cooling, where warm arterial blood destined for the brain is cooled in the carotid rete via counter-current heat exchange when in close proximity to cooler venous blood, contributes to the conservation of body water. We simultaneously measured carotid blood and hypothalamic temperature in four gemsbok, five red hartebeest and six blue wildebeest to assess the extent to which these free-living animals, with varying water dependency, routinely rely on selective brain cooling. We investigated the hypothesis that innate differences in selective brain cooling exist in large, sympatric artiodactyls with varying water dependency. All three species used selective brain cooling, without any discernible differences in three selective brain cooling indices. GLMMs revealed no species differences in the threshold temperature for selective brain cooling (z = 0.79, P = 0.43), the magnitude (z = -0.51, P = 0.61), or the frequency of selective brain cooling use (z = -0.47, P = 0.64), after controlling for carotid blood temperature and black globe temperature. Comparison of anatomical attributes of the carotid retes of the three species revealed that the volume (F 2,9 = 5.54, P = 0.03) and height (F 2,9 = 5.43, P = 0.03) of the carotid rete, per kilogram body mass, were greater in the red hartebeest than in the blue wildebeest. Nevertheless, intraspecific variability in the magnitude, the frequency of use, and the threshold temperature for selective brain cooling exceeded any interspecific variability in the three indices of selective brain cooling. We conclude that the three species have similar underlying ability to make use of selective brain cooling in an environment with freely available water. It remains to be seen to what extent these three species would rely on selective brain cooling, as a water conservation mechanism, when challenged by aridity, a condition likely to become prevalent throughout much of southern Africa under future climate change

  14. A nonsynonymous mutation in the transcriptional regulator lbh is associated with cichlid craniofacial adaptation and neural crest cell development.

    PubMed

    Powder, Kara E; Cousin, Hélène; McLinden, Gretchen P; Craig Albertson, R

    2014-12-01

    Since the time of Darwin, biologists have sought to understand the origins and maintenance of life's diversity of form. However, the nature of the exact DNA mutations and molecular mechanisms that result in morphological differences between species remains unclear. Here, we characterize a nonsynonymous mutation in a transcriptional coactivator, limb bud and heart homolog (lbh), which is associated with adaptive variation in the lower jaw of cichlid fishes. Using both zebrafish and Xenopus, we demonstrate that lbh mediates migration of cranial neural crest cells, the cellular source of the craniofacial skeleton. A single amino acid change that is alternatively fixed in cichlids with differing facial morphologies results in discrete shifts in migration patterns of this multipotent cell type that are consistent with both embryological and adult craniofacial phenotypes. Among animals, this polymorphism in lbh represents a rare example of a coding change that is associated with continuous morphological variation. This work offers novel insights into the development and evolution of the craniofacial skeleton, underscores the evolutionary potential of neural crest cells, and extends our understanding of the genetic nature of mutations that underlie divergence in complex phenotypes.

  15. A Nonsynonymous Mutation in the Transcriptional Regulator lbh Is Associated with Cichlid Craniofacial Adaptation and Neural Crest Cell Development

    PubMed Central

    Powder, Kara E.; Cousin, Hélène; McLinden, Gretchen P.; Craig Albertson, R.

    2014-01-01

    Since the time of Darwin, biologists have sought to understand the origins and maintenance of life’s diversity of form. However, the nature of the exact DNA mutations and molecular mechanisms that result in morphological differences between species remains unclear. Here, we characterize a nonsynonymous mutation in a transcriptional coactivator, limb bud and heart homolog (lbh), which is associated with adaptive variation in the lower jaw of cichlid fishes. Using both zebrafish and Xenopus, we demonstrate that lbh mediates migration of cranial neural crest cells, the cellular source of the craniofacial skeleton. A single amino acid change that is alternatively fixed in cichlids with differing facial morphologies results in discrete shifts in migration patterns of this multipotent cell type that are consistent with both embryological and adult craniofacial phenotypes. Among animals, this polymorphism in lbh represents a rare example of a coding change that is associated with continuous morphological variation. This work offers novel insights into the development and evolution of the craniofacial skeleton, underscores the evolutionary potential of neural crest cells, and extends our understanding of the genetic nature of mutations that underlie divergence in complex phenotypes. PMID:25234704

  16. The susceptibility of five African Anopheles species to Anabaena PCC 7120 expressing Bacillus thuringiensis subsp. israelensis mosquitocidal cry genes

    PubMed Central

    2012-01-01

    Background Malaria, one of the leading causes of death in Africa, is transmitted by the bite of an infected female Anopheles mosquito. Problems associated with the development of resistance to chemical insecticides and concerns about the non-target effects and persistence of chemical insecticides have prompted the development of environmentally friendly mosquito control agents. The aim of this study was to evaluate the larvicidal activity of a genetically engineered cyanobacterium, Anabaena PCC 7120#11, against five African Anopheles species in laboratory bioassays. Findings There were significant differences in the susceptibility of the anopheline species to PCC 7120#11. The ranking of the larvicidal activity of PCC 7120#11 against species in the An. gambiae complex was: An. merus

  17. Species boundaries and taxonomy of the African river frogs (Amphibia: Pyxicephalidae: Amietia).

    PubMed

    Channing, A; Dehling, J M; Lötters, S; Ernst, R

    2016-08-25

    A molecular phylogeny of the Afrotropical anuran genus Amietia based on 323 16S sequences indicates that there are 19 species, including four not yet described. No genetic material was available for the nominal A. inyangae. We consider them to represent full species, and define them based on 16S genetic distances, as well as differences in morphology, tadpoles and advertisement call where known. An analysis based on two mitochondrial and two nuclear genes (12S, 16S, 28S and tyrosinase exon 1), from 122 samples, confirmed the phylogenetic relationships suggested by the 16S tree. We recognise and (re-) describe the following species: Amietia angolensis (Bocage, 1866), A. chapini (Noble, 1924), A. delalandii (Duméril & Bibron, 1841), A. desaegeri (Laurent, 1972), A. fuscigula (Duméril & Bibron, 1841), A. hymenopus (Boulenger, 1920), A. inyangae (Poynton, 1966), A. johnstoni (Günther, 1893), A. moyerorum sp. nov., A. nutti (Boulenger, 1896), A. poyntoni Channing & Baptista, 2013, A. ruwenzorica (Laurent, 1972), A. tenuoplicata (Pickersgill, 2007), A. vandijki (Visser & Channing, 1997), A. vertebralis (Hewitt, 1927), and A. wittei (Angel, 1924). Three further candidate species of Larson et al. (2016) await formal naming. We provisionally regard A. amieti (Laurent, 1976) as a junior synonym of A. chapini (Noble, 1924). Amietia lubrica (Pickersgill, 2007) is shown to be a junior synonym of A. nutti, while A. quecketti (Boulenger, 1895) is shown to be a junior synonym of A. delalandii (Duméril & Bibron, 1841), and A. viridireticulata (Pickersgill, 2007) is placed as a junior synonym of A. tenuoplicata (Pickersgill, 2007). On the basis of similarity of 16S sequences, we assign A. sp. 1, A. sp. 3 and A. sp. 6 of Larson et al (2016) to the nomina A. chapini (Noble, 1924), A. desaegeri (Laurent, 1972), and A. nutti (Boulenger, 1896) respectively.

  18. The spatial distribution of African savannah herbivores: species associations and habitat occupancy in a landscape context.

    PubMed

    Anderson, T Michael; White, Staci; Davis, Bryant; Erhardt, Rob; Palmer, Meredith; Swanson, Alexandra; Kosmala, Margaret; Packer, Craig

    2016-09-19

    Herbivores play an important role in determining the structure and function of tropical savannahs. Here, we (i) outline a framework for how interactions among large mammalian herbivores, carnivores and environmental variation influence herbivore habitat occupancy in tropical savannahs. We then (ii) use a Bayesian hierarchical model to analyse camera trap data to quantify spatial patterns of habitat occupancy for lions and eight common ungulates of varying body size across an approximately 1100 km(2) landscape in the Serengeti ecosystem. Our results reveal strong positive associations among herbivores at the scale of the entire landscape. Lions were positively associated with migratory ungulates but negatively associated with residents. Herbivore habitat occupancy differed with body size and migratory strategy: large-bodied migrants, at less risk of predation and able to tolerate lower quality food, were associated with high NDVI, while smaller residents, constrained to higher quality forage, avoided these areas. Small herbivores were strongly associated with fires, likely due to the subsequent high-quality regrowth, while larger herbivores avoided burned areas. Body mass was strongly related to herbivore habitat use, with larger species more strongly associated with riverine and woodlands than smaller species. Large-bodied migrants displayed diffuse habitat occupancy, whereas smaller species demonstrated fine-scale occupancy reflecting use of smaller patches of high-quality habitat. Our results demonstrate the emergence of strong positive spatial associations among a diverse group of savannah herbivores, while highlighting species-specific habitat selection strongly determined by herbivore body size.This article is part of the themed issue 'Tropical grassy biomes: linking ecology, human use and conservation'.

  19. Breeding experience and parental behaviour in convict cichlids (Cichlasoma nigrofasciatum ).

    PubMed

    Colgan, P W; Salmon, A B

    1986-06-01

    Changes in the levels of activities by parental female and male convict cichlids were studied over three successive reproductive episodes and within each episode. No evidence was found for behavioural maturation independent of experience. With successive episodes, young survived for longer times, nests were cleaner, males ate less and females more, and males became more aggressive while females focused more on the nest. Within an episode there were also marked variations in activities by each sex. Reproductive behaviour is therefore open in a number of respects both within and across episodes to environmental inputs.

  20. Using Social Media to Measure the Contribution of Red List Species to the Nature-Based Tourism Potential of African Protected Areas

    PubMed Central

    Drakou, Evangelia G.; Burgess, Neil D.

    2015-01-01

    Cultural ecosystem services are defined by people’s perception of the environment, which make them hard to quantify systematically. Methods to describe cultural benefits from ecosystems typically include resource-demanding survey techniques, which are not suitable to assess cultural ecosystem services for large areas. In this paper we explore a method to quantify cultural benefits through the enjoyment of natured-based tourism, by assessing the potential tourism attractiveness of species for each protected area in Africa using the IUCN’s Red List of Threatened Species. We use the number of pictures of wildlife posted on a photo sharing website as a proxy for charisma, popularity, and ease of observation, as these factors combined are assumed to determine how attractive species are for the global wildlife tourist. Based on photo counts of 2473 African animals and plants, species that seem most attractive to nature-based tourism are the Lion, African Elephant and Leopard. Combining the photo counts with species range data, African protected areas with the highest potential to attract wildlife tourists based on attractive species occurrence were Samburu National Reserve in Kenya, Mukogodo Forest Reserve located just north of Mount Kenya, and Addo Elephant National Park in South-Africa. The proposed method requires only three data sources which are freely accessible and available online, which could make the proposed index tractable for large scale quantitative ecosystem service assessments. The index directly links species presence to the tourism potential of protected areas, making the connection between nature and human benefits explicit, but excludes other important contributing factors for tourism, such as accessibility and safety. This social media based index provides a broad understanding of those species that are popular globally; in many cases these are not the species of highest conservation concern. PMID:26068111

  1. Using Social Media to Measure the Contribution of Red List Species to the Nature-Based Tourism Potential of African Protected Areas.

    PubMed

    Willemen, Louise; Cottam, Andrew J; Drakou, Evangelia G; Burgess, Neil D

    2015-01-01

    Cultural ecosystem services are defined by people's perception of the environment, which make them hard to quantify systematically. Methods to describe cultural benefits from ecosystems typically include resource-demanding survey techniques, which are not suitable to assess cultural ecosystem services for large areas. In this paper we explore a method to quantify cultural benefits through the enjoyment of natured-based tourism, by assessing the potential tourism attractiveness of species for each protected area in Africa using the IUCN's Red List of Threatened Species. We use the number of pictures of wildlife posted on a photo sharing website as a proxy for charisma, popularity, and ease of observation, as these factors combined are assumed to determine how attractive species are for the global wildlife tourist. Based on photo counts of 2473 African animals and plants, species that seem most attractive to nature-based tourism are the Lion, African Elephant and Leopard. Combining the photo counts with species range data, African protected areas with the highest potential to attract wildlife tourists based on attractive species occurrence were Samburu National Reserve in Kenya, Mukogodo Forest Reserve located just north of Mount Kenya, and Addo Elephant National Park in South-Africa. The proposed method requires only three data sources which are freely accessible and available online, which could make the proposed index tractable for large scale quantitative ecosystem service assessments. The index directly links species presence to the tourism potential of protected areas, making the connection between nature and human benefits explicit, but excludes other important contributing factors for tourism, such as accessibility and safety. This social media based index provides a broad understanding of those species that are popular globally; in many cases these are not the species of highest conservation concern.

  2. Female promiscuity promotes the evolution of faster sperm in cichlid fishes.

    PubMed

    Fitzpatrick, John L; Montgomerie, Robert; Desjardins, Julie K; Stiver, Kelly A; Kolm, Niclas; Balshine, Sigal

    2009-01-27

    Sperm competition, the contest among ejaculates from rival males to fertilize ova of a female, is a common and powerful evolutionary force influencing ejaculate traits. During competitive interactions between ejaculates, longer and faster spermatozoa are expected to have an edge; however, to date, there has been mixed support for this key prediction from sperm competition theory. Here, we use the spectacular radiation of cichlid fishes from Lake Tanganyika to examine sperm characteristics in 29 closely related species. We provide phylogenetically robust evidence that species experiencing greater levels of sperm competition have faster-swimming sperm. We also show that sperm competition selects for increases in the number, size, and longevity of spermatozoa in the ejaculate of a male, and, contrary to expectations from theory, we find no evidence of trade-offs among sperm traits in an interspecific analysis. Also, sperm swimming speed is positively correlated with sperm length among, but not within, species. These different responses to sperm competition at intra- and interspecific levels provide a simple, powerful explanation for equivocal results from previous studies. Using phylogenetic analyses, we also reconstructed the probable evolutionary route of trait evolution in this taxon, and show that, in response to increases in the magnitude of sperm competition, the evolution of sperm traits in this clade began with the evolution of faster (thus, more competitive) sperm.

  3. Symmetry perception in bamboo sharks (Chiloscyllium griseum) and Malawi cichlids (Pseudotropheus sp.).

    PubMed

    Schluessel, V; Beil, O; Weber, T; Bleckmann, H

    2014-09-01

    Several species have been shown to perceive symmetry as a measure of superior genetic quality, useful for assessing potential mates or mediating other visual activities such as the selection of food sources. The current study assessed whether Pseudotropheus sp. and Chiloscyllium griseum, two fish species from distantly related groups, possess symmetry perception. In alternative two choice experiments, individuals were tested for spontaneous preferences and trained to discriminate between abstract symmetrical and asymmetrical stimulus pairs. Pair discriminations were followed by extensive categorization experiments. Transfer tests elucidated whether bilaterally symmetrical and rotationally symmetrical stimuli could be distinguished. Sharks were also tested for the degree of dissimilarity between two symbols that could still be detected. While sharks showed both a spontaneous preference for symmetry as well as remarkable discrimination abilities by succeeding in all of the presented tasks, cichlids showed no spontaneous preference, had difficulties in discriminating between symbols and performed poorly in the categorization experiments. Sharks distinguished between bilaterally and rotationally symmetrical stimuli and easily differentiated between a four-armed cross (all arms 90° apart) and a cross where one of the arms was only 45° spaced from the one next to it. Performance did not decline when the separation was extended to 70°, but was significantly reduced at an 80° separation. Results indicate that the ability for symmetry perception varies across fish species and individuals, whereby some can detect even subtle differences in this respect.

  4. New species of haemosporidian parasites (Haemosporida) from African rainforest birds, with remarks on their classification.

    PubMed

    Valkiūnas, Gediminas; Iezhova, Tatjana A; Loiseau, Claire; Chasar, Anthony; Smith, Thomas B; Sehgal, Ravinder N M

    2008-10-01

    Plasmodium (Novyella) megaglobularis n. sp. was recorded in the olive sunbird Cyanomitra olivacea, and Plasmodium (Novyella) globularis n. sp. and Haemoproteus (Parahaemoproteus) vacuolatus n. sp. were found in the yellow-whiskered greenbul Andropadus latirostris in rainforests of Ghana and Cameroon. These parasites are described based on the morphology of their blood stages and a segment of the mitochondrial cytochrome b gene, which can be used for molecular identification and diagnosis of these species. Illustrations of blood stages of new species are given, and phylogenetic analysis identifies deoxyribonucleic acid (DNA) lineages closely related to these parasites. Traditional taxonomy of avian pigment-forming haemosporidians of the families Plasmodiidae and Haemoproteidae is discussed based on the recent molecular phylogenies of these parasites. We conclude that further work to increase the number of precise linkages between haemosporidian DNA sequences and their corresponding morphospecies is needed before revising the current classification of haemosporidians. This study emphasises the value of both the polymerase chain reaction and microscopy in the identification of avian haemosporidian parasites.

  5. The Function of Anal Fin Egg-Spots in the Cichlid Fish Astatotilapia burtoni

    PubMed Central

    Theis, Anya; Salzburger, Walter; Egger, Bernd

    2012-01-01

    Color and pigmentation patterns of animals are often targets of sexual selection because of their role in communication. Although conspicuous male traits are typically implicated with intersexual selection, there are examples where sex-specific displays play a role in an intrasexual context, e.g. when they serve as signals for aggression level and/or status. Here, we focus on the function of a conspicuous male ornament in the most species-rich tribe of cichlid fishes, the haplochromines. A characteristic feature of these ca. 1500 species are so-called egg-spots in form of ovoid markings on the anal fins of males, which are made up of carotenoid based pigment cells. It has long been assumed that these yellow, orange or reddish egg-spots play an important role in the courtship and spawning behavior of these maternal mouth-brooding fishes by mimicking the eggs of a conspecific female. The exact function of egg-spots remains unknown, however, and there are several hypotheses about their mode of action. To uncover the function of this cichlid-specific male ornament, we used female mate choice experiments and a male aggression test in the haplochromine species Astatotilapia burtoni. We manipulated the number and arrangement of egg-spots on the anal fins of males, or removed them entirely, and tested (1) female preference with visual contact only using egg-traps, (2) female preference with free contact using paternity testing with microsatellites and (3) male aggression. We found that females did not prefer males with many egg-spots over males with fewer egg-spots and that females tended to prefer males without egg-spots over males with egg-spots. Importantly, males without egg-spots sired clutches with the same fertilization rate as males with egg-spots. In male aggression trials, however, males with fewer egg-spots received significantly more attacks, suggesting that egg-spots are an important signal in intrasexual communication. PMID:22242184

  6. Molecular basis of the remarkable species selectivity of an insecticidal sodium channel toxin from the African spider Augacephalus ezendami

    NASA Astrophysics Data System (ADS)

    Herzig, Volker; Ikonomopoulou, Maria; Smith, Jennifer J.; Dziemborowicz, Sławomir; Gilchrist, John; Kuhn-Nentwig, Lucia; Rezende, Fernanda Oliveira; Moreira, Luciano Andrade; Nicholson, Graham M.; Bosmans, Frank; King, Glenn F.

    2016-07-01

    The inexorable decline in the armament of registered chemical insecticides has stimulated research into environmentally-friendly alternatives. Insecticidal spider-venom peptides are promising candidates for bioinsecticide development but it is challenging to find peptides that are specific for targeted pests. In the present study, we isolated an insecticidal peptide (Ae1a) from venom of the African spider Augacephalus ezendami (family Theraphosidae). Injection of Ae1a into sheep blowflies (Lucilia cuprina) induced rapid but reversible paralysis. In striking contrast, Ae1a was lethal to closely related fruit flies (Drosophila melanogaster) but induced no adverse effects in the recalcitrant lepidopteran pest Helicoverpa armigera. Electrophysiological experiments revealed that Ae1a potently inhibits the voltage-gated sodium channel BgNaV1 from the German cockroach Blattella germanica by shifting the threshold for channel activation to more depolarized potentials. In contrast, Ae1a failed to significantly affect sodium currents in dorsal unpaired median neurons from the American cockroach Periplaneta americana. We show that Ae1a interacts with the domain II voltage sensor and that sensitivity to the toxin is conferred by natural sequence variations in the S1–S2 loop of domain II. The phyletic specificity of Ae1a provides crucial information for development of sodium channel insecticides that target key insect pests without harming beneficial species.

  7. Molecular basis of the remarkable species selectivity of an insecticidal sodium channel toxin from the African spider Augacephalus ezendami.

    PubMed

    Herzig, Volker; Ikonomopoulou, Maria; Smith, Jennifer J; Dziemborowicz, Sławomir; Gilchrist, John; Kuhn-Nentwig, Lucia; Rezende, Fernanda Oliveira; Moreira, Luciano Andrade; Nicholson, Graham M; Bosmans, Frank; King, Glenn F

    2016-07-07

    The inexorable decline in the armament of registered chemical insecticides has stimulated research into environmentally-friendly alternatives. Insecticidal spider-venom peptides are promising candidates for bioinsecticide development but it is challenging to find peptides that are specific for targeted pests. In the present study, we isolated an insecticidal peptide (Ae1a) from venom of the African spider Augacephalus ezendami (family Theraphosidae). Injection of Ae1a into sheep blowflies (Lucilia cuprina) induced rapid but reversible paralysis. In striking contrast, Ae1a was lethal to closely related fruit flies (Drosophila melanogaster) but induced no adverse effects in the recalcitrant lepidopteran pest Helicoverpa armigera. Electrophysiological experiments revealed that Ae1a potently inhibits the voltage-gated sodium channel BgNaV1 from the German cockroach Blattella germanica by shifting the threshold for channel activation to more depolarized potentials. In contrast, Ae1a failed to significantly affect sodium currents in dorsal unpaired median neurons from the American cockroach Periplaneta americana. We show that Ae1a interacts with the domain II voltage sensor and that sensitivity to the toxin is conferred by natural sequence variations in the S1-S2 loop of domain II. The phyletic specificity of Ae1a provides crucial information for development of sodium channel insecticides that target key insect pests without harming beneficial species.

  8. Molecular basis of the remarkable species selectivity of an insecticidal sodium channel toxin from the African spider Augacephalus ezendami

    PubMed Central

    Herzig, Volker; Ikonomopoulou, Maria; Smith, Jennifer J.; Dziemborowicz, Sławomir; Gilchrist, John; Kuhn-Nentwig, Lucia; Rezende, Fernanda Oliveira; Moreira, Luciano Andrade; Nicholson, Graham M.; Bosmans, Frank; King, Glenn F.

    2016-01-01

    The inexorable decline in the armament of registered chemical insecticides has stimulated research into environmentally-friendly alternatives. Insecticidal spider-venom peptides are promising candidates for bioinsecticide development but it is challenging to find peptides that are specific for targeted pests. In the present study, we isolated an insecticidal peptide (Ae1a) from venom of the African spider Augacephalus ezendami (family Theraphosidae). Injection of Ae1a into sheep blowflies (Lucilia cuprina) induced rapid but reversible paralysis. In striking contrast, Ae1a was lethal to closely related fruit flies (Drosophila melanogaster) but induced no adverse effects in the recalcitrant lepidopteran pest Helicoverpa armigera. Electrophysiological experiments revealed that Ae1a potently inhibits the voltage-gated sodium channel BgNaV1 from the German cockroach Blattella germanica by shifting the threshold for channel activation to more depolarized potentials. In contrast, Ae1a failed to significantly affect sodium currents in dorsal unpaired median neurons from the American cockroach Periplaneta americana. We show that Ae1a interacts with the domain II voltage sensor and that sensitivity to the toxin is conferred by natural sequence variations in the S1–S2 loop of domain II. The phyletic specificity of Ae1a provides crucial information for development of sodium channel insecticides that target key insect pests without harming beneficial species. PMID:27383378

  9. Incipient speciation driven by hypertrophied lips in Midas cichlid fishes?

    PubMed

    Machado-Schiaffino, Gonzalo; Kautt, Andreas F; Torres-Dowdall, Julian; Baumgarten, Lukas; Henning, Frederico; Meyer, Axel

    2017-01-30

    Sympatric speciation has been debated in evolutionary biology for decades. Although it has gained in acceptance recently, still only a handful of empirical examples are seen as valid (e.g. crater lake cichlids). In this study, we disentangle the role of hypertrophied lips in the repeated adaptive radiations of Nicaraguan crater lake cichlid fish. We assessed the role of disruptive selection and assortative mating during the early stages of divergence and found a functional trade-off in feeding behaviour between thick- and thin-lipped ecotypes, suggesting that this trait is a target of disruptive selection. Thick-lipped fish perform better on nonevasive prey at the cost of a poorer performance on evasive prey. Using enclosures in the wild, we found that thick-lipped fish perform significantly better in rocky than in sandy habitats. We found almost no mixed pairs during two breeding seasons and hence significant assortative mating. Genetic differentiation between ecotypes seems to be related to the time since colonization, being subtle in L. Masaya (1600 generations ago) and absent in the younger L. Apoyeque (<600 generations ago). Genome-wide differentiation between ecotypes was higher in the old source lakes than in the young crater lakes. Our results suggest that hypertrophied lips might be promoting incipient sympatric speciation through divergent selection (ecological divergence in feeding performance) and nonrandom mating (assortative mating) in the young Nicaraguan crater lakes. Nonetheless, further manipulative experiments are needed in order to confirm the role of hypertrophied lips as the main cue for assortative mating.

  10. Contribution to the knowledge of Afrotropical Dryinidae, Embolemidae and Sclerogibbidae (Hymenoptera), with description of new species from Central African Republic and Uganda

    PubMed Central

    Olmi, Massimo; van Noort, Simon; Guglielmino, Adalgisa

    2016-01-01

    Abstract An updated checklist of Dryinidae, Embolemidae and Sclerogibbidae from Central African Republic and Uganda is presented. The following new species of Dryinidae are described: from Central African Republic: Anteon dzanganum sp. n. (Anteoninae); from Uganda: Anteon granulatum sp. n., Anteon kibalense sp. n., Anteon makererense sp. n., Anteon mubfs sp. n. (Anteoninae); Bocchus kibalensis sp. n. (Bocchinae); Dryinus kibalus sp. n. (Dryininae); Gonatopus kanyawarus sp. n. (Gonatopodinae). The following species have been recorded for the first time from Central African Republic: Embolemidae: Ampulicomorpha madecassa Olmi, 1999a; Embolemus capensis Olmi, 1997; Dryinidae: Aphelopus mediocarinatus (Benoit, 1951d), Aphelopus testaceus Olmi, 1991, Aphelopus wittei Benoit, 1951c (Aphelopinae); Anteon cautum Olmi, 1994a, Anteon evertsi Olmi, 1989, Anteon gutturnium (Benoit, 1951b), Anteon inflatrix Benoit, 1951b, Anteon kivuanum (Benoit, 1951c), Anteon semajanna Olmi, Copeland & Guglielmino, 2015, Anteon zairense Benoit, 1951d (Anteoninae); Pseudodryinus townesi (Olmi, 1984) (Dryininae); Echthrodelphax tauricus Ponomarenko, 1970, Gonatopus camerounensis Olmi, 2011, Gonatopus kolyadai Olmi, 2007b, Neodryinus antiquus Benoit, 1954, Neodryinus tussaci Olmi, 2004b (Gonatopodinae); Sclerogibbidae: Probethylus callani Richards, 1939b; Sclerogibba algerica Benoit, 1963, Sclerogibba rapax Olmi, 2005a. The following species have been recorded for the first time from Uganda: Embolemidae: Ampulicomorpha magna Olmi, 1996; Dryinidae: Anteon cautum Olmi, 1994a, Anteon fisheri Olmi, 2003, Anteon hoyoi Olmi, 1984, Anteon kivuanum (Benoit, 1951c), Anteon townesi Olmi, 1984, Anteon zairense Benoit, 1951d (Anteoninae); Bocchus bini Olmi, 1984 (Bocchinae); Dryinus saussurei (Ceballos, 1936) (Dryininae); Echthrodelphax migratorius Benoit, 1954, Neodryinus tussaci Olmi, 2004b (Gonatopodinae). The following further species has been recorded for the first time from Mali: Sclerogibba algerica

  11. A new African soft scale genus, Pseudocribrolecanium gen. nov. (Hemiptera: Coccoidea: Coccidae), erected for two species, including the citrus pest P. andersoni (Newstead) comb. nov

    PubMed Central

    Kondo, Takumasa

    2006-01-01

    A new African genus of soft scale insects, Pseudocribrolecanium gen. nov. is erected to accommodate Akermes colae Green & Laing and Cribrolecanium andersoni (Newstead). The adult females and first-instar nymphs of the two species are redescribed and illustrated. Taxonomic keys to separate the adult females and first-instar nymphs are provided. The affinity of Pseudocribrolecanium with the tribe Paralecaniini in the subfamily Coccinae is discussed. PMID:19537997

  12. A new African soft scale genus, Pseudocribrolecanium gen. nov. (Hemiptera: Coccoidea: Coccidae), erected for two species, including the citrus pest P. andersoni (Newstead) comb. nov.

    PubMed

    Kondo, Takumasa

    2006-01-01

    A new African genus of soft scale insects, Pseudocribrolecanium gen. nov. is erected to accommodate Akermes colae Green & Laing and Cribrolecanium andersoni (Newstead). The adult females and first-instar nymphs of the two species are redescribed and illustrated. Taxonomic keys to separate the adult females and first-instar nymphs are provided. The affinity of Pseudocribrolecanium with the tribe Paralecaniini in the subfamily Coccinae is discussed.

  13. Patterns of style polymorphism in five species of the South African genus Nivenia (Iridaceae)

    PubMed Central

    Sánchez, J. M.; Ferrero, V.; Arroyo, J.; Navarro, L.

    2010-01-01

    Background and Aims Heterostylous plants have been characterized by the presence of two or three discrete morphs that differ in their sex organ position within populations. This polymorphism is widely distributed among the angiosperms, but detailed studies are limited to few taxonomic groups. Although a small representation, evolutionary meaningful variations of the heterostylous syndrome have been reported when precise measurements of the sexual whorls were taken. A thorough exploration of groups where heterostyly has been reported should offer new opportunities to further testing the evolutionary hypotheses explaining heterostyly. Here, the traits defining heterostyly were explored in half of the species in Nivenia, the only genus of Iridiaceae where heterostyly has been reported. Methods Detailed morphometric analysis of the flower sexual whorls and some traits considered as ancillary are supplied to determine for each population (a) the kind of stylar polymorphism, (b) the morph ratio and (c) the degree of reciprocity between sexual whorls. Also the rates of assortative (within morph) versus disassortative (between morphs) pollen transfer were estimated by analysing pollen loads on stigmas. The association between floral phenotypic integration and the reciprocity between sexual whorls was estimated; both characteristics have been quoted as dependent on the accuracy of the fit between pollinators and flowers and therefore related to the efficiency of pollen transfer. Key Results Different types of polymorphism, differing in their degree of reciprocity, were found in Nivenia. Effective disassortative mating appears to be common, since (a) all dimorphic populations show equal morph-ratios (isoplethy), and (b) the pollen placed on the stigmas of each morph is likely to be coming from the other (complementary) morph. The most reciprocal populations of the heterostylous species have also the highest values of phenotypical integration. Conclusions Stigma height

  14. Mandelalides A-D, cytotoxic macrolides from a new Lissoclinum species of South African tunicate.

    PubMed

    Sikorska, Justyna; Hau, Andrew M; Anklin, Clemens; Parker-Nance, Shirley; Davies-Coleman, Michael T; Ishmael, Jane E; McPhail, Kerry L

    2012-07-20

    Mandelalides A-D are variously glycosylated, unusual polyketide macrolides isolated from a new species of Lissoclinum ascidian collected from South Africa, Algoa Bay near Port Elizabeth and the surrounding Nelson Mandela Metropole. Their planar structures were elucidated on submilligram samples by comprehensive analysis of 1D and 2D NMR data, supported by mass spectrometry. The assignment of relative configuration was accomplished by consideration of homonuclear and heteronuclear coupling constants in tandem with ROESY data. The absolute configuration was assigned for mandelalide A after chiral GC-MS analysis of the hydrolyzed monosaccharide (2-O-methyl-α-L-rhamnose) and consideration of ROESY correlations between the monosaccharide and aglycone in the intact natural product. The resultant absolute configuration of the mandelalide A macrolide was extrapolated to propose the absolute configurations of mandelalides B-D. Remarkably, mandelalide B contained the C-4' epimeric 2-O-methyl-6-dehydro-α-L-talose. Mandelalides A and B showed potent cytotoxicity to human NCI-H460 lung cancer cells (IC(50), 12 and 44 nM, respectively) and mouse Neuro-2A neuroblastoma cells (IC(50), 29 and 84 nM, respectively).

  15. Mandelalides A-D, cytotoxic macrolides from a new Lissoclinum species of South African tunicate

    PubMed Central

    Sikorska, Justyna; Hau, Andrew M.; Anklin, Clemens; Parker-Nance, Shirley; Davies-Coleman, Michael T.; Ishmael, Jane E.; McPhail, Kerry L.

    2012-01-01

    Mandelalides A-D are variously glycosylated, unusual polyketide macrolides isolated from a new species of Lissoclinum ascidian collected from South Africa, Algoa Bay near Port Elizabeth and the surrounding Nelson Mandela Metropole. Their planar structures were elucidated on sub-milligram samples by comprehensive analysis of 1D and 2D NMR data, supported by mass spectrometry. The assignment of relative configuration was accomplished by consideration of homonuclear and heteronuclear coupling constants in tandem with ROESY data. The absolute configuration was assigned for mandelalide A after chiral GC-MS analysis of the hydrolyzed monosaccharide (2-O-methyl-α-L-rhamnose) and consideration of ROESY correlations between the monosaccharide and aglycone in the intact natural product. The resultant absolute configuration of the mandelalide A macrolide was extrapolated to propose the absolute configurations of mandelalides B-D. Remarkably, mandelalide B contained the C-4′ epimeric 2-O-methyl-6-dehydro-α-L-talose. Mandelalides A and B showed potent cytotoxicity to human NCI-H460 lung cancer cells (IC50, 12 and 44 nM, respectively) and mouse Neuro-2A neuroblastoma cells (IC50, 29 and 84 nM, respectively). PMID:22712890

  16. Phylogeographic Diversity of the Lower Central American Cichlid Andinoacara coeruleopunctatus (Cichlidae)

    PubMed Central

    McCafferty, S. Shawn; Martin, Andrew; Bermingham, Eldredge

    2012-01-01

    It is well appreciated that historical and ecological processes are important determinates of freshwater biogeographic assemblages. Phylogeography can potentially lend important insights into the relative contribution of historical processes in biogeography. However, the extent that phylogeography reflects historical patterns of drainage connection may depend in large part on the dispersal capability of the species. Here, we test the hypothesis that due to their relatively greater dispersal capabilities, the neotropical cichlid species Andinoacara coeruleopunctatus will display a phylogeographic pattern that differs from previously described biogeographic assemblages in this important region. Based on an analysis of 318 individuals using mtDNA ATPase 6/8 sequence and restriction fragment length polymorphism data, we found eight distinct clades that are closely associated with biogeographic patterns. The branching patterns among the clades and a Bayesian clock analysis suggest a relatively rapid colonization and diversification among drainages in the emergent Isthmus of Panama followed by the coalescing of some drainages due to historical connections. We also present evidence for extensive cross-cordillera sharing of clades in central Panama and the Canal region. Our results suggest that contemporary phylogeographic patterns and diversification in Lower Central American fishes reflect an interaction of historical drainage connections, dispersal, and demographic processes. PMID:23008800

  17. Dear Enemies Elicit Lower Androgen Responses to Territorial Challenges than Unfamiliar Intruders in a Cichlid Fish

    PubMed Central

    Oliveira, Tânia F.; Ros, Albert F. H.; Oliveira, Rui F.

    2015-01-01

    In many territorial species androgen hormones are known to increase in response to territorial intrusions as a way to adjust the expression of androgen-dependent behaviour to social challenges. The dear enemy effect has also been described in territorial species and posits that resident individuals show a more aggressive response to intrusions by strangers than by other territorial neighbours. Therefore, we hypothesized that the dear enemy effect may also modulate the androgen response to a territorial intrusion. Here we tested this hypothesis in male cichlid fish (Mozambique tilapia, Oreochromis mossambicus) using a paradigm of four repeated territorial intrusions, either by the same neighbour or by four different unfamiliar intruders. Neighbour intruders elicited lower aggression and a weaker androgen response than strangers on the first intrusion of the experiment. With repeated intrusions, the agonistic behaviour of the resident males against familiar intruders was similar to that displayed towards strangers. By the fourth intrusion the androgen response was significantly reduced and there was no longer a difference between the responses to the two types of intruders. These results suggest that the dear enemy effect modulates the androgen response to territorial intrusions and that repeated intrusions lead to a habituation of the androgen response. PMID:26379045

  18. Living on the wedge: female control of paternity in a cooperatively polyandrous cichlid.

    PubMed

    Kohda, Masanori; Heg, Dik; Makino, Yoshimi; Takeyama, Tomohiro; Shibata, Jun-ya; Watanabe, Katsutoshi; Munehara, Hiroyuki; Hori, Michio; Awata, Satoshi

    2009-12-07

    Theories suggest that, in cooperatively breeding species, female control over paternity and reproductive output may affect male reproductive skew and group stability. Female paternity control may come about through cryptic female choice or female reproductive behaviour, but experimental studies are scarce. Here, we show a new form of female paternity control in a cooperatively polyandrous cichlid fish (Julidochromis transcriptus), in which females prefer wedge-shaped nesting sites. Wedge-shaped sites allowed females to manipulate the siring success of the group member males by spawning the clutch at the spot where the large males were just able to enter and fertilize the outer part of the clutch. Small males fertilized the inner part of the clutch, protected from the large aggressive males, leading to low male reproductive skew. Small males provided more brood care than large males. Multiple paternity induced both males to provide brood care and reduced female brood care accordingly. This is, to our knowledge, the first documented case in a species with external fertilization showing female mating behaviour leading to multiple male paternity and increased male brood care as a result.

  19. Living on the wedge: female control of paternity in a cooperatively polyandrous cichlid

    PubMed Central

    Kohda, Masanori; Heg, Dik; Makino, Yoshimi; Takeyama, Tomohiro; Shibata, Jun-ya; Watanabe, Katsutoshi; Munehara, Hiroyuki; Hori, Michio; Awata, Satoshi

    2009-01-01

    Theories suggest that, in cooperatively breeding species, female control over paternity and reproductive output may affect male reproductive skew and group stability. Female paternity control may come about through cryptic female choice or female reproductive behaviour, but experimental studies are scarce. Here, we show a new form of female paternity control in a cooperatively polyandrous cichlid fish (Julidochromis transcriptus), in which females prefer wedge-shaped nesting sites. Wedge-shaped sites allowed females to manipulate the siring success of the group member males by spawning the clutch at the spot where the large males were just able to enter and fertilize the outer part of the clutch. Small males fertilized the inner part of the clutch, protected from the large aggressive males, leading to low male reproductive skew. Small males provided more brood care than large males. Multiple paternity induced both males to provide brood care and reduced female brood care accordingly. This is, to our knowledge, the first documented case in a species with external fertilization showing female mating behaviour leading to multiple male paternity and increased male brood care as a result. PMID:19726479

  20. Niche divergence facilitated by fine‐scale ecological partitioning in a recent cichlid fish adaptive radiation

    PubMed Central

    Ford, Antonia G. P.; Rüber, Lukas; Newton, Jason; Dasmahapatra, Kanchon K.; Balarin, John D.; Bruun, Kristoffer; Day, Julia J.

    2016-01-01

    Ecomorphological differentiation is a key feature of adaptive radiations, with a general trend for specialization and niche expansion following divergence. Ecological opportunity afforded by invasion of a new habitat is thought to act as an ecological release, facilitating divergence, and speciation. Here, we investigate trophic adaptive morphology and ecology of an endemic clade of oreochromine cichlid fishes (Alcolapia) that radiated along a herbivorous trophic axis following colonization of an isolated lacustrine environment, and demonstrate phenotype‐environment correlation. Ecological and morphological divergence of the Alcolapia species flock are examined in a phylogenomic context, to infer ecological niche occupation within the radiation. Species divergence is observed in both ecology and morphology, supporting the importance of ecological speciation within the radiation. Comparison with an outgroup taxon reveals large‐scale ecomorphological divergence but shallow genomic differentiation within the Alcolapia adaptive radiation. Ancestral morphological reconstruction suggests lake colonization by a generalist oreochromine phenotype that diverged in Lake Natron to varied herbivorous morphologies akin to specialist herbivores in Lakes Tanganyika and Malawi. PMID:27659769

  1. Gross morphology and histology of the alimentary tract of the convict cichlid Amatitlania nigrofasciata.

    PubMed

    Hopperdietzel, C; Hirschberg, R M; Hünigen, H; Wolter, J; Richardson, K; Plendl, J

    2014-11-01

    The primary objectives of this study were to document the macroscopic and histological structure of the alimentary tract (AT) of the convict cichlid Amatitlania nigrofasciata, because there are no data available for this omnivorous freshwater fish of the family Cichlidae. The morphology of the AT of A. nigrofasciata resembles that of related species. While having morphological criteria of the AT typical of most omnivorous fishes, such as a blind sac stomach and medium length intestine, A. nigrofasciata also has some structural peculiarities: the oesophagus is lined by a uniform stratified squamous epithelial layer with interspersed goblet cells along its entire length. Additionally, it has well-developed layers of the tunica muscularis including muscle fibre bundles that ascend into its mucosal folds. Occasionally, taste buds are present. In the transitional area between oesophagus and stomach, a prominent torus-like closure device is present. The mucosa of the stomach cannot be divided into different regions according to mucosal and morphological properties. The simple pattern of intestinal loops of A. nigrofasciata has few variations, irrespective of sex, mass and length of the individual fish. The first segment of the intestine is characterized by the largest mucososerosal ratio and the most complex mucosal surface architecture. A distinction of midgut and hindgut was not possible in A. nigrofasciata due to lack of defining structural components as described for other fish species.

  2. A small number of genes underlie male pigmentation traits in Lake Malawi cichlid fishes.

    PubMed

    O'Quin, Claire T; Drilea, Alexi C; Roberts, Reade B; Kocher, Thomas D

    2012-05-01

    Pigmentation patterns are one of the most recognizable forms of phenotypic diversity and an important component of organismal fitness. While much progress has been made in understanding the genes controlling pigmentation in model systems, many questions remain about the genetic basis of pigment traits observed in nature. Lake Malawi cichlid fishes are known for their diversity of male pigmentation patterns, which have been shaped by sexual selection. To begin the process of identifying the genes underlying this diversity, we quantified the number of pigment cells on the body and fins of two species of the genus Metriaclima and their hybrids. We then used the Castle-Wright equation to estimate that differences in individual pigmentation traits between these species are controlled by one to four genes each. Different pigmentation traits are highly correlated in the F(2) , suggesting shared developmental pathways and genetic pleiotropy. Melanophore and xanthophore traits fall on opposite ends of the first principal component axis of the F(2) phenotypes, suggesting a tradeoff during the development of these two pigment cell types.

  3. Two types of dominant male cichlid fish: behavioral and hormonal characteristics

    PubMed Central

    Becker, Lisa; Hilliard, Austin T.; Kent, Kai R.; Fernald, Russell D.

    2016-01-01

    ABSTRACT Male African cichlid fish, Astatotilapia burtoni, have been classified as dominant or subordinate, each with unique behavioral and endocrine profiles. Here we characterize two distinct subclasses of dominant males based on types of aggressive behavior: (1) males that display escalating levels of aggression and court females while they establish a territory, and (2) males that display a stable level of aggression and delay courting females until they have established a territory. To profile differences in their approach to a challenge, we used an intruder assay. In every case, there was a male-male confrontation between the resident dominant male and the intruder, with the intruder quickly taking a subordinate role. However, we found that dominant males with escalating aggression spent measurably more time attacking subordinates than did dominant males with stable aggression that instead increased their attention toward the females in their tank. There was no difference in the behavior of intruders exposed to either type of dominant male, suggesting that escalating aggression is an intrinsic characteristic of some dominant males and is not elicited by the behavior of their challengers. Male behavior during the first 15 min of establishing a territory predicts their aggressive class. These two types of dominant males also showed distinctive physiological characteristics. After the intruder assay, males with escalating aggression had elevated levels of 11-ketotestosterone (11-KT), testosterone, estradiol, and cortisol, while those with stable aggression did not. These observations show that the same stimulus can elicit different behavioral and endocrine responses among A. burtoni dominant males that characterize them as either escalating or stable aggressive types. Our ability to identify which individuals within a population have escalating levels of aggressive responses versus those which have stable levels of aggressive responses when exposed to the same

  4. Visual Information Alone Changes Behavior and Physiology during Social Interactions in a Cichlid Fish (Astatotilapia burtoni)

    PubMed Central

    Chen, Chun-Chun; Fernald, Russell D.

    2011-01-01

    Social behavior can influence physiological systems dramatically yet the sensory cues responsible are not well understood. Behavior of male African cichlid fish, Astatotilapia burtoni, in their natural habitat suggests that visual cues from conspecifics contribute significantly to regulation of social behavior. Using a novel paradigm, we asked whether visual cues alone from a larger conspecific male could influence behavior, reproductive physiology and the physiological stress response of a smaller male. Here we show that just seeing a larger, threatening male through a clear barrier can suppress dominant behavior of a smaller male for up to 7 days. Smaller dominant males being “attacked” visually by larger dominant males through a clear barrier also showed physiological changes for up to 3 days, including up-regulation of reproductive- and stress-related gene expression levels and lowered plasma 11-ketotestesterone concentrations as compared to control animals. The smaller males modified their appearance to match that of non-dominant males when exposed to a larger male but they maintained a physiological phenotype similar to that of a dominant male. After 7 days, reproductive- and stress- related gene expression, circulating hormone levels, and gonad size in the smaller males showed no difference from the control group suggesting that the smaller male habituated to the visual intruder. However, the smaller male continued to display subordinate behaviors and assumed the appearance of a subordinate male for a full week despite his dominant male physiology. These data suggest that seeing a larger male alone can regulate the behavior of a smaller male but that ongoing reproductive inhibition depends on additional sensory cues. Perhaps, while experiencing visual social stressors, the smaller male uses an opportunistic strategy, acting like a subordinate male while maintaining the physiology of a dominant male. PMID:21633515

  5. A new cryptogonimid (Digenea) from the Mayan cichlid, Cichlasoma urophthalmus (Osteichthyes: Cichlidae), in several localities of the Yucatán Peninsula, Mexico.

    PubMed

    Razo-Mendivil, Ulises; Rosas-Valdez, Rogelio; Pérez-Ponce de León, Gerardo

    2008-12-01

    Oligogonotylus mayae n.sp. is described from the intestine of the Mayan cichlid Cichlasoma urophthalmus (Günther) in Ría Lagartos, Ría Celestún, and Estero Progreso, Yucatán State. This is the second species described for Oligogonotylus Watson, 1976, the other being O.manteri Watson, 1976. The new species is readily distinguished from O. manteri by the anterior extension of the vitelline follicles. In O. Manteri, Vitelline follicles are found entirely in the hindbody, extending posteriorly to mid-testicular level. Vitelline follicles in the new species extend from teh anterior margin of posterior testis to the region between the bentral sucker and the pharynx. comparison of approximately 1,850 bases of ribosomal DNA (ITS1, ITS2, 5.8S, and 28S), and 400 bases of cytochrome c oxidase subunit I (cox1) strongly supports the status of O. mayae as a new species, as compared to O. manteri collected from cichlids in other localities of Mexico, Belize, and Guatemala.

  6. Comparative cytogenetics of Neotropical cichlid fishes (Nannacara, Ivanacara and Cleithracara) indicates evolutionary reduction of diploid chromosome numbers

    PubMed Central

    Hodaňová, Lucie; Kalous, Lukáš; Musilová, Zuzana

    2014-01-01

    Abstract A comparative cytogenetic analysis was carried out in five species of a monophyletic clade of neotropical Cichlasomatine cichlids, namely Cleithracara maronii Steindachner, 1881, Ivanacara adoketa (Kullander & Prada-Pedreros, 1993), Nannacara anomala Regan, 1905, N. aureocephalus Allgayer, 1983 and N. taenia Regan, 1912. Karyotypes and other chromosomal characteristics were revealed by CDD banding and mapped onto the phylogenetic hypothesis based on molecular analyses of four genes, namely cyt b, 16S rRNA, S7 and RAG1. The diploid numbers of chromosomes ranged from 44 to 50, karyotypes were composed predominantly of monoarmed chromosomes and one to three pairs of CMA3 signal were observed. The results showed evolutionary reduction in this monophyletic clade and the cytogenetic mechanisms (fissions/fusions) were hypothesized and discussed. PMID:25349669

  7. Salinity effects on behavioural response to hypoxia in the non-native Mayan cichlid Cichlasoma urophthalmus from Florida Everglades wetlands

    USGS Publications Warehouse

    Schofield, P.J.; Loftus, W.F.; Fontaine, J.A.

    2009-01-01

    This study quantified the hypoxia tolerance of the Mayan cichlid Cichlasoma urophthalmus over a range of salinities. The species was very tolerant of hypoxia, using aquatic surface respiration (ASR) and buccal bubble holding when oxygen tensions dropped to <20 mmHg (c. 1??0 mg l-1) and 6 mmHg, respectively. Salinity had little effect on the hypoxia tolerance of C. urophthalmus, except that bubble holding was more frequent at the higher salinities tested. Levels of aggression were greatest at the highest salinity. The ASR thresholds of C. urophthalmus were similar to native centrarchid sunfishes from the Everglades, however, aggression levels for C. uropthalmus were markedly higher. ?? 2009 The Fisheries Society of the British Isles.

  8. Genetics, Morphology, Advertisement Calls, and Historical Records Distinguish Six New Polyploid Species of African Clawed Frog (Xenopus, Pipidae) from West and Central Africa

    PubMed Central

    Evans, Ben J.; Carter, Timothy F.; Greenbaum, Eli; Gvoždík, Václav; Kelley, Darcy B.; McLaughlin, Patrick J.; Pauwels, Olivier S. G.; Portik, Daniel M.; Stanley, Edward L.; Tinsley, Richard C.; Tobias, Martha L.; Blackburn, David C.

    2015-01-01

    African clawed frogs, genus Xenopus, are extraordinary among vertebrates in the diversity of their polyploid species and the high number of independent polyploidization events that occurred during their diversification. Here we update current understanding of the evolutionary history of this group and describe six new species from west and central sub-Saharan Africa, including four tetraploids and two dodecaploids. We provide information on molecular variation, morphology, karyotypes, vocalizations, and estimated geographic ranges, which support the distinctiveness of these new species. We resurrect Xenopus calcaratus from synonymy of Xenopus tropicalis and refer populations from Bioko Island and coastal Cameroon (near Mt. Cameroon) to this species. To facilitate comparisons to the new species, we also provide comments on the type specimens, morphology, and distributions of X. epitropicalis, X. tropicalis, and X. fraseri. This includes significantly restricted application of the names X. fraseri and X. epitropicalis, the first of which we argue is known definitively only from type specimens and possibly one other specimen. Inferring the evolutionary histories of these new species allows refinement of species groups within Xenopus and leads to our recognition of two subgenera (Xenopus and Silurana) and three species groups within the subgenus Xenopus (amieti, laevis, and muelleri species groups). PMID:26672747

  9. Genetics, Morphology, Advertisement Calls, and Historical Records Distinguish Six New Polyploid Species of African Clawed Frog (Xenopus, Pipidae) from West and Central Africa.

    PubMed

    Evans, Ben J; Carter, Timothy F; Greenbaum, Eli; Gvoždík, Václav; Kelley, Darcy B; McLaughlin, Patrick J; Pauwels, Olivier S G; Portik, Daniel M; Stanley, Edward L; Tinsley, Richard C; Tobias, Martha L; Blackburn, David C

    2015-01-01

    African clawed frogs, genus Xenopus, are extraordinary among vertebrates in the diversity of their polyploid species and the high number of independent polyploidization events that occurred during their diversification. Here we update current understanding of the evolutionary history of this group and describe six new species from west and central sub-Saharan Africa, including four tetraploids and two dodecaploids. We provide information on molecular variation, morphology, karyotypes, vocalizations, and estimated geographic ranges, which support the distinctiveness of these new species. We resurrect Xenopus calcaratus from synonymy of Xenopus tropicalis and refer populations from Bioko Island and coastal Cameroon (near Mt. Cameroon) to this species. To facilitate comparisons to the new species, we also provide comments on the type specimens, morphology, and distributions of X. epitropicalis, X. tropicalis, and X. fraseri. This includes significantly restricted application of the names X. fraseri and X. epitropicalis, the first of which we argue is known definitively only from type specimens and possibly one other specimen. Inferring the evolutionary histories of these new species allows refinement of species groups within Xenopus and leads to our recognition of two subgenera (Xenopus and Silurana) and three species groups within the subgenus Xenopus (amieti, laevis, and muelleri species groups).

  10. Reproductive-tactic-specific variation in sperm swimming speeds in a shell-brooding cichlid.

    PubMed

    Fitzpatrick, J L; Desjardins, J K; Milligan, N; Montgomerie, R; Balshine, S

    2007-08-01

    Theory predicts that males experiencing elevated levels of sperm competition will invest more in gonads and produce faster-swimming sperm. Although there is ample evidence in support of the first prediction, few studies have examined sperm swimming speed in relation to sperm competition. In this study, we tested these predictions from sperm competition theory by examining sperm characteristics in Telmatochromis vittatus, a small shell-brooding cichlid fish endemic to Lake Tanganyika. Males exhibit four different reproductive tactics: pirate, territorial, satellite, and sneaker. Pirate males temporarily displace all other competing males from a shell nest, whereas sneaker males always release sperm in the presence of territorial and satellite males. Due to the fact that sneakers spawn in the presence of another male, sneakers face the highest levels of sperm competition and pirates the lowest, whereas satellites and territorials experience intermediate levels. In accordance with predictions, sperm from sneakers swam faster than sperm from males adopting the other reproductive tactics, whereas sperm from pirates was slowest. Interestingly, we were unable to detect any variation in sperm tail length among these reproductive tactics. Thus, sperm competition appears to have influenced sperm energetics in this species without having any influence on sperm size.

  11. Quantifying mating success of territorial males and sneakers in a bower-building cichlid fish.

    PubMed

    Magalhaes, I S; Smith, A M; Joyce, D A

    2017-01-27

    The strategies and traits males evolve to mate with females are incredible in their diversity. Theory on the evolution of secondary sexual characters suggests that evolving any costly trait or strategy will pay off and stabilise in the population if it is advantageous compared to the alternative less costly strategy, but quantifying the relative success of the two can be difficult. In Lake Malawi, Africa, there are >200 species of cichlid fish in which the males form leks and spend several weeks per year building sand-castle "bowers" several times their size. We tested the idea that a less costly "sneaking" strategy could be successful by quantifying the mating success of bower-holding versus non-bower-holding males. We PIT-tagged every fish in a semi-natural experimental set-up and placed tag-readers on the side of bowers to determine which fish held a bower. We then genotyped the eggs removed from females' mouths to assign paternity of each egg. Broods were fathered by up to 3 different males. Although paternity was mostly assigned to males that held a bower, a small number of males who did not own a bower were more successful than some of those that did, indicating a role for an alternative strategy in these bower builders.

  12. A test of male infanticide as a reproductive tactic in a cichlid fish

    PubMed Central

    Bose, Aneesh P. H.; O'Connor, Constance M.; Balshine, Sigal

    2017-01-01

    Infanticide and offspring cannibalism are taxonomically widespread phenomena. In some group-living species, a new dominant individual taking over a group can benefit from infanticide if doing so induces potential mates to become reproductively available sooner. Despite widespread observations of infanticide (i.e. egg cannibalism) among fishes, no study has investigated whether egg cannibalism occurs in fishes as a result of group takeovers, or how this type of cannibalism might be adaptive. Using the cooperatively breeding cichlid, Neolamprologus pulcher, we tested whether new unrelated males entering the dominant position in a social group were more likely to cannibalize eggs, and whether such cannibalism would shorten the interval until the female's next spawning. Females spawned again sooner if their broods were removed than if they were cared for. Egg cannibalism occurred frequently after a group takeover event, and was rarer if the original male remained with the group. While dominant breeder females were initially highly aggressive towards newcomer males that took over the group, the degree of resistance depended on relative body size differences between the new pair and, ultimately, female aggression did not prevent egg cannibalism. Egg cannibalism, however, did not shorten the duration until subsequent spawning, or increase fecundity during subsequent breeding in our laboratory setting. Our results show that infanticide as mediated through group takeovers is a taxonomically widespread behaviour.

  13. Quantifying mating success of territorial males and sneakers in a bower-building cichlid fish

    PubMed Central

    Magalhaes, I. S.; Smith, A. M.; Joyce, D. A.

    2017-01-01

    The strategies and traits males evolve to mate with females are incredible in their diversity. Theory on the evolution of secondary sexual characters suggests that evolving any costly trait or strategy will pay off and stabilise in the population if it is advantageous compared to the alternative less costly strategy, but quantifying the relative success of the two can be difficult. In Lake Malawi, Africa, there are >200 species of cichlid fish in which the males form leks and spend several weeks per year building sand-castle “bowers” several times their size. We tested the idea that a less costly “sneaking” strategy could be successful by quantifying the mating success of bower-holding versus non-bower-holding males. We PIT-tagged every fish in a semi-natural experimental set-up and placed tag-readers on the side of bowers to determine which fish held a bower. We then genotyped the eggs removed from females’ mouths to assign paternity of each egg. Broods were fathered by up to 3 different males. Although paternity was mostly assigned to males that held a bower, a small number of males who did not own a bower were more successful than some of those that did, indicating a role for an alternative strategy in these bower builders. PMID:28128313

  14. Predation risk is an ecological constraint for helper dispersal in a cooperatively breeding cichlid.

    PubMed Central

    Heg, Dik; Bachar, Zina; Brouwer, Lyanne; Taborsky, Michael

    2004-01-01

    Environmental conditions are thought to be responsible for the extent and benefits of cooperative breeding in many animal societies, but experimental tests are scarce. We manipulated predator pressure in the cooperatively breeding cichlid Neolamprologus pulcher in Lake Tanganyika, where predators have been suggested to influence helper and breeder survival, helper dispersal and group reproductive success. We varied the type and intensity of predation by releasing medium, large, or no predators inside large underwater cages enclosing two or three group territories. Helper and breeder survival, helper dispersal and group reproductive success decreased from the control, to the medium- and large-predator treatments. These effects were modified by helper body size and the number of adults protecting the group from predators, supporting the 'group augmentation hypothesis'. Predators forced helpers to stay closer to, and spend more time inside, protective shelters. The results demonstrate the importance of predators for group living in this species, and support the 'ecological constraints hypothesis' of cooperative breeding, in the sense that subordinates stay at home rather than leave and breed independently under the risk of predation. PMID:15556889

  15. Clinorotation Increases the Growth of Utricular Otoliths of Developing Cichlid Fish

    NASA Astrophysics Data System (ADS)

    Anken, Ralf H.; Baur, Ulrich; Hilbig, Reinhard

    2010-04-01

    It has been shown earlier that hypergravity slows down inner ear otolith growth in developing fish as an adaptation towards increased environmental gravity. Suggesting that otolith growth is regulated by the central nervous system, thus adjusting otolithic weight to produce a test mass, applying functional weightlessness should yield an opposite effect, i.e. larger than normal otoliths. Therefore, larval siblings of cichlid fish ( Oreochromis mossambicus) were housed for 7 days in a submersed, two-dimensional clinostat, which provided a residual gravity of approximately 0.007g. After the experiment, otoliths were dissected and their size (area grown during the experiment) was determined. Maintenance in the clinostat resulted in significantly larger utricular otoliths (lapilli, involved in graviperception). There were no statistical significant differences regarding saccular otoliths obtained (sagittae, involved in transmitting linear acceleration and, especially, in the hearing process). These results indicated, that the animals had in fact received functional weightlessness. In line and contrasting results on the otoliths of other teleost species kept at actual microgravity (spaceflight) or within rotating wall vessels are discussed.

  16. The snake family Psammophiidae (Reptilia: Serpentes): phylogenetics and species delimitation in the African sand snakes (Psammophis Boie, 1825) and allied genera.

    PubMed

    Kelly, Christopher M R; Barker, Nigel P; Villet, Martin H; Broadley, Donald G; Branch, William R

    2008-06-01

    This study constitutes the first evolutionary investigation of the snake family Psammophiidae--the most widespread, most clearly defined, yet perhaps the taxonomically most problematic of Africa's family-level snake lineages. Little is known of psammophiid evolutionary relationships, and the type genus Psammophis is one of the largest and taxonomically most complex of the African snake genera. Our aims were to reconstruct psammophiid phylogenetic relationships and to improve characterisation of species boundaries in problematic Psammophis species complexes. We used approximately 2500 bases of DNA sequence from the mitochondrial and nuclear genomes, and 114 terminals covering all psammophiid genera and incorporating approximately 75% of recognised species and subspecies. Phylogenetic reconstructions were conducted primarily in a Bayesian framework and we used the Wiens/Penkrot protocol to aid species delimitation. Rhamphiophis is diphyletic, with Rhamphiophis acutus emerging sister to Psammophylax. Consequently we transfer the three subspecies of Rhamphiophis acutus to the genus Psammophylax. The monotypic genus Dipsina is sister to Psammophis. The two species of Dromophis occupy divergent positions deeply nested within Psammophis, and we therefore relegate Dromophis to the synonymy of Psammophis. Our results allow division of the taxonomically problematic Psammophis 'sibilans' species complex into two monophyletic entities, provisionally named the 'phillipsii' and 'subtaeniatus' complexes. Within these two clades we found support for the status of many existing species, but not for a distinction between P.p. phillipsii and P. mossambicus. Additionally, P. cf. phillipsii occidentalis deserves species status as the sister taxon of P. brevirostris.

  17. Spring-cleaning of African agathidines: new combinations for five species previously placed in Cremnops Förster (Hymenoptera: Braconidae).

    PubMed

    Tucker, Erika M; Sharkey, Michael J

    2015-04-08

    Little work has been done with the African species of Cremnops since their original descriptions. Herein we propose new combinations for five species that are currently placed in Cremnops, i.e., C. atripennis Szépligeti 1914 and C. elegantissima Szépligeti 1908 are moved to Disophrys; C. borealis (Szépligeti 1914) and C. rubrigaster Masi 1944 are moved to Biroia; and C. pulchripennis Szépligeti 1905 is moved to and renamed Biroia neopulchipennis. These changes result in Disophrys atripennis (Szépligeti 1915) becoming a jr. homonym, which we change to Disophrys szatripennis. Additionally, two species are proposed as nomen dubia: C. rufitarsis Szépligeti 1913 and C. schubotzi Szépligeti 1915.

  18. Parsing parallel evolution: ecological divergence and differential gene expression in the adaptive radiations of thick-lipped Midas cichlid fishes from Nicaragua.

    PubMed

    Manousaki, Tereza; Hull, Pincelli M; Kusche, Henrik; Machado-Schiaffino, Gonzalo; Franchini, Paolo; Harrod, Chris; Elmer, Kathryn R; Meyer, Axel

    2013-02-01

    The study of parallel evolution facilitates the discovery of common rules of diversification. Here, we examine the repeated evolution of thick lips in Midas cichlid fishes (the Amphilophus citrinellus species complex)-from two Great Lakes and two crater lakes in Nicaragua-to assess whether similar changes in ecology, phenotypic trophic traits and gene expression accompany parallel trait evolution. Using next-generation sequencing technology, we characterize transcriptome-wide differential gene expression in the lips of wild-caught sympatric thick- and thin-lipped cichlids from all four instances of repeated thick-lip evolution. Six genes (apolipoprotein D, myelin-associated glycoprotein precursor, four-and-a-half LIM domain protein 2, calpain-9, GTPase IMAP family member 8-like and one hypothetical protein) are significantly underexpressed in the thick-lipped morph across all four lakes. However, other aspects of lips' gene expression in sympatric morphs differ in a lake-specific pattern, including the magnitude of differentially expressed genes (97-510). Generally, fewer genes are differentially expressed among morphs in the younger crater lakes than in those from the older Great Lakes. Body shape, lower pharyngeal jaw size and shape, and stable isotopes (δ(13)C and δ(15)N) differ between all sympatric morphs, with the greatest differentiation in the Great Lake Nicaragua. Some ecological traits evolve in parallel (those related to foraging ecology; e.g. lip size, body and head shape) but others, somewhat surprisingly, do not (those related to diet and food processing; e.g. jaw size and shape, stable isotopes). Taken together, this case of parallelism among thick- and thin-lipped cichlids shows a mosaic pattern of parallel and nonparallel evolution.

  19. From Lake Malawi Drilling: East African Climate May Have Caused Major Evolutionary Turnover in Mammalian Species During MIS 14

    NASA Astrophysics Data System (ADS)

    Johnson, Thomas; Werne, Josef

    2016-04-01

    Hominin evolution underwent important changes in the last 1.3 million years, including the extinction of Paranthropus at about 1.2 Ma, leaving Homo as the sole hominin genus. Our genus experienced a major increase in cranial capacity at about 500 ka, and our species, H. sapiens, first appeared at ~200 ka. There was a major turnover in mammalian species in East Africa between 540 and 400 ka, favoring descendants of smaller size and less specialized diet. An understanding of what drove evolution in these directions is fundamental to understanding the development of modern H. sapiens. Climate certainly played a role, for it is the principal factor that influences the distribution of vegetation and habitability on the landscape. We present a 1.3 million year record of temperature and hydroclimate in the basin of Lake Malawi, the second deepest lake in Africa, derived from a 380 m sediment sequence taken from a water depth of 590 m by the Lake Malawi Drilling Project. Seismic reflection profiles used to select the site portray an undisturbed sedimentary section that was not impacted by erosion, turbidity currents or mass wasting events. Sediment samples were analyzed to produce records of temperature (TEX86) and aridity (Ca content and leaf wax δ13C). The temperature record displays progressively larger amplitude glacial-interglacial variations from MIS 13 (~500 ka) to MIS 5 (~125 ka). Intervals of low Ca abundance, which reflect lake high stands, correlate with times of depleted δ13Cwax and relatively warm temperatures. The Malawi basin experienced warm, wet interglacials and cooler (by about 2 - 4°C), dry glacial periods, with roughly a 100 ky periodicity since the Mid-Pleistocene Transition (MPT), about 900 ka. The paleoclimate record from Lake Malawi sediments portrays a transition from a highly variable and predominantly arid climate prior to 900 ka to a progressively more humid environment after the MPT dominated by 100 ky cycles consisting of warm, wet

  20. Biologically meaningful expression profiling across species using heterologous hybridization to a cDNA microarray

    PubMed Central

    Renn, Susan CP; Aubin-Horth, Nadia; Hofmann, Hans A

    2004-01-01

    Background Unravelling the path from genotype to phenotype, as it is influenced by an organism's environment, is one of the central goals in biology. Gene expression profiling by means of microarrays has become very prominent in this endeavour, although resources exist only for relatively few model systems. As genomics has matured into a comparative research program, expression profiling now also provides a powerful tool for non-traditional model systems to elucidate the molecular basis of complex traits. Results Here we present a microarray constructed with ~4500 features, derived from a brain-specific cDNA library for the African cichlid fish Astatotilapia burtoni (Perciformes). Heterologous hybridization, targeting RNA to an array constructed for a different species, is used for eight different fish species. We quantified the concordance in gene expression profiles across these species (number of genes and fold-changes). Although most robust when target RNA is derived from closely related species (<10 MA divergence time), our results showed consistent profiles for other closely related taxa (~65 MA divergence time) and, to a lesser extent, even very distantly related species (>200 MA divergence time). Conclusion This strategy overcomes some of the restrictions imposed on model systems that are of importance for evolutionary and ecological studies, but for which only limited sequence information is available. Our work validates the use of expression profiling for functional genomics within a comparative framework and provides a foundation for the molecular and cellular analysis of complex traits in a wide range of organisms. PMID:15238158

  1. Isolation and sequencing of cDNA clones coding for the catalytic unit of glucose-6-phosphatase from two haplochromine cichlid fishes.

    PubMed

    Nagl, S; Mayer, W E; Klein, J

    1999-01-01

    Complementary DNA clones coding for the catalytic unit of the enzyme glucose-6-phosphatase (G6Pase) were obtained from Haplochromis nubilus and Haplochromis xenognathus, two cichlid fish species from Lake Victoria. The translated sequence of these two cDNAs identifies a polypeptide consisting of 352 amino acid residues and showing a 54.4% similarity to the human form of G6Pase. The amino acid sequences of the two fish species are identical. The comparison of the fish amino acid sequence with the corresponding sequences of rat, mouse, and human G6Pase revealed that the amino acid residues, which are involved in G6Pase catalysis in humans, are also conserved in fish G6Pase. Northern blot analysis showed that G6Pase is expressed at the same level in 6- and 10-day-old fish. A three base pair insertion/deletion polymorphism was found in the 3'-untranslated region of the fish G6Pase gene. The polymorphism will be a useful marker in a phylogenetic study of Lake Victoria cichlids.

  2. Reduced host-specificity in a parasite infecting non-littoral Lake Tanganyika cichlids evidenced by intraspecific morphological and genetic diversity

    PubMed Central

    Kmentová, Nikol; Gelnar, Milan; Mendlová, Monika; Van Steenberge, Maarten; Koblmüller, Stephan; Vanhove, Maarten P. M.

    2016-01-01

    Lake Tanganyika is well-known for its high species-richness and rapid radiation processes. Its assemblage of cichlid fishes recently gained momentum as a framework to study parasite ecology and evolution. It offers a rare chance to investigate the influence of a deepwater lifestyle in a freshwater fish-parasite system. Our study represents the first investigation of parasite intraspecific genetic structure related to host specificity in the lake. It focused on the monogenean flatworm Cichlidogyrus casuarinus infecting deepwater cichlids belonging to Bathybates and Hemibates. Morphological examination of C. casuarinus had previously suggested a broad host range, while the lake’s other Cichlidogyrus species are usually host specific. However, ongoing speciation or cryptic diversity could not be excluded. To distinguish between these hypotheses, we analysed intraspecific diversity of C. casuarinus. Monogeneans from nearly all representatives of the host genera were examined using morphometrics, geomorphometrics and genetics. We confirmed the low host-specificity of C. casuarinus based on morphology and nuclear DNA. Yet, intraspecific variation of sclerotized structures was observed. Nevertheless, the highly variable mitochondrial DNA indicated recent population expansion, but no ongoing parasite speciation, confirming, for the first time in freshwater, reduced parasite host specificity in the deepwater realm, probably an adaptation to low host availability. PMID:28004766

  3. Functional groups in the social behavior of a cichlid fish, the Oscar, Astronotus ocellatus.

    PubMed

    Beeching, S C

    1997-01-01

    Dummy conspecifics were presented to isolated adults of the cichlid fish Astronotus ocellatus to investigate the functional organization of cichlid social behavior. Body size and 15 dummy-elicited activities were recorded during 15 min sessions and analyzed by principal components analysis (PCA) to reveal their temporal organization. Five principal components explained almost 80% of the variation in dummy-elicited behavior, and these five factors define functional groups for Nest-oriented and attack modal action patterns are not mutually inhibitory during this time frame, and biting does not appear to function exclusively during an attack on a conspecific. Comparison with previous studies of New and Old World cichlids suggests evolutionary conservation of the functional organization of social behavior.

  4. Extraordinarily long sperm in the socially monogamous cichlid fish Pelvicachromis taeniatus

    NASA Astrophysics Data System (ADS)

    Thünken, Timo; Bakker, Theo C. M.; Kullmann, Harald

    2007-06-01

    The main function of the spermatozoon is the transfer of the male haploid genome during fertilisation. In animals in general and in fishes in particular, there is huge variation in sperm size. In fishes, sperm size ranges from 13 μm in Mugil cephlus to nearly 100 μm in the channel catfish Ictalurus punctatus. We examined intra-specific variation in sperm morphometry in the socially monogamous cichlid Pelvicachromis taeniatus using scanning electron microscopy. The mean total sperm length of nearly 70 μm was extraordinarily large for cichlids. Furthermore, within-male variation was remarkably high. To our knowledge, P. taeniatus produces the longest cichlid sperm ever documented. Several hypotheses concerning the adaptive significance of these results are presented.

  5. Incipient speciation in sympatric Nicaraguan crater lake cichlid fishes: sexual selection versus ecological diversification.

    PubMed Central

    Wilson, A B; Noack-Kunnmann, K; Meyer, A

    2000-01-01

    The growing body of empirical evidence for sympatric speciation has been complemented by recent theoretical treatments that have identified evolutionary conditions conducive to speciation in sympatry. The Neotropical Midas cichlid (Amphilophus citrinellum) fits both of the key characteristics of these models, with strong assortative mating on the basis of a colour polymorphism coupled with trophic and ecological differentiation derived from a polymorphism in their pharyngeal jaws. We used microsatellite markers and a 480 bp fragment of the mitochondrial DNA control region to study four polymorphic populations of the Midas cichlid from three crater lakes and one large lake in Nicaragua in an investigation of incipient sympatric speciation. All populations were strongly genetically differentiated on the basis of geography. We identified strong genetic separation based on colour polymorphism for populations from Lake Nicaragua and one crater lake (Lake Apoyo), but failed to find significant genetic structuring based on trophic differences and ecological niche separation in any of the four populations studied. These data support the idea that sexual selection through assortative mating contributes more strongly or earlier during speciation in sympatry than ecological separation in these cichlids. The long-term persistence of divergent cichlid ecotypes (as measured by the percentage sequence divergence between populations) in Central American crater lakes, despite a lack of fixed genetic differentiation, differs strikingly from the patterns of extremely rapid speciation in the cichlids in Africa, including its crater lakes. It is unclear whether extrinsic environmental factors or intrinsic biological differences, e.g. in the degree of phenotypic plasticity, promote different mechanisms and thereby rates of speciation of cichlid fishes from the Old and New Worlds. PMID:11413624

  6. The biosynthesis, structure and gelatinization properties of starches from wild and cultivated African rice species (Oryza barthii and Oryza glaberrima).

    PubMed

    Wang, Kai; Wambugu, Peterson W; Zhang, Bin; Wu, Alex Chi; Henry, Robert J; Gilbert, Robert G

    2015-09-20

    The molecular structure and gelatinization properties of starches from domesticated African rice (Oryza glaberrima) and its wild progenitor (Oryza barthii) are determined and comparison made with Asian domesticated rice (Oryza sativa), the commonest commercial rice. This suggests possible enzymatic processes contributing to the unique traits of the African varieties. These have similar starch structures, including smaller amylose molecules, but larger amounts of amylose chains across the whole amylose chain-length distribution, and higher amylose contents, than O. sativa. They also show a higher proportion of two- and three-lamellae spanning amylopectin branch chains (degree of polymerization 34-100) than O. sativa, which contributes to their higher gelatinization temperatures. Fitting amylopectin chain-length distribution with a biosynthesis-based mathematical model suggests that the reason for this difference might be because O. glaberrima and O. barthii have more active SSIIIa and/or less active SBEIIb enzymes.

  7. High prevalence of non-synonymous substitutions in mtDNA of cichlid fishes from Lake Victoria.

    PubMed

    Shirai, Kazumasa; Inomata, Nobuyuki; Mizoiri, Shinji; Aibara, Mitsuto; Terai, Yohey; Okada, Norihiro; Tachida, Hidenori

    2014-12-01

    When a population size is reduced, genetic drift may fix slightly deleterious mutations, and an increase in nonsynonymous substitution is expected. It has been suggested that past aridity has seriously affected and decreased the populations of cichlid fishes in Lake Victoria, while geographical studies have shown that the water levels in Lake Tanganyika and Lake Malawi have remained fairly constant. The comparably stable environments in the latter two lakes might have kept the populations of cichlid fishes large enough to remove slightly deleterious mutations. The difference in the stability of cichlid fish population sizes between Lake Victoria and the Lakes Tanganyika and Malawi is expected to have caused differences in the nonsynonymous/synonymous ratio, ω (=dN/dS), of the evolutionary rate. Here, we estimated ω and compared it between the cichlids of the three lakes for 13 mitochondrial protein-coding genes using maximum likelihood methods. We found that the lineages of the cichlids in Lake Victoria had a significantly higher ω for several mitochondrial loci. Moreover, positive selection was indicated for several codons in the mtDNA of the Lake Victoria cichlid lineage. Our results indicate that both adaptive and slightly deleterious molecular evolution has taken place in the Lake Victoria cichlids' mtDNA genes, whose nonsynonymous sites are generally conserved.

  8. Phylogeographic patterning among two codistributed shrimp species (Crustacea: Decapoda: Palaemonidae) reveals high levels of connectivity across biogeographic regions along the South African coast

    PubMed Central

    Wood, Louisa E.; De Grave, Sammy; Daniels, Savel R.

    2017-01-01

    We compare the genetic structuring and demographic history of two sympatric caridean shrimp species with distinct life history traits, one amphidromous species Palaemon capensis and one marine/estuarine species Palaemon peringueyi, in the historical biogeographical context of South Africa. A total of 103 specimens of P. capensis collected from 12 localities and 217 specimens of P. peringueyi collected from 24 localities were sequenced for the mitochondrial cytochrome oxidase one (CO1) locus. Results from analyses of molecular variance (AMOVA), pairwise ΦST comparisons and haplotype networks demonstrate weak to moderate genetic differentiation in P. capensis and P. peringueyi respectively. P. peringueyi exhibits partial isolation between populations associated with distinct biogeographic regions, likely driven by the region’s oceanography. However, there is minimal evidence for the occurrence of discrete regional evolutionary lineages. This demonstrated lack of genetic differentiation is consistent with a marine, highly dispersive planktonic phase in both the amphidromous P. capensis and the marine/estuarine P. peringueyi. Bayesian skyline plots, mismatch expansions and time since expansion indicate that both species maintained stable populations during the Last Glacial Maximum (LGM), unlike other southern African aquatic species. PMID:28282399

  9. Enterotoxins and emetic toxins production by Bacillus cereus and other species of Bacillus isolated from Soumbala and Bikalga, African alkaline fermented food condiments.

    PubMed

    Ouoba, Labia Irene I; Thorsen, Line; Varnam, Alan H

    2008-06-10

    The ability of various species of Bacillus from fermented seeds of Parkia biglobosa known as African locust bean (Soumbala) and fermented seeds of Hibiscus sabdariffa (Bikalga) was investigated. The study included screening of the isolates by haemolysis on blood agar, detection of toxins in broth and during the fermentation of African locust bean using the Bacillus cereus Enterotoxin Reverse Passive Latex Agglutination test kit (BCET-RPLA) and the Bacillus Diarrhoeal Enterotoxin Visual Immunoassay (BDEVIA). Detection of genes encoding cytotoxin K (CytK), haemolysin BL (Hbl A, Hbl C, Hbl D), non-hemolytic enterotoxin (NheA, NheB, NheC) and EM1 specific of emetic toxin producers was also investigated using PCR with single pair and multiplex primers. Of 41 isolates, 29 Bacillus belonging to the species of B. cereus, Bacillus subtilis, Bacillus licheniformis and Bacillus pumilus showed haemolysis on blood agar. Using RPLA, enterotoxin production was detected for three isolates of B. cereus in broth and all B. cereus (9) in fermented seeds. Using BDEVIA, enterotoxin production was detected in broth as well as in fermented seeds for all B. cereus isolates. None of the isolates belonging to the other Bacillus species was able to produce enterotoxins either by RPLA or BDEVIA. Nhe genes were detected in all B. cereus while Hbl and CytK genes were detected respectively in five and six B. cereus strains. A weak presence of Hbl (A, D) and CytK genes was detected in two isolates of B. subtilis and one of B. licheniformis but results were inconsistent, especially for Hbl genes. The emetic specific gene fragment EM1 was not detected in any of the isolates studied.

  10. The influence of socioeconomic factors on the densities of high-value cross-border species, the African elephant.

    PubMed

    Selier, Sarah-Anne Jeanetta; Slotow, Rob; Di Minin, Enrico

    2016-01-01

    Unprecedented poaching levels triggered by demand for ivory in Far East Asia are threatening the persistence of African elephant Loxodonta africana. Southern African countries make an important contribution to elephant conservation and could soon become the last stronghold of elephant conservation in Africa. While the ecological factors affecting elephant distribution and densities have extensively been accounted for, there is a need to understand which socioeconomic factors affect elephant numbers in order to prevent conflict over limited space and resources with humans. We used elephant count data from aerial surveys for seven years in a generalized linear model, which accounted for temporal correlation, to investigate the effect of six socioeconomic and ecological variables on the number of elephant at the country level in the Greater Mapungubwe Transfrontier Conservation Area (GMTFCA). Important factors in predicting elephant numbers were the proportion of total land surface under cultivation, human population density and the number of tourists visiting the country. Specifically, elephant numbers were higher where the proportion of total land surface under cultivation was the lowest; where population density was the lowest and where tourist numbers had increased over the years. Our results confirm that human disturbance is affecting elephant numbers, but highlight that the benefits provided by ecotourism could help enhance elephant conservation. While future studies should include larger areas and more detailed data at the site level, we stress that the development of coordinated legislation and policies to improve land-use planning are needed to reduce the impact of increasing human populations and agriculture on elephant.

  11. Aggressive interactions between the invasive Rio Grande cichlid (Herichthys cyanoguttatus) and native bluegill (Lepomis macrochirus), with notes on redspotted sunfish (Lepomis miniatus)

    USGS Publications Warehouse

    Lorenz, O. Thomas; O' Connell, Martin T.; Schofield, Pamela J.

    2010-01-01

    The Rio Grande cichlid (Herichthys cyanoguttatus) has been established in the Greater New Orleans Metropolitan area for at least 20 years, and its effect on native fishes is unknown. Behavioral trials were performed to determine if aggressive interactions occur between invasive H. cyanoguttatus and native bluegill (Lepomis macrochirus). When defending a territory as the resident, L. macrochirus were markedly aggressive, averaging 11.6 aggressive actions per lO-min behavioral trial. In contrast, L. macrochirus were extremely passive as invaders, with 0.5 aggressive actions per trial. Herichthys cyanoguttatus were equally aggressive as residents and as invaders, averaging 4.9 and 6.0 aggressive actions per trial, respectively. Herichthys cyanoguttatus interacted aggressively with native species whether they held territory or not, indicating that this invasive species may have fundamentally different strategies of aggression compared with native L. macrochirus. These differences may explain the continued success of H. cyanoguttatus as an invasive fish in southeastern Louisiana.

  12. The effects of different predator species on antipredator behavior in the Trinidadian guppy, Poecilia reticulata

    NASA Astrophysics Data System (ADS)

    Botham, M. S.; Kerfoot, C. J.; Louca, V.; Krause, J.

    2006-09-01

    Different types of predators often elicit different antipredator responses in a common type of prey. Alternatively, some prey species may adopt a general response, which provides limited protection from many different types of predator. The Trinidadian guppy, Poecilia reticulata, is faced with a wide range of different predators throughout its range and is known to display varying levels of antipredator behavior depending on the predator assemblage. Pike cichlids, Crenicichla frenata, are regarded as the primary aquatic guppy predator in streams in the northern mountain range in Trinidad. As such, they are seen to be responsible for many of the differences in morphology, life history traits, and behavior between guppy populations from areas with few predators and those from areas with many pike cichlids. In this study we investigated how guppies responded when faced with different predator species using three common aquatic predators. We exposed shoals of ten guppies to one out of four treatments: no predator (control), pike cichlid, acara cichlid ( Aequidens pulcher), and wolf fish ( Hoplias malabaricus); and we made behavioral observations on both focal individuals and the shoal as a whole. Guppies showed significantly greater levels of predator inspection and shoaling behavior, foraged less, spent more time in the surface water, and stayed in significantly larger shoals when faced with pike cichlids than in other treatments. We discuss these results in the context of multiple predator effects.

  13. Contrasting Patterns of Species Richness and Functional Diversity in Bird Communities of East African Cloud Forest Fragments.

    PubMed

    Ulrich, Werner; Lens, Luc; Tobias, Joseph A; Habel, Jan C

    2016-01-01

    Rapid fragmentation and degradation of large undisturbed habitats constitute major threats to biodiversity. Several studies have shown that populations in small and highly isolated habitat patches are prone to strong environmental and demographic stochasticity and increased risk of extinction. Based on community assembly theory, we predict recent rapid forest fragmentation to cause a decline in species and functional guild richness of forest birds combined with a high species turnover among habitat patches, and well defined dominance structures, if competition is the major driver of community assembly. To test these predictions, we analysed species co-occurrence, nestedness, and competitive strength to infer effects of interspecific competition, habitat structure, and species' traits on the assembly of bird species communities from 12 cloud forest fragments in southern Kenya. Our results do not point to a single ecological driver of variation in species composition. Interspecific competition does not appear to be a major driver of species segregation in small forest patches, while its relative importance appears to be higher in larger ones, which may be indicative for a generic shift from competition-dominated to colonisation-driven community structure with decreasing fragment size. Functional trait diversity was independent of fragment size after controlling for species richness. As fragmentation effects vary among feeding guilds and habitat generalists, in particular, tend to decline in low quality forest patches, we plead for taking species ecology fully into account when predicting tropical community responses to habitat change.

  14. Crotalarieae and Genisteae of the South African Great Escarpment are nodulated by novel Bradyrhizobium species with unique and diverse symbiotic loci.

    PubMed

    Beukes, Chrizelle W; Stępkowski, Tomasz; Venter, Stephanus N; Cłapa, Tomasz; Phalane, Francina L; le Roux, Marianne M; Steenkamp, Emma T

    2016-07-01

    The genus Bradyrhizobium contains predominantly nitrogen-fixing legume symbionts. Phylogenetic analysis of the genes responsible for their symbiotic abilities (i.e., those encoded on the nodulation [nod] and nitrogen-fixation [nif] loci) has facilitated the development of an extensive phylogeographic framework for the genus. This framework however contains only a few nodulating isolates from Africa. Here we focused on nodulating Bradyrhizobium isolates associated with native southern African legumes in the tribes Genisteae and Crotalarieae found along the Great Escarpment in the Mpumalanga Province of South Africa. The aims of this study were to: (1) obtain rhizobial isolates from legumes in the Genisteae and Crotalarieae; (2) verify their nodulation ability; (3) characterize them to species level based on phylogenetic analyses of several protein coding gene regions (atpD, dnaK, glnII, recA, rpoB and gyrB) and (4) determine their placement in the phylogeographic framework inferred from the sequences of the symbiotic loci nodA and nifD. Twenty of the 21 Bradyrhizobium isolates belonged to six novel species, while one was conspecific with the recently described B. arachidis. Among these isolates, the nodA phylogeny revealed several new clades, with 18 of our isolates found in Clades XIV and XV, and only three forming part of the cosmopolitan Clade III. These strains formed predominantly the same groups in the nifD phylogeny although with slight differences; indicating that both vertical and horizontal inheritance of the symbiotic loci occurred. These findings suggest that the largely unexplored diversity of indigenous African rhizobia are characterized by unique ancestries that might mirror the distribution of their hosts and the environmental factors driving their evolution.

  15. The influence of socioeconomic factors on the densities of high-value cross-border species, the African elephant

    PubMed Central

    Slotow, Rob; Di Minin, Enrico

    2016-01-01

    Unprecedented poaching levels triggered by demand for ivory in Far East Asia are threatening the persistence of African elephant Loxodonta africana. Southern African countries make an important contribution to elephant conservation and could soon become the last stronghold of elephant conservation in Africa. While the ecological factors affecting elephant distribution and densities have extensively been accounted for, there is a need to understand which socioeconomic factors affect elephant numbers in order to prevent conflict over limited space and resources with humans. We used elephant count data from aerial surveys for seven years in a generalized linear model, which accounted for temporal correlation, to investigate the effect of six socioeconomic and ecological variables on the number of elephant at the country level in the Greater Mapungubwe Transfrontier Conservation Area (GMTFCA). Important factors in predicting elephant numbers were the proportion of total land surface under cultivation, human population density and the number of tourists visiting the country. Specifically, elephant numbers were higher where the proportion of total land surface under cultivation was the lowest; where population density was the lowest and where tourist numbers had increased over the years. Our results confirm that human disturbance is affecting elephant numbers, but highlight that the benefits provided by ecotourism could help enhance elephant conservation. While future studies should include larger areas and more detailed data at the site level, we stress that the development of coordinated legislation and policies to improve land-use planning are needed to reduce the impact of increasing human populations and agriculture on elephant. PMID:27812404

  16. Competition between a Lawn-Forming Cynodon dactylon and a Tufted Grass Species Hyparrhenia hirta on a South-African Dystrophic Savanna.

    PubMed

    Zwerts, J A; Prins, H H T; Bomhoff, D; Verhagen, I; Swart, J M; de Boer, W F

    2015-01-01

    South African savanna grasslands are often characterised by indigestible tufted grass species whereas lawn grasses are far more desirable in terms of herbivore sustenance. We aimed to investigate the role of nutrients and/or the disturbance (grazing, trampling) by herbivores on the formation of grazing lawns. We conducted a series of common garden experiments to test the effect of nutrients on interspecific competition between a typical lawn-forming grass species (Cynodon dactylon) and a species that is frequently found outside grazing lawns (Hyparrhenia hirta), and tested for the effect of herbivore disturbance in the form of trampling and clipping. We also performed a vegetation and herbivore survey to apply experimentally derived insights to field observations. Our results showed that interspecific competition was not affected by soil nutrient concentrations. C. dactylon did show much more resilience to disturbance than H. hirta, presumably due to the regenerative capacity of its rhizomes. Results from the field survey were in line with these findings, describing a correlation between herbivore pressure and C. dactylon abundance. We conclude that herbivore disturbance, and not soil nutrients, provide C. dactylon with a competitive advantage over H. hirta, due to vegetative regeneration from its rhizomes. This provides evidence for the importance of concentrated, high herbivore densities for the creation and maintenance of grazing lawns.

  17. Competition between a Lawn-Forming Cynodon dactylon and a Tufted Grass Species Hyparrhenia hirta on a South-African Dystrophic Savanna

    PubMed Central

    Zwerts, J. A.; Prins, H. H. T.; Bomhoff, D.; Verhagen, I.; Swart, J. M.; de Boer, W. F.

    2015-01-01

    South African savanna grasslands are often characterised by indigestible tufted grass species whereas lawn grasses are far more desirable in terms of herbivore sustenance. We aimed to investigate the role of nutrients and/or the disturbance (grazing, trampling) by herbivores on the formation of grazing lawns. We conducted a series of common garden experiments to test the effect of nutrients on interspecific competition between a typical lawn-forming grass species (Cynodon dactylon) and a species that is frequently found outside grazing lawns (Hyparrhenia hirta), and tested for the effect of herbivore disturbance in the form of trampling and clipping. We also performed a vegetation and herbivore survey to apply experimentally derived insights to field observations. Our results showed that interspecific competition was not affected by soil nutrient concentrations. C. dactylon did show much more resilience to disturbance than H. hirta, presumably due to the regenerative capacity of its rhizomes. Results from the field survey were in line with these findings, describing a correlation between herbivore pressure and C. dactylon abundance. We conclude that herbivore disturbance, and not soil nutrients, provide C. dactylon with a competitive advantage over H. hirta, due to vegetative regeneration from its rhizomes. This provides evidence for the importance of concentrated, high herbivore densities for the creation and maintenance of grazing lawns. PMID:26510157

  18. Contrasting Patterns of Species Richness and Functional Diversity in Bird Communities of East African Cloud Forest Fragments

    PubMed Central

    Ulrich, Werner; Lens, Luc; Tobias, Joseph A.; Habel, Jan C.

    2016-01-01

    Rapid fragmentation and degradation of large undisturbed habitats constitute major threats to biodiversity. Several studies have shown that populations in small and highly isolated habitat patches are prone to strong environmental and demographic stochasticity and increased risk of extinction. Based on community assembly theory, we predict recent rapid forest fragmentation to cause a decline in species and functional guild richness of forest birds combined with a high species turnover among habitat patches, and well defined dominance structures, if competition is the major driver of community assembly. To test these predictions, we analysed species co-occurrence, nestedness, and competitive strength to infer effects of interspecific competition, habitat structure, and species′ traits on the assembly of bird species communities from 12 cloud forest fragments in southern Kenya. Our results do not point to a single ecological driver of variation in species composition. Interspecific competition does not appear to be a major driver of species segregation in small forest patches, while its relative importance appears to be higher in larger ones, which may be indicative for a generic shift from competition-dominated to colonisation-driven community structure with decreasing fragment size. Functional trait diversity was independent of fragment size after controlling for species richness. As fragmentation effects vary among feeding guilds and habitat generalists, in particular, tend to decline in low quality forest patches, we plead for taking species ecology fully into account when predicting tropical community responses to habitat change. PMID:27855174

  19. Muhaka icipeins, an enigmatic new genus and species of Kleidotomini (Hymenoptera: Figitidae: Eucoilinae) from an East African coastal forest

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A remarkable new eucoiline genus and species, Muhaka icipeins, is described herein. The genus is clearly a Kleidotomini, but is distinguished from other genera in the tribe by the unique head and scutellar morphology of Muhaka. The genus belongs to the ‘wedge-head’-syndrome group of species that, ...

  20. A taxonomic revision of South African Sharphydrus, with the description of two new species (Coleoptera: Dytiscidae: Bidessini).

    PubMed

    Bilton, David T

    2013-12-17

    Sharphydrus Omer-Cooper, 1958 is one of two endemic bidessine genera currently recognised from South Africa. Here Sharphydrus brincki sp. nov. and Sharphydrus kamiesbergensis sp. nov. are described from the Cederberg and Gydopas areas of the Western Cape, and the high Kamiesberg of the Northern Cape respectively, doubling the known species of this genus. It is shown that S. brincki sp. nov. has been included under S. capensis (Omer-Cooper, 1955) in the past, but that these are quite distinct taxa, differing in the extent of their elytral keels and male genitalia. Sharphydrus species are inhabitants of pools in seasonally fluctuating rivers, the new species described here occurring in areas which are somewhat transitional between fynbos and karoo biomes. An updated key is presented to Sharphydrus species, together with data on the distribution and ecology of known species, and a discussion of the status of the genus within the Bidessini.

  1. Alternative reproductive tactics in snail shell-brooding cichlids diverge in energy reserve allocation

    PubMed Central

    von Kuerthy, Corinna; Tschirren, Linda; Taborsky, Michael

    2015-01-01

    Life history theory predicts that the amount of resources allocated to reproduction should maximize an individual's lifetime reproductive success. So far, resource allocation in reproduction has been studied mainly in females. Intraspecific variation of endogenous energy storage and utilization patterns of males has received little attention, although these patterns may vary greatly between individuals pursuing alternative reproductive tactics (ARTs). ARTs are characterized by systematic variation of behavioral, physiological, and often morphological traits among same-sex conspecifics. Some individuals may rely on previously accumulated reserves, because of limited foraging opportunities during reproduction. Others may be able to continue foraging during reproduction, thus relying on reserves to a lesser extent. We therefore predicted that, if male tactics involve such divergent limitations and trade-offs within a species, ARTs should correspondingly differ in energy reserve allocation and utilization. To test this prediction, we studied short-term and long-term reserve storage patterns of males in the shell-brooding cichlid Lamprologus callipterus. In this species, bourgeois males investing in territory defense, courtship, and guarding of broods coexist with two distinct parasitic male tactics: (1) opportunistic sneaker males attempting to fertilize eggs by releasing sperm into the shell opening when a female is spawning; and (2) specialized dwarf males attempting to enter the shell past the spawning female to fertilize eggs from inside the shell. Sneaker males differed from other male types by showing the highest amount of accumulated short-term and long-term fat stores, apparently anticipating their upcoming adoption of the nest male status. In contrast, nest males depleted previously accumulated energy reserves with increasing nest holding period, as they invest heavily into costly reproductive behaviors while not taking up any food. This conforms to a capital

  2. Alternative reproductive tactics in snail shell-brooding cichlids diverge in energy reserve allocation.

    PubMed

    von Kuerthy, Corinna; Tschirren, Linda; Taborsky, Michael

    2015-05-01

    Life history theory predicts that the amount of resources allocated to reproduction should maximize an individual's lifetime reproductive success. So far, resource allocation in reproduction has been studied mainly in females. Intraspecific variation of endogenous energy storage and utilization patterns of males has received little attention, although these patterns may vary greatly between individuals pursuing alternative reproductive tactics (ARTs). ARTs are characterized by systematic variation of behavioral, physiological, and often morphological traits among same-sex conspecifics. Some individuals may rely on previously accumulated reserves, because of limited foraging opportunities during reproduction. Others may be able to continue foraging during reproduction, thus relying on reserves to a lesser extent. We therefore predicted that, if male tactics involve such divergent limitations and trade-offs within a species, ARTs should correspondingly differ in energy reserve allocation and utilization. To test this prediction, we studied short-term and long-term reserve storage patterns of males in the shell-brooding cichlid Lamprologus callipterus. In this species, bourgeois males investing in territory defense, courtship, and guarding of broods coexist with two distinct parasitic male tactics: (1) opportunistic sneaker males attempting to fertilize eggs by releasing sperm into the shell opening when a female is spawning; and (2) specialized dwarf males attempting to enter the shell past the spawning female to fertilize eggs from inside the shell. Sneaker males differed from other male types by showing the highest amount of accumulated short-term and long-term fat stores, apparently anticipating their upcoming adoption of the nest male status. In contrast, nest males depleted previously accumulated energy reserves with increasing nest holding period, as they invest heavily into costly reproductive behaviors while not taking up any food. This conforms to a capital

  3. Molecular identification and safety of Bacillus species involved in the fermentation of African oil beans (Pentaclethra macrophylla Benth) for production of Ugba.

    PubMed

    Ahaotu, I; Anyogu, A; Njoku, O H; Odu, N N; Sutherland, J P; Ouoba, L I I

    2013-03-01

    Molecular identification of Bacillus spp. involved in the fermentation of African oil bean seeds for production of Ugba, as well as ability of the Bacillus spp. isolated to produce toxins, were investigated. Forty-nine bacteria were isolated from Ugba produced in different areas of South Eastern Nigeria and identified by phenotyping and sequencing of 16S rRNA, gyrB and rpoB genes. Genotypic diversities at interspecies and intraspecies level of the isolates were screened by PCR amplification of the 16S-23S rDNA intergenic transcribed spacer (ITS-PCR) and repetitive sequence-based PCR (rep-PCR). The ability of the bacteria to produce toxins was also investigated by detection of genes encoding production of haemolysin BL (HblA, HblC, HblD), non-haemolytic enterotoxin (NheA, NheB, NheC), cytotoxin K (CytK) and emetic toxin (EM1) using PCR with specific primers. Moreover, a Bacillus cereus Enterotoxin Reverse Passive Latex Agglutination test kit (BCET-RPLA) was used to screen ability of the isolates to produce haemolysin in broth and during fermentation of African oil bean seeds. The isolates were characterized as motile, rod-shaped, endospore forming, catalase positive, Gram-positive bacteria. They were identified as Bacillus cereus sensu lato (42), Lysinibacillus xylanilyticus (3), Bacillus clausii (1), Bacillus licheniformis (1), Bacillus subtilis (1), and Bacillus safensis (1). B. cereus was the predominant Bacillus species and was present in all samples studied. Using ITS-PCR, interspecies diversity was observed among isolates, with six clusters representing each of the pre-cited species. Rep-PCR was more discriminatory (eight clusters) and allowed further differentiation at intraspecies level for the B. cereus and L. xylanilyticus isolates with two genotypes for each species. Genes encoding production of non-haemolytic enterotoxin (NheA, NheB, NheC) and cytotoxin K (CytK) genes were detected in all B. cereus isolates, while Hbl genes (HblA, HblC, HblD) were

  4. Regionally-defined niche-breadth of tropical African freshwater plant species predicts their global latitudinal range

    NASA Astrophysics Data System (ADS)

    Kennedy, Michael; Lang, Pauline; Tapia-Grimaldo, Julissa; Varandas-Martins, Sara; Bruce, Allanah; Moore, Isabel; Sichingabula, Henry; Bottino, Flávia; Murphy, Kevin

    2016-04-01

    This study tested the hypothesis that the measured niche-breadth of river plant species (macrophytes) occurring within a closely-defined geographical area in southern tropical Africa (Zambia), may predict the larger-scale biogeographical range of these species. Two measures of niche-breadth were calculated for 44 riverine macrophyte species commonly occurring in Zambia, using an approach based on PCA ordination with bio-physico-chemical ordination input variables: altitude, stream order, stream flow, pH, conductivity, soluble reactive phosphate concentration (SRP), benthic macroinvertebrate Average Score per Taxon (ASPT), and individual abundance of nine benthic macroinvertebrate families showing differing water quality tolerance, as indicated by their Sensitivity Weightings within the Zambian Invertebrate Scoring System (ZISS). Macrophyte large-scale latitudinal range was derived from world geopositional records held by online databases, supplemented by records held by the authors. The two niche-breadth metrics divided the species into narrow-niche and intermediate/broad-niche categories, showing significant variation in altitude, stream flow, conductivity, SRP and ASPT, but not stream order or pH. There was no evidence to suggest that macrophyte alpha-diversity (as a measure of number of individual niches that may co-exist in a given habitat) showed any significant relationship with individual species niche-breadth. However, macrophyte alpha-diversity was significantly positively correlated with altitude, and significantly negatively related to conductivity, pH, ASPT, SRP, stream flow, and stream order. Narrow-niche macrophyte species included a higher proportion of Afrotropical endemics than did species with broader niche size. There were significant predictive relationships between macrophyte niche breadth and latitudinal range of the target species at global and Afrotropical scales, but not for the Neotropical range of species which occurred in both the

  5. A new cichlid fish in the Sahara: The Ounianga Serir lakes (Chad), a biodiversity hotspot in the desert.

    PubMed

    Trape, Sébastien

    In the rare perennial bodies of water of the Sahara desert, only a few fish species have survived to increasing aridification since the end of the last humid period at the Holocene, approximately 5000 years BP. Here, I report the occurrence of an undescribed haplochomine cichlid fish in Lake Boukou, one of the seven Ounianga Serir lakes (Chad). These lakes are located in one of the most arid areas of the Sahara desert, but they persist by virtue of subsurface inflow of fresh groundwater from a large fossil aquifer. Astatotilapia tchadensis sp. nov. is characterized by a black bar between eye and corner of mouth, rounded orange spots on anal fin, scales ctenoid, lower limb of first gill arch with 7-8 gill rackers, dorsal fin with 13-14 spines and 9-11 soft rays, anal fin with 3 spines and 8-9 soft rays, 29 or 30 lateral line scales, and lower pharyngeal dentition with enlarged molariform teeth. The new species is easily distinguished from A. desfontainii and A. flaviijosephii, the northernmost haplochromine species currently isolated from its other group members, and appears close to an unnamed species of Lake Chad basin. Ounianga Serir lakes and especially Lake Boukou present a remarkable diversity of fish, the highest known in the Sahara desert with a total of at least six fish species belonging to six genera and three families. They also constitute an exceptional natural landscape inscribed on the UNESCO world heritage list in 2012 and a biodiversity hotspot for desert vertebrate species.

  6. Wood Specific Gravity Variations and Biomass of Central African Tree Species: The Simple Choice of the Outer Wood

    PubMed Central

    Bastin, Jean-François; Fayolle, Adeline; Tarelkin, Yegor; Van den Bulcke, Jan; de Haulleville, Thales; Mortier, Frederic; Beeckman, Hans; Van Acker, Joris; Serckx, Adeline; Bogaert, Jan; De Cannière, Charles

    2015-01-01

    Context Wood specific gravity is a key element in tropical forest ecology. It integrates many aspects of tree mechanical properties and functioning and is an important predictor of tree biomass. Wood specific gravity varies widely among and within species and also within individual trees. Notably, contrasted patterns of radial variation of wood specific gravity have been demonstrated and related to regeneration guilds (light demanding vs. shade-bearing). However, although being repeatedly invoked as a potential source of error when estimating the biomass of trees, both intraspecific and radial variations remain little studied. In this study we characterized detailed pith-to-bark wood specific gravity profiles among contrasted species prominently contributing to the biomass of the forest, i.e., the dominant species, and we quantified the consequences of such variations on the biomass. Methods Radial profiles of wood density at 8% moisture content were compiled for 14 dominant species in the Democratic Republic of Congo, adapting a unique 3D X-ray scanning technique at very high spatial resolution on core samples. Mean wood density estimates were validated by water displacement measurements. Wood density profiles were converted to wood specific gravity and linear mixed models were used to decompose the radial variance. Potential errors in biomass estimation were assessed by comparing the biomass estimated from the wood specific gravity measured from pith-to-bark profiles, from global repositories, and from partial information (outer wood or inner wood). Results Wood specific gravity profiles from pith-to-bark presented positive, neutral and negative trends. Positive trends mainly characterized light-demanding species, increasing up to 1.8 g.cm-3 per meter for Piptadeniastrum africanum, and negative trends characterized shade-bearing species, decreasing up to 1 g.cm-3 per meter for Strombosia pustulata. The linear mixed model showed the greater part of wood specific

  7. Sampling strategies and variability in fruit pulp micronutrient contents of west and central african bananas and plantains (Musa species).

    PubMed

    Davey, Mark W; Stals, Ellen; Ngoh-Newilah, Gérard; Tomekpe, Kodjo; Lusty, Charlotte; Markham, Richard; Swennen, Rony; Keulemans, Johan

    2007-04-04

    The variability in fruit micronutrient contents in a selection of Central and West African Musa varieties cultivated under standardized field conditions was studied. Analysis of the within-fruit, within-hand, and within-plant as well as the between-plant variations demonstrated that both provitamin A carotenoids (pVACs) and mineral micronutrient (Fe, Zn) contents vary significantly across all sample groups. The variations in pVACs contents appear to be at least partly related to differences in the developmental status of the fruit, but the observed trends were genotype-specific. The mean pVACs concentrations per genotype indicated that there is substantial genetic variation in the fruit pVACs contents between Musa cultivars, with orange-fleshed plantain varieties (AAB) having generally higher fruit pVACs contents than dessert bananas (AAA). It was not possible to identify consistent trends between the sampling position and fruit Fe/Zn contents. Once the within-bunch micronutrient variability has been accounted for, the mean variations in fruit micronutrient contents between individual plants of a variety generally fell to within acceptable limits. Results are discussed within the framework of standardizing sampling and developing strategies to screen for the nutritional values of new and existing Musa varieties.

  8. Documenting Biogeographical Patterns of African Timber Species Using Herbarium Records: A Conservation Perspective Based on Native Trees from Angola

    PubMed Central

    Romeiras, Maria M.; Figueira, Rui; Duarte, Maria Cristina; Beja, Pedro; Darbyshire, Iain

    2014-01-01

    In many tropical regions the development of informed conservation strategies is hindered by a dearth of biodiversity information. Biological collections can help to overcome this problem, by providing baseline information to guide research and conservation efforts. This study focuses on the timber trees of Angola, combining herbarium (2670 records) and bibliographic data to identify the main timber species, document biogeographic patterns and identify conservation priorities. The study recognized 18 key species, most of which are threatened or near-threatened globally, or lack formal conservation assessments. Biogeographical analysis reveals three groups of species associated with the enclave of Cabinda and northwest Angola, which occur primarily in Guineo-Congolian rainforests, and evergreen forests and woodlands. The fourth group is widespread across the country, and is mostly associated with dry forests. There is little correspondence between the spatial pattern of species groups and the ecoregions adopted by WWF, suggesting that these may not provide an adequate basis for conservation planning for Angolan timber trees. Eight of the species evaluated should be given high conservation priority since they are of global conservation concern, they have very restricted distributions in Angola, their historical collection localities are largely outside protected areas and they may be under increasing logging pressure. High conservation priority was also attributed to another three species that have a large proportion of their global range concentrated in Angola and that occur in dry forests where deforestation rates are high. Our results suggest that timber tree species in Angola may be under increasing risk, thus calling for efforts to promote their conservation and sustainable exploitation. The study also highlights the importance of studying historic herbarium collections in poorly explored regions of the tropics, though new field surveys remain a priority to

  9. Documenting biogeographical patterns of African timber species using herbarium records: a conservation perspective based on native trees from Angola.

    PubMed

    Romeiras, Maria M; Figueira, Rui; Duarte, Maria Cristina; Beja, Pedro; Darbyshire, Iain

    2014-01-01

    In many tropical regions the development of informed conservation strategies is hindered by a dearth of biodiversity information. Biological collections can help to overcome this problem, by providing baseline information to guide research and conservation efforts. This study focuses on the timber trees of Angola, combining herbarium (2670 records) and bibliographic data to identify the main timber species, document biogeographic patterns and identify conservation priorities. The study recognized 18 key species, most of which are threatened or near-threatened globally, or lack formal conservation assessments. Biogeographical analysis reveals three groups of species associated with the enclave of Cabinda and northwest Angola, which occur primarily in Guineo-Congolian rainforests, and evergreen forests and woodlands. The fourth group is widespread across the country, and is mostly associated with dry forests. There is little correspondence between the spatial pattern of species groups and the ecoregions adopted by WWF, suggesting that these may not provide an adequate basis for conservation planning for Angolan timber trees. Eight of the species evaluated should be given high conservation priority since they are of global conservation concern, they have very restricted distributions in Angola, their historical collection localities are largely outside protected areas and they may be under increasing logging pressure. High conservation priority was also attributed to another three species that have a large proportion of their global range concentrated in Angola and that occur in dry forests where deforestation rates are high. Our results suggest that timber tree species in Angola may be under increasing risk, thus calling for efforts to promote their conservation and sustainable exploitation. The study also highlights the importance of studying historic herbarium collections in poorly explored regions of the tropics, though new field surveys remain a priority to

  10. Circadian rhythms of locomotor activity in solitary and social species of African mole-rats (family: Bathyergidae).

    PubMed

    Oosthuizen, Maria K; Cooper, Howard M; Bennett, Nigel C

    2003-12-01

    Mole-rats are strictly subterranean and hardly, if ever, come into contact with external light. As a result, their classical visual system is severely regressed and the circadian system proportionally expanded. The family Bathyergidae presents a unique opportunity to study the circadian system in the absence of the classical visual system in a range of species. Daily patterns of activity were studied in the laboratory under constant temperature but variable lighting regimes in individually housed animals from 3 species of mole-rat exhibiting markedly different degrees of sociality. All 3 species possessed individuals that exhibited endogenous circadian rhythms under constant darkness that entrained to a light-dark cycle. In the solitary species, Georychus capensis, 9 animals exhibited greater activity during the dark phase of the light cycle, while 2 individuals expressed more activity in the light phase of the light cycle. In the social, Cryptomys hottentotus pretoriae, 5 animals displayed the majority of their activity during the dark phase of the light cycle and the remaining 2 exhibited more activity during the light phase of the light cycle. Finally in the eusocial Cryptomys damarensis, 6 animals displayed more activity during the light phase of the light cycle, and the other 2 animals displayed more activity during the dark phase of the light cycle. Since all three mole-rat species are able to entrain their locomotor activity to an external light source, light must reach the SCN, suggesting a functional circadian clock. In comparison to the solitary species, the 2 social species display a markedly poorer response to light in all aspects. Thus, in parallel with the sociality continuum, there exists a continuum of sensitivity of the circadian clock to light.

  11. Climate change sensitivity of the African ivory nut palm, Hyphaene petersiana Klotzsch ex Mart. (Arecaceae) - a keystone species in SE Africa

    NASA Astrophysics Data System (ADS)

    Blach-Overgaard, A.; Svenning, J.-C.; Balslev, H.

    2009-11-01

    Africa is the most vulnerable continent to future climate change. Profound changes are projected for southwestern Africa with increased drying, notably with delayed onset of the rainy season in September-November, and temperature increases in all seasons. The projected climate changes combined with land-use changes are thought to constitute the main threats to biodiversity in the 21st century. To be able to predict the potential impact on biodiversity, it is crucial to achieve a better insight into the controls of contemporary species ranges. Using species distribution modeling, we assessed the climate sensitivity of the key-stone palm species Hyphaene petersiana (African ivory nut palm) in southern Africa. We tested the relative roles of climate vs. non-climatic range-controls and found that climate had a clear effect on the range of H. petersiana and that especially water-related variables (annual precipitation and precipitation driest quarter) were of high importance. Nevertheless, latitude was the overall most dominant variable, reflecting spatial constraints on the continental-scale distribution. Of the remaining non-climatic factors, soil type and human influence were as important as the climatic factors. A future decrease in annual precipitation below 400 mm and hydrological changes towards drier conditions could cause a dramatic decline in H. petersiana populations, while the influence of temperature changes is less clear. The ongoing, unsustainable utilization pressures on this palm species by humans and livestock are likely to exacerbate the negative effect of future climate changes on its populations, especially, given the expected human population increase in Africa.

  12. Living in biological soil crust communities of African deserts-Physiological traits of green algal Klebsormidium species (Streptophyta) to cope with desiccation, light and temperature gradients.

    PubMed

    Karsten, Ulf; Herburger, Klaus; Holzinger, Andreas

    2016-05-01

    Green algae of the genus Klebsormidium (Klebsormidiales, Streptophyta) are typical members of biological soil crusts (BSCs) worldwide. The phylogeny and ecophysiology of Klebsormidium has been intensively studied in recent years, and a new lineage called superclade G, which was isolated from BSCs in arid southern Africa and comprising undescribed species, was reported. Three different African strains, that have previously been isolated from hot-desert BSCs and molecular-taxonomically characterized, were comparatively investigated. In addition, Klebsormidium subtilissimum from a cold-desert habitat (Alaska, USA, superclade E) was included in the study as well. Photosynthetic performance was measured under different controlled abiotic conditions, including dehydration and rehydration, as well as under a light and temperature gradient. All Klebsormidium strains exhibited optimum photosynthetic oxygen production at low photon fluence rates, but with no indication of photoinhibition under high light conditions pointing to flexible acclimation mechanisms of the photosynthetic apparatus. Respiration under lower temperatures was generally much less effective than photosynthesis, while the opposite was true for higher temperatures. The Klebsormidium strains tested showed a decrease and inhibition of the effective quantum yield during desiccation, however with different kinetics. While the single celled and small filamentous strains exhibited relatively fast inhibition, the uniserate filament forming isolates desiccated slower. Except one, all other strains fully recovered effective quantum yield after rehydration. The presented data provide an explanation for the regular occurrence of Klebsormidium strains or species in hot and cold deserts, which are characterized by low water availability and other stressful conditions.

  13. Termites in the hominin diet: a meta-analysis of termite genera, species and castes as a dietary supplement for South African robust australopithecines.

    PubMed

    Lesnik, Julie J

    2014-06-01

    Termite foraging by chimpanzees and present-day modern humans is a well-documented phenomenon, making it a plausible hypothesis that early hominins were also utilizing this resource. Hominin termite foraging has been credited by some to be the explanation for the unexpected carbon isotope signatures present in South African hominin teeth, which suggest the diet was different from that of extant non-human great apes, consisting of a significant amount of resources that are not from woody-plants. Grass-eating termites are one potential resource that could contribute to the carbon signature. However, not all termites eat grasses, and in fact, the termites that are most widely consumed by chimpanzees and by many present-day human populations at best have a mixed diet that includes small amounts of grasses. Here I review the ecology of termites and how it affects their desirability as a food resource for hominins, and conduct a meta-analysis of nutritional values for various genera, species and castes from the literature. Termites are very diverse, even within species, and this variability affects both their carbon signatures and nutritional value, hindering generalizations regarding the contribution of termites to the hominin diet. It is concluded here that a combination of soldiers and alates of the genus Macrotermes be used to model the insectivory component of the Plio-Pleistocene hominin diet due to their significant amounts of energy-yielding nutrients and potential role as a critical resource for supporting larger-brained hominins.

  14. Living in biological soil crust communities of African deserts—Physiological traits of green algal Klebsormidium species (Streptophyta) to cope with desiccation, light and temperature gradients

    PubMed Central

    Karsten, Ulf; Herburger, Klaus; Holzinger, Andreas

    2015-01-01

    Green algae of the genus Klebsormidium (Klebsormidiales, Streptophyta) are typical members of biological soil crusts (BSCs) worldwide. The phylogeny and ecophysiology of Klebsormidium has been intensively studied in recent years, and a new lineage called superclade G, which was isolated from BSCs in arid southern Africa and comprising undescribed species, was reported. Three different African strains, that have previously been isolated from hot-desert BSCs and molecular-taxonomically characterized, were comparatively investigated. In addition, Klebsormidium subtilissimum from a cold-desert habitat (Alaska, USA, superclade E) was included in the study as well. Photosynthetic performance was measured under different controlled abiotic conditions, including dehydration and rehydration, as well as under a light and temperature gradient. All Klebsormidium strains exhibited optimum photosynthetic oxygen production at low photon fluence rates, but with no indication of photoinhibition under high light conditions pointing to flexible acclimation mechanisms of the photosynthetic apparatus. Respiration under lower temperatures was generally much less effective than photosynthesis, while the opposite was true for higher temperatures. The Klebsormidium strains tested showed a decrease and inhibition of the effective quantum yield during desiccation, however with different kinetics. While the single celled and small filamentous strains exhibited relatively fast inhibition, the uniserate filament forming isolates desiccated slower. Except one, all other strains fully recovered effective quantum yield after rehydration. The presented data provide an explanation for the regular occurrence of Klebsormidium strains or species in hot and cold deserts, which are characterized by low water availability and other stressful conditions. PMID:26422081

  15. Parasites of South African wildlife. XVI. Helminths of some antelope species from the Eastern and Western Cape Provinces.

    PubMed

    Boomker, J; Horak, I G; Watermeyer, R; Booyse, D G

    2000-03-01

    The numbers and species of helminths recovered from one black wildebeest, Connochaetes gnou, three eland, Taurotragus oryx, 18 mountain reedbuck, Redunca fulvorufula, one red hartebeest, AIcelaphus buselaphus and two springbok, Antidorcas marsupialis, in the Mountain Zebra National Park, Eastern Cape Province; two black wildebeest, two grey rhebuck, Pelea capreolus, two mountain reedbuck and four springbok in the Karoo National Park, Western Cape Province; two bontebok, Damaliscus pygargus dorcas, two eland, two gemsbok, Oryx gazella and two springbok in the West Coast National Park, Western Cape Province; and a single springbok on a farm near Bredasdorp, Western Cape Province, are recorded. Nematodes belonging to a total of 12 genera and 20 species were identified. A single cestode was also recovered. Sixteen new host associations are recorded for the nematodes and one for the cestode Moniezia benedeni. Nematodirus spathiger had the widest host spectrum and with the exception of black wildebeest, was collected from all the host species examined.

  16. Trypanosoma livingstonei: a new species from African bats supports the bat seeding hypothesis for the Trypanosoma cruzi clade

    PubMed Central

    2013-01-01

    Background Bat trypanosomes have been implicated in the evolutionary history of the T. cruzi clade, which comprises species from a wide geographic and host range in South America, Africa and Europe, including bat-restricted species and the generalist agents of human American trypanosomosis T. cruzi and T. rangeli. Methods Trypanosomes from bats (Rhinolophus landeri and Hipposideros caffer) captured in Mozambique, southeast Africa, were isolated by hemoculture. Barcoding was carried out through the V7V8 region of Small Subunit (SSU) rRNA and Fluorescent Fragment Length barcoding (FFLB). Phylogenetic inferences were based on SSU rRNA, glyceraldehyde phosphate dehydrogenase (gGAPDH) and Spliced Leader (SL) genes. Morphological characterization included light, scanning and transmission electron microscopy. Results New trypanosomes from bats clustered together forming a clade basal to a larger assemblage called the T. cruzi clade. Barcoding, phylogenetic analyses and genetic distances based on SSU rRNA and gGAPDH supported these trypanosomes as a new species, which we named Trypanosoma livingstonei n. sp. The large and highly polymorphic SL gene repeats of this species showed a copy of the 5S ribosomal RNA into the intergenic region. Unique morphological (large and broad blood trypomastigotes compatible to species of the subgenus Megatrypanum and cultures showing highly pleomorphic epimastigotes and long and slender trypomastigotes) and ultrastructural (cytostome and reservosomes) features and growth behaviour (when co-cultivated with HeLa cells at 37°C differentiated into trypomastigotes resembling the blood forms and do not invaded the cells) complemented the description of this species. Conclusion Phylogenetic inferences supported the hypothesis that Trypanosoma livingstonei n. sp. diverged from a common ancestral bat trypanosome that evolved exclusively in Chiroptera or switched at independent opportunities to mammals of several orders forming the clade T. cruzi

  17. Snapshot Serengeti, high-frequency annotated camera trap images of 40 mammalian species in an African savanna

    PubMed Central

    Swanson, Alexandra; Kosmala, Margaret; Lintott, Chris; Simpson, Robert; Smith, Arfon; Packer, Craig

    2015-01-01

    Camera traps can be used to address large-scale questions in community ecology by providing systematic data on an array of wide-ranging species. We deployed 225 camera traps across 1,125 km2 in Serengeti National Park, Tanzania, to evaluate spatial and temporal inter-species dynamics. The cameras have operated continuously since 2010 and had accumulated 99,241 camera-trap days and produced 1.2 million sets of pictures by 2013. Members of the general public classified the images via the citizen-science website www.snapshotserengeti.org. Multiple users viewed each image and recorded the species, number of individuals, associated behaviours, and presence of young. Over 28,000 registered users contributed 10.8 million classifications. We applied a simple algorithm to aggregate these individual classifications into a final ‘consensus’ dataset, yielding a final classification for each image and a measure of agreement among individual answers. The consensus classifications and raw imagery provide an unparalleled opportunity to investigate multi-species dynamics in an intact ecosystem and a valuable resource for machine-learning and computer-vision research. PMID:26097743

  18. Snapshot Serengeti, high-frequency annotated camera trap images of 40 mammalian species in an African savanna.

    PubMed

    Swanson, Alexandra; Kosmala, Margaret; Lintott, Chris; Simpson, Robert; Smith, Arfon; Packer, Craig

    2015-01-01

    Camera traps can be used to address large-scale questions in community ecology by providing systematic data on an array of wide-ranging species. We deployed 225 camera traps across 1,125 km(2) in Serengeti National Park, Tanzania, to evaluate spatial and temporal inter-species dynamics. The cameras have operated continuously since 2010 and had accumulated 99,241 camera-trap days and produced 1.2 million sets of pictures by 2013. Members of the general public classified the images via the citizen-science website www.snapshotserengeti.org. Multiple users viewed each image and recorded the species, number of individuals, associated behaviours, and presence of young. Over 28,000 registered users contributed 10.8 million classifications. We applied a simple algorithm to aggregate these individual classifications into a final 'consensus' dataset, yielding a final classification for each image and a measure of agreement among individual answers. The consensus classifications and raw imagery provide an unparalleled opportunity to investigate multi-species dynamics in an intact ecosystem and a valuable resource for machine-learning and computer-vision research.

  19. An analysis of reproductive behavior in the mouthbreeding cichlid fish, Tilapia macrocephala (Bleeker).

    PubMed

    ARONSON, L R

    1949-01-01

    Qualitative descriptions and quantitative measurements of the patterns of reproductive behavior of the African mouthbreeding cichlid fish, Tilapia macrocephala (Bleeker), have been presented. These patterns have been grouped into three categories. The first, namely courtship, includes head-nods, approach-throat-puffs, body-quivers and tail-slaps. Most the females exhibited these courtship items during the observation periods, and at a relatively high frequency. The males performed these courtship acts at a considerably lower frequency. A high percentage of males showed some tail-slaps and body-quivers, and it is believed that if the entire spans of the pre-spawning activity of the pairs could have observed, all of the males would have performed these courtship patterns. On the other hand, it appears that a measurable portion of males do not head-nod or approach-throat-puff prior to the spawning. It is hypothesized that courtship behavior is an expression of the level of excitability of the individual. It may be thought of as a trophallactic process which through mutual stimulation serves to regulate the behavioral activities and physiological processes of the male and female so that well synchronized spawnings result. Nipping, which is closely related to courtship and which also appears to be mutually stimulating, was performed equally by the male female before the spawning, but nipping on the part of the female rises sharply directly after oviposition. Similar post-spawning increases on the part of the female were noted for all of the courtship patterns. It is suggested that the physiological changes following oviposition plus the presence of eggs are the factors responsible for this heightened activity. During the inter-spawning interval, a low level of courtship is in evidence, especially on the part of the females. The second group of reproductive patterns includes those acts which are concerned with the immediate preparation for spawing. Included here are nest

  20. High frequency of multiple paternity in broods of a socially monogamous cichlid fish with biparental nest defence.

    PubMed

    Sefc, Kristina M; Mattersdorfer, Karin; Sturmbauer, Christian; Koblmüller, Stephan

    2008-05-01

    In several animal taxa, genetic analyses have demonstrated that social monogamy and biparental brood care do not preclude polygamous reproduction. Few studies have been conducted in fish, but in fish species without alternative reproductive phenotypes, social monogamy was largely congruent with genetic parentage. In contrast to these findings, we report an exceptionally high level of multiple paternity in a socially monogamous cichlid fish with biparental nest defence (Variabilichromis moorii), inferred from microsatellite and mitochondrial data of 10 broods. Whereas all offspring in a nest shared a common mother, each brood was sired by 2 to > 10 males. None of the inferred sires was assigned a large proportion of the brood. Paternity was estimated as the minimum number of sires required to explain multilocus offspring genotypes, and as the maximum-likelihood number of sires given population allele frequencies. Analysis of simulated brood genotypes suggested that, although these two methods tend to under- and overestimate, respectively, the true number of sires, primary sires with many offspring in a brood would have been detected. Hence, the genetic data indicate that the nest tending males suffer substantial cuckoldry and provide alloparental care for a large number of unrelated fry. We have no data on the social status of the cuckolding males, but due to synchronous spawning of pairs and commitment to brood care of paired males, it is possible that most of the parasitic spawners are solitary males.

  1. Yolk-sac larval development of the substrate-brooding cichlid Archocentrus nigrofasciatus in relation to temperature.

    PubMed

    Vlahos, Nikolaos; Vasilopoulos, Michael; Mente, Eleni; Hotos, George; Katselis, George; Vidalis, Kosmas

    2015-09-01

    In order to conserve and culture the cichlid fish Archocentrus nigrofasciatus, more information about its reproductive biology and its larval behavior and morphogenesis is necessary. Currently, temperatures ranging from 21 to 27 °C are used in ornamental aquaculture hatcheries. Lower temperatures are preferred to reduce the costs of water heating, and 23 °C is usually the selected temperature. However, there is limited information on culturing protocols for ornamental species and most of the information generated on this topic remains scarce. Thus, the present study examines the morphological development of Archocentrus nigrofasciatus during the yolk-sac period up to the age of 100 h post-hatching in relation to 2 temperature regimes used in ornamental aquaculture: a temperature of 27 °C (thermal optimum) and a decreased temperature of 23 °C (thermal tolerance). The results of this study suggest that the 27 °C temperature generates intense morphological changes in yolk-sac development in a shorter period. This has advantages as it reduces the time of yolk-sac larval development, and, thus, minimizes the transition phase to exogenous feeding and maximizes the efficiency at which yolk is converted into body tissues. The present paper provides necessary information to produce freshwater ornamental fish with better practices so as to increase larval survival and capitalize on time for growth.

  2. Variation in glucocorticoid levels in relation to direct and third-party interactions in a social cichlid fish.

    PubMed

    Ligocki, Isaac Y; Earley, Ryan L; Hellmann, Jennifer K; Hamilton, Ian M

    2015-11-01

    In complex animal societies, direct interactions between group members can influence the behavior and glucocorticoid levels of individuals involved. Recently, it has become apparent that third-party group members can influence dyadic interactions, and vice versa. Thus, glucocorticoid levels may vary depending on interactions of other members of the social group. Using the social cichlid fish Neolamprologus pulcher, we examined the relationship between levels of the glucocorticoid hormone cortisol in subordinate females and 1) direct interactions with dominant group members, as well as 2) dyadic interactions between the dominant male and female, in which the subordinate female was not directly involved. Subordinate females that frequently engaged in non-aggressive interactions with dominant females had lower cortisol levels. There was no relationship between subordinate female cortisol and agonistic interactions between the subordinate female and either dominant. Subordinate females had higher cortisol levels when in groups in which the dominant breeding pair behaved agonistically towards each other and performed fewer courtship behaviors. For subordinate females in this species, variation in cortisol levels is associated with their own affiliative behavior, but also can be explained by the broader social context of interactions between dominant members of the group.

  3. Brain nonapeptide levels are related to social status and affiliative behaviour in a cooperatively breeding cichlid fish.

    PubMed

    Reddon, Adam R; O'Connor, Constance M; Marsh-Rollo, Susan E; Balshine, Sigal; Gozdowska, Magdalena; Kulczykowska, Ewa

    2015-02-01

    The mammalian nonapeptide hormones, vasopressin and oxytocin, are known to be potent regulators of social behaviour. Teleost fishes possess vasopressin and oxytocin homologues known as arginine vasotocin (AVT) and isotocin (IT), respectively. The role of these homologous nonapeptides in mediating social behaviour in fishes has received far less attention. The extraordinarily large number of teleost fish species and the impressive diversity of their social systems provide us with a rich test bed for investigating the role of nonapeptides in regulating social behaviour. Existing studies, mostly focused on AVT, have revealed relationships between the nonapeptides, and both social behaviour and dominance status in fishes. To date, much of the work on endogenous nonapeptides in fish brains has measured genomic or neuroanatomical proxies of nonapeptide production rather than the levels of these molecules in the brain. In this study, we measure biologically available AVT and IT levels in the brains of Neolamprologus pulcher, a cooperatively breeding cichlid fish, using high performance liquid chromatography with fluorescence detection. We found that brain AVT levels were higher in the subordinate than in dominant animals, and levels of IT correlated negatively with the expression of affiliative behaviour. We contrast these results with previous studies, and we discuss the role the nonapeptide hormones may play in the regulation of social behaviour in this highly social animal.

  4. Social cichlid fish change behaviour in response to a visual predator stimulus, but not the odour of damaged conspecifics.

    PubMed

    O'Connor, Constance M; Reddon, Adam R; Odetunde, Aderinsola; Jindal, Shagun; Balshine, Sigal

    2015-12-01

    Predation is one of the primary drivers of fitness for prey species. Therefore, there should be strong selection for accurate assessment of predation risk, and whenever possible, individuals should use all available information to fine-tune their response to the current threat of predation. Here, we used a controlled laboratory experiment to assess the responses of individual Neolamprologus pulcher, a social cichlid fish, to a live predator stimulus, to the odour of damaged conspecifics, or to both indicators of predation risk combined. We found that fish in the presence of the visual predator stimulus showed typical antipredator behaviour. Namely, these fish decreased activity and exploration, spent more time seeking shelter, and more time near conspecifics. Surprisingly, there was no effect of the chemical cue alone, and fish showed a reduced response to the combination of the visual predator stimulus and the odour of damaged conspecifics relative to the visual predator stimulus alone. These results demonstrate that N. pulcher adjust their anti-predator behaviour to the information available about current predation risk, and we suggest a possible role for the use of social information in the assessment of predation risk in a cooperatively breeding fish.

  5. Environmental change explains cichlid adaptive radiation at Lake Malawi over the past 1.2 million years.

    PubMed

    Ivory, Sarah J; Blome, Margaret W; King, John W; McGlue, Michael M; Cole, Julia E; Cohen, Andrew S

    2016-10-18

    Long paleoecological records are critical for understanding evolutionary responses to environmental forcing and unparalleled tools for elucidating the mechanisms that lead to the development of regions of high biodiversity. We use a 1.2-My record from Lake Malawi, a textbook example of biological diversification, to document how climate and tectonics have driven ecosystem and evolutionary dynamics. Before ∼800 ka, Lake Malawi was much shallower than today, with higher frequency but much lower amplitude water-level and oxygenation changes. Since ∼800 ka, the lake has experienced much larger environmental fluctuations, best explained by a punctuated, tectonically driven rise in its outlet location and level. Following the reorganization of the basin, a change in the pacing of hydroclimate variability associated with the Mid-Pleistocene Transition resulted in hydrologic change dominated by precession rather than the high-latitude teleconnections recorded elsewhere. During this time, extended, deep lake phases have abruptly alternated with times of extreme aridity and ecosystem variability. Repeated crossings of hydroclimatic thresholds within the lake system were critical for establishing the rhythm of diversification, hybridization, and extinction that dominate the modern system. The chronology of these changes closely matches both the timing and pattern of phylogenetic history inferred independently for the lake's extraordinary array of cichlid fish species, suggesting a direct link between environmental and evolutionary dynamics.

  6. The interrenal gland in males of the cichlid fish Cichlasoma dimerus: relationship with stress and the establishment of social hierarchies.

    PubMed

    Morandini, Leonel; Honji, Renato Massaaki; Ramallo, Martín Roberto; Moreira, Renata Guimarães; Pandolfi, Matías

    2014-01-01

    In teleosts, cortisol is the primary glucocorticoid secreted by the steroidogenic cells of the interrenal gland and an increase in its plasma concentration is a frequent indicator of stress. Cortisol has been postulated as an endogenous mediator involved in the regulation of reproduction and aggression related to social dynamics. The cichlid fish Cichlasoma dimerus, is a monogamous species that exhibits complex social hierarchies; males appear in one of two basic alternative phenotypes: non-territorial and territorial males. In this work, we postulated as a general hypothesis that the morphometry of the interrenal gland cells and the plasma levels of cortisol and 11-ketotestosterone (11-KT) are related to the social rank in adult males of C. dimerus. First, the location and distribution of the interrenal gland with respect to its context - the kidney - was studied. Plasma levels of cortisol and 11-KT in territorial and non-territorial males were established by ELISA. Finally, a morphometric analysis of steroidogenic and chromaffin cells of the interrenal gland was performed. Results showed that the interrenal gland was exclusively located in the posterior portion of the cephalic kidney. Non-territorial males presented a greater nuclear area of their steroidogenic cells. Additionally, plasma cortisol and 11-KT levels were lower and higher, respectively, in territorial males. Finally, plasma cortisol levels positively correlated with the nuclear area of interrenal steroidogenic cells. Thus, the interrenal gland, by means of one of its products, cortisol, may be fulfilling an important role in the establishment of social hierarchies and their stability.

  7. Brain nonapeptide levels are related to social status and affiliative behaviour in a cooperatively breeding cichlid fish

    PubMed Central

    Reddon, Adam R.; O'Connor, Constance M.; Marsh-Rollo, Susan E.; Balshine, Sigal; Gozdowska, Magdalena; Kulczykowska, Ewa

    2015-01-01

    The mammalian nonapeptide hormones, vasopressin and oxytocin, are known to be potent regulators of social behaviour. Teleost fishes possess vasopressin and oxytocin homologues known as arginine vasotocin (AVT) and isotocin (IT), respectively. The role of these homologous nonapeptides in mediating social behaviour in fishes has received far less attention. The extraordinarily large number of teleost fish species and the impressive diversity of their social systems provide us with a rich test bed for investigating the role of nonapeptides in regulating social behaviour. Existing studies, mostly focused on AVT, have revealed relationships between the nonapeptides, and both social behaviour and dominance status in fishes. To date, much of the work on endogenous nonapeptides in fish brains has measured genomic or neuroanatomical proxies of nonapeptide production rather than the levels of these molecules in the brain. In this study, we measure biologically available AVT and IT levels in the brains of Neolamprologus pulcher, a cooperatively breeding cichlid fish, using high performance liquid chromatography with fluorescence detection. We found that brain AVT levels were higher in the subordinate than in dominant animals, and levels of IT correlated negatively with the expression of affiliative behaviour. We contrast these results with previous studies, and we discuss the role the nonapeptide hormones may play in the regulation of social behaviour in this highly social animal. PMID:26064593

  8. Differentiation of morphology, genetics and electric signals in a region of sympatry between sister species of African electric fish (Mormyridae).

    PubMed

    Lavoué, S; Sullivan, J P; Arnegard, M E; Hopkins, C D

    2008-07-01

    Mormyrid fishes produce and sense weak electric organ discharges (EODs) for object detection and communication, and they have been increasingly recognized as useful model organisms for studying signal evolution and speciation. EOD waveform variation can provide important clues to sympatric species boundaries between otherwise similar or morphologically cryptic forms. Endemic to the watersheds of Gabon (Central Africa), Ivindomyrus marchei and Ivindomyrus opdenboschi are morphologically similar to one another. Using morphometric, electrophysiological and molecular characters [cytochrome b sequences and amplified fragment length polymorphism (AFLP) genotypes], we investigated to what extent these nominal mormyrid species have diverged into biological species. Our sampling covered the known distribution of each species with a focus on the Ivindo River, where the two taxa co-occur. An overall pattern of congruence among datasets suggests that I. opdenboschi and I. marchei are mostly distinct. Electric signal analysis showed that EODs of I. opdenboschi tend to have a smaller initial head-positive peak than those of I. marchei, and they often possess a small third waveform peak that is typically absent in EODs of I. marchei. Analysis of sympatric I. opdenboschi and I. marchei populations revealed slight, but significant, genetic partitioning between populations based on AFLP data (F(ST) approximately 0.04). Taken separately, however, none of the characters we evaluated allowed us to discriminate two completely distinct or monophyletic groups. Lack of robust separation on the basis of any single character set may be a consequence of incomplete lineage sorting due to recent ancestry and/or introgressive hybridization. Incongruence between genetic datasets in one individual, which exhibited a mitochondrial haplotype characteristic of I. marchei but nevertheless fell within a genetic cluster of I. opdenboschi based on AFLP genotypes, suggests that a low level of recent

  9. Leaching characteristics of selected South African fly ashes: Effect of pH on the release of major and trace species

    SciTech Connect

    Gitari, W.M.; Fatoba, O.O.; Petrik, L.F.; Vadapalli, V.R.K.

    2009-07-01

    Fly ash samples from two South African coal-fired power stations were subjected to different leaching tests under alkaline and acidic conditions in an attempt to assess the effect of pH on the leachability of species from the fly ashes and also assess the potential impact of the fly ashes disposal on groundwater and the receiving environment. To achieve this, German Standard leaching (DIN-S4) and Acid Neutralization Capacity (ANC) tests were employed. Ca, Mg, Na, K and SO{sub 4} were significantly leached into solution under the two leaching conditions with the total amounts in ANC leachates higher than that of DIN-S4. This indicates that a large fraction of the soluble salts in unweathered fly ash are easily leached. These species represents the fraction that can be flushed off initially from the surface of ash particles on contacting the ash with water. The amounts of toxic trace elements such as As, Se, Cd, Cr and Pb leached out of the fly ashes when in contact with de-mineralized water (DIN-S4 test) were low and below the Target Water Quality Range (TWQR) of South Africa. This is explained by their low concentrations in the fly ashes and their solubility dependence on the pH of the leaching solution. However the amounts of some minor elements such as B, Mn, Fe, As and Se leached out at lower pH ranging between 10 to 4 (ANC test) were slightly higher than the TWQR, an indication that the pH of the leaching solution plays a significant role on the leaching of species in fly ash. The high concentrations of the toxic elements released from the fly ashes at lower pH gives an indication that the disposal of the fly ash could have adverse effects on the receiving environment if the pH of the solution contacting the ashes is not properly monitored.

  10. Evaluation of a real-time PCR test for the detection and discrimination of theileria species in the African buffalo (Syncerus caffer).

    PubMed

    Chaisi, Mamohale E; Janssens, Michiel E; Vermeiren, Lieve; Oosthuizen, Marinda C; Collins, Nicola E; Geysen, Dirk

    2013-01-01

    A quantitative real-time PCR (qPCR) assay based on the cox III gene was evaluated for the simultaneous detection and discrimination of Theileria species in buffalo and cattle blood samples from South Africa and Mozambique using melting curve analysis. The results obtained were compared to those of the reverse line blot (RLB) hybridization assay for the simultaneous detection and differentiation of Theileria spp. in mixed infections, and to the 18S rRNA qPCR assay results for the specific detection of Theileria parva. Theileria parva, Theileria sp. (buffalo), Theileria taurotragi, Theileria buffeli and Theileria mutans were detected by the cox III assay. Theileria velifera was not detected from any of the samples analysed. Seventeen percent of the samples had non-species specific melting peaks and 4.5% of the samples were negative or below the detection limit of the assay. The cox III assay identified more T. parva and Theileria sp. (buffalo) positive samples than the RLB assay, and also detected more T. parva infections than the 18S assay. However, only a small number of samples were positive for the benign Theileria spp. To our knowledge T. taurotragi has never been identified from the African buffalo, its identification in some samples by the qPCR assay was unexpected. Because of these discrepancies in the results, cox III qPCR products were cloned and sequenced. Sequence analysis indicated extensive inter- and intra-species variations in the probe target regions of the cox III gene sequences of the benign Theileria spp. and therefore explains their low detection. The cox III assay is specific for the detection of T. parva infections in cattle and buffalo. Sequence data generated from this study can be used for the development of a more inclusive assay for detection and differentiation of all variants of the mildly pathogenic and benign Theileria spp. of buffalo and cattle.

  11. The high cost of mutualism: effects of four species of East African ant symbionts on their myrmecophyte host tree.

    PubMed

    Stanton, Maureen L; Palmer, Todd M

    2011-05-01

    Three recent meta-analyses of protective plant-ant mutualisms report a surprisingly weak relationship between herbivore protection and measured demographic benefits to ant-plants, suggesting high tolerance for herbivory, substantial costs of ant-mediated defense, and/or benefits that are realized episodically rather than continuously. Experimental manipulations of protective ant-plant associations typically last for less than a year, yet virtually all specialized myrmecophytes are long-lived perennials for which the costs and benefits of maintaining ant symbionts could accrue at different rates over the host's lifetime. To complement long-term monitoring studies, we experimentally excluded each of four ant symbionts from their long-lived myrmecophyte host trees (Acacia drepanolobium) for 4.5 years. Ant species varied in their effectiveness against herbivores and in their effects on intermediate-term growth and reproduction, but the level of herbivore protection provided was a poor predictor of the net impact they had on host trees. Removal of the three Crematogaster species resulted in cumulative gains in host tree growth and/or reproduction over the course of the experiment, despite the fact that two of those species significantly reduce chronic herbivore damage. In contrast, although T. penzigi is a relatively poor defender, the low cost of maintaining this ant symbiont apparently eliminated negative impacts on overall tree growth and reproduction, resulting in enhanced allocation to new branch growth by the final census. Acacia drepanolobium is evidently highly tolerant of herbivory by insects and small browsers, and the costs of maintaining Crematogaster colonies exceeded the benefits received during the study. No experimental trees were killed by elephants, but elephant damage was uniquely associated with reduced tree growth, and at least one ant species (C. mimosae) strongly deterred elephant browsing. We hypothesize that rare but catastrophic damage by

  12. Implementing telemetry on new species in remote areas: Recommendations from a large-scale satellite tracking study of African waterfowl

    USGS Publications Warehouse

    Cappelle, J.; Iverson, S.A.; Takekawa, J.Y.; Newman, S.H.; Dodman, T.; Gaidet, N.

    2011-01-01

    We provide recommendations for implementing telemetry studies on waterfowl on the basis of our experience in a tracking study conducted in three countries of sub-Saharan Africa. The aim of the study was to document movements by duck species identified as priority candidates for the potential spread of avian influenza. Our study design included both captive and field test components on four wild duck species (Garganey, Comb Duck, White-faced Duck and Fulvous Duck). We used our location data to evaluate marking success and determine when signal loss occurred. The captive study of eight ducks marked with non-working transmitters in a zoo in Montpellier, France, prior to fieldwork showed no evidence of adverse effects, and the harness design appeared to work well. The field study in Malawi, Nigeria and Mali started in 2007 on 2 February, 6 February and 14 February, and ended on 22 November 2007 (288 d), 20 January 2010 (1 079 d), and 3 November 2008 (628 d), respectively. The field study indicated that 38 of 47 (81%) of the platform transmitter terminals (PTTs) kept transmitting after initial deployment, and the transmitters provided 15 576 locations. Signal loss during the field study was attributed to three main causes: PTT loss, PTT failure and mortality (natural, human-caused and PTT-related). The PTT signal quality varied by geographic region, and interference caused signal loss in the Mediterranean Sea region. We recommend careful attention at the beginning of the study to determine the optimum timing of transmitter deployment and the number of transmitters to be deployed per species. These sample sizes should be calculated by taking into account region-specific causes of signal loss to ensure research objectives are met. These recommendations should be useful for researchers undertaking a satellite tracking program, especially when working in remote areas of Africa where logistics are difficult or with poorly-known species. ?? NISC (Pty) Ltd.

  13. Sensitivity of Above-Ground Biomass Estimates to Height-Diameter Modelling in Mixed-Species West African Woodlands

    PubMed Central

    Aynekulu, Ermias; Pitkänen, Sari; Packalen, Petteri

    2016-01-01

    It has been suggested that above-ground biomass (AGB) inventories should include tree height (H), in addition to diameter (D). As H is a difficult variable to measure, H-D models are commonly used to predict H. We tested a number of approaches for H-D modelling, including additive terms which increased the complexity of the model, and observed how differences in tree-level predictions of H propagated to plot-level AGB estimations. We were especially interested in detecting whether the choice of method can lead to bias. The compared approaches listed in the order of increasing complexity were: (B0) AGB estimations from D-only; (B1) involving also H obtained from a fixed-effects H-D model; (B2) involving also species; (B3) including also between-plot variability as random effects; and (B4) involving multilevel nested random effects for grouping plots in clusters. In light of the results, the modelling approach affected the AGB estimation significantly in some cases, although differences were negligible for some of the alternatives. The most important differences were found between including H or not in the AGB estimation. We observed that AGB predictions without H information were very sensitive to the environmental stress parameter (E), which can induce a critical bias. Regarding the H-D modelling, the most relevant effect was found when species was included as an additive term. We presented a two-step methodology, which succeeded in identifying the species for which the general H-D relation was relevant to modify. Based on the results, our final choice was the single-level mixed-effects model (B3), which accounts for the species but also for the plot random effects reflecting site-specific factors such as soil properties and degree of disturbance. PMID:27367857

  14. Taxonomy of Atlantic Central African orchids 2. A second species of the rare genus Distylodon (Orchidaceae, Angraecinae) collected in Cameroon.

    PubMed

    Droissart, Vincent; Cribb, Phillip J; Simo-Droissart, Murielle; Stévart, Tariq

    2014-01-01

    While conducting field inventories in South Cameroon, we collected two specimens of a new species that we considered to belong to the genus Angraecopsis. Afterwards, a careful examination of specimens housed at main herbaria, along with the nomenclatural types, allows us to place it in Distylodon, a monotypic genus previously known from East Africa. Distylodon sonkeanum Droissart, Stévart & P.J.Cribb, sp. nov. was collected in the lowland coastal forest of Atlantic Central Africa. It is known from a single locality in the surroundings of the Campo-Ma'an National Park. The species differs from D. comptum, by its several-flowered inflorescences, longer leaves and spur, and shorter pedicel and ovary. The species appears to be rare and is assessed as Critically Endangered [CR B2ab(iii)] according to IUCN Red List Categories and Criteria. New field investigations are required to attempt to find it in the low-elevation parts of the Campo-Ma'an National Park in Cameroon.

  15. Taxonomy of Atlantic Central African orchids 2. A second species of the rare genus Distylodon (Orchidaceae, Angraecinae) collected in Cameroon

    PubMed Central

    Droissart, Vincent; Cribb, Phillip J.; Simo-Droissart, Murielle; Stévart, Tariq

    2014-01-01

    Abstract While conducting field inventories in South Cameroon, we collected two specimens of a new species that we considered to belong to the genus Angraecopsis. Afterwards, a careful examination of specimens housed at main herbaria, along with the nomenclatural types, allows us to place it in Distylodon, a monotypic genus previously known from East Africa. Distylodon sonkeanum Droissart, Stévart & P.J.Cribb, sp. nov. was collected in the lowland coastal forest of Atlantic Central Africa. It is known from a single locality in the surroundings of the Campo-Ma’an National Park. The species differs from D. comptum, by its several-flowered inflorescences, longer leaves and spur, and shorter pedicel and ovary. The species appears to be rare and is assessed as Critically Endangered [CR B2ab(iii)] according to IUCN Red List Categories and Criteria. New field investigations are required to attempt to find it in the low-elevation parts of the Campo-Ma’an National Park in Cameroon. PMID:24843291

  16. Metabolic and water loss rates of two cryptic species in the African velvet worm genus Opisthopatus (Onychophora).

    PubMed

    Weldon, Christopher W; Daniels, Savel R; Clusella-Trullas, Susana; Chown, Steven L

    2013-04-01

    Velvet worms (Onychophora) are characterised by a dearth of mechanisms to retain water, yet recently identified cryptic species are located in areas with seemingly different climates. Using flow-through respirometry, this study determined the metabolic, water loss and cuticular water loss rates of two cryptic species of Opisthopatus cinctipes s.l. from locations that differ in their current climate. When controlling for trial temperature and body mass, velvet worms from the drier and warmer site had significantly lower water loss rates than the wetter and cooler site. Mass-corrected metabolic rate and cuticular water loss did not differ significantly between the two sites. The scaling exponent for the relationship between log metabolic rate and log body mass for O. cinctipes s.l. declined with an increase in temperature from 5 to 15 °C. Females in the two cryptic Opisthopatus species had higher metabolic, water loss and cuticular water loss rates than males, which may represent the increased energetic demands of embryonic growth and development in these viviparous taxa.

  17. Wallaceochromis gen. nov, a new chromidotilapiine cichlid genus (Pisces: Perciformes) from West Africa.

    PubMed

    Lamboj, Anton; Trummer, Franziska; Metscher, Brian D

    2016-07-26

    A new genus, Wallaceochromis, is described for the chromidotilapiine cichlids of the Pelvicachromis humilis group. It differs from Pelvicachromis sensu stricto in the number and arrangement of tubular infraorbitals, a straighter and sloping dorsal head profile with a low supraoccipital crest, higher abdominal vertebral counts (14-15 vs. 13-14), and in displaying a pattern of vertical bars on the body in several behavioral situations.

  18. Photoperiod modulation of aggressive behavior is independent of androgens in a tropical cichlid fish.

    PubMed

    Gonçalves-de-Freitas, Eliane; Carvalho, Thaís Billalba; Oliveira, Rui F

    2014-10-01

    Photoperiod is a major environmental cue that signals breeding conditions in animals living in temperate climates. Therefore, the activity of the reproductive (i.e. hypothalamic-pituitary-gonadal, HPG) axis and of the expression of reproductive behaviors, including territoriality, is responsive to changes in day length. However, at low latitudes the seasonal variation in day length decreases dramatically and photoperiod becomes less reliable as a breeding entraining cue in tropical species. In spite of this, some tropical mammals and birds have been found to still respond to small amplitude changes in photoperiod (e.g. 17min). Here we tested the effect of 2 photoperiod regimes, referred to as long-day (LD: 16L:08D) and short-day (SD: 08L:16D), on the activity of the HPG axis, on aggressive behavior and in the androgen response to social challenges in males of the tropical cichlid fish Tilapia rendalli. For each treatment, fish were transferred from a pre-treatment photoperiod of 12L:12D to their treatment photoperiod (either LD or SD) in which they were kept for 20days on stock tanks. Afterwards, males were isolated for 4days in glass aquaria in order to establish territories and initial androgen levels (testosterone, T; 11-ketotestosterone, KT) were assessed. On the 4th day, territorial intrusions were promoted such that 1/3 of the isolated males acted as residents and another 1/3 as intruders. Territorial intrusions lasted for 1h to test the effects of a social challenge under different photoperiod regimes. Photoperiod treatment (either SD or LD) failed to induce significant changes in the HPG activity, as measured by androgen levels and gonadosomatic index. However, SD increased the intensity of aggressive behaviors and shortened the time to settle a dominance hierarchy in an androgen-independent manner. The androgen responsiveness to the simulated territorial intrusion was only present in KT but not for T. The percent change in KT levels in response to the

  19. Phenotypic integration of brain size and head morphology in Lake Tanganyika Cichlids

    PubMed Central

    2014-01-01

    Background Phenotypic integration among different anatomical parts of the head is a common phenomenon across vertebrates. Interestingly, despite centuries of research into the factors that contribute to the existing variation in brain size among vertebrates, little is known about the role of phenotypic integration in brain size diversification. Here we used geometric morphometrics on the morphologically diverse Tanganyikan cichlids to investigate phenotypic integration across key morphological aspects of the head. Then, while taking the effect of shared ancestry into account, we tested if head shape was associated with brain size while controlling for the potentially confounding effect of feeding strategy. Results The shapes of the anterior and posterior parts of the head were strongly correlated, indicating that the head represents an integrated morphological unit in Lake Tanganyika cichlids. After controlling for phylogenetic non-independence, we also found evolutionary associations between head shape, brain size and feeding ecology. Conclusions Geometric morphometrics and phylogenetic comparative analyses revealed that the anterior and posterior parts of the head are integrated, and that head morphology is associated with brain size and feeding ecology in Tanganyikan cichlid fishes. In light of previous results on mammals, our results suggest that the influence of phenotypic integration on brain diversification is a general process. PMID:24593160

  20. New species and new records of Pterosthetops: eumadicolous water beetles of the South African Cape (Coleoptera, Hydraenidae).

    PubMed

    Bilton, David T

    2014-06-05

    Pterosthetops is one of a number of hydraenid genera endemic to the Cape of South Africa, whose minute moss beetle fauna is amongst the most diverse on earth. Here seven species are described as new: Pterosthetops baini sp. nov., Pterosthetops coriaceus sp. nov., Pterosthetops indwei sp. nov., Ptersothetops pulcherrimus sp. nov., Pterosthetops swartbergensis sp. nov., Pterosthetops tuberculatus sp. nov. and Pterosthetops uitkyki sp. nov., all from mountains in the Western Cape region. New collection records are also provided for all five previously described members of the genus, together with a revised key. Pterosthetops appear to be specialist inhabitants of seepages over rock faces (hygropetric/madicolous habitats), rarely being found outside such situations.

  1. Cytotoxic Activity of Crude Extracts as well as of Pure Components from Jatropha Species, Plants Used Extensively in African Traditional Medicine

    PubMed Central

    Aiyelaagbe, Olapeju O.; Hamid, Amao A.; Fattorusso, Ernesto; Taglialatela-Scafati, Orazio; Schröder, Heinz C.; Müller, Werner E. G.

    2011-01-01

    Extracts from Jatropha curcas, a plant used in African traditional medicine for various diseases, were tested for cytotoxic activity. The root extracts strongly reduced cell growth of tumor cells in vitro, a result consistent with the knowledge of the application of these plant extracts in traditional medicine, especially to cure/ameliorate cancer. A selection of pure diterpenoids existing in extracts from Jatropha species and isolated from J. curcas, for example, curcusone C, curcusone D, multidione, 15-epi-4Z-jatrogrossidentadion, 4Z-jatrogrossidentadion, 4E-jatrogrossidentadion, 2-hydroxyisojatrogrossidion, and 2-epi-hydroxyisojatrogrossidion, were likewise tested, and they also showed strong cytotoxic activity. It turned out that these extracts are highly active against L5178y mouse lymphoma cells and HeLa human cervix carcinoma cells, while they cause none or only very low activity against neuronal cell, for example, PC12. These data underscore that extracts from J. curcas or pure secondary metabolites from the plant are promising candidates to be anticancer drug, combined with low neuroactive effects. PMID:21754941

  2. Four plant defensins from an indigenous South African Brassicaceae species display divergent activities against two test pathogens despite high sequence similarity in the encoding genes

    PubMed Central

    2011-01-01

    Background Plant defensins are an important component of the innate defence system of plants where they form protective antimicrobial barriers between tissue types of plant organs as well as around seeds. These peptides also have other activities that are important for agricultural applications as well as the medical sector. Amongst the numerous plant peptides isolated from a variety of plant species, a significant number of promising defensins have been isolated from Brassicaceae species. Here we report on the isolation and characterization of four defensins from Heliophila coronopifolia, a native South African Brassicaceae species. Results Four defensin genes (Hc-AFP1-4) were isolated with a homology based PCR strategy. Analysis of the deduced amino acid sequences showed that the peptides were 72% similar and grouped closest to defensins isolated from other Brassicaceae species. The Hc-AFP1 and 3 peptides shared high homology (94%) and formed a unique grouping in the Brassicaceae defensins, whereas Hc-AFP2 and 4 formed a second homology grouping with defensins from Arabidopsis and Raphanus. Homology modelling showed that the few amino acids that differed between the four peptides had an effect on the surface properties of the defensins, specifically in the alpha-helix and the loop connecting the second and third beta-strands. These areas are implicated in determining differential activities of defensins. Comparing the activities after recombinant production of the peptides, Hc-AFP2 and 4 had IC50 values of 5-20 μg ml-1 against two test pathogens, whereas Hc-AFP1 and 3 were less active. The activity against Botrytis cinerea was associated with membrane permeabilization, hyper-branching, biomass reduction and even lytic activity. In contrast, only Hc-AFP2 and 4 caused membrane permeabilization and severe hyper-branching against the wilting pathogen Fusarium solani, while Hc-AFP1 and 3 had a mild morphogenetic effect on the fungus, without any indication of

  3. Some southern African plant species used to treat helminth infections in ethnoveterinary medicine have excellent antifungal activities

    PubMed Central

    2012-01-01

    Background Diseases caused by microorganisms and parasites remain a major challenge globally and particularly in sub-Saharan Africa to man and livestock. Resistance to available antimicrobials and the high cost or unavailability of antimicrobials complicates matters. Many rural people use plants to treat these infections. Because some anthelmintics e.g. benzimidazoles also have good antifungal activity we examined the antifungal activity of extracts of 13 plant species used in southern Africa to treat gastrointestinal helminth infections in livestock and in man. Methods Antifungal activity of acetone leaf extracts was determined by serial microdilution with tetrazolium violet as growth indicator against Aspergillus fumigatus, Cryptococcus neoformans and Candida albicans. These pathogens play an important role in opportunistic infections of immune compromised patients. Cytotoxicity was determined by MTT cellular assay. Therapeutic indices were calculated and selectivity for different pathogens determined. We proposed a method to calculate the relation between microbicidal and microbistatic activities. Total activities for different plant species were calculated. Results On the whole, all 13 extracts had good antifungal activities with MIC values as low as 0.02 mg/mL for extracts of Clausena anisata against Aspergillus fumigatus and 0.04 mg/mL for extracts of Zanthoxylum capense, Clerodendrum glabrum, and Milletia grandis, against A. fumigatus. Clausena anisata extracts had the lowest cytotoxicity (LC50) of 0.17 mg/mL, a reasonable therapeutic index (2.65) against A. fumigatus. It also had selective activity against A. fumigatus, an overall fungicidal activity of 98% and a total activity of 3395 mL/g against A. fumigatus. This means that 1 g of acetone leaf extract can be diluted to 3.4 litres and it would still inhibit the growth. Clerodendrum glabrum, Zanthoxylum capense and Milletia grandis extracts also yielded promising results. Conclusions Some plant extracts

  4. Genomewide SNP data reveal cryptic phylogeographic structure and microallopatric divergence in a rapids-adapted clade of cichlids from the Congo River.

    PubMed

    Alter, S Elizabeth; Munshi-South, Jason; Stiassny, Melanie L J

    2017-03-01

    The lower Congo River is a freshwater biodiversity hot spot in Africa characterized by some of the world's largest rapids. However, little is known about the evolutionary forces shaping this diversity, which include numerous endemic fishes. We investigated phylogeographic relationships in Teleogramma, a small clade of rheophilic cichlids, in the context of regional geography and hydrology. Previous studies have been unable to resolve phylogenetic relationships within Teleogramma due to lack of variation in nuclear genes and discrete morphological characters among putative species. To sample more broadly across the genome, we analysed double-digest restriction-associated sequencing (ddRAD) data from 53 individuals across all described species in the genus. We also assessed body shape and mitochondrial variation within and between taxa. Phylogenetic analyses reveal previously unrecognized lineages and instances of microallopatric divergence across as little as ~1.5 km. Species ranges appear to correspond to geographic regions broadly separated by major hydrological and topographic barriers, indicating these features are likely important drivers of diversification. Mitonuclear discordance indicates one or more introgressive hybridization events, but no clear evidence of admixture is present in nuclear genomes, suggesting these events were likely ancient. A survey of female fin patterns hints that previously undetected lineage-specific patterning may be acting to reinforce species cohesion. These analyses highlight the importance of hydrological complexity in generating diversity in certain freshwater systems, as well as the utility of ddRAD-Seq data in understanding diversification processes operating both below and above the species level.

  5. A novel multilocus variable number tandem repeat analysis typing scheme for African phylotype III strains of the Ralstonia solanacearum species complex.

    PubMed

    Ravelomanantsoa, Santatra; Robène, Isabelle; Chiroleu, Frédéric; Guérin, Fabien; Poussier, Stéphane; Pruvost, Olivier; Prior, Philippe

    2016-01-01

    Background. Reliable genotyping that provides an accurate description of diversity in the context of pathogen emergence is required for the establishment of strategies to improve disease management. MultiLocus variable number tandem repeat analysis (MLVA) is a valuable genotyping method. It can be performed at small evolutionary scales where high discriminatory power is needed. Strains of the Ralstonia solanacearum species complex (RSSC) are highly genetically diverse. These destructive pathogens are the causative agent of bacterial wilt on an unusually broad range of host plants worldwide. In this study, we developed an MLVA scheme for genotyping the African RSSC phylotype III. Methods. We selected different publicly available tandem repeat (TR) loci and additional TR loci from the genome of strain CMR15 as markers. Based on these loci, a new phylotype III-MLVA scheme is presented. MLVA and multiLocus sequence typing (MLST) were compared at the global, regional, and local scales. Different populations of epidemiologically related and unrelated RSSC phylotype III strains were used. Results and Discussion. Sixteen polymorphic TR loci, which included seven microsatellites and nine minisatellites, were selected. These TR loci were distributed throughout the genome (chromosome and megaplasmid) and located in both coding and intergenic regions. The newly developed RS3-MLVA16 scheme was more discriminative than MLST. RS3-MLVA16 showed good ability in differentiating strains at global, regional, and local scales, and it especially highlighted epidemiological links between closely related strains at the local scale. RS3-MLVA16 also underlines genetic variability within the same MLST-type and clonal complex, and gives a first overview of population structure. Overall, RS3-MLVA16 is a promising genotyping method for outbreak investigation at a fine scale, and it could be used for outbreak investigation as a first-line, low-cost assay for the routine screening of RSSC

  6. A novel multilocus variable number tandem repeat analysis typing scheme for African phylotype III strains of the Ralstonia solanacearum species complex

    PubMed Central

    Ravelomanantsoa, Santatra; Robène, Isabelle; Chiroleu, Frédéric; Guérin, Fabien; Poussier, Stéphane; Pruvost, Olivier

    2016-01-01

    Background. Reliable genotyping that provides an accurate description of diversity in the context of pathogen emergence is required for the establishment of strategies to improve disease management. MultiLocus variable number tandem repeat analysis (MLVA) is a valuable genotyping method. It can be performed at small evolutionary scales where high discriminatory power is needed. Strains of the Ralstonia solanacearum species complex (RSSC) are highly genetically diverse. These destructive pathogens are the causative agent of bacterial wilt on an unusually broad range of host plants worldwide. In this study, we developed an MLVA scheme for genotyping the African RSSC phylotype III. Methods. We selected different publicly available tandem repeat (TR) loci and additional TR loci from the genome of strain CMR15 as markers. Based on these loci, a new phylotype III-MLVA scheme is presented. MLVA and multiLocus sequence typing (MLST) were compared at the global, regional, and local scales. Different populations of epidemiologically related and unrelated RSSC phylotype III strains were used. Results and Discussion. Sixteen polymorphic TR loci, which included seven microsatellites and nine minisatellites, were selected. These TR loci were distributed throughout the genome (chromosome and megaplasmid) and located in both coding and intergenic regions. The newly developed RS3-MLVA16 scheme was more discriminative than MLST. RS3-MLVA16 showed good ability in differentiati