Science.gov

Sample records for amphibia gymnophiona caeciliidae

  1. Ultrastructure of the mature spermatozoa of caecilians (Amphibia: Gymnophiona).

    PubMed

    Scheltinga, David M; Wilkinson, Mark; Jamieson, Barrie G M; Oommen, Oommen V

    2003-11-01

    The spermatozoa of Gymnophiona show the following autapomorphies: 1) penetration of the distal centriole by the axial fiber; 2) presence of an acrosomal baseplate; 3) presence of an acrosome seat (flattened apical end of nucleus); and 4) absence of juxta-axonemal fibers. The wide separation of the plasma membrane bounding the undulating membrane is here also considered to be apomorphic. Three plesiomorphic spermatozoal characters are recognized that are not seen in other Amphibia but occur in basal amniotes: 1) presence of mitochondria with a delicate array of concentric cristae (concentric cristae of salamander spermatozoa differ in lacking the delicate array); 2) presence of peripheral dense fibers associated with the triplets of the distal centriole; and 3) presence of a simple annulus (a highly modified, elongate annulus is present in salamander sperm). The presence of an endonuclear canal containing a perforatorium is a plesiomorphic feature of caecilian spermatozoa that is shared with urodeles, some basal anurans, sarcopterygian fish, and some amniotes. Spermatozoal synapomorphies are identified for 1) the Uraeotyphlidae and Ichthyophiidae, and 2) the Caeciliidae and Typhlonectidae, suggesting that the members of each pair of families are more closely related to each other than to other caecilians. Although caecilian spermatozoa exhibit the clear amphibian synapomorphy of the unilateral location of the undulating membrane and its axial fiber, they have no apomorphic characters that suggest a closer relationship to either the Urodela or Anura.

  2. Mitochondrial evidence on the phylogenetic position of caecilians (Amphibia: Gymnophiona).

    PubMed Central

    Zardoya, R; Meyer, A

    2000-01-01

    The complete nucleotide sequence (17,005 bp) of the mitochondrial genome of the caecilian Typhlonectes natans (Gymnophiona, Amphibia) was determined. This molecule is characterized by two distinctive genomic features: there are seven large 109-bp tandem repeats in the control region, and the sequence for the putative origin of replication of the L strand can potentially fold into two alternative secondary structures (one including part of the tRNA(Cys)). The new sequence data were used to assess the phylogenetic position of caecilians and to gain insights into the origin of living amphibians (frogs, salamanders, and caecilians). Phylogenetic analyses of two data sets-one combining protein-coding genes and the other combining tRNA genes-strongly supported a caecilian + frog clade and, hence, monophyly of modern amphibians. These two data sets could not further resolve relationships among the coelacanth, lungfishes, and tetrapods, but strongly supported diapsid affinities of turtles. Phylogenetic relationships among a larger set of species of frogs, salamanders, and caecilians were estimated with a mitochondrial rRNA data set. Maximum parsimony analysis of this latter data set also recovered monophyly of living amphibians and favored a frog + salamander (Batrachia) relationship. However, bootstrap support was only moderate at these nodes. This is likely due to an extensive among-site rate heterogeneity in the rRNA data set and the narrow window of time in which the three main groups of living amphibians were originated. PMID:10835397

  3. Mitochondrial evidence on the phylogenetic position of caecilians (Amphibia: Gymnophiona).

    PubMed

    Zardoya, R; Meyer, A

    2000-06-01

    The complete nucleotide sequence (17,005 bp) of the mitochondrial genome of the caecilian Typhlonectes natans (Gymnophiona, Amphibia) was determined. This molecule is characterized by two distinctive genomic features: there are seven large 109-bp tandem repeats in the control region, and the sequence for the putative origin of replication of the L strand can potentially fold into two alternative secondary structures (one including part of the tRNA(Cys)). The new sequence data were used to assess the phylogenetic position of caecilians and to gain insights into the origin of living amphibians (frogs, salamanders, and caecilians). Phylogenetic analyses of two data sets-one combining protein-coding genes and the other combining tRNA genes-strongly supported a caecilian + frog clade and, hence, monophyly of modern amphibians. These two data sets could not further resolve relationships among the coelacanth, lungfishes, and tetrapods, but strongly supported diapsid affinities of turtles. Phylogenetic relationships among a larger set of species of frogs, salamanders, and caecilians were estimated with a mitochondrial rRNA data set. Maximum parsimony analysis of this latter data set also recovered monophyly of living amphibians and favored a frog + salamander (Batrachia) relationship. However, bootstrap support was only moderate at these nodes. This is likely due to an extensive among-site rate heterogeneity in the rRNA data set and the narrow window of time in which the three main groups of living amphibians were originated.

  4. A mitogenomic perspective on the phylogeny and biogeography of living caecilians (Amphibia: Gymnophiona).

    PubMed

    Zhang, Peng; Wake, Marvalee H

    2009-11-01

    The caecilians, members of the amphibian Order Gymnophiona, are the least known Order of tetrapods, and their intra-relationships, especially within its largest group, the Family Caeciliidae (57% of all caecilian species), remain controversial. We sequenced thirteen complete caecilian mitochondrial genomes, including twelve species of caeciliids, using a universal primer set strategy. These new sequences, together with eight published caecilian mitochondrial genomes, were analyzed by maximum parsimony, partitioned maximum-likelihood and partitioned Bayesian approaches at both nucleotide and amino acid levels, to study the intra-relationships of caecilians. An additional multiple gene dataset including most of the caecilian nucleotide sequences currently available in GenBank produced phylogenetic results that are fully compatible with those based on the mitogenomic data. Our phylogenetic results are summarized as follow. The caecilian family Rhinatrematidae is the sister taxon to all other caecilians. Beyond Rhinatrematidae, a clade comprising the Ichthyophlidae and Uraeotyphlidae is separated from a clade containing all remaining caecilians (Scolecomorphidae, Typhlonectidae and Caeciliidae). Within this large clade, Scolecomorphidae is the sister taxon of Typhlonectidae and Caeciliidae but this placement did not receive strong support in all analyses. Caeciliidae is paraphyletic with regard to Typhlonectidae, and can be divided into three well-supported groups: Caeciliidae group 1 contains the African caeciliids Boulengerula and Herpele; Caeciliidae group 2 contains Caecilia and Oscaecilia and it is the sister taxon of Typhlonectidae; Caeciliidae group 3 comprises the remaining species of caeciliids. The mitochondrial genome data were also used to calculate divergence times for caecilian evolution using the penalized likelihood method implemented in the program R8S. The newly obtained dating results are compatible with (but a little older than) previous time

  5. Morphology of the kidney in the West African caecilian, Geotrypetes seraphini (Amphibia, Gymnophiona, Caeciliidae).

    PubMed

    Møbjerg, N; Jespersen, A; Wilkinson, M

    2004-11-01

    This study deals with the morphology and ultrastructure of the mesonephros in adult caecilians of the species Geotrypetes seraphini. Based on serial sections in paraffin and araldite, nephrons are reconstructed and the cellular characteristics of different nephron segments described. The long and slender mesonephric kidneys of G. seraphini are broadest caudally and taper toward the front, where the organs are divided into smaller segmental divisions. Two nephron types can be distinguished on the basis of their connections to the coelom and their position within the nephric tissue: ventral nephrons connect to the coelom via a ciliated peritoneal funnel, whereas medial nephrons lack this connection. Both nephron types are composed of a filtration unit, the Malpighian corpuscle, and a renal tubule, which can be divided into six morphologically distinct segments: neck segment, proximal tubule, intermediate segment, early distal tubule, late distal tubule, and collecting tubule. Collecting tubules merge and form a branch system that opens into collecting ducts. Collecting ducts empty into the Wolffian duct. Proximal tubules of nephrons in the frontal divisions are morphologically different from the proximal tubules of more caudal kidney regions. Distal tubule subdivision is only clearly recognizable at the electron microscopic level. The length of each nephron segment is calculated from a ventral nephron with a total length of approximately 3.8 mm, and the course of the segments within the nephric tissue is reported. The number of nephrons was estimated at 1,700 units in each kidney. The segmentation and ultrastructure of the mesonephric nephrons in G. seraphini are discussed in relation to nephron descriptions from other caecilians and we further discuss the evolutionary origin of the amphibian nephron.

  6. Extreme variation in the atrial septation of caecilians (Amphibia: Gymnophiona)

    PubMed Central

    de Bakker, Desiderius M; Wilkinson, Mark; Jensen, Bjarke

    2015-01-01

    Caecilians (order Gymnophiona) are elongate, limbless, snake-like amphibians that are the sister-group (closest relatives) of all other recent amphibians (frogs and salamanders). Little is known of their cardiovascular anatomy and physiology, but one nearly century old study suggests that Hypogeophis (family Indotyphlidae), commonly relied upon as a representative caecilian species, has atrial septation in the frontal plane and more than one septum. In contrast, in other vertebrates there generally is one atrial septum in the sagittal plane. We studied the adult heart of Idiocranium (also Indotyphlidae) using immunohistochemistry and confirm that the interatrial septum is close to the frontal plane. Additionally, a parallel right atrial septum divides three-fourths of the right atrial cavity of this species. Idiocranium embryos in the Hill collection reveal that atrial septation initiates in the sagittal plane as in other tetrapods. Late developmental stages, however, see a left-ward shift of visceral organs and a concordant rotation of the atria that reorients the atrial septa towards the frontal plane. The gross anatomies of species from six other caecilian families reveal that (i) the right atrial septum developed early in caecilian evolution (only absent in Rhinatrematidae) and that (ii) rotation of the atria evolved later and its degree varies between families. In most vertebrates a prominent atrial trabeculation associates with the sinuatrial valve, the so-called septum spurium, and the right atrial septum seems homologous to this trabeculation but much more developed. The right atrial septum does not appear to be a consequence of body elongation because it is absent in some caecilians and in snakes. The interatrial septum of caecilians shares multiple characters with the atrial septum of lungfishes, salamanders and the embryonic septum primum of amniotes. In conclusion, atrial septation in caecilians is based on evolutionarily conserved structures but

  7. Extreme variation in the atrial septation of caecilians (Amphibia: Gymnophiona).

    PubMed

    de Bakker, Desiderius M; Wilkinson, Mark; Jensen, Bjarke

    2015-01-01

    Caecilians (order Gymnophiona) are elongate, limbless, snake-like amphibians that are the sister-group (closest relatives) of all other recent amphibians (frogs and salamanders). Little is known of their cardiovascular anatomy and physiology, but one nearly century old study suggests that Hypogeophis (family Indotyphlidae), commonly relied upon as a representative caecilian species, has atrial septation in the frontal plane and more than one septum. In contrast, in other vertebrates there generally is one atrial septum in the sagittal plane. We studied the adult heart of Idiocranium (also Indotyphlidae) using immunohistochemistry and confirm that the interatrial septum is close to the frontal plane. Additionally, a parallel right atrial septum divides three-fourths of the right atrial cavity of this species. Idiocranium embryos in the Hill collection reveal that atrial septation initiates in the sagittal plane as in other tetrapods. Late developmental stages, however, see a left-ward shift of visceral organs and a concordant rotation of the atria that reorients the atrial septa towards the frontal plane. The gross anatomies of species from six other caecilian families reveal that (i) the right atrial septum developed early in caecilian evolution (only absent in Rhinatrematidae) and that (ii) rotation of the atria evolved later and its degree varies between families. In most vertebrates a prominent atrial trabeculation associates with the sinuatrial valve, the so-called septum spurium, and the right atrial septum seems homologous to this trabeculation but much more developed. The right atrial septum does not appear to be a consequence of body elongation because it is absent in some caecilians and in snakes. The interatrial septum of caecilians shares multiple characters with the atrial septum of lungfishes, salamanders and the embryonic septum primum of amniotes. In conclusion, atrial septation in caecilians is based on evolutionarily conserved structures but

  8. A subterranean generalist predator: diet of the soil-dwelling caecilian Gegeneophis ramaswamii (Amphibia; Gymnophiona; Caeciliidae) in southern India.

    PubMed

    Measey, John G; Gower, David J; Oommen, Oommen V; Wilkinson, Mark

    2004-01-01

    Biologists have paid relatively little attention to subterranean predators, especially their ecology. Although diets of some subterranean lower vertebrates suggest specialisation, there remains a lack of quantitative data. The diet of the caecilian amphibian Gegeneophis ramaswamii was investigated through analyses of gut contents of 67 specimens collected in randomised surveys at three localities in Kerala, southern India, in early and mid-monsoon. Although termites were the most frequently ingested items in the mid-monsoon, the specialist predator hypothesis was rejected because of differences in diet found in early monsoon samples, when earthworms contributed the greatest mass. That guts of some G. ramaswamii contained many individuals of only a single dietary taxon was interpreted as feeding on patchily distributed prey rather than specialisation. No ontogenetic differences in diet were apparent, but more sampling is required to investigate this further. Subadults largely feed on fewer items of the same prey as adults, though there is an indication that subadult diet is less diverse. The data do not support differences between male and female diet. High densities of G. ramaswamii, and perhaps of other terrestrial caecilians and subterranean lower vertebrates feeding on soil-ecosystem engineers (termites, earthworms and ants), might substantially impact soil ecology.

  9. Phylogeny of caecilian amphibians (Gymnophiona) based on complete mitochondrial genomes and nuclear RAG1.

    PubMed

    San Mauro, Diego; Gower, David J; Oommen, Oommen V; Wilkinson, Mark; Zardoya, Rafael

    2004-11-01

    We determined the complete nucleotide sequence of the mitochondrial (mt) genome of five individual caecilians (Amphibia: Gymnophiona) representing five of the six recognized families: Rhinatrema bivittatum (Rhinatrematidae), Ichthyophis glutinosus (Ichthyophiidae), Uraeotyphlus cf. oxyurus (Uraeotyphlidae), Scolecomorphus vittatus (Scolecomorphidae), and Gegeneophis ramaswamii (Caeciliidae). The organization and size of these newly determined mitogenomes are similar to those previously reported for the caecilian Typhlonectes natans (Typhlonectidae), and for other vertebrates. Nucleotide sequences of the nuclear RAG1 gene were also determined for these six species of caecilians, and the salamander Mertensiella luschani atifi. RAG1 (both at the amino acid and nucleotide level) shows slower rates of evolution than almost all mt protein-coding genes (at the amino acid level). The new mt and nuclear sequences were compared with data for other amphibians and subjected to separate and combined phylogenetic analyses (Maximum Parsimony, Minimum Evolution, Maximum Likelihood, and Bayesian Inference). All analyses strongly support the monophyly of the three amphibian Orders. The Batrachia hypothesis (Gymnophiona, (Anura, Caudata) receives moderate or good support depending on the method of analysis. Within Gymnophiona, the optimal tree (Rhinatrema, (Ichthyophis, Uraeotyphlus), (Scolecomorphus, (Gegeneophis Typhlonectes) agrees with the most recent morphological and molecular studies. The sister group relationship between Rhinatrematidae and all other caecilians, that between Ichthyophiidae and Uraeotyphlidae, and the monophyly of the higher caecilians Scolecomorphidae+Caeciliidae+Typhlonectidae, are strongly supported, whereas the relationships among the higher caecilians are less unambiguously resolved. Analysis of RAG1 is affected by a spurious local rooting problem and associated low support that is ameliorated when outgroups are excluded. Comparisons of trees using the

  10. Phylogenetic relationships of Indian caecilians (Amphibia: Gymnophiona) inferred from mitochondrial rRNA gene sequences.

    PubMed

    Wilkinson, Mark; A Sheps, Jonathan; Oommen, Oommen V; Cohen, Bernard L

    2002-06-01

    India has a diverse caecilian fauna, including representatives of three of the six currently recognized families, the Caeciliidae, Ichthyophiidae, the endemic Uraeotyphlidae, but previous molecular phylogenetic studies of caecilians have not included sequences for any Indian caecilians. Partial 12S and 16S mitochondrial gene sequences were obtained for a single representative of each of the caecilian families found in India and aligned against previously reported sequences for 13 caecilian species. The resulting alignment (16 taxa, 1200 sites, of which 288 cannot be aligned unambiguously) was analyzed using parsimony, maximum-likelihood, and distance methods. As judged by bootstrap proportions, decay indices, and leaf stabilities, well-supported relationships of the Indian caecilians are recovered from the alignment. The data (1) corroborate the hypothesis, based on morphology, that the Uraeotyphlidae and Ichthyophiidae are sister taxa, (2) recover a monophyletic Ichthyophiidae, including Indian and South East Asian representatives, and (3) place the Indian caeciliid Gegeneophis ramaswamii as the sister group of the caeciliid caecilians of the Seychelles. Rough estimates of divergence times suggest an origin of the Uraeotyphlidae and Ichthyophiidae while India was isolated from Laurasia and Africa and are most consistent with an Indian origin of these families and subsequent dispersal of ichthyophiids into South East Asia.

  11. Histology of the trachea and lung of Siphonops annulatus (Amphibia, Gymnophiona).

    PubMed

    Kuehne, B; Junqueira, L C

    2000-02-01

    The structure of the trachea and lung of Siphonops annulatus was studied in ten specimens of routinely fed animals. The trachea is constituted mainly by incomplete cartilage rings lined by a respiratory epithelium (ciliated and mucous cells) with variable morphology according to the region observed. A rich vascularization of this organ suggests its participation in blood-air gas exchange. The right lung in this species is developed and the left one is atrophied. This organ is constituted mainly by longitudinal septa formed by connective tissue, smooth muscle cells and blood capillaries. These structures are covered by pneumocytes of one type only, which present cytoplasmic particles that have been related with surfactant activity described in the lung of Gymnophiona.

  12. Molecular systematics of caeciliid caecilians (Amphibia: Gymnophiona) of the Western Ghats, India.

    PubMed

    Gower, David J; San Mauro, Diego; Giri, Varad; Bhatta, Gopalakrishna; Govindappa, Venu; Kotharambath, Ramachandran; Oommen, Oommen V; Fatih, Farrah A; Mackenzie-Dodds, Jacqueline A; Nussbaum, Ronald A; Biju, S D; Shouche, Yogesh S; Wilkinson, Mark

    2011-06-01

    Together, Indian plus Seychelles caeciliid caecilian amphibians (Gymnophiona) constitute approximately 10% of the extant species of this order. A molecular phylogenetic analysis of all but one (or two) nominal species (16, in five genera) is presented based on mitochondrial (12S, 16S, cytb, cox1) and nuclear (RAG1) sequence data. Results strongly support monophyly of both Seychelles and peninsular Indian caeciliids, and their sister-group status. Within the Indian caeciliids, Indotyphlus and Gegeneophis are monophyletic sister genera. The phylogenetic position of Gegeneophis ramaswamii, Gegeneophis seshachari, and Gegeneophis carnosus are not well resolved, but all lie outside a well-supported clade of most northern Western Ghats Gegeneophis (madhavai, mhadeiensis, goaensis, danieli/nadkarnii). Most nominal species of Indian caeciliid are diagnosed by robust haplotype clades, though the systematics of G. carnosus-like forms in northern Kerala and southern Karnataka requires substantial further investigation. For the most part, Indian caeciliid species comprise narrowly distributed, allopatric taxa with low genetic diversity. Much greater geographic genetic diversity exists among populations referred to G. seshachari, such that some populations likely represent undescribed species. This, the first phylogenetic analysis of Indian caeciliids, generally provides additional support for recent increases in described species (eight since 1999), and a framework for ongoing taxonomic revision.

  13. Embryonic and larval development in the caecilian Ichthyophis kohtaoensis (Amphibia, gymnophiona): a staging table.

    PubMed

    Dünker, N; Wake, M H; Olson, W M

    2000-01-01

    Little is known about the developmental biology of caecilians-tropical, elongate, limbless, mostly fossorial amphibians that are members of the Order Gymnophiona. Ichthyophis kohtaoensis (Family Ichthyophiidae; southeast Asia) is an oviparous species in which maternal care of the clutch is provided. The clutch is laid in a burrow on land, and the embryos develop in their egg membranes, curved around a large yolk mass. Larvae are aquatic and exhibit characteristic features that are not present in the terrestrial adults. Because accurate descriptions of ontogenies and the establishment of standardized stages of embryonic and larval development are useful for both experimental and comparative embryology, a staging table for I.kohtaoensis was developed based on external morphological features. Development from the end of neurulation to metamorphosis was divided into 20 stages. Principal diagnostic features include development of the lateral line organs, formation of three pairs of external gills, development of the eyes, changes in yolk structure, changes in the structure of the cloacal aperture and growth of the tail, including the formation and regression of the tail fin. This study provides a comparison with descriptions of embryonic stages of I.glutinosus and Hypogeophis rostratus and with a recent staging table for the aquatic, viviparous caecilian Typhlonectes compressicauda, the only other caecilians for which reasonably complete ontogenetic information exists in the literature. Comparisons with established staging tables for selected frogs and salamanders are also presented.

  14. A molecular phylogeny of ichthyophiid caecilians (Amphibia: Gymnophiona: Ichthyophiidae): out of India or out of South East Asia?

    PubMed Central

    Gower, David J; Kupfer, Alex; Oommen, Oommen V; Himstedt, Werner; Nussbaum, Ronald A; Loader, Simon P; Presswell, Bronwen; Müller, Hendrik; Krishna, Sharath B; Boistel, Renaud; Wilkinson, Mark

    2002-01-01

    Recent molecular phylogenetic studies indicate that the rafting Indian plate harboured several isolated vertebrate lineages between ca. 130 and 56 Myr ago that dispersed and diversified 'out of India' following accretion with Eurasia. A single family of the amphibian order Gymnophiona, the Ichthyophiidae, presently occurs on the Indian plate and across much of South East Asia. Ichthyophiid phylogeny is investigated in order to test competing out of India and out of South East Asia hypotheses for their distribution. Partial sequences of mitochondrial 12S and 16S rRNA and cytochrome b genes for 20 ichthyophiids and proximate outgroups were assembled. Parsimony, maximum-likelihood and distance analyses all recover optimum trees in which uraeotyphlids plus Ichthyophis cf. malabarensis are the sister taxa to all other Ichthyophis, among which the South East Asian taxa are monophyletic. Tree topology and branch lengths indicate that the Indian lineages are more basal and older, and thus are more consistent with the hypothesis that ichthyophiids dispersed from the Indian subcontinent into South East Asia. The estimated relationships also support monophyly of Sri Lankan Ichthyophis, and non-monophyly of striped and unstriped Ichthyophis species groups. Mitochondrial DNA sequences provide evidence that should assist current problematic areas of caecilian taxonomy. PMID:12184826

  15. A molecular phylogeny of ichthyophiid caecilians (Amphibia: Gymnophiona: Ichthyophiidae): out of India or out of South East Asia?

    PubMed

    Gower, David J; Kupfer, Alex; Oommen, Oommen V; Himstedt, Werner; Nussbaum, Ronald A; Loader, Simon P; Presswell, Bronwen; Müller, Hendrik; Krishna, Sharath B; Boistel, Renaud; Wilkinson, Mark

    2002-08-07

    Recent molecular phylogenetic studies indicate that the rafting Indian plate harboured several isolated vertebrate lineages between ca. 130 and 56 Myr ago that dispersed and diversified 'out of India' following accretion with Eurasia. A single family of the amphibian order Gymnophiona, the Ichthyophiidae, presently occurs on the Indian plate and across much of South East Asia. Ichthyophiid phylogeny is investigated in order to test competing out of India and out of South East Asia hypotheses for their distribution. Partial sequences of mitochondrial 12S and 16S rRNA and cytochrome b genes for 20 ichthyophiids and proximate outgroups were assembled. Parsimony, maximum-likelihood and distance analyses all recover optimum trees in which uraeotyphlids plus Ichthyophis cf. malabarensis are the sister taxa to all other Ichthyophis, among which the South East Asian taxa are monophyletic. Tree topology and branch lengths indicate that the Indian lineages are more basal and older, and thus are more consistent with the hypothesis that ichthyophiids dispersed from the Indian subcontinent into South East Asia. The estimated relationships also support monophyly of Sri Lankan Ichthyophis, and non-monophyly of striped and unstriped Ichthyophis species groups. Mitochondrial DNA sequences provide evidence that should assist current problematic areas of caecilian taxonomy.

  16. Identification and characterization of visual pigments in caecilians (Amphibia: Gymnophiona), an order of limbless vertebrates with rudimentary eyes.

    PubMed

    Mohun, S M; Davies, W L; Bowmaker, J K; Pisani, D; Himstedt, W; Gower, D J; Hunt, D M; Wilkinson, M

    2010-10-15

    In comparison with the other amphibian orders, the Anura (frogs) and Urodela (salamanders), knowledge of the visual system of the snake-like Gymnophiona (caecilians) is relatively sparse. Most caecilians are fossorial with, as far as is known any surface activity occurring mainly at night. They have relatively small, poorly developed eyes and might be expected to possess detectable changes in the spectral sensitivity of their visual pigments. Microspectrophotometry was used to determine the spectral sensitivities of the photoreceptors in three species of caecilian, Rhinatrema bivittatum, Geotrypetes seraphini and Typhlonectes natans. Only rod opsin visual pigment, which may be associated with scotopic (dim light) vision when accompanied by other 'rod-specific' components of the phototransduction cascade, was found to be present. Opsin sequences were obtained from the eyes of two species of caecilian, Ichthyophis cf. kohtaoensis and T. natans. These rod opsins were regenerated in vitro with 11-cis retinal to give pigments with spectral sensitivity peaks close to 500 nm. No evidence for cone photoreception, associated with diurnal and colour vision, was detected using molecular and physiological methods. Additionally, visual pigments are short-wavelength shifted in terms of the maximum absorption of light when compared with other amphibian lineages.

  17. Frequency of independent origins of viviparity among caecilians (Gymnophiona): evidence from the first 'live-bearing' Asian amphibian.

    PubMed

    Gower, D J; Giri, V; Dharne, M S; Shouche, Y S

    2008-09-01

    Viviparity is reported for Gegeneophis seshachari (Gymnophiona: Caeciliidae) from a gravid female containing four oviductal foetuses. The oviducts are highly vascularized and contain patches of thickened, layered tissue similar to foetal gut contents. Gegeneophis seshachari probably resemble other viviparous caecilians in having foetuses that ingest thickened oviduct lining using specialized deciduous teeth. This is the first report of viviparity in Asian amphibians and Indo-Seychellean caeciliids. Gegeneophis is the only caecilian genus known to include oviparous and viviparous species, and G. seshachari is the smallest known viviparous caecilian. Phylogenetic analysis of mitochondrial DNA sequences supports assignment of G. seshachari to a monophyletic Gegeneophis. Character optimization indicates that viviparity has evolved independently at least four times within Gymnophiona--a rate of incidence relative to the number of extant species that is higher than for other vertebrate groups except squamate reptiles. Our findings strengthen the proposal that caecilian reproduction demands further attention.

  18. A new lungless caecilian (Amphibia: Gymnophiona) from Guyana

    PubMed Central

    Wake, Marvalee H.; Donnelly, Maureen A.

    2010-01-01

    We report the discovery of a single specimen of a small, terrestrial, lungless caecilian, the second known taxon of lungless caecilians. It differs from all other caecilians in lacking open external nares, and from the large aquatic lungless species described by Nussbaum & Wilkinson (Nussbaum, R. A. & Wilkinson, M. 1995 Proc. R. Soc. Lond. B 261, 331–335) in having no significant skull modifications. All modifications are of ‘soft morphology’ (covered external nares and choanae, lung and pulmonary vessel loss, etc.). A new genus and species are described to accommodate this form. Aspects of its skull and visceral morphology are described and considered in terms of the possible life history and evolution of the species, and compared with those of other lungless amphibians. PMID:19923127

  19. A new lungless caecilian (Amphibia: Gymnophiona) from Guyana.

    PubMed

    Wake, Marvalee H; Donnelly, Maureen A

    2010-03-22

    We report the discovery of a single specimen of a small, terrestrial, lungless caecilian, the second known taxon of lungless caecilians. It differs from all other caecilians in lacking open external nares, and from the large aquatic lungless species described by Nussbaum & Wilkinson (Nussbaum, R. A. & Wilkinson, M. 1995 Proc. R. Soc. Lond. B 261, 331-335) in having no significant skull modifications. All modifications are of 'soft morphology' (covered external nares and choanae, lung and pulmonary vessel loss, etc.). A new genus and species are described to accommodate this form. Aspects of its skull and visceral morphology are described and considered in terms of the possible life history and evolution of the species, and compared with those of other lungless amphibians.

  20. First Quaternary Fossil Record of Caecilians from a Mexican Archaeological Site

    NASA Astrophysics Data System (ADS)

    Wake, Thomas A.; Wake, Marvalee H.; Lesure, Richard G.

    1999-07-01

    A single vertebra from an Early Formative period archaeological site in coastal Chiapas, México, is identified as belonging to the amphibian Dermophis mexicanus (Duméril and Bibron) 1841 (Amphibia: Gymnophiona: Caeciliidae). The vertebra was recovered from deposits dated to approximately 1200-1350 B.C. The specimen represents the first Quaternary fossil record for gymnophiones. Its presence suggests the possible role of the species as a bioturbator. Its recovery is further evidence of the utility of fine-grained archaeological recovery techniques.

  1. Histology of the kidney and urinary bladder of Siphonops annulatus (Amphibia-Gymnophiona).

    PubMed

    Carvalho, E T; Junqueira, L C

    1999-03-01

    The histology of the kidney and urinary bladder of Siphonops annulatus was studied by light microscopy in semithin sections of tissue embedded in hydrophilic resin. The kidney's nephron comprises the renal corpuscle, neck segment, proximal tubule, intermediate segment, distal tubule and collecting tubule. Nephrostomes are present. This structure, the neck segment, and intermediate tubules present long cilia, and probably play important roles in the propulsion of the peritoneal fluid and glomerular filtrate. The proximal tubule cells possess loosely packed microvilli and contain abundant polymorphic granules and vesicles that assume the aspect of lysosomes in different stages of intracellular digestion. The distal tubules are characterized by large, vertically disposed mitochondria assuming the aspect of ions transporting cells. The urinary bladder is lined with a transitional epithelium, whose aspect varies according to the quantity of urine.

  2. Chromosomal homology of Uraeotyphlus oxyurus group of species (Amphibia, Gymnophiona, Ichthyophiidae)

    PubMed Central

    Venu, G.; Venkatachalaiah, G.

    2013-01-01

    Abstract Uraeotyphlus oxyurus (Dumeril et Bibron, 1841), Uraeotyphlus interruptus Pillai et Ravichandran, 1999, Uraeotyphlus narayani Seshachar, 1939 and Uraeotyphlus menoni Annandale, 1913 were cytogenetically analysed following conventional and differential staining techniques. These species show similar karyotypes with 2n=36 (FN=58). There were no traces of species-specific features in regard to C-banding and NOR staining. The comparative study of karyotypes shows chromosomal homologies among the four species. Chromosomal data seem to support the concept that two species groups exist in the genus Uraeotyphlus. PMID:24260686

  3. The karyotype of Typhlonectes compressicauda (Amphibia: Gymnophiona) with comments on chromosome evolution in caecilians.

    PubMed

    Wake, M H; Hafner, J C; Hafner, M S; Klosterman, L L; Patton, J L

    1980-02-15

    Typhlonectes compressicauda has a diploid number of 28. Its karyotype, when compared to that of other caecilians, suggests some discordance in the hypothesized model of chromosome reduction in the evolution of amphibian lineages.

  4. A new species of Microcaecilia Taylor, 1968 (Amphibia: Gymnophiona: Siphonopidae) from Amazonian Brazil.

    PubMed

    Wilkinson, Mark; Antoniazzi, Marta Maria; Jared, Carlos

    2015-01-13

    A new species of siphonopid caecilian, Microcaecilia butantan sp. nov., is described based on four specimens from Belterra, in the State of Pará, Brazil. The new species differs from all other Microcaecilia in having a combination of more than 135 primary annuli and long premaxillary-maxillary tooth series that extend posteriorly beyond the choanae. Some specimens were dug from soil in a cupuaçu (Theobroma grandiflorum) plantation suggesting that this form of agriculture provides an environment suitable for at least some caecilians.

  5. Patterns of peripheral innervation of the tongue and hyobranchial apparatus in caecilians (Amphibia: Gymnophiona).

    PubMed

    Wake, M H

    1992-04-01

    The innervation of the musculature of the tongue and the hyobranchial apparatus of caecilians has long been assumed to be simple and to exhibit little interspecific variation. A study of 14 genera representing all six families of caecilians demonstrates that general patterns of innervation by the trigeminal, facial, glossopharyngeal, and vagus nerves are similar across taxa but that the composition of the "hypoglossal" nerve is highly variable. Probably in all caecilians, spinal nerves 1 and 2 contribute to the hypoglossal. In addition, in certain taxa, an "occipital," the vagus, and/or spinal 3 appear to contribute fibers to the composition of the hypoglossal nerve. These patterns, the lengths of fusion of the contributing elements, and the branching patterns of the hypoglossal are assessed according to the currently accepted hypothesis of phylogenetic relationships of caecilians, and of amphibians. An hypothesis is proposed that limblessness and a simple tongue, with concomitant reduced complexity of innervation of muscles associated with limbs and the tongue, has released a constraint on pattern of innervation. As a consequence, a greater diversity and, in several taxa, greater complexity of neuroanatomical associations of nerve roots to form the hypoglossal are expressed.

  6. One hundred million years of skin feeding? Extended parental care in a Neotropical caecilian (Amphibia: Gymnophiona).

    PubMed

    Wilkinson, Mark; Kupfer, Alexander; Marques-Porto, Rafael; Jeffkins, Hilary; Antoniazzi, Marta M; Jared, Carlos

    2008-08-23

    Maternal dermatophagy, the eating of maternal skin by offspring, is an unusual form of parental investment involving co-evolved specializations of both maternal skin and offspring dentition, which has been recently discovered in an African caecilian amphibian. Here we report the discovery of this form of parental care in a second, distantly related Neotropical species Siphonops annulatus, where it is characterized by the same syndrome of maternal and offspring specializations. The detailed similarities of skin feeding in different caecilian species provide strong evidence of its homology, implying its presence in the last common ancestor of these species. Biogeographic considerations, the separation of Africa and South American land masses and inferred timescales of amphibian diversification all suggest that skin feeding is an ancient form of parental care in caecilians, which has probably persisted in multiple lineages for more than 100 Myr. These inferences support the hypotheses that (i) maternal dermatophagy is widespread in oviparous direct-developing caecilians, and (ii) that viviparous caecilians that feed on the hypertrophied maternal oviduct evolved from skin-feeding ancestors. In addition to skin-feeding, young S. annulatus were observed to congregate around, and imbibe liquid exuded from, the maternal cloacal opening.

  7. Batrachochytrium dendrobatidis infection and lethal chytridiomycosis in caecilian amphibians (Gymnophiona).

    PubMed

    Gower, David J; Doherty-Bone, Thomas; Loader, Simon P; Wilkinson, Mark; Kouete, Marcel T; Tapley, Benjamin; Orton, Frances; Daniel, Olivia Z; Wynne, Felicity; Flach, Edmund; Müller, Hendrik; Menegon, Michele; Stephen, Ian; Browne, Robert K; Fisher, Mathew C; Cunningham, Andrew A; Garner, Trenton W J

    2013-06-01

    Batrachochytrium dendrobatidis (Bd) is commonly termed the 'amphibian chytrid fungus' but thus far has been documented to be a pathogen of only batrachian amphibians (anurans and caudatans). It is not proven to infect the limbless, generally poorly known, and mostly soil-dwelling caecilians (Gymnophiona). We conducted the largest qPCR survey of Bd in caecilians to date, for more than 200 field-swabbed specimens from five countries in Africa and South America, representing nearly 20 species, 12 genera, and 8 families. Positive results were recovered for 58 specimens from Tanzania and Cameroon (4 families, 6 genera, 6+ species). Quantities of Bd were not exceptionally high, with genomic equivalent (GE) values of 0.052-17.339. In addition, we report the first evidence of lethal chytridiomycosis in caecilians. Mortality in captive (wild-caught, commercial pet trade) Geotrypetes seraphini was associated with GE scores similar to those we detected for field-swabbed, wild animals.

  8. Patterns of Apoptosis and Proliferation throughout the Biennial Reproductive Cycle of Viviparous Female Typhlonectes compressicauda (Amphibia, Gymnophiona)

    PubMed Central

    Raquet, Michel; Brun, Claire; Exbrayat, Jean-Marie

    2016-01-01

    Typhlonectes compressicauda is an aquatic gymnophionan amphibian living in South America. Its breeding cycle is linked to seasons, characterized by a regular alternation of rainy and dry seasons. During a complex biennial cycle, the female genital tract undergoes a series of alternations of increasing and decreasing, governed by equilibrium of proliferation and apoptotic phenomena. Immunohistochemical methods were used to visualize cell proliferation with the detection of Ki67 antibody, a protein present in proliferative cells; terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and Apostain were performed to detect apoptotic cells on sections of ovaries and oviducts. In ovaries, both phenomena affect the germinal nests and follicles according to the cycle period. In the oviduct, the balance was in favor of proliferation during preparation for reproduction, and in favor of apoptosis when genital ducts regress. Apoptosis and proliferation are narrowly implicated in the remodeling of the genital tract and they are accompanied by the differentiation of tissues according to the phase of the breeding cycle. These variations permit the capture of oocytes at ovulation, always at the same period, and the parturition after 6–7 months of gestation, at a period in which the newborns live with their mother, protected in burrows in the mud. During the intervening year of sexual inactivity, the female reconstitutes body reserves. PMID:28025499

  9. Systematics of the caecilian family Chikilidae (Amphibia: Gymnophiona) with the description of three new species of Chikila from northeast India.

    PubMed

    Kamei, Rachunliu G; Gower, David J; Wilkinson, Mark; Biju, S D

    2013-01-01

    A taxonomic review of the monogeneric northeast Indian caecilian family Chikilidae is presented based on 64 specimens. Chikila fuilleri (Alcock, 1904), known previously only from a single specimen collected more than 100 years ago, is rediagnosed and characterised based on recent collections. We describe three additional species new to science, Chikila alcocki sp. nov., Chikila darlong sp. nov., and Chikila gaiduwani sp. nov. This species-level taxonomy is consistent with mitochondrial DNA sequence data. A key to the species of Chikila is presented.

  10. A New Species of Skin-Feeding Caecilian and the First Report of Reproductive Mode in Microcaecilia (Amphibia: Gymnophiona: Siphonopidae)

    PubMed Central

    Wilkinson, Mark; Sherratt, Emma; Starace, Fausto; Gower, David J.

    2013-01-01

    A new species of siphonopid caecilian, Microcaecilia dermatophaga sp. nov., is described based on nine specimens from French Guiana. The new species is the first new caecilian to be described from French Guiana for more than 150 years. It differs from all other Microcaecilia in having fewer secondary annular grooves and/or in lacking a transverse groove on the dorsum of the first collar. Observations of oviparity and of extended parental care in M. dermatophaga are the first reproductive mode data for any species of the genus. Microcaecilia dermatophaga is the third species, and represents the third genus, for which there has been direct observation of young animals feeding on the skin of their attending mother. The species is named for this maternal dermatophagy, which is hypothesised to be characteristic of the Siphonopidae. PMID:23483926

  11. Sertoli cells in the testis of caecilians, Ichthyophis tricolor and Uraeotyphlus cf. narayani (Amphibia: Gymnophiona): light and electron microscopic perspective.

    PubMed

    Smita, Mathew; Oommen, Oommen V; George, Jancy M; Akbarsha, M A

    2003-12-01

    The caecilians have evolved a unique pattern of cystic spermatogenesis in which cysts representing different stages in spermatogenesis coexist in a testis lobule. We examined unsettled issues relating to the organization of the caecilian testis lobules, including the occurrence of a fatty matrix, the possibility of both peripheral and central Sertoli cells, the origin of Sertoli cells from follicular cells, and the disengagement of older Sertoli cells to become loose central Sertoli cells. We subjected the testis of Ichthyophis tricolor (Ichthyophiidae) and Uraeotyphlus cf. narayani (Uraeotyphliidae) from the Western Ghats of Kerala, India, to light and transmission electron microscopic studies. Irrespective of the functional state of the testis, whether active or regressed, Sertoli cells constitute a permanent feature of the lobules. The tall Sertoli cells adherent to the basal lamina with basally located pleomorphic nuclei extend deeper into the lobule to meet at the core. There they provide for association of germ cells at different stages of differentiation, an aspect that has earlier been misconceived as the fatty matrix. Germ cells up to the 4-cell stage remain in the intercalating region of the Sertoli cells and they are located at the apices of the Sertoli cells from the 8-cell stage onwards. The developing germ cells are intimately associated with the Sertoli cell adherent to the basal lamina until spermiation. There are ameboid cells in the core of the lobules that appear to interact with the germ cells at the face opposite to their attachment with the Sertoli cells. Adherence of the Sertoli cells to the basal lamina is a permanent feature of the caecilian testicular lobules. The ameboid cells in the core are neither Sertoli cells nor their degeneration products.

  12. Spermiogenesis in caecilians Ichthyophis tricolor and Uraeotyphlus cf. narayani (Amphibia: Gymnophiona): analysis by light and transmission electron microscopy.

    PubMed

    Smita, Mathew; George, Jancy M; Girija, R; Akbarsha, M A; Oommen, Oommen V

    2004-10-01

    Spermiogenesis, known as spermateleosis in lower vertebrates, is the transformation of the round spermatid into a highly specialized spermatozoon with a species-specific structure. Spermateleosis and sperm morphology of two species of caecilians, Ichthyophis tricolor and Uraeotyphlus cf. narayani, from the Western Ghats of Kerala, India, were studied using light and transmission electron microscopy. Spermateleosis is described in early, mid-, and late phases. During the early phase, the spermatid nucleus does not elongate, but the acrosome vesicle is Golgi-derived and its material is produced as a homogeneous substance rather than as discrete granules. In development of the acrosome, the centrioles shift in position to the lower half of the cell. The acrosomal vesicles take the full shape of the acrosome with the establishment of the perforatorium in midphase. An endonuclear canal develops and accommodates the perforatorium. The incipient flagellum is laid down when the proximal centriole attaches to the posterior side of the nucleus and the distal centriole connects to the proximal centriole, which forms the basal granule of the acrosome. The axial fiber also appears during midphase. The mitochondria shift in position to the posterior pole of the cell to commence establishment of the midphase. Late phase is characterized by nuclear condensation and elongation. Consequently, the final organization of the sperm is established with the head containing the nucleus and the acrosome. The undulating membrane separates the axoneme and axial fiber. Most of the cytoplasm is lost as residual bodies.

  13. Distribution of somatostatin-like immunoreactivity in the brain of the caecilian Dermophis mexicanus (Amphibia: Gymnophiona): comparative aspects in amphibians.

    PubMed

    López, Jesús M; Moreno, Nerea; Morona, Ruth; Muñoz, Margarita; Domínguez, Laura; González, Agustín

    2007-03-20

    The organization of the somatostatin-like-immunoreactive (SOM-ir) structures in the brain of anuran and urodele amphibians has been well documented, and significant differences were noted between the two amphibian orders. However, comparable data are not available for the third order of amphibians, the gymnophionans (caecilians). In the present study, we analyzed the anatomical distribution of SOM-ir cells and fibers in the brain of the gymnophionan Dermophis mexicanus. In addition, because of its known relationship with catecholamines in other vertebrates, double immunostaining for SOM and tyrosine hydroxylase was used to investigate this situation in the gymnophionan. Abundant SOM-ir cell bodies and fibers were widely distributed throughout the brain. In the telencephalon, pallial and subpallial cells were labeled, being most numerous in the medial pallium and amygdaloid region. Most of the SOM-ir neurons were found in the preoptic area and hypothalamus and showed a clear projection to the median eminence. Less conspicuously, SOM-ir structures were found in the thalamus, tectum, tegmentum, and reticular formation. Both SOM-ir cells and fibers were demonstrated in the spinal cord. The double-immunohistofluorescence technique revealed that catecholaminergic neurons and SOM-ir cells are largely intermingled in many brain regions but form totally separated populations. Many differences were found between the distribution of SOM-ir structures in Dermophis and that in anurans or urodeles. Some features were shared only with anurans, such as the abundant pallial SOM-ir cells, whereas others were common only to urodeles, such as the organization of the hypothalamohypophysial SOM-ir system. In addition, some characteristics were found only in Dermophis, such as the localization of the SOM-ir spinal cells and the lack of colocalization of catecholamines and SOM throughout the brain. Therefore, any conclusions concerning the SOM system in amphibians are incomplete without considering evidence for gymnophionans.

  14. AmphibiaChina: an online database of Chinese Amphibians.

    PubMed

    Che, Jing; Wang, Kai

    2016-01-18

    AmphibiaChina, an open-access, web-based database, is designed to provide comprehensive and up-to-date information on Chinese amphibians. It offers an integrated module with six major sections. Compared to other known databases including AmphibiaWeb and Amphibian Species of the World, AmphibiaChina has the following new functions: (1) online species identification based on DNA barcode sequences; (2) comparisons and discussions of different major taxonomic systems; and (3) phylogenetic progress on Chinese amphibians. This database offers a window for the world to access available information of Chinese amphibians. AmphibiaChina with its Chinese version can be accessed at http://www.amphibiachina.org.

  15. The spleen pigment cells in some amphibia.

    PubMed

    Scalia, Marina; Di Pietro, Cinzia; Poma, Mariangela; Ragusa, Marco; Sichel, Giovanni; Corsaro, Concetta

    2004-04-01

    It was demonstrated that the spleen pigment cells of Amphibia are macrophages: they show an ultrastructurally distinctive morphology, are able to phagocytose and react positively for non-specific esterases. These pigmented macrophages express mRNA for tyrosinase and also they show dopa oxidase activity; therefore they are able to synthesize melanins, as Kupffer cells do.

  16. Cranial musculature in the larva of the caecilian, Ichthyophis kohtaoensis (Lissamphibia: Gymnophiona).

    PubMed

    Kleinteich, Thomas; Haas, Alexander

    2007-01-01

    Within the Gymnophiona (caecilians) oviparous species with biphasic life-cycles possess a free living semi-aquatic larval stage that feeds in aquatic habitats. The larvae pass through a metamorphosis to a purely terrestrial adult stage. It is likely that the cranial morphology of caecilian larvae has specializations for aquatic feeding. However, little is known about the cranial morphology, and the cranial musculature is especially neglected in the literature. This study provides a detailed description of the jaw and hyobranchial musculature in larval stages of a caecilian. We studied late embryonic and early larval specimens of Ichthyophis kohtaoensis. Furthermore, we compared and homologized the cranial muscles found in larval I. kohtaoensis with the muscles described for adult caecilians. Most cranial muscles of larval I. kohtaoensis are also present in the adult, except for the m. levator mandibulae externus and the m. subarcualis obliquus II. Our results were compared with the data available for larval frogs and salamanders in order to hypothesize the cranial musculature in the larva of the most recent common ancestor of the Lissamphibia. Larval caecilians, frog tadpoles, and salamander larvae share many characters in their cranial musculature, which, consequently, can be assigned to the lissamphibian ground pattern. However, the m. pterygoideus and the m. levator quadrati are unique to the Gymnophiona.

  17. Characterisation of Kupffer cells in some Amphibia

    PubMed Central

    CORSARO, CONCETTA; SCALIA, MARINA; LEOTTA, NICOLA; MONDIO, FILIPPO; SICHEL, GIOVANNI

    2000-01-01

    A study on the Kupffer cells (KCs) of Amphibia was undertaken in order to compare these cells with those of endothermic animals. Liver tissue and isolated and cultured KCs were studied by light microscopy and by transmission and scanning electron microscopy. We have shown that amphibian KCs can be divided into 2 principal types: ‘small’ and ‘large’. Both cell types possess the distinctive KC morphology. They show nonspecific esterase activity, weak endogenous peroxidase activity in the nuclear envelope and in the rough endoplasmic reticulum, and the ability to engulf naturally present cell debris or experimentally administered zymosan or latex particles. The principal difference between the small and the large cells consists in the substantial quantity of inclusion bodies that exist only in the latter. We conclude that amphibian KCs, apart from their ability to build melanosomes and synthesise melanins, are very similar to mammalian KCs. PMID:10739021

  18. Molecular phylogeny and biogeography of caecilians from Southeast Asia (Amphibia, Gymnophiona, Ichthyophiidae), with special reference to high cryptic species diversity in Sundaland.

    PubMed

    Nishikawa, Kanto; Matsui, Masafumi; Yong, Hoi-Sen; Ahmad, Norhayati; Yambun, Paul; Belabut, Daicus M; Sudin, Ahmad; Hamidy, Amir; Orlov, Nikolai L; Ota, Hidetoshi; Yoshikawa, Natsuhiko; Tominaga, Atsushi; Shimada, Tomohiko

    2012-06-01

    We investigated the phylogenetic relationships and estimated the history of species diversification and character evolution in two ichthyophiid genera: Caudacaecilia and Ichthyophis. We estimated the phylogenetic relationships of 67 samples from 33 localities in Southeast Asia from 3840-bp sequences of the mitochondrial 12S rRNA, 16S rRNA, and cyt b genes using Bayesian inference, maximum likelihood, and maximum parsimony methods. The Southeast Asian samples formed a well-supported clade differentiated from a South Asian sample. The Southeast Asian clade was divided into two subclades, one containing samples from South China, Indochina, Malay Peninsula, and Java. The other consisted of samples from Borneo and the Philippines. Neither Caudacaecilia nor Ichthyophis was monophyletic, nor did samples with or without light stripes lateral to the body form clades. We found several distinct sympatric lineages and undescribed species, especially from Sundaland.

  19. Distribution of NADPH-diaphorase/nitric oxide synthase in the brain of the caecilian Dermophis mexicanus (amphibia: gymnophiona): comparative aspects in amphibians.

    PubMed

    González, Augustín; Moreno, Nerea; López, Jesús M

    2002-01-01

    The organization of nitrergic systems in the brains of anuran and urodele amphibians was recently studied and significant differences were noted between both amphibian orders. However, comparable data are not available for the third order of amphibians, the gymnophionans (caecilians). In the present study we have investigated the distribution of neuronal elements that express nitric oxide synthase (NOS) in the brain of the gymnophionan amphibian Dermophis mexicanus by means of immunohistochemistry with specific antibodies against NOS and enzyme histochemistry for NADPH-diaphorase. Both techniques yielded identical results and were equally suitable to demonstrate the nitrergic system. In addition, they were useful tools in the identification of cell groups and brain structures, otherwise indistinct in the brains of caecilians. The distribution of nitrergic structures observed in Dermophis conforms to the overall amphibian pattern but numerous distinct peculiarities were also noted. These included a dense innervation of the olfactory bulbs but a lack of reactivity in olfactory and vomeronasal fibers and glomeruli. A large population of nitrergic cells in the striatum and the presence of thalamic neurons, as well as the specific distribution of nitrergic cells in the isthmic region, are some of the differential features in the gymnophionan brain. Given the variability among species in the same class of vertebrates any discussion including amphibians should also include evidence for gymnophionans.

  20. Contribution of the secretory material of caecilian (amphibia: Gymnophiona) male Mullerian gland to motility of sperm: a study in Uraeotyphlus narayani.

    PubMed

    George, Jancy M; Smita, Mathew; Kadalmani, Balamuthu; Girija, Ramankutty; Oommen, Oommen V; Akbarsha, Mohammad A

    2005-02-01

    Caecilians are a unique group of limbless burrowing amphibians with discontinuous distribution. Several caecilian species are viviparous, and all practice internal fertilization. In amniotic vertebrates the sperm undergo post-testicular physiological maturation when they are initiated into motility under the influence of an epididymal secretion. Further, during ejaculation mammalian sperm are suspended in a fluid secreted by the male accessory sex glands, viz., prostate gland and seminal vesicles. Caecilians lack comparable glands, but still practice internal fertilization. Uniquely, male caecilians retain the Mullerian ducts in the adults as a pair of functional glands. It has long been hypothesized, based on indirect evidence, that the Mullerian gland would be a male accessory sex gland, secreting a fluid in which sperm are suspended during ejaculation and which would also provide nutritional support to the ejaculated sperm. In the present study, the secretory material of the Mullerian gland of Uraeotyphlus narayani was mixed with sperm obtained from the testis, and the changes in motility were recorded. Uraeotyphlus narayani sperm possess a perforatorium of the acrosome proceeding deep into the endonuclear canal of the nucleus. The midpiece is characterized by closely applied centrioles, the anterior ends of the axoneme and axial fiber, and a mitochondrial sheath. The long tail has an undulating membrane on one side, supported by the axoneme and an axial fiber. The live sperm possess a mitochondrial vesicle, also known as the cytoplasmic droplet, anywhere along the head and the midpiece, as in anuran sperm, which is shed from sperm that have ceased motility. Uraeotyphlus narayani sperm are motile the moment they are released directly from the testis, indicating that the sperm do not require post-testicular physiological maturation. On being mixed with the secretory material of the Mullerian gland, the spermatozoa are enhanced in speed as well as duration of motility. Therefore, the caecilian male Mullerian gland is considered to be the male accessory sex gland.

  1. Secretory and basal cells of the epithelium of the tubular glands in the male Mullerian gland of the caecilian Uraeotyphlus narayani (Amphibia: Gymnophiona).

    PubMed

    George, Jancy M; Smita, Matthew; Kadalmani, Balamuthu; Girija, Ramankutty; Oommen, Oommen V; Akbarsha, Mohammad A

    2004-12-01

    Caecilians are exceptional among the vertebrates in that males retain the Mullerian duct as a functional glandular structure. The Mullerian gland on each side is formed from a large number of tubular glands connecting to a central duct, which either connects to the urogenital duct or opens directly into the cloaca. The Mullerian gland is believed to secrete a substance to be added to the sperm during ejaculation. Thus, the Mullerian gland could function as a male accessory reproductive gland. Recently, we described the male Mullerian gland of Uraeotyphlus narayani using light and transmission electron microscopy (TEM) and histochemistry. The present TEM study reports that the secretory cells of both the tubular and basal portions of the tubular glands of the male Mullerian gland of this caecilian produce secretion granules in the same manner as do other glandular epithelial cells. The secretion granules are released in the form of structured granules into the lumen of the tubular glands, and such granules are traceable to the lumen of the central duct of the Mullerian gland. This is comparable to the situation prevailing in the epididymal epithelium of several reptiles. In the secretory cells of the basal portion of the tubular glands, mitochondria are intimately associated with fabrication of the secretion granules. The structural and functional organization of the epithelium of the basal portion of the tubular glands is complicated by the presence of basal cells. This study suggests the origin of the basal cells from peritubular tissue leukocytes. The study also indicates a role for the basal cells in acquiring secretion granules from the neighboring secretory cells and processing them into lipofuscin material in the context of regression of the Mullerian gland during the period of reproductive quiescence. In these respects the basal cells match those in the epithelial lining of the epididymis of amniotes.

  2. A new Eimeria sP. from the plumbeous Central American caecilian, Dermophis mexicanus (amphibia: gymnophiona) from Volcán Tajumulco, Department of San Marcos, Guatemala.

    PubMed

    Asmundsson, I M; Campbell, J A; Duszynski, D W

    2000-04-01

    Fresh fecal samples from 5 caecilians (Dermophis mexicanus) were collected and examined for coccidia in the summer of 1998. The caecilians were collected in the Department of San Marcos, Guatemala. Two of the 5 (40%) specimens of caecilians contained an Eimeria species that is described here as new. This represents the first coccidia described from a gymnophionian host. Sporulated oocysts are spheroidal to subspheroidal, 19.5 X 17.7 (16-23 x 15-21) microm, micropyle and oocyst residuum are absent, and 3 (or more) polar granules are always present. Sporocysts are ovoidal, 11.0 X 7.2 (10-12 x 6-9); a Stieda body and sporocyst residuum are present.

  3. Stages in spermatogenesis of two species of caecilians, Ichthyophis tricolor and Uraeotyphlus cf. narayani (Amphibia: Gymnophiona): Light and electron microscopic study.

    PubMed

    Smita, Mathew; Oommen, Oommen V; Jancy, M George; Akbarsha, M A

    2004-07-01

    The sequential changes during spermatogenesis in the testis of two species of caecilians, Ichthyophis tricolor (Ichthyophiidae) and Uraeotyphlus cf. narayani (Uraeotyphliidae), of Western Ghats of Kerala, India, were traced using both histological techniques and transmission electron microscopy. The cell nests were assigned to stages in spermatogenesis based on the classification of van Oordt (1956, Thesis, Utrecht University). To the best of our knowledge, this is the first identification and ultrastructural description of stages in spermatogenesis in caecilians. The article illustrates not only the stages, but also the cell divisions, mitotic and meiotic, as specified. The observations indicate that, although caecilians have undergone considerable modifications in morphology and anatomy, including reproductive anatomy, in the context of a subterranean and concealed life, they appear to have conserved the typical amphibian pattern of spermatogenesis for the events of development of spermatids.

  4. The authorships and dates of the specific nomina Megophrys shuichengensis and Pseudohynobius shuichengensis (Amphibia).

    PubMed

    Ohler, Annemarie; Frétey, Thierry; Dubois, Alain

    2015-05-28

    Two amphibian species from China are designated by the specific nomen shuichengensis, which refers to the Shuicheng County (26°34'N, 104°51'E), south of the city of Liupanshui in the province of Guizhou: Megophrys shuichengensis (Amphibia, Anura) and Pseudohynobius shuichengensis (Amphibia, Urodela). The holotypes (holophoronts) of both species were deposited in Department of Biology of the Liupanshui Teachers Higher College (LTHC below). Both species share the particularity of having been described as new twice, at different dates, in different journals and with different authorships. Although this has been acknowledged for the salamander, it has not yet been so for the frog.

  5. Phylogenetic relationships linking Duttaphrynus (Amphibia: Anura: Bufonidae) species based on 12S and 16S rDNA sequences.

    PubMed

    Pratihar, Suman; Bhattacharya, Manojit; Deuti, Kaushik

    2016-07-01

    Genus Duttaphrynus (Amphibia: Anura: Bufonidae) is endemic to southwestern and southern China and throughout southern Asia. Duttaphrynus phylogeny was also under debate for many years. 12S and 16S rDNAs help us to elucidate Duttaphrynus phylogeny.

  6. The different meanings of the nomen Amphibia: a correction.

    PubMed

    Dubois, Alain

    2015-07-17

    I recently published a survey of the different meanings of the nomen Amphibia in taxonomic publications since 1758 (Dubois 2015). The 'meaning' of a nomen in zoological nomenclature depends on the system used for the allocation of nomina to taxa, and several such systems can be used (see e.g. Dubois 2006a-b). In the paper at stake, I used the 'orostensional nomenclatural system' (OONS) for class-series nomenclature. In this system, a class-series nomen-i.e., a nomen above the rank superfamily, therefore one whose taxonomic allocation is not regulated by the Code (Anonymous 1999)-applies, in a given classification, to the most inclusive class-series taxon that includes all its originally expressly included nominal genera (conucleogenera) and excludes all its originally expressly excluded nominal genera (alienogenera)-if such a taxon indeed exists in this classification. However, if one a least of the alienogenera is now part of the most inclusive taxon including all the conucleogenera, the nomen cannot be taxonomically allocated and qualifies as an anaptonym in the classification used as reference (Dubois 2006a-b, 2011), although it may not be so under another taxonomic frame.

  7. [Helminth fauna of amphibians (Vertebrata: Amphibia) in the Republic of Belarus].

    PubMed

    Shimalov, V V

    2009-01-01

    Historical review of the investigations of helminth fauna in amphibians from Belarus is presented. In 12 amphibian species examined by different authors 46 helminth species were found, including 29 Trematoda, 13 Nematoda, 1 Monogenea, 2 Cestoda, and 1 Acanthocephala. Original data on helminths parasitizing Amphibia in Byelorussian Polesie, by the results of long-term investigations in 1986-2004 are given. Distribution of 40 helminth species by hosts and respective infestation rates are reported.

  8. Species-specificity of amphibia carbohydrate chains: the Bufo viridis case study.

    PubMed

    Coppin, Alexandra; Maes, Emmanuel; Strecker, Gérard

    2002-02-05

    The jelly coat surrounding the eggs of amphibia is composed of oviducal mucins and plays an important role in the fertilization process. From a structural and chemical point of view, these jellies are very different from one species to another. Bufo viridis is the 13th amphibia species studied in term of carbohydrate structural analysis. The oligosaccharides have been released from the oviducal mucins by reductive beta elimination, purified by various chromatography procedures and analyzed by (1)H and (13)C 1D-2D NMR spectroscopy. Among the 15 compounds, ten have novel structures, although they possess some well-known structural patterns as blood group epitopes (Le(x), Le(y)) or other sequences already observed in other amphibia species. These results reinforce our hypothesis about the strict species-specificity of these carbohydrate chains. It must be noted that such species-specificity does not depend on one particular monosaccharide but it is rather due to a set of particular tri- or tetrasaccharide sequences. Hence, B. viridis species could be characterized by the simultaneous presence of a 2,3,6-trisubstituted galactosyl residue, the GlcNAc(beta 1-3)[Fuc(alpha 1-4)]GlcNAc beta sequence and the Le(x), Le(y) or Cad determinants. The anionic charge of the oligosaccharides is carried only by sialic acid alpha-(2-->6)-linked to GalNAc-ol residue as in Bufo bufo or in Bufo arenarum.

  9. Applying x-ray tomography in the field of vertebrate biology: form, function, and evolution of the skull of caecilians (Lissamphibia: Gymnophiona)

    NASA Astrophysics Data System (ADS)

    Kleinteich, Thomas; Beckmann, Felix; Herzen, Julia; Summers, Adam P.; Haas, Alexander

    2008-08-01

    Evolutionary research in biology relies on the comparison of different individuals of different species in order to explore the history of today's biodiversity. Synchrotron radiation based high resolution X-ray tomography (SRμCT) rapidly generates detailed three dimensional datasets. At the beamlines W2 and BW2 of the storage ring DORIS at DESY, Hamburg, Germany, we used SRμCT to study the cranial anatomy of different species and different developmental stages of caecilians (Lissamphibia: Gymnophiona). Here we describe a work-flow for analysis of the SRμCT data that covers segmentation of tissues in Amira® (Mercury Computer Systems), photorealistic rendering and animation in MayaTM, rapid prototyping, and morphometrics. The integration of different analyses of SRμCT data in our study resulted in a comprehensive understanding of form, function, and evolution of caecilian skulls. SRμCT imaging has the potential to become a standard technique for life sciences applications in the near future.

  10. Rhabdias kongmongthaensis sp. n. (Nematoda: Rhabdiasidae) from Polypedates leucomystax (Amphibia: Anura: Rhacophoridae) in Thailand.

    PubMed

    Kuzmin, Yuriy; Tkach, Vasyl V; Vaughan, Jefferson A

    2005-11-01

    Rhabdias kongmongthaensis sp. n. is described based on specimens found in the lungs of the tree frog Polypedates leucomystax (Gravenhorst) (Amphibia: Rhacophoridae) from Kanchanaburi Province, western Thailand. The new species is similar to two North-American species, Rhabdias ranae and R. americanus, by presence of two lateral pseudolabia, each with two inner submedian protuberances. R. kongmongthaensis differs from both species by relative length and shape of the tail, and by its distribution and host specificity. Presence of lateral pseudolabia distinguishes the new species from the geographically closest Rhabdias species as well as from those parasitizing other rhacophorid frogs.

  11. Cosmocercoides himalayanus sp. nov. (Nematoda, Cosmocercidae) in Duttaphrynus himalayanus (Amphibia, Anura) from Dehradun (Uttarakhand), India.

    PubMed

    Rizvi, Anjum N; Bursey, Charles R

    2014-03-01

    Cosmocercoides himalayanus sp. nov. (Nematoda, Cosmocercidae) from the large intestine of Duttaphrynus himalayanus (Amphibia, Anura) from Dehradun, India is described and illustrated. Cosmocercoides himalayanus sp. nov. represents the 21st species assigned to the genus and the 9th species from the Oriental biogeographical region. Cosmocercoides himalayanus sp. nov. differs from the previously described Oriental species in number and position of rosette papillae; it is the only species possessing 24 or more rosette papillae to have 4 postcloacal papillae. In addition, a list of species assigned to Cosmocercoides is provided; however, C. fotedari Arya, 1992 is removed from the genus and until further study is considered a species inquirenda.

  12. Comparative morphometric study of the vestibular system of the vertebrata: reptilia, aves, amphibia, and pisces.

    PubMed

    Ramprashad, F; Landolt, J P; Money, K E; Laufer, J

    1986-01-01

    Morphometric measurements were made from serial sections of the vestibular system in four classes of vertebrates: Reptilia, Aves, Amphibia, and Pisces. Representative species of reptile studied were the lizard (Gekko gecko), the common garter snake (Thamnophis sp.), and the common turtle (Chelonia sp.). The budgie (Melopsittacus undulatas), the common pigeon (Columba domestica), the yellow-bellied sapsucker (Sphyrapicus varius), and the horned owl (Bubo virginianus) were chosen as representative of the bird. For the amphibian, the leopard frog (Rana pipiens), and the mud puppy (Necturus maculatus) were chosen for study. As representative of the fish, the goldfish (Carassius auratus), the tilapia (Tilapia mossambica), the guppy (Lebistes sp.), and the sea horse (Hippocampus sp.) were used in these measurements. The morphometric data obtained were then used in estimates of the time constants in the Steinhausen equation which describes the biophysics of fluid flow in the semicircular canals. In general, the time constants (theta/II in the Steinhausen equation) of these representatives of Reptilia, Aves, and Amphibia were of magnitude similar to those reported in mammals, despite the dissimilarities in the diameters of the ducts, the duct radii of curvature, the dimensions of the cristae ampullares and the utricle, and volumes of endolymph within the vestibular system. However, the short-time constants in Pisces were larger (therefore providing a slower response) than those in other vertebrates, and were similar to that of the turtle and the mud puppy.

  13. The biology of some intraerythrocytic parasites of fishes, amphibia and reptiles.

    PubMed

    Davies, A J; Johnston, M R

    2000-01-01

    Fishes, amphibia and reptiles, the ectothermic vertebrates, are hosts for a variety of intraerythrocytic parasites including protists, prokaryotes, viruses and structures of uncertain status. These parasites may experience host temperature fluctuations, host reproductive strategies, population genetics, host habitat and migratory behaviour quite unlike those of endothermic hosts. Few blood infections of fishes, amphibia and reptiles have proven pathogenicity, in contrast to the many intraerythrocytic parasites of mammals and some birds which harm their hosts. Although not given the attention afforded to intraerythrocytic parasites of endotherms, those of ectotherms have been studied for more than a century. This review reports on the diversity, general biology and phylogeny of intraerythrocytic parasites of ectotherms. The existence of taxonomic confusion is emphasized and the main taxonomic features of most of the 23 better characterized genera, particularly the kinetoplastid and apicomplexan protists, are summarized. Transmission of protistan infections of aquatic ectotherms is also discussed. Leeches can transfer sporozoties or merozoites to the vertebrate host during feeding. Dormant sporozoites of Lankesterella may permit transmission of species of this genus between vertebrates by predation. The fish haemogregarine, Haemogregarina bigemina, probably has gnathiid isopods, rather than leeches, as its definitive hosts. Hepatozoon spp. in aquatic hosts, and Progarnia of caiman, may also use invertebrate hosts other than leeches. Protistan infections of terrestrial or semi-terrestrial hosts are transmitted by a variety of arthropods, or, in some cases, leeches, contaminated paratenic hosts, or sporocysts free in water. Transfer of protists between vertebrates by predation and congenitally may also occur. The biology of the host cells of these infections, the red blood cells of ectotherm vertebrates, is summarized and compared with that of mammalian erythrocytes

  14. A new species of Mesocoelium (Digenea: Mesocoeliidae) found in Rhinella marina (Amphibia: Bufonidae) from Brazilian Amazonia.

    PubMed

    Gomes, Tássia F F; Melo, Francisco T V; Giese, Elane G; Furtado, Adriano P; Gonçalves, Evonnildo C; Santos, Jeannie N

    2013-04-01

    Mesocoelium lanfrediae sp. nov. (Digenea: Mesocoeliidae) inhabits the small intestine of Rhinella marina (Amphibia: Bufonidae) and is described here, with illustrations provided by light, scanning electron microscopy and molecular approachs. M. lanfrediae sp. nov. presents the typical characteristics of the genus, but is morphometrically and morphologically different from the species described previously. The main diagnostic characteristics of M. lanfrediae sp. nov. are (i) seven pairs of regularly-distributed spherical papillae on the oral sucker, (ii) ventral sucker outlined by four pairs of papillae distributed in a uniform pattern and interspersed with numerous spines, which are larger at the posterior margin and (iii) small, rounded tegumentary papillae around the opening of the oral sucker, which are morphologically different from those of the oral sucker itself, some of which are randomly disposed in the ventrolateral tegumentary region of the anterior third of the body. Addionally, based on SSU rDNA, a phylogenetic analysis including Brachycoeliidae and Mesocoeliidae taxa available on GenBank established the close relationship between M. lanfrediae sp. nov. and Mesocoelium sp.

  15. A new species of Mesocoelium (Digenea: Mesocoeliidae) found in Rhinella marina (Amphibia: Bufonidae) from Brazilian Amazonia

    PubMed Central

    Gomes, Tássia FF; Melo, Francisco TV; Giese, Elane G; Furtado, Adriano P; Gonçalves, Evonnildo C; Santos, Jeannie N

    2013-01-01

    Mesocoelium lanfrediaesp. nov. (Digenea: Mesocoeliidae) inhabits the small intestine of Rhinella marina (Amphibia: Bufonidae) and is described here, with illustrations provided by light, scanning electron microscopy and molecular approachs. M. lanfrediae sp. nov. presents the typical characteristics of the genus, but is morphometrically and morphologically different from the species described previously. The main diagnostic characteristics of M. lanfrediae sp. nov. are (i) seven pairs of regularly-distributed spherical papillae on the oral sucker, (ii) ventral sucker outlined by four pairs of papillae distributed in a uniform pattern and interspersed with numerous spines, which are larger at the posterior margin and (iii) small, rounded tegumentary papillae around the opening of the oral sucker, which are morphologically different from those of the oral sucker itself, some of which are randomly disposed in the ventrolateral tegumentary region of the anterior third of the body. Addionally, based on SSU rDNA, a phylogenetic analysis including Brachycoeliidae and Mesocoeliidae taxa available on GenBank established the close relationship between M. lanfrediae sp. nov. and Mesocoelium sp. PMID:23579798

  16. Morphology, ultrastructure and molecular characterisation of Spiroxys japonica Morishita, 1926 (Spirurida: Gnathostomatidae) from Pelophylax nigromaculatus (Hallowell) (Amphibia: Ranidae).

    PubMed

    Li, Liang; Hasegawa, Hideo; Roca, Vicente; Xu, Zhen; Guo, Yan-Ning; Sato, Akiko; Zhang, Lu-Ping

    2014-03-01

    Gnathostomatid nematodes identified morphologically as Spiroxys japonica Morishita, 1926 were collected from the dark-spotted frog Pelophylax nigromaculatus (Hallowell) (Amphibia: Ranidae) in China. Light and scanning electron microscopy were used to study the morphology of this species in detail. Previously unreported morphological features are revealed and others corrected. In addition, adult nematodes of S. japonica collected from P. nigromaculatus and Spiroxys hanzaki Hasegawa, Miyata & Doi, 1998 collected from Andrias japonicus (Temminck) (Caudata: Cryptobranchidae) in China and Japan, respectively, and the third-stage larva of S. japonica collected from Lithobates catesbeianus (Shaw) (Anura: Ranidae) in Japan, were characterised using molecular methods by sequencing and analysing ribosomal [large ribosomal DNA (18S) and internal transcribed space] and mitochondrial [cytochrome c oxidase subunit 1] target regions, respectively. The new morphological and genetic data contributes to a more accurate diagnosis of this hitherto little known nematode genus.

  17. Complete mitochondrial genome of the Seoul frog Rana chosenica (Amphibia, Ranidae): comparison of R. chosenica and R. plancyi.

    PubMed

    Ryu, Shi Hyun; Hwang, Ui Wook

    2011-06-01

    Here, we have sequenced the complete mitochondrial genome of the Seoul frog Rana chosenica (Amphibia, Ranidae), which is known as a Korean endemic species. It is listed as a vulnerable species by IUCN Red List and also an endangered species in South Korea. The complete mitochondrial genome of R. chosenica consists of 18,357 bp. Its gene arrangement pattern was identical with those of other Rana frogs. We compared the mitochondrial genome of R. chosenica with that of the Peking frog Rana plancyi that has been known closely related to R. chosenica. Nucleotide sequence similarity between the two whole mitochondrial genomes was 95.7%, and the relatively low similarity seems to indicate that the two species are distinctly separated on the species level. The information of mitochondrial genome comparison of the two species was discussed in detail.

  18. Montagnuphilones A-G, Azaphilones from Montagnulaceae sp. DM0194, a Fungal Endophyte of Submerged Roots of Persicaria amphibia.

    PubMed

    Luo, Jian-Guang; Xu, Ya-Ming; Sandberg, Dustin C; Arnold, A Elizabeth; Gunatilaka, A A Leslie

    2017-01-27

    Seven azaphilones, montagnuphilones A-G (1-7), together with previously known azaphilones 8-11, were encountered in Montagnulaceae sp. DM0194, an endophytic fungus isolated from submerged roots of Persicaria amphibia. The structures of 1-7 were elucidated on the basis of their MS and NMR spectroscopic analysis. Compounds 1-8 were evaluated for their cytotoxicity and ability to inhibit nitric oxide (NO) production in lipopolysaccharide-activated RAW264.7 macrophage cells. Among these, none were found to be cytotoxic to RAW264.7 cells up to 100.0 μM, but 8, 5, and 2 showed NO inhibitory activity with IC50 values of 9.2 ± 0.9, 25.5 ± 1.1, and 39.6 ± 1.8 μM, respectively.

  19. Chromosome banding in Amphibia. XVII. First demonstration of multiple sex chromosomes in amphibians: Eleutherodactylus maussi (Anura, leptodactylidae).

    PubMed

    Schmid, M; Steinlein, C; Feichtinger, W

    1992-03-01

    A cytogenetic study performed on a population of the South American leptodactylid frog Eleutherodactylus maussi revealed multiple sex chromosomes of the X1X1X2X2 female/X1X2Y male (= XXAA female/XXAY male) type. The diploid chromosome number is 2n = 36 in all females and 2n = 35 in most males. The multiple sex chromosomes originated by a centric fusion between the original Y chromosome and a large autosome. In male meiosis the X1X2Y (= XXAY) multiple sex chromosomes form a classical trivalent configuration. E. maussi is the first species discovered in the class Amphibia that is distinguished by a system of multiple sex chromosomes. Only one single male was found in the population with 2n = 36 chromosomes and lacking the Y-autosomal fusion. This karyotype (XYAA male) is interpreted as the ancestral condition, preceding the occurrence of the Y-autosome fusion.

  20. Carnosine in the brain and olfactory system of amphibia and reptilia: a comparative study using immunocytochemical and biochemical methods.

    PubMed

    Artero, C; Martì, E; Biffo, S; Mulatero, B; Andreone, C; Margolis, F L; Fasolo, A

    1991-09-16

    The pattern of distribution of carnosine-like immunoreactivity and its relation to glial fibrillary acidic protein immunoreactivity have been studied in two lizards (Gallotia galloti and Tarentola delalandii) and in two anuran amphibians (Rana esculenta and Xenopus laevis) using immunocytochemical techniques. Biochemical data obtained by paper electrophoresis show that the dipeptides carnosine and homocarnosine are both present in the brain of all the species examined. In the central nervous system of both anurans and reptilians, carnosine immunoreactivity is localized in glial cells. An important species difference is, however, seen in the olfactory system since primary olfactory neurons and their processes extending to the olfactory bulb are carnosine positive in reptiles, whereas they are not immunostained in anurans. Thus, the cellular distribution of carnosine immunoreactivity in reptilians is very similar to that observed in birds and mammals and is distinct from that seen in amphibia.

  1. Effects of a glyphosate-based herbicide on the development of Common toads (Bufo bufo L.; Amphibia) at different temperatures

    NASA Astrophysics Data System (ADS)

    Baier, Fabian; Gruber, Edith; Spangl, Bernhard; Zaller, Johann G.

    2016-04-01

    Herbicides based on the active ingredient glyphosate are frequently applied in agriculture, horticulture and private gardens all over the world. Recently, leaching of glyphosate or its metabolite (AMPA) into water bodies inhabited by amphibians has been reported. However, very little is known about non-target effects of these herbicides on amphibians and even less is known to what extent different temperatures might alter these effects. Using climate chambers, we investigated the effects of the glyphosate-based herbicide Roundup PowerFlex® (480 g L-1 glyphosate, formulated as 588 g L-1 potassium salt) on the larval development of Common toads (Bufo bufo L.; Amphibia: Anura) under different temperature regimes (15°C vs. 20°C). We established five herbicide concentrations: 0, 1.5, 3, 4 mg acid equivalent L-1 and a 4 mg a.e. L-1 pulse treatment (totally three applications of 1.5, 1.5 and another 1 mg a.e. L-1) at each temperature in a full-factorial design. Each treatment combination was replicated five times, the experiment ran for 24 days. Results showed a highly significant effect of temperature on body length and body width but no effect of herbicide concentration on these growth parameters. Moreover, highly significant interactions between herbicide and temperature on body length and body width were observed suggesting that herbicides had different effects on different temperatures. In conclusion, although Roundup PowerFlex® at the tested concentrations appeared to have no acute toxicity to larvae of Common toads, the observed effects on tadpole morphology will potentially affect competitive interactions in spawning ponds of amphibia. Our findings of herbicide x temperature interactions might become more prevalent when human-induced climate change will lead to more extreme temperatures.

  2. Immunohistochemical localization of insulin-like growth factor I and II in the endocrine pancreas of birds, reptiles, and amphibia.

    PubMed

    Reinecke, M; Broger, I; Brun, R; Zapf, J; Maake, C

    1995-12-01

    Immunoreactive insulin-like growth factors I and II (IGF-I, IGF-II) were sought in the endocrine pancreas of representative birds, reptiles, and amphibia using antisera specific for mammalian IGF-I and IGF-II and the classical islet hormones insulin (INS), glucagon (GLUC), somatostatin (SOM), and pancreatic polypeptide (PP) in double immunofluorescence. Both IGF-I and IGF-II immunoreactivities were present in the endocrine pancreas of all species. IGF-II immunoreactivity was exclusively found in INS-immunoreactive (-IR) cells, indicating evolutionary conservation of the islet IGF-II system. In contrast, IGF-I immunoreactivity was distributed differently among the species and never occurred in INS-IR cells. In the anuran Xenopus laevis, IGF-I immunoreactivity was present in islet cells showing coexistence of GLUC and PP immunoreactivities. In reptiles, the lizards (Lacerta viridis, Scincus officinalis) exhibited IGF-I immunoreactivity in PP-IR and SOM-IR cells and the snakes (Psamophis leniolatum, Coluber ravergieri) in SOM-IR and GLUC-IR cells. In birds, IGF-I immunoreactivity was located either in SOM-IR cells only (Gallus g. domesticus, Streptopelia roseogrisea) or in PP-IR and SOM-IR cells (Coturnix c. japonica). Thus, the distribution patterns of islet IGF-I immunoreactivities in birds, reptiles, and amphibia are equivalent to those in mammals and most bony fish. They differ, however, from those found in cartilaginous fish, cyclostomes, and protochordates, where a total or partial coexistence of IGF-I and INS immunoreactivities has been obtained. Therefore, the divergence of IGF-I and INS seems to have occurred early in vertebrate phylogeny. Furthermore, the existence of IGF-I immunoreactivity likely is common in the islets of all vertebrates. Finally, no phylogenetic trend to concentrate IGF-I immunoreactivity in a particular islet cell type is apparent.

  3. Ornithodoros faccinii n. sp. (Acari: Ixodida: Argasidae) parasitizing the frog Thoropa miliaris (Amphibia: Anura: Cycloramphidae) in Brazil.

    PubMed

    Barros-Battesti, Darci Moraes; Landulfo, Gabriel Alves; Luz, Hermes Ribeiro; Marcili, Arlei; Onofrio, Valeria Castilho; Famadas, Kátia Maria

    2015-05-13

    Most argasid ticks from the Neotropical region are parasites of mammals and birds, with a few records from reptiles. Many species of the genus Ornithodoros are known only through larval descriptions, and their chaetotaxy and morphological characteristics have been used to separate the taxa. In the present study, we describe the larva and the nymph of first instar of a new species of the genus Ornithodoros that was collected from frogs of the species Thoropa miliaris. Larvae of Ornithodoros were collected from frogs of the species T. miliaris at waterfalls in the state of Rio de Janeiro, southeastern Brazil. The larval and nymphal description was based on optical and scanning electron microscopy. Molecular analysis using the argasid 16S rRNA sequences available in GenBank was also conducted. Ornithodoros faccinii sp. n. is closely related to Ornithodoros clarki Jones & Clifford, Ornithodoros marinkellei Kohls, Clifford & Jones, Ornithodoros capensis Neumann and Ornithodoros sawaii Kitaoka & Susuki. However, the larval morphology of the new species is unique. The mitochondrial 16S rDNA partial sequence of O. faccinii generated in the present study was deposited in GenBank under the number KP861242. The larvae collected from Thoropa miliaris are a new species, Ornithodoros faccinii n. sp. This is the first report of argasid ticks on frogs in Brazil, the second on frogs and the third on Amphibia in the Neotropical region.

  4. Static osteogenesis does not precede dynamic osteogenesis in periosteal ossification of Pleurodeles (Caudata, Amphibia) and Pogona (Squamata, Lepidosauria).

    PubMed

    Cubo, Jorge; Hui, Mylaine; Clarac, François; Quilhac, Alexandra

    2017-02-01

    Two successive mechanisms have been described in perichondral ossification: (1) in static osteogenesis, mesenchymal cells differentiate into stationary osteoblasts oriented randomly, which differentiate into osteocytes in the same site; (2) in dynamic osteogenesis, mesenchymal cells differentiate into osteoblasts that are all oriented in the same direction and move back as they secrete collagen fibers. This study is aimed at testing the hypothesis that the ontogenetic sequence static then dynamic osteogenesis observed in the chicken and in the rabbit is homologous and was acquired by the last common ancestor of amniotes or at a more inclusive node. For this we analyze the developmental patterns of Pleurodeles (Caudata, Amphibia) and those of the lizard Pogona (Squamata, Lepidosauria). We processed Pleurodeles larvae and Pogona embryos, prepared thin and ultrathin sections of appendicular bones, and analyzed them using light and transmission electron microscopy. We show that static osteogenesis does not precede dynamic osteogenesis in periosteal ossification of Pleurodeles and Pogona. Therefore, the null hypothesis is rejected and according to the parsimony method the ontogenetic sequence observed in the chicken and in the rabbit are convergent. In Pleurodeles and Pogona dynamic osteogenesis occur without a previous rigid mineralized framework, whereas in the chicken and in the rabbit dynamic osteogenesis seems to take place over a mineralized support whether bone (in perichondral ossification) or calcified cartilage (in endochondral ossification). Interestingly, in typical dynamic osteogenesis, osteoblasts show an axis (basal nucleus-distal endoplasmic reticulum) perpendicular to the front of secreted unmineralized bone matrix, whereas in Pleurodeles and Pogona this axis is parallel to the bone matrix.

  5. A new species of Rhabdias Stiles et Hassall, 1905 (Nematoda: Rhabdiasidae) from Blommersia domerguei (Guibé) (Amphibia: Mantellidae) in Madagascar.

    PubMed

    Kuzmin, Yuriy; Junker, Kerstin; du Preez, Louis; Bain, Odile

    2013-11-01

    Rhabdias blommersiae sp. n. (Nematoda: Rhabdiasidae) is described from the lungs of Domergue's Madagascar frog, Blommersia domerguei (Guibé) (Amphibia: Mantellidae), in Madagascar. The new species differs from congeners parasitizing amphibians in having a smaller body and buccal capsule, six equal lips, large excretory glands of unequal length and a posteriorly inflated body vesicle. A combination of characters distinguishes it from Afromalagasy species of Rhabdias Stiles et Hassall, 1905. Rhabdias blommersiae is the third species of the genus described from amphibians in Madagascar. Close similarities in the number and shape of circumoral structures in two Rhabdias species described from mantellid hosts in Madagascar suggest a close relationship and common origin of the two species, with subsequent adaptation to separate hosts within the Mantellidae.

  6. Chromosome banding in amphibia. XXIII. Giant W sex chromosomes and extremely small genomes in Eleutherodactylus euphronides and Eleutherodactylus shrevei (Anura, Leptodactylidae).

    PubMed

    Schmid, M; Feichtinger, W; Steinlein, C; Rupprecht, A; Haaf, T; Kaiser, H

    2002-01-01

    Highly differentiated, heteromorphic ZZ female symbol /ZW male symbol sex chromosomes were found in the karyotypes of the neotropical leptodactylid frogs Eleutherodactylus euphronides and E. shrevei. The W chromosomes are the largest heterochromatic, female-specific chromosomes so far discovered in the class Amphibia. The analyses of the banding patterns with AT- and GC base-pair specific fluorochromes show that the constitutive heterochromatin in the giant W chromosomes consists of various categories of repetitive DNA sequences. The W chromosomes of both species are similar in size, morphology and banding patterns, whereas their Z chromosomes exhibit conspicuous differences. In the cell nuclei of female animals, the W chromosomes form very prominent chromatin bodies (W chromatin). DNA flow cytometric measurements demonstrate clear differences in the DNA content of male and female erythrocytes caused by the giant W chromosome, and also shows that these Eleutherodactylus genomes are among the smallest of all amphibian genomes. The importance of the heteromorphic ZW sex chromosomes for the study of Z-linked genes, the similarities and differences of the two karyotypes, and the significance of the exceptionally small genomes are discussed.

  7. Non-target effects of a glyphosate-based herbicide on Common toad larvae (Bufo bufo, Amphibia) and associated algae are altered by temperature.

    PubMed

    Baier, Fabian; Gruber, Edith; Hein, Thomas; Bondar-Kunze, Elisabeth; Ivanković, Marina; Mentler, Axel; Brühl, Carsten A; Spangl, Bernhard; Zaller, Johann G

    2016-01-01

    Glyphosate-based herbicides are the most widely used pesticides in agriculture, horticulture, municipalities and private gardens that can potentially contaminate nearby water bodies inhabited by amphibians and algae. Moreover, the development and diversity of these aquatic organisms could also be affected by human-induced climate change that might lead to more periods with extreme temperatures. However, to what extent non-target effects of these herbicides on amphibians or algae are altered by varying temperature is not well known. We studied effects of five concentrations of the glyphosate-based herbicide formulation Roundup PowerFlex (0, 1.5, 3, 4 mg acid equivalent glyphosate L(-1) as a one time addition and a pulse treatment of totally 4 mg a.e. glyphosate L(-1)) on larval development of Common toads (Bufo bufo, L.; Amphibia: Anura) and associated algae communities under two temperature regimes (15 vs. 20 °C). Herbicide contamination reduced tail growth (-8%), induced the occurrence of tail deformations (i.e. lacerated or crooked tails) and reduced algae diversity (-6%). Higher water temperature increased tadpole growth (tail and body length (tl/bl) +66%, length-to-width ratio +4%) and decreased algae diversity (-21%). No clear relation between herbicide concentrations and tadpole growth or algae density or diversity was observed. Interactive effects of herbicides and temperature affected growth parameters, tail deformation and tadpole mortality indicating that the herbicide effects are temperature-dependent. Remarkably, herbicide-temperature interactions resulted in deformed tails in 34% of all herbicide treated tadpoles at 15 °C whereas no tail deformations were observed for the herbicide-free control at 15 °C or any tadpole at 20 °C; herbicide-induced mortality was higher at 15 °C but lower at 20 °C. These herbicide- and temperature-induced changes may have decided effects on ecological interactions in freshwater ecosystems. Although no clear dose

  8. Non-target effects of a glyphosate-based herbicide on Common toad larvae (Bufo bufo, Amphibia) and associated algae are altered by temperature

    PubMed Central

    Baier, Fabian; Gruber, Edith; Bondar-Kunze, Elisabeth; Ivanković, Marina; Mentler, Axel; Brühl, Carsten A.; Spangl, Bernhard

    2016-01-01

    Background Glyphosate-based herbicides are the most widely used pesticides in agriculture, horticulture, municipalities and private gardens that can potentially contaminate nearby water bodies inhabited by amphibians and algae. Moreover, the development and diversity of these aquatic organisms could also be affected by human-induced climate change that might lead to more periods with extreme temperatures. However, to what extent non-target effects of these herbicides on amphibians or algae are altered by varying temperature is not well known. Methods We studied effects of five concentrations of the glyphosate-based herbicide formulation Roundup PowerFlex (0, 1.5, 3, 4 mg acid equivalent glyphosate L−1 as a one time addition and a pulse treatment of totally 4 mg a.e. glyphosate L−1) on larval development of Common toads (Bufo bufo, L.; Amphibia: Anura) and associated algae communities under two temperature regimes (15 vs. 20 °C). Results Herbicide contamination reduced tail growth (−8%), induced the occurrence of tail deformations (i.e. lacerated or crooked tails) and reduced algae diversity (−6%). Higher water temperature increased tadpole growth (tail and body length (tl/bl) +66%, length-to-width ratio +4%) and decreased algae diversity (−21%). No clear relation between herbicide concentrations and tadpole growth or algae density or diversity was observed. Interactive effects of herbicides and temperature affected growth parameters, tail deformation and tadpole mortality indicating that the herbicide effects are temperature-dependent. Remarkably, herbicide-temperature interactions resulted in deformed tails in 34% of all herbicide treated tadpoles at 15 °C whereas no tail deformations were observed for the herbicide-free control at 15 °C or any tadpole at 20 °C; herbicide-induced mortality was higher at 15 °C but lower at 20 °C. Discussion These herbicide- and temperature-induced changes may have decided effects on ecological interactions in

  9. Evolution of alanine:glyoxylate aminotransferase 1 peroxisomal and mitochondrial targeting. A survey of its subcellular distribution in the livers of various representatives of the classes Mammalia, Aves and Amphibia.

    PubMed

    Danpure, C J; Fryer, P; Jennings, P R; Allsop, J; Griffiths, S; Cunningham, A

    1994-08-01

    As part of a wider study on the molecular evolution of alanine:glyoxylate aminotransferase 1 (AGT1) intracellular compartmentalization, we have determined the subcellular distribution of immunoreactive AGT1, using postembedding protein A-gold immunoelectron microscopy, in the livers of various members of the classes Mammalia, Aves, and Amphibia. As far as organellar distribution is concerned, three categories could be distinguished. In members of the first category (type I), all, or nearly all, of the immunoreactive AGT1 was concentrated within the peroxisomes. In the second category (type II), AGT1 was found more evenly distributed in both peroxisomes and mitochondria. In the third category (type III), AGT1 was localized mainly within the mitochondria with much lower, but widely variable, amounts in the peroxisomes. Type I animals include the human, two great apes (gorilla, orangutan), two Old World monkeys (anubis baboon, Japanese macaque), a New World monkey (white-faced Saki monkey), a lago, morph (European rabbit), a bat (Seba's short-tailed fruit bat), two caviomorph rodents (guinea pig, orange-rumped agouti), and two Australian marsupials (koala, Bennett's wallaby). Type II animals include two New World monkeys (common marmoset, cotton-top tamarin), three prosimians (brown lemur, fat-tailed dwarf lemur, pygmy slow loris), five rodents (a hybrid crested porcupine, Colombian ground squirrel, laboratory rat, laboratory mouse, golden hamster), an American marsupial (grey short-tailed opossum), and a bird (raven). Type III animals include the large tree shrew, three insectivores (common Eurasian mole, European hedgehog, house shrew), four carnivores (domestic cat, ocelot, domestic dog, polecat ferret), and an amphibian (common frog). In addition to these categories, some animals (e.g. guinea pig, common frog) possessed significant amounts of cytosolic AGT1. Whereas the subcellular distribution of AGT1 in some orders (e.g. Insectivora and Carnivora) did not appear

  10. [Neuromuscular spindles of several amphibia and reptiles].

    PubMed

    Kurkina, E A

    1976-09-01

    The work presents data on the structure and innervation of the nerve-muscle spindles in the soleus of the lake from Rana ridibunda, Bufo bufo, turtle Testudo horsfieldi, lizzard Lacerta agilis. The animals under study were shown to have different structure and innervation of these receptors. The thickness of the spindle connective tissue capsule has certain correlation with the width of the subcapsular space. The innervation apparatus in the muscle spindles of reptiles and turtles are similar in the following: sensory nerve terminations in the equatorial area of the spindle are represented by reticulars, bushes, loops and in the lizzard there appear annulo-spirals with a small amount of coils. The character of motor nerve terminations in polar zones of intrafusal muscle fibres in the spindles of reptiles is similar to that of the extrafusal fibres: in the shape of "bayonets" and end bundles (Endbüuschel). In the muscle fibres of the turtle and lizzard in addition to typical motor plaques there occur trail endings.

  11. Cranial kinesis in the amphibia: a review.

    PubMed

    Iordanskiĭ, N N

    2000-01-01

    All extant orders of amphibians are characterized by kinetic skulls. Main type of intracranial movability in amphibians is pleurokinetism, that is supplemented in different amphibian groups by various types of rhyncho- and prokinetism. The most primitive pattern of cranial kinesis is revealed in the stegocrotaphic gymnophions. More paedomorphic species retain general cranial flexibility that is characteristic of larval skull. That is unfavourable for evolution of well-regulated (adult) cranial kinesis and related feeding adaptations. Kinetism is also reduced in the species with heavily ossified skulls. Adaptive role and evolution of cranial kinesis in amphibians are discussed.

  12. The Braincase of Eocaecilia micropodia (Lissamphibia, Gymnophiona) and the Origin of Caecilians

    PubMed Central

    Maddin, Hillary C.; Jenkins, Farish A.; Anderson, Jason S.

    2012-01-01

    The scant fossil record of caecilians has obscured the origin and evolution of this lissamphibian group. Eocaecilia micropodia from the Lower Jurassic of North America remains the only stem-group caecilian with an almost complete skull preserved. However, this taxon has been controversial, engendering re-evaluation of traits considered to be plesiomorphic for extant caecilians. Both the validity of the placement of E. micropodia as a stem caecilian and estimates of the plesiomorphic condition of extant caecilians have been questioned. In order to address these issues, the braincase of E. micropodia was examined via micro-computed tomography. The braincase is considered to be a more reliable phylogenetic indicator than peripheral regions of the skull. These data reveal significant new information, including the possession of an ossified nasal septum, ossified anterior wall of the sphenethmoid, long anterolateral processes on the sphenethmoid, and paired olfactory nerve foramina, which are known only to occur in extant caecilians; the latter are possibly related to the evolution of the tentacle, a caecilian autapomorphy. A phylogenetic analysis that included 64 non-amniote taxa and 308 characters represents the first extensive test of the phylogenetic affinities of E. micropodia. The results place E. micropodia securely on the stem of extant caecilians, representing a clade within Temnospondyli that is the sister taxon to batrachians plus Gerobatrachus. Ancestral character state reconstruction confirms the braincase of E. micropodia to be largely representative of the plesiomorphic condition of extant caecilians. Additionally, the results refine the context within which the evolution of the caecilian form can be evaluated. The robust construction and pattern of the dermal skull of E. micropodia is interpreted as symplesiomorphic with advanced dissorophoid temnospondyls, rather than being autapomorphic in its robust construction. Together these data increase confidence in incorporating E. micropodia into discussions of caecilian evolution. PMID:23227204

  13. The braincase of Eocaecilia micropodia (Lissamphibia, Gymnophiona) and the origin of Caecilians.

    PubMed

    Maddin, Hillary C; Jenkins, Farish A; Anderson, Jason S

    2012-01-01

    The scant fossil record of caecilians has obscured the origin and evolution of this lissamphibian group. Eocaecilia micropodia from the Lower Jurassic of North America remains the only stem-group caecilian with an almost complete skull preserved. However, this taxon has been controversial, engendering re-evaluation of traits considered to be plesiomorphic for extant caecilians. Both the validity of the placement of E. micropodia as a stem caecilian and estimates of the plesiomorphic condition of extant caecilians have been questioned. In order to address these issues, the braincase of E. micropodia was examined via micro-computed tomography. The braincase is considered to be a more reliable phylogenetic indicator than peripheral regions of the skull. These data reveal significant new information, including the possession of an ossified nasal septum, ossified anterior wall of the sphenethmoid, long anterolateral processes on the sphenethmoid, and paired olfactory nerve foramina, which are known only to occur in extant caecilians; the latter are possibly related to the evolution of the tentacle, a caecilian autapomorphy. A phylogenetic analysis that included 64 non-amniote taxa and 308 characters represents the first extensive test of the phylogenetic affinities of E. micropodia. The results place E. micropodia securely on the stem of extant caecilians, representing a clade within Temnospondyli that is the sister taxon to batrachians plus Gerobatrachus. Ancestral character state reconstruction confirms the braincase of E. micropodia to be largely representative of the plesiomorphic condition of extant caecilians. Additionally, the results refine the context within which the evolution of the caecilian form can be evaluated. The robust construction and pattern of the dermal skull of E. micropodia is interpreted as symplesiomorphic with advanced dissorophoid temnospondyls, rather than being autapomorphic in its robust construction. Together these data increase confidence in incorporating E. micropodia into discussions of caecilian evolution.

  14. Ontogenetic differences in the feeding biomechanics of oviparous and viviparous caecilians (Lissamphibia: Gymnophiona).

    PubMed

    Kleinteich, Thomas

    2010-10-01

    Caecilians have a unique dual jaw-closing system in that jaw closure is driven by the ancestral jaw-closing muscles (mm. levatores mandibulae) plus a secondarily recruited hyobranchial muscle (m. interhyoideus posterior). There is a variety of feeding habits (suction feeding, skin feeding, intrauterine scraping, and biting) during ontogeny that relate to reproductive modes in different caecilian species. This study examines the cranial biomechanics of caecilians in the suction-feeding larva of Ichthyophis cf. kohtaoensis, in the embryo and juvenile of the skin-feeding Boulengerula taitana, and in a newborn of the intrauterine feeder Typhlonectes natans. A lever arm model was applied to calculate effective mechanical advantages of jaw-closing muscles over gape angles and to predict total bite force in developing caecilians. In I. cf. kohtaoensis, Notable differences were found in the larval jaw-closing system compared to that of the adult. The suction-feeding larva of I. cf. kohtaoensis has comparatively large mm. levatores mandibulae that insert with an acute muscle fiber angle to the lower jaw and a m. interhyoideus posterior that has its optimal leverage at small gape angles. Conversely, the skin-feeding juvenile of B. taitana and the neonate T. natans are very similar in the feeding parameters considered herein compared to adult caecilians. Some ontogenetic variation in the feeding system of B. taitana before the onset of feeding was present. This study contributes to our understanding of the functional demands that feeding habits put on the development of cranial structures.

  15. Meteterakis saotomensis n. sp. (Nematoda: Heterakidae) from Schistometopum thomense (Bocage) (Gymnophiona: Dermophiidae) on São Tomé Island.

    PubMed

    Junker, Kerstin; Mariaux, Jean; Measey, G John; Mutafchiev, Yasen

    2015-10-01

    Meteterakis saotomensis n. sp. is described from Schistometopum thomense (Bocage), a gymnophionan endemic to the oceanic island of São Tomé in the Gulf of Guinea. The specimens were assigned to Meteterakis Karve, 1930, based on the possession of a head with three rounded lips, not set-off from the body, the absence of interlabia and cordons, females with a long vagina and males with a preanal sucker, surrounded by a cuticularised rim and caudal alae that are supported by fleshy papillae. The new species is characterised by: body length 4.2-4.5 mm (males) and 5.1-6.4 mm (females); total length of oesophagus, including pharyngeal portion and oesophageal bulb, 820-856 µm (males) and 898-1,070 µm (females); length of pharynx 57-58 µm (males) and 65-68 µm (females); spicules equal, 410-521 µm long, with tessellated ornamentation throughout their length and alae, and with bevelled tip; gubernaculum or 'gubernacular mass' absent; tail length 164-176 µm (males) and 214-239 µm (females), with elongated tip; vulva at 2.3-2.8 mm from anterior end, with anterior lip forming small flap. This is the second species of Meteterakis reported from gymnophionan hosts and the first from the Afrotropical region. Selected comparative morphological data for Meteterakis spp. are presented, and data on host range and geographic distribution are updated. The name M. striaturus Oshmarin & Demshin, 1972 is corrected to M. striatura to reflect the female gender of the genus name.

  16. Population Genetics of the São Tomé Caecilian (Gymnophiona: Dermophiidae: Schistometopum thomense) Reveals Strong Geographic Structuring

    PubMed Central

    Stoelting, Ricka E.; Measey, G. John; Drewes, Robert C.

    2014-01-01

    Islands provide exciting opportunities for exploring ecological and evolutionary mechanisms. The oceanic island of São Tomé in the Gulf of Guinea exhibits high diversity of fauna including the endemic caecilian amphibian, Schistometopum thomense. Variation in pigmentation, morphology and size of this taxon over its c. 45 km island range is extreme, motivating a number of taxonomic, ecological, and evolutionary hypotheses to explain the observed diversity. We conducted a population genetic study of S. thomense using partial sequences of two mitochondrial DNA genes (ND4 and 16S), together with morphological examination, to address competing hypotheses of taxonomic or clinal variation. Using Bayesian phylogenetic analysis and Spatial Analysis of Molecular Variance, we found evidence of four geographic clades, whose range and approximated age (c. 253 Kya – 27 Kya) are consistent with the spread and age of recent volcanic flows. These clades explained 90% of variation in ND4 (φCT = 0.892), and diverged by 4.3% minimum pairwise distance at the deepest node. Most notably, using Mismatch Distributions and Mantel Tests, we identified a zone of population admixture that dissected the island. In the northern clade, we found evidence of recent population expansion (Fu's Fs = −13.08 and Tajima's D = −1.80) and limited dispersal (Mantel correlation coefficient = 0.36, p = 0.01). Color assignment to clades was not absolute. Paired with multinomial regression of chromatic data, our analyses suggested that the genetic groups and a latitudinal gradient together describe variation in color of S. thomense. We propose that volcanism and limited dispersal ability are the likely proximal causes of the observed genetic structure. This is the first population genetic study of any caecilian and demonstrates that these animals have deep genetic divisions over very small areas in accordance with previous speculations of low dispersal abilities. PMID:25171066

  17. The development and replacement of teeth in viviparous caecilians.

    PubMed

    Wake, M H

    1976-01-01

    Tooth development and replacement in fetal and adult viviparous caecilians (Amphibia: Gymnophiona) are described and analyzed according to current theories of tooth succession. The fetal dentition differs from that of the adult in morphology, position, and function. Teeth are used by fetuses to scrape the oviducal epithelium, thus stimulating the secretion of a nutrient substance. Fetal dentitions vary in morphology and position in different species. The ontogeny of teeth of several species is described and the patterns of addition of loci and of replacement are analyzed. Loci are added both posteriorly along the jaw and between existing loci as the jaw grows prior to ossification; subsequently addition is restricted to the posterior part of the jaw. Tooth replacement is alternate. The several rows and patches of teeth are the result of retention of replacement series on the dentigerous elements. Tooth development and replacement in a series of juveniles and adults of different sizes in a single species are also considered. Post-fetal patterns of development and replacement are similar to those seen in larvae and adults of oviparous species. Variation in numbers of teeth and proportions of teeth at particular stages occurs ontogenetically and among individuals of the same size, though proportions occur in a similar pattern throughout the series. The general pattern of tooth replacement in fetuses and adults can be explained by either Edmund's Zahnreihen theory or by Osborn's Tooth Family theory, but replacement in fetal tooth patches and the fetal-adult dentitional transition are explained by neither.

  18. Ty1-copia group retrotransposon sequences in amphibia and reptilia.

    PubMed

    Flavell, A J; Jackson, V; Iqbal, M P; Riach, I; Waddell, S

    1995-01-06

    We have isolated sequences belonging to Ty1-copia group retrotransposons from the genomes of an amphibian (Pyxicephalus adspersa) and three reptiles (Conolophus subscristatus, Amblyrynchus cristatus and Pytas mucosus). Two different sequences were found in the amphibian (Tpa1 and Tpa2). Each is present in several copies per genome and absent from the genomes of two other amphibian species. The C. subcristatus sequence Tcs1 is present in multiple copies in both its host genome (Galapagos land iguana) and the genome of the related Galapagos marine iguana (A. cristatus). There is little or no polymorphism in Tcs1 insertions between different individual animals, suggesting that this sequence is not transposing rapidly in either iguana genome. The P. mucosus sequence Tpm1 shows a discontinuous distribution in snake species, suggesting that it has either been lost from many lineages during vertical germline transmission or has been transferred horizontally in some snake species. Phylogenetic comparisons of all these sequences with each other and with other members of this retrotransposon group from other animals and plants show that sequences within a particular vertebrate species are most closely related to each other, consistent with a vertical transmission model for their evolution.

  19. Cranial features of dendrobatid larvae (Amphibia: Anura: Dendrobatidae).

    PubMed

    Haas, A

    1995-06-01

    The larval neurocranium and visceral arches of seven dendrobatid species representing four genera are described, based on cleared-and-stained and serially sectioned specimens. A variety of characters is shared by all seven species. Larval features do not substantiate the assumption of close ranoid affinities of the Dendrobatidae. Instead dendrobatid larvae share features such as the special quadripartite cartilago suprarostralis, the lack of the larval processus oticus, the presence of three foramina acustica, and the lack of a foramen perilymphaticum accessorius with many bufonoid larvae. The first of these characters is unique to bufonids, hylids, dendrobatids, and some New World leptodactylids; the other characters also occur in pelobatids and are presumably plesiomorphic for the Neobatrachia. The free proximal ends of Ceratobranchialia II and III are an autapomorphy of the Dendrobatidae supporting the monophyly of the family. Some features of the cranium are paedomorphic: low cartilago orbitalis, lack of connection between cartilage orbitalis and otic capsule (most species), and vestigal taeniae tecti. New anatomical terms are introduced.

  20. A new species of Odorrana (Amphibia: Anura: Ranidae) from Vietnam.

    PubMed

    Pham, Cuong The; Nguyen, Truong Quang; Le, Minh Duc; Bonkowski, Michael; Ziegler, Thomas

    2016-02-26

    A new species of Odorrana is described from the karst forests in northeastern Vietnam based on morphological differences and molecular divergence. Morphologically, the new species is distinguishable from its congeners on the basis of a combination of the following diagnostic characters: (1) size large (SVL 85.9-91.6 mm in males, 108.7-110.1 mm in females); (2) head longer than wide; (3) vomerine teeth present; (4) external vocal sacs absent; (5) snout short (SL/SVL 0.16-0.17); (6) tympanum large (TD/ED 0.70 in males, 0.68 in females); (7) dorsal surface of head and anterior part of body smooth, posterior part of body and flanks with small tubercles; (8) supratympanic fold present; (9) dorsolateral fold absent; (10) webbing formula I0-0II0-0III0-1/2IV1/2-0V; (11) in life, dorsum green with dark brown spots; (12) flanks greyish brown with dark brown spots; (13) throat and chest grey, underside of limbs with large dark brown spots, edged in white, forming a network. In the phylogenetic analyses, the new species is unambiguously nested within the O. andersonii group, and placed as the sister taxon to O. wuchuanensis.

  1. Spermatogenic cycle of a plethodontid salamander, Eurycea longicauda (Amphibia, Urodela)

    PubMed Central

    Siegel, Dustin S; Alvino, Sam; Trauth, Stanley E; Sever, David M; Gribbins, Kevin M

    2014-01-01

    Previous investigators have described the spermatogenic cycles of numerous species of plethodontid salamanders. Most studies describe a fairly stereotypical cycle with meiotic divisions of spermatogenesis commencing in the spring/summer. However, many studies lack details obtainable from histological examination and/or testicular squashes and, instead, provide only mensural data from the testes. Studies that lacked microscopic evaluation often revealed spermatogenic cycles that varied greatly from that of the stereotypical cycle with meiotic divisions commencing in the fall/winter. Those studies hamper comparisons between the spermatogenic cycles of different species and their environments, as they do not provide a correlation between testicular size and any aspect of the spermatogenic cycle. In the following manuscript, we elucidate the spermatogenic cycle of Eurycea longicauda longicauda in an effort to outline an appropriate protocol for analyzing spermatogenesis in salamanders that will facilitate future comparative studies. Like many Nearctic plethodontids, E. l. longicauda exhibits a meiotic wave that travels through the testes during the summer; this process is followed by spermiogenesis, spermiation, and recrudescence in the fall, winter, and spring. PMID:26413402

  2. Proton pump-driven cutaneous chloride uptake in anuran amphibia.

    PubMed

    Jensen, Lars Jørn; Willumsen, Niels Johannes; Amstrup, Jan; Larsen, Erik Hviid

    2003-12-30

    Krogh introduced the concept of active ion uptake across surface epithelia of freshwater animals, and proved independent transports of Na(+) and Cl(-) in anuran skin and fish gill. He suggested that the fluxes of Na(+) and Cl(-) involve exchanges with ions of similar charge. In the so-called Krogh model, Cl(-)/HCO(3)(-) and Na(+)/H(+) antiporters are located in the apical membrane of the osmoregulatory epithelium. More recent studies have shown that H(+) excretion in anuran skin is due to a V-ATPase in mitochondria-rich (MR) cells. The pump has been localized by immunostaining and H(+) fluxes estimated by pH-stat titration and mathematical modelling of pH-profiles in the unstirred layer on the external side of the epithelium. H(+) secretion is voltage-dependent, sensitive to carbonic-anhydrase inhibitors, and rheogenic with a charge/ion-flux ratio of unity. Cl(-) uptake from freshwater is saturating, voltage independent, and sensitive to DIDS and carbonic-anhydrase inhibitors. Depending on anuran species and probably on acid/base balance of the animal, apical exit of protons is coupled to an exchange of Cl(-) with base (HCO(3)(-)) either in the apical membrane (gamma-type of MR cell) or in the basolateral membrane (alpha-type MR cell). The gamma-cell model accounts for the rheogenic active uptake of Cl(-) observed in several anuran species. There is indirect evidence also for non-rheogenic active uptake accomplished by a beta-type MR cell with apical base secretion and basolateral proton pumping. Several studies have indicated that the transport modes of MR cells are regulated via ion- and acid/base balance of the animal, but the signalling mechanisms have not been investigated. Estimates of energy consumption by the H(+)-ATPase and the Na(+)/K(+)-ATPase indicate that the gamma-cell accomplishes uptake of NaCl in normal and diluted freshwater. Under common freshwater conditions with serosa-positive or zero V(t), the K(+) conductance of the basolateral membrane would have to maintain the inward driving force for Na(+) uptake across the apical membrane. With the K(+) equilibrium potential across the basolateral membrane estimated to -105 mV, this would apply to external Na(+) concentrations down to 40-120 micromol/l. NaCl uptake from concentrations down to 10 micromol/l, as observed by Krogh, presupposes that the H(+) pump hyperpolarizes the apical membrane, which would then have to be associated with serosa-negative V(t). In diluted freshwater, exchange of cellular HCO(3)(-) with external Cl(-) seems to be possible only if the proton pump has the additional function of keeping the external concentration of HCO(3)(-) low. Quantitative considerations also lead to the conclusion that with the above extreme demand, at physiological intracellular pH of 7.2, the influx of Cl(-) via the apical antiporter and the passive exit of Cl(-) via basolateral channels would be possible within a common range of intracellular Cl(-) concentrations.

  3. Spermatogenic cycle of a plethodontid salamander, Eurycea longicauda (Amphibia, Urodela).

    PubMed

    Siegel, Dustin S; Alvino, Sam; Trauth, Stanley E; Sever, David M; Gribbins, Kevin M

    2014-01-01

    Previous investigators have described the spermatogenic cycles of numerous species of plethodontid salamanders. Most studies describe a fairly stereotypical cycle with meiotic divisions of spermatogenesis commencing in the spring/summer. However, many studies lack details obtainable from histological examination and/or testicular squashes and, instead, provide only mensural data from the testes. Studies that lacked microscopic evaluation often revealed spermatogenic cycles that varied greatly from that of the stereotypical cycle with meiotic divisions commencing in the fall/winter. Those studies hamper comparisons between the spermatogenic cycles of different species and their environments, as they do not provide a correlation between testicular size and any aspect of the spermatogenic cycle. In the following manuscript, we elucidate the spermatogenic cycle of Eurycea longicauda longicauda in an effort to outline an appropriate protocol for analyzing spermatogenesis in salamanders that will facilitate future comparative studies. Like many Nearctic plethodontids, E. l. longicauda exhibits a meiotic wave that travels through the testes during the summer; this process is followed by spermiogenesis, spermiation, and recrudescence in the fall, winter, and spring.

  4. Chromosome Banding in Amphibia. XXXII. The Genus Xenopus (Anura, Pipidae).

    PubMed

    Schmid, Michael; Steinlein, Claus

    2015-01-01

    Mitotic chromosomes of 16 species of the frog genus Xenopus were prepared from kidney and lung cell cultures. In the chromosomes of 7 species, high-resolution replication banding patterns could be induced by treating the cultures with 5-bromodeoxyuridine (BrdU) and deoxythymidine (dT) in succession, and in 6 of these species the BrdU/dT-banded chromosomes could be arranged into karyotypes. In the 3 species of the clade with 2n = 20 and 4n = 40 chromosomes (X. tropicalis, X. epitropicalis, X. new tetraploid 1), as well as in the 3 species with 4n = 36 chromosomes (X. laevis, X. borealis, X. muelleri), the BrdU/dT-banded karyotypes show a high degree of homoeology, though differences were detected between these groups. Translocations, inversions, insertions or sex-specific replication bands were not observed. Minor replication asynchronies found between chromosomes probably involve heterochromatic regions. BrdU/dT replication banding of Xenopus chromosomes provides the landmarks necessary for the exact physical mapping of genes and repetitive sequences. FISH with an X. laevis 5S rDNA probe detected multiple hybridization sites at or near the long-arm telomeric regions in most chromosomes of X. laevis and X. borealis, whereas in X. muelleri, the 5S rDNA sequences are located exclusively at the long-arm telomeres of a single chromosome pair. Staining with the AT base pair-specific fluorochrome quinacrine mustard revealed brightly fluorescing heterochromatic regions in the majority of X. borealis chromosomes which are absent in other Xenopus species.

  5. Ossification sequence heterochrony among amphibians.

    PubMed

    Harrington, Sean M; Harrison, Luke B; Sheil, Christopher A

    2013-01-01

    Heterochrony is an important mechanism in the evolution of amphibians. Although studies have centered on the relationship between size and shape and the rates of development, ossification sequence heterochrony also may have been important. Rigorous, phylogenetic methods for assessing sequence heterochrony are relatively new, and a comprehensive study of the relative timing of ossification of skeletal elements has not been used to identify instances of sequence heterochrony across Amphibia. In this study, a new version of the program Parsimov-based genetic inference (PGi) was used to identify shifts in ossification sequences across all extant orders of amphibians, for all major structural units of the skeleton. PGi identified a number of heterochronic sequence shifts in all analyses, the most interesting of which seem to be tied to differences in metamorphic patterns among major clades. Early ossification of the vomer, premaxilla, and dentary is retained by Apateon caducus and members of Gymnophiona and Urodela, which lack the strongly biphasic development seen in anurans. In contrast, bones associated with the jaws and face were identified as shifting late in the ancestor of Anura. The bones that do not shift late, and thereby occupy the earliest positions in the anuran cranial sequence, are those in regions of the skull that undergo the least restructuring throughout anuran metamorphosis. Additionally, within Anura, bones of the hind limb and pelvic girdle were also identified as shifting early in the sequence of ossification, which may be a result of functional constraints imposed by the drastic metamorphosis of most anurans. © 2013 Wiley Periodicals, Inc.

  6. Phylogeny and biogeography of the family Salamandridae (Amphibia: Caudata) inferred from complete mitochondrial genomes.

    PubMed

    Zhang, Peng; Papenfuss, Theodore J; Wake, Marvalee H; Qu, Lianghu; Wake, David B

    2008-11-01

    Phylogenetic relationships of members of the salamander family Salamandridae were examined using complete mitochondrial genomes collected from 42 species representing all 20 salamandrid genera and five outgroup taxa. Weighted maximum parsimony, partitioned maximum likelihood, and partitioned Bayesian approaches all produce an identical, well-resolved phylogeny; most branches are strongly supported with greater than 90% bootstrap values and 1.0 Bayesian posterior probabilities. Our results support recent taxonomic changes in finding the traditional genera Mertensiella, Euproctus, and Triturus to be non-monophyletic species assemblages. We successfully resolved the current polytomy at the base of the salamandrid tree: the Italian newt genus Salamandrina is sister to all remaining salamandrids. Beyond Salamandrina, a clade comprising all remaining newts is separated from a clade containing the true salamanders. Among these newts, the branching orders of well-supported clades are: primitive newts (Echinotriton, Pleurodeles, and Tylototriton), New World newts (Notophthalmus-Taricha), Corsica-Sardinia newts (Euproctus), and modern European newts (Calotriton, Lissotriton, Mesotriton, Neurergus, Ommatotriton, and Triturus) plus modern Asian newts (Cynops, Pachytriton, and Paramesotriton).Two alternative sets of calibration points and two Bayesian dating methods (BEAST and MultiDivTime) were used to estimate timescales for salamandrid evolution. The estimation difference by dating methods is slight and we propose two sets of timescales based on different calibration choices. The two timescales suggest that the initial diversification of extant salamandrids took place in Europe about 97 or 69Ma. North American salamandrids were derived from their European ancestors by dispersal through North Atlantic Land Bridges in the Late Cretaceous ( approximately 69Ma) or Middle Eocene ( approximately 43Ma). Ancestors of Asian salamandrids most probably dispersed to the eastern Asia from Europe, after withdrawal of the Turgai Sea ( approximately 29Ma).

  7. Population Genetic Structure of the Endangered Kaiser's Mountain Newt, Neurergus kaiseri (Amphibia: Salamandridae).

    PubMed

    Farasat, Hossein; Akmali, Vahid; Sharifi, Mozafar

    2016-01-01

    Species often exhibit different levels of genetic structuring correlated to their environment. However, understanding how environmental heterogeneity influences genetic variation is difficult because the effects of gene flow, drift and selection are confounded. We investigated the genetic variation and its ecological correlates in an endemic and critically endangered stream breeding mountain newt, Neurergus kaiseri, within its entire range in southwestern Iran. We identified two geographic regions based on phylogenetic relationships using Bayesian inference and maximum likelihood of 779 bp mtDNA (D-loop) in 111 individuals from ten of twelve known breeding populations. This analysis revealed a clear divergence between northern populations, located in more humid habitats at higher elevation, and southern populations, from drier habitats at lower elevations regions. From seven haplotypes found in these populations none was shared between the two regions. Analysis of molecular variance (AMOVA) of N. kaiseri indicates that 94.03% of sequence variation is distributed among newt populations and 5.97% within them. Moreover, a high degree of genetic subdivision, mainly attributable to the existence of significant variance among the two regions is shown (θCT = 0.94, P = 0.002). The positive and significant correlation between geographic and genetic distances (r = 0.61, P = 0.002) following controlling for environmental distance suggests an important influence of geographic divergence of the sites in shaping the genetic variation and may provide tools for a possible conservation based prioritization policy for the endangered species.

  8. A molecular assessment of phylogenetic relationships and lineage accumulation rates within the family Salamandridae (Amphibia, Caudata).

    PubMed

    Weisrock, David W; Papenfuss, Theodore J; Macey, J Robert; Litvinchuk, Spartak N; Polymeni, Rosa; Ugurtas, Ismail H; Zhao, Ermi; Jowkar, Houman; Larson, Allan

    2006-11-01

    We examine phylogenetic relationships among salamanders of the family Salamandridae using approximately 2700 bases of new mtDNA sequence data (the tRNALeu, ND1, tRNAIle, tRNAGln, tRNAMet, ND2, tRNATrp, tRNAAla, tRNAAsn, tRNACys, tRNATyr, and COI genes and the origin for light-strand replication) collected from 96 individuals representing 61 of the 66 recognized salamandrid species and outgroups. Phylogenetic analyses using maximum parsimony and Bayesian analysis are performed on the new data alone and combined with previously reported sequences from other parts of the mitochondrial genome. The basal phylogenetic split is a polytomy of lineages ancestral to (1) the Italian newt Salamandrina terdigitata, (2) a strongly supported clade comprising the "true" salamanders (genera Chioglossa, Mertensiella, Lyciasalamandra, and Salamandra), and (3) a strongly supported clade comprising all newts except S. terdigitata. Strongly supported clades within the true salamanders include monophyly of each genus and grouping Chioglossa and Mertensiella as the sister taxon to a clade comprising Lyciasalamandra and Salamandra. Among newts, genera Echinotriton, Pleurodeles, and Tylototriton form a strongly supported clade whose sister taxon comprises the genera Calotriton, Cynops, Euproctus, Neurergus, Notophthalmus, Pachytriton, Paramesotriton, Taricha, and Triturus. Our results strongly support monophyly of all polytypic newt genera except Paramesotriton and Triturus, which appear paraphyletic, and Calotriton, for which only one of the two species is sampled. Other well-supported clades within newts include (1) Asian genera Cynops, Pachytriton, and Paramesotriton, (2) North American genera Notophthalmus and Taricha, (3) the Triturus vulgaris species group, and (4) the Triturus cristatus species group; some additional groupings appear strong in Bayesian but not parsimony analyses. Rates of lineage accumulation through time are evaluated using this nearly comprehensive sampling of salamandrid species-level lineages. Rate of lineage accumulation appears constant throughout salamandrid evolutionary history with no obvious fluctuations associated with origins of morphological or ecological novelties.

  9. Cloacal anatomy of the male Carpathian newt, Lissotriton montandoni (Amphibia, Salamandridae), in the breeding season.

    PubMed

    Osikowski, Artur; Cierniak-Zuzia, Karolina

    2013-09-01

    This study presents the first light microscopy-based description of the cloacal anatomy of male Carpathian newts (Lissotriton montandoni). This European newt species hybridizes with its sister species, the smooth newt (L. vulgaris), despite a high level of prezygotic isolation. The goal of the study was to ascertain possible anatomical differences in cloacal anatomy, especially pheromone and spermatophore producing glands, which might potentially affect reproductive isolation between L. montandoni and L. vulgaris. The cloaca of L. montandoni males consists of the cloacal tube, cloacal chamber, pseudopenis, and aggregations of cloacal glands. Four main types of cloacal glands were recognized. Pheromone-producing dorsal glands are of two types due to differences in their secretory epithelium: cuboidal and high prismatic. The remaining glands: ventral, pelvic, and Kingsbury's glands, are most likely involved in the synthesis of spermatophore components. Two distinct groups of ventral glands were identified: posterior and anterior ventral glands. In comparison with L. vulgaris, no evident differences were found that could potentially affect courtship pheromone synthesis by dorsal glands or the base and the cap of the spermatophore produced by the remaining cloacal glands.

  10. Divergence in the face of gene flow: the case of two newts (amphibia: salamandridae).

    PubMed

    Nadachowska, Krystyna; Babik, Wieslaw

    2009-04-01

    Understanding the process of divergence requires the quantitative characterization of patterns of gene flow between diverging taxa. New and powerful coalescent-based methods give insight into these processes in unprecedented details by enabling the reconstruction of the temporal distribution of past gene flow. Here, we use sequence variation at eight nuclear markers and mitochondrial DNA (mtDNA) in multiple populations to study diversity, divergence, and gene flow between two subspecies of a salamander, the smooth newt (Lissotriton vulgaris kosswigi and Lissotriton vulgaris vulgaris) in Turkey. The ranges of both subspecies encompass mainly the areas of this important glacial refugial area. Populations in refugia where species have been present for a long time and differentiated in situ should better preserve the record of past gene flow than young populations in postglacial expansion areas. Sequence diversity in both subspecies was substantial (nuclear pi(sil) = 0.69% and 1.31%). We detected long-term demographic stability in these refugial populations with large effective population sizes (N(e)) of the order of 1.5-3 x 10(5) individuals. Gene trees and the isolation with migration (IM) analysis complemented by tests of nested IM models showed that despite deep, pre-Pleistocene divergence of the studied newts, asymmetric introgression from vulgaris to kosswigi has occurred, with signatures of recent gene flow in mtDNA and an anonymous nuclear marker, and evidence for more ancient introgression in nuclear introns. The distribution of migration times raises the intriguing possibility that even the initial divergence may have occurred in the face of gene flow.

  11. The distribution and taxonomy of Lissotriton newts in Turkey (Amphibia, Salamandridae).

    PubMed

    Wielstra, Ben; Bozkurt, Emin; Olgun, Kurtuluş

    2015-01-01

    Two and perhaps three taxa of Lissotriton newt occur in Turkey. Their species status is controversial. The distribution of these taxa and the taxonomic status of each are reviewed and discussed. A database of 128 Turkish Lissotriton localities was compiled and species distribution models were constructed. We reiterate that the presence of Lissotriton (vulgaris) lantzi in Turkey is disputed and needs confirmation. The range of Lissotriton (vulgaris) kosswigi is restricted to north-western Anatolia - given the small global range of this Turkey endemic, a closer look at its conservation status is warranted. The distribution of Lissotritonvulgarisschmidtleri covers western Asiatic and European Turkey. The findings support an allopatric distribution of the Turkish Lissotriton species. We reflect on the biological significance of previously reported morphological intermediates between Lissotriton (vulgaris) kosswigi and Lissotritonvulgarisschmidtleri in the light of the recent proposal to recognize kosswigi at the species level. The available data are in line with species status for Lissotriton (vulgaris) lantzi and Lissotriton (vulgaris) kosswigi. Although Lissotritonvulgarisschmidtleri is a genetically diverged taxon as well, the extent of gene flow with parapatric European Lissotriton taxa is as yet unknown.

  12. Toxins and pharmacologically active compounds from species of the family Bufonidae (Amphibia, Anura).

    PubMed

    Rodríguez, Candelario; Rollins-Smith, Louise; Ibáñez, Roberto; Durant-Archibold, Armando A; Gutiérrez, Marcelino

    2017-02-23

    Among amphibians, 15 of the 47 species reported to be used in traditional medicines belong to the family Bufonidae, which demonstrates their potential in pharmacological and natural products research. For example, Asian and American tribes use the skin and the parotoid gland secretions of some common toads in the treatment of hemorrhages, bites and stings from venomous animals, skin and stomach disorders, as well as several types of cancers. In addition to reviewing the occurrence of chemical constituents present in the family Bufonidae, the cytotoxic and biomedical potential of the active compounds produced by different taxa are presented. Available information on bioactive compounds isolated from species of the family Bufonidae was obtained from ACS Publications, Google, Google Scholar, Pubmed, Sciendirect and Springer. Papers written in Chinese, English, German and Spanish were considered. Recent reports show more than 30% of amphibians are in decline and some of bufonid species are considered to be extinct. For centuries, bufonids have been used as traditional folk remedies to treat allergies, inflammation, cancer, infections and other ailments, highlighting their importance as a prolific source for novel drugs and therapies. Toxins and bioactive chemical constituents from skin and parotid gland secretions of bufonid species can be grouped in five families, the guanidine alkaloids isolated and characterized from Atelopus, the lipophilic alkaloids isolated from Melanophryniscus, the indole alkaloids and bufadienolides known to be synthesized by species of bufonids, and peptides and proteins isolated from the skin and gastrointestinal extracts of some common toads. Overall, the bioactive secretions of this family of anurans may have antimicrobial, protease inhibitor and anticancer properties, as well as being active at the neuromuscular level. In this article, the traditional uses, toxicity and pharmacological potential of chemical compounds from bufonids have been summarized. In spite of being reported to be used to treat several diseases, neither extracts nor metabolites from bufonids have been tested in such illness like acne, osteoporosis, arthritis and other illnesses. However, the cytotoxicity of these metabolites needs to be evaluated on adequate animal models due to the limited conditions of in vitro assays. Novel qualitative and quantitative tools based on MS spectrometry and Nuclear Magnetic Resonance spectroscopy is now available to study the complex secretions of bufonids. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

  13. Redescription of the advertisement call of Physalaemus albifrons (Spix, 1824) (Amphibia, Anura, Leptodactylidae).

    PubMed

    Pederassi, Jonas; Lima, Mauro Sérgio Cruz Souza; Caramaschi, Ulisses; Souza, Patrícia Dos Santos; Santos, Mayra Caroliny De Oliveira; Silva, Islaíane Costa

    2015-08-03

    The genus Physalaemus Fitzinger, 1826 is composed by 46 species occurring from north to southern South America, east of the Andes (Frost 2015). Physalaemus albifrons is morphologically differentiated from the other species mainly due to the presence of a second tarsal tubercle located nearly the tibio-tarsal articulation (Bokermann 1966). Physalaemus albifrons occurs in Brazil from north of the State of Maranhão through the states of Piauí, Ceará, Bahia, Paraíba, Pernambuco, and Alagoas, being its more austral occurrence in the State of Minas Gerais (Frost 2015). The advertisement call of P. albifrons was described by Bokermann (1966); however, the description needs improvement by applying new technologies, which we provide herein.

  14. A new species of glossiphoniid leech from Rana pretiosa (Amphibia: Ranidae) in Oregon.

    PubMed

    Siddall, Mark E; Bowerman, Jay

    2006-08-01

    A new species of ectoparasitic glossiphoniid leech was found feeding on frogs in the Nature Center Pond and elsewhere in Deschutes County, Oregon. The new species of Placobdella resembles the southern alligator leech, Placobdella multilineata Moore, 1953, notwithstanding their vast geographic separation in North America. The new species is readily distinguished by possessing subdivided annuli, by its papillation and pigmentation patterns as well as by the arrangement of ovarian tissues. There is strong evidence of nocturnality and of the potential for parasitizing humans.

  15. A new species of spiny-backed treefrog (Osteocephalus) from Central Amazonian Brazil (Amphibia: Anura: Hylidae).

    PubMed

    Jungfer, Karl-Heinz; Verdade, Vanessa K; Faivovich, Julián; Rodrigues, Miguel T

    2016-05-23

    A new species of treefrog of the genus Osteocephalus is described from the Rio Abacaxis, a southern tributary of the Amazonas in the state of Amazonas, Brazil. This member of the O. buckleyi group is characterized by green dorsal colouration with irregular blotches of various shades of brown, light venter with tan spots and bold dark markings on the posterior surfaces of the thighs. It can be distinguished from its closest relative, O. helenae from the same general area, by the lack of an axillary membrane, a few indistinct tubercles on the proximal segment of Finger IV and single ulnar tubercles.

  16. The vocal sac of Hylodidae (Amphibia, Anura): Phylogenetic and functional implications of a unique morphology.

    PubMed

    Elias-Costa, Agustin J; Montesinos, Rachel; Grant, Taran; Faivovich, Julián

    2017-07-25

    Anuran vocal sacs are elastic chambers that recycle exhaled air during vocalizations and are present in males of most species of frogs. Most knowledge of the diversity of vocal sacs relates to external morphology; detailed information on internal anatomy is available for few groups of frogs. Frogs of the family Hylodidae, which is endemic to the Atlantic Forest of Brazil and adjacent Argentina and Paraguay, have three patterns of vocal sac morphology-that is, single, subgular; paired, lateral; and absent. The submandibular musculature and structure of the vocal sac mucosa (the internal wall of the vocal sac) of exemplar species of this family and relatives were studied. In contrast to previous accounts, we found that all species of Crossodactylus and Hylodes possess paired, lateral vocal sacs, with the internal mucosa of each sac being separate from the contralateral one. Unlike all other frogs for which data are available, the mucosa of the vocal sacs in these genera is not supported externally by the mm. intermandibularis and interhyoideus. Rather, the vocal sac mucosa projects through the musculature and is free in the submandibular lymphatic sac. The presence of paired, lateral vocal sacs, the internal separation of the sac mucosae, and their projection through the m. interhyoideus are synapomorphies of the family. Furthermore, the specific configuration of the m. interhyoideus allows asymmetric inflation of paired vocal sacs, a feature only reported in species of these diurnal, stream-dwelling frogs. © 2017 Wiley Periodicals, Inc.

  17. A New Basal Salamandroid (Amphibia, Urodela) from the Late Jurassic of Qinglong, Hebei Province, China

    PubMed Central

    Jia, Jia; Gao, Ke-Qin

    2016-01-01

    A new salamandroid salamander, Qinglongtriton gangouensis (gen. et sp. nov.), is named and described based on 46 fossil specimens of juveniles and adults collected from the Upper Jurassic (Oxfordian) Tiaojishan Formation cropping out in Hebei Province, China. The new salamander displays several ontogenetically and taxonomically significant features, most prominently the presence of a toothed palatine, toothed coronoid, and a unique pattern of the hyobranchium in adults. Comparative study of the new salamander with previously known fossil and extant salamandroids sheds new light on the early evolution of the Salamandroidea, the most species-diverse clade in the Urodela. Cladistic analysis places the new salamander as the sister taxon to Beiyanerpeton, and the two taxa together form the basalmost clade within the Salamandroidea. Along with recently reported Beiyanerpeton from the same geological formation in the neighboring Liaoning Province, the discovery of Qinglongtriton indicates that morphological disparity had been underway for the salamandroid clade by early Late Jurassic (Oxfordian) time. PMID:27144770

  18. Cranial bone histology of Metoposaurus krasiejowensis (Amphibia, Temnospondyli) from the Late Triassic of Poland

    PubMed Central

    Konietzko-Meier, Dorota; Bodzioch, Adam

    2016-01-01

    In this study, 21 skull bones of Metoposaurus krasiejowensis from the Late Triassic of Poland were investigated histologically. Dermal bones show a diploë structure, with an ornamented external surface. The ridges consist of mostly well vascularized parallel-fibered bone; the valleys are built of an avascular layer of lamellar bone. The thick middle region consists of cancellous bone, with varying porosity. The thin and less vascularized internal cortex consists of parallel-fibered bone. The numerous Sharpey’s fibers and ISF are present in all bones. The cyclicity of growth is manifested as an alternation of thick, avascular annuli and high vascularized zones as well as a sequence of resting lines. The detailed histological framework of dermal bones varies even within a single bone; this seems to be related to the local biomechanical loading of the particular part of the skull. The dynamic processes observed during the ornamentation creation indicate that the positions of the ridges and grooves change during growth and could be a specific adaptation to changing biomechanical conditions and stress distribution during bone development. In the supratemporal, the cementing lines show that the remodeling process could be involved in the creations of sculpture. The common occurrence of ISF suggests that metaplastic ossification plays an important role during cranial development. Endochondral bones preserved the numerous remains of calcified cartilage. This indicates that ossification follows a pattern known for stereospondyl intercentra, with relatively slow ossification of the trabecular part and late development of the periosteal cortex. The large accumulation of Sharpey’s fibers in the occipital condyles indicates the presence of strong muscles and ligaments connecting the skull to the vertebral column. PMID:27843719

  19. Internal oral morphology in larvae of the genus Rhinella Fitzinger, 1826 (Amphibia, Anura, Bufonidae) .

    PubMed

    De Oliveira, Marianna Isabella Rosa Rodrigues; Weber, Luiz Norberto; Napoli, Marcelo Felgueiras

    2013-12-09

    From the 86 species allocated in the genus Rhinella, 25 have their tadpoles described and only R. arenarum, R. chrysophora, R. icterica, R. ornata, R. schneideri and R. spinulosa have aspects of the internal oral morphology evidenced. Herein, the internal oral morphology from 12 species of Rhinella distributed between the morphological groups of R. crucifer, R. granulosa, R. marina and R margaritifera is described and compared. The internal oral morphology of Rhinella is little variable in many aspects. Despite the many similarities found between the tadpoles of Rhinella, the study showed that there are characteristics that exhibit interspecific variation that can be used in the taxonomy of the genus. Important features to distinguish species were: number of infrarrostral projections; number and shape of the infralabial papillae; size, arrangement, shape and apex of the lingual papillae; shape of the buccal floor arena papillae; number of projections of the ventral velum; shape of the prenarial ridge; choanae arrangement; number and apex of the postnarial papillae; number and shape of the secondary branches on the lateral ridge papilla; buccal roof arena papillae arrangement. 

  20. Genetic analysis reveals candidate species in the Scinax catharinae clade (Amphibia: Anura) from Central Brazil.

    PubMed

    Nogueira, Lídia; Solé, Mirco; Siqueira, Sérgio; Affonso, Paulo Roberto Antunes de Mello; Strüssmann, Christine; Sampaio, Iracilda

    2016-03-01

    Scinax (Anura: Hylidae) is a species-rich genus of amphibians (113 spp.), divided into five species groups by morphological features. Cladistic analyses however revealed only two monophyletic clades in these groups: Scinax catharinae and Scinax ruber. Most species from the S. catharinae clade are found in Atlantic rainforest, except for Scinax canastrensis,S. centralis, S. luizotavioi, S. machadoi,S. pombali and S. skaios. In the present work, specimens of Scinax collected in Chapada dos Guimarães, central Brazil, were morphologically compatible with species from theS. catharinae group. On the other hand, genetic analysis based on mitochondrial (16S and 12S) and nuclear (rhodopsin) sequences revealed a nucleotide divergence of 6 to 20% between Scinax sp. and other congeners from the Brazilian savannah (Cerrado). Accordingly, Bayesian inference placed Scinax sp. in the S. catharinae clade with high support values. Hence, these findings strongly indicate the presence of a new species in the S. catharinae clade from the southwestern portion of the Brazilian savannah. To be properly validated as a novel species, detailed comparative morphological and bioacustic studies with other taxa from Brazil such asS. canastrensis, S. centralis, S. luizotavioi, S. machadoi, S. pombali and S. skaios are required.

  1. The distribution and taxonomy of Lissotriton newts in Turkey (Amphibia, Salamandridae)

    PubMed Central

    Wielstra, Ben; Bozkurt, Emin; Olgun, Kurtuluş

    2015-01-01

    Abstract Two and perhaps three taxa of Lissotriton newt occur in Turkey. Their species status is controversial. The distribution of these taxa and the taxonomic status of each are reviewed and discussed. A database of 128 Turkish Lissotriton localities was compiled and species distribution models were constructed. We reiterate that the presence of Lissotriton (vulgaris) lantzi in Turkey is disputed and needs confirmation. The range of Lissotriton (vulgaris) kosswigi is restricted to north-western Anatolia – given the small global range of this Turkey endemic, a closer look at its conservation status is warranted. The distribution of Lissotriton vulgaris schmidtleri covers western Asiatic and European Turkey. The findings support an allopatric distribution of the Turkish Lissotriton species. We reflect on the biological significance of previously reported morphological intermediates between Lissotriton (vulgaris) kosswigi and Lissotriton vulgaris schmidtleri in the light of the recent proposal to recognize kosswigi at the species level. The available data are in line with species status for Lissotriton (vulgaris) lantzi and Lissotriton (vulgaris) kosswigi. Although Lissotriton vulgaris schmidtleri is a genetically diverged taxon as well, the extent of gene flow with parapatric European Lissotriton taxa is as yet unknown. PMID:25829839

  2. Feeding biomechanics of Late Triassic metoposaurids (Amphibia: Temnospondyli): a 3D finite element analysis approach.

    PubMed

    Fortuny, Josep; Marcé-Nogué, Jordi; Konietzko-Meier, Dorota

    2017-03-29

    The Late Triassic freshwater ecosystems were occupied by different tetrapod groups including large-sized anamniotes, such as metoposaurids. Most members of this group of temnospondyls acquired gigantic sizes (up to 5 m long) with a nearly worldwide distribution. The paleoecology of metoposaurids is controversial; they have been historically considered passive, bottom-dwelling animals, waiting for prey on the bottom of rivers and lakes, or they have been suggested to be active mid-water feeders. The present study aims to expand upon the paleoecological interpretations of these animals using 3D finite element analyses (FEA). Skulls from two taxa, Metoposaurus krasiejowensis, a gigantic taxon from Europe, and Apachesaurus gregorii, a non-gigantic taxon from North America, were analyzed under different biomechanical scenarios. Both 3D models of the skulls were scaled to allow comparisons between them and reveal that the general stress distribution pattern found in both taxa is clearly similar in all scenarios. In light of our results, both previous hypotheses about the paleoecology of these animals can be partly merged: metoposaurids probably were ambush and active predators, but not the top predators of these aquatic environments. The FEA results demonstrate that they were particularly efficient at bilateral biting, and together with their characteristically anteropositioned orbits, optimal for an ambush strategy. Nonetheless, the results also show that these animals were capable of lateral strikes of the head, suggesting active hunting of prey. Regarding the important skull size differences between the taxa analyzed, our results suggest that the size reduction in the North American taxon could be related to drastic environmental changes or the increase of competitors. The size reduction might have helped them expand into new ecological niches, but they likely remained fully aquatic, as are all other metoposaurids.

  3. Oviduct modifications in foam-nesting frogs, with emphasis on the genus Leptodactylus (Amphibia, Leptodactylidae)

    USGS Publications Warehouse

    Furness, Andrew I.; McDiarmid, Roy W.; Heyer, W. Ronald; Zug, George R.

    2010-01-01

    Various species of frogs produce foam nests that hold their eggs during development. We examined the external morphology and histology of structures associated with foam nest production in frogs of the genus Leptodactylus and a few other taxa. We found that the posterior convolutions of the oviducts in all mature female foam-nesting frogs that we examined were enlarged and compressed into globular structures. This organ-like portion of the oviduct has been called a "foam gland" and these structures almost certainly produce the secretion that is beaten by rhythmic limb movements into foam that forms the nest. However, the label "foam gland" is a misnomer because the structures are simply enlarged and tightly folded regions of the pars convoluta of the oviduct, rather than a separate structure; we suggest the name pars convoluta dilata (PCD) for this feature. Although all the foam-nesters we examined had a pars convoluta dilata, its size and shape showed considerable interspecific variation. Some of this variation likely reflects differences in the breeding behaviors among species and in the size, type, and placement of their foam nests. Other variation, particularly in size, may be associated with the physiological periodicity and reproductive state of the female, her age, and/or the number of times she has laid eggs.

  4. The 100th: An appealing new species of Dendropsophus (Amphibia: Anura: Hylidae) from northeastern Brazil

    PubMed Central

    Haddad, Célio Fernando Baptista; Argôlo, Antônio Jorge Suzart; Orrico, Victor Goyannes Dill

    2017-01-01

    We describe a new species of the Dendropsophus leucophyllatus Group from the Atlantic Forest of the southern region of State of Bahia, Brazil. It can be distinguished from all species of the D. leucophyllatus Group on the basis of morphological characters (especially its unique dorsal pattern and snout in dorsal view), advertisement calls and divergence in mitochondrial DNA gene sequences. The inclusion of D. anceps on the group remains controversial but our phylogenetic analyses do not recover the new species as sister to syntopic species of the D. leucophyllatus Group (with or without D. anceps). These results also highlight the palimpsest that is past relation between the Atlantic and Amazon forests. PMID:28273092

  5. Description of a new species of crested newt, previously subsumed in Triturus ivanbureschi (Amphibia: Caudata: Salamandridae).

    PubMed

    Wielstra, B; Arntzen, J W

    2016-05-05

    Multilocus molecular data play a pivotal role in diagnosing cryptic species (i.e. genetically distinct but morphologically similar species). A multilocus phylogeographic survey has provided compelling evidence that Triturus ivanbureschi sensu lato comprises two distinct gene pools with restricted gene flow. We conclude that this taxon had better be treated as two distinct (albeit morphologically cryptic) species. The name T. ivanbureschi should be restricted to the western species, which is distributed in western Asiatic Turkey plus the south-eastern Balkan Peninsula. No name is as yet available for the eastern species, which is distributed in northern Asiatic Turkey. We propose the name T. anatolicus sp. nov. for the eastern species and provide a formal species description.

  6. A new Leptolalax from the mountains of Sabah, Borneo (Amphibia, Anura, Megophryidae).

    PubMed

    Matsui, Masafumi; Nishikawa, Kanto; Yambun, Paul

    2014-01-09

    A new species of Leptolalax is described from Kinabalu National Park in western Sabah, Malaysian Borneo. The new species had been assigned to L. dringi, L. gracilis, or L. fritinniens in the past. It differs from all congeners, including these species, by a unique combination of morphological characters, including small body size, rounded snout, narrower interorbital than upper eyelid, basal toe webbing, smooth skin with tiny tubercles on dorsum and dorsal side of head, small pectoral glands, absence of supraaxillary glands and ventrolateral glandular ridges, spotted venter, advertisement call consisting of long series of 1-149 notes, each composed of three or four pulses, and dominant frequency at 6.90-7.35 kHz, without prominent frequency modulation.

  7. Unusual chromosomal distribution of a major satellite DNA from Discoglossus pictus (Amphibia, Anura).

    PubMed

    Amor, N; Odierna, G; Chinali, G; Said, K; Picariello, O

    2009-01-01

    A new highly abundant satellite DNA from Discoglossus pictus (Dp-sat1) was isolated and characterized. The repetitive unit (0.51 kb) has 2 HindIII sites and only one SpeI site: digestion of genomic DNA with HindIII produces 3 fragments: HA (0.17 kb), HB (0.34 kb), and HC = HA + HB (0.51 kb), while digestion with SpeI produces the whole repetitive unit (0.51 kb) that contains both HindIII sites. Sequence analysis of cloned repeats indicates an average A + T content of 71%, with many A- and T-runs. Southern blot analysis shows an arrangement of multiple bands of the 0.51 kb monomer in SpeI-digested DNA, while HindIII-digested DNA shows a ladder composed of all the possible combinations of the 3 digested fragments. Quantitative dot-blot indicates that Dp-sat1 accounts for about 6% of the D. pictus genome: this value represents about 1.5 x 10(6) copies of repetitive units per nucleus. This satellite DNA is also a major repetitive DNA in 4 other Discoglossus species, in which the repetitive unit presents the same size and restriction sites except in D. montalentii where it contains a unique HindIII site. This satellite DNA was absent in all the other tested archaeo- and neo-bratrachian species, as well as non-amphibian species. Fluorescent in situ hybridization (FISH) analysis shows that Dp-sat1 is localized only in peri- and/or para-centromeric areas of the 7 small chromosome pairs, while no labeling was observed in the 7 large chromosome pairs. Remarkably, Dp-sat1 heterochromatin is found only at one pole of the nucleus, suggesting that during interphase all 7 small chromosome pairs are located in the same nuclear region.

  8. Phylogenetic relationships of Oriental torrent frogs in the genus Amolops and its allies (Amphibia, Anura, Ranidae).

    PubMed

    Matsui, Masafumi; Shimada, Tomohiko; Liu, Wan-Zhao; Maryati, Mohamed; Khonsue, Wichase; Orlov, Nikolai

    2006-03-01

    We investigated the phylogenetic relationships among 20 species of Oriental torrent frogs in the genus Amolops and its allies from China and Southeast Asia based on 1346-bp sequences of the mitochondrial 12S and 16S rRNA genes. Oriental species of the tribe Ranini form a monophyletic group containing 11 clades (Rana temporaria + Pseudoamolops, R. chalconota, four clades of Amolops, Meristogenys, three clades of Huia species, and Staurois) for which the phylogenetic relationships are unresolved. The genus Amolops consists of southern Chinese, southwestern Chinese, Thai, and Vietnamese-Malaysian lineages, but their relationships are also unresolved. The separation of southern and southwestern lineages within China conforms to previous morphological and karyological results. Species of Huia do not form a monophyletic group, whereas those of Meristogenys are monophyletic. Because P. sauteri is a sister species of R. temporaria, distinct generic status of Pseudoamolops is unwarranted.

  9. A new species of the genus Amolops (Amphibia: Ranidae) from southeastern Tibet, China.

    PubMed

    Jiang, Ke; Wang, Kai; Yan, Fang; Xie, Jiang; Zou, Da-Hu; Liu, Wu-Lin; Jiang, Jian-Ping; Li, Cheng; Che, Jing

    2016-01-18

    A new species of the genus Amolops Cope, 1865 is described from Nyingchi, southeastern Tibet, China, based on morphological and molecular data. The new species, Amolops nyingchiensis sp. nov. is assigned to the Amolops monticola group based on its skin smooth, dorsolateral fold distinct, lateral side of head black, upper lip stripe white extending to the shoulder. Amolops nyingchiensis sp. nov. is distinguished from all other species of Amolops by the following combination of characters: (1) medium body size, SVL 48.5-58.3 mm in males, and 57.6-70.7 mm in females; (2) tympanum distinct, slightly larger than one third of the eye diameter; (3) a small tooth-like projection on anteromedial edge of mandible; (4) the absence of white spine on dorsal surface of body; (5) the presence of circummarginal groove on all fingers; (6) the presence of vomerine teeth; (7) background coloration of dorsal surface brown, lateral body gray with yellow; (8) the presence of transverse bands on the dorsal limbs; (9) the presence of nuptial pad on the first finger in males; (10) the absence of vocal sac in males. Taxonomic status of the populations that were previously identified to A. monticola from Tibet is also discussed.

  10. Cytonuclear discordance and historical demography of two brown frogs, Rana tagoi and R. sakuraii (Amphibia: Ranidae).

    PubMed

    Eto, Koshiro; Matsui, Masafumi

    2014-10-01

    Prior studies of mitochondrial genomic variation reveal that the Japanese brown frog Rana tagoi comprises a complex of cryptic species lineages, and that R. sakuraii arose from within this complex. Neither species forms a monophyletic group on the mitochondrial haplotype tree, precluding a simple explanation for the evolutionary origins of R. sakuraii. We present a more complete sampling of mitochondrial haplotypic variation (from the ND1 and 16S genes) plus DNA sequence variation for five nuclear loci (from the genes encoding NCX1, NFIA, POMC, SLC8A3, and TYR) to resolve the evolutionary histories of these species. We test hypotheses of population assignment (STRUCTURE) and isolation-with-migration (IM) using the more slowly evolving nuclear markers. These demographic analyses of nuclear genetic variation confirm species-level distinctness and integrity of R. sakuraii despite its apparent polyphyly on the mitochondrial haplotype tree. Divergence-time estimates from both the mitochondrial haplotypes and nuclear genomic markers suggest that R. sakuraii originated approximately one million years ago, and that incomplete sorting of mitochondrial haplotype lineages best explains non-monophyly of R. sakuraii mitochondrial haplotypes. Cytonuclear discordance elsewhere in R. tagoi reveals a case of mitochondrial introgression between two species lineages on Honshu. The earliest phylogenetic divergence within this species group occurred approximately four million years ago, followed by cladogenetic events in the Pliocene and early Pleistocene yielding 10-13 extant species lineages, including R. sakuraii as one of the youngest.

  11. Climatic oscillations triggered post-Messinian speciation of Western Palearctic brown frogs (Amphibia, Ranidae).

    PubMed

    Veith, M; Kosuch, J; Vences, M

    2003-02-01

    Oscillating glacial cycles over the past 2.4 million years are proposed to have had a major impact on the diversity of contemporary species communities. We used mitochondrial and nuclear DNA sequence data to infer phylogenetic relationships within Western Palearctic brown frogs and to test the influence of Pliocene and Pleistocene climatic changes on their evolution. We sequenced 1976bp of the mitochondrial genes 16S rRNA and cytochrome b and of the nuclear rhodopsin gene for all current species and subspecies. Based on an established allozyme clock for Western Palearctic water frogs and substitution rate constancy among water frogs and brown frogs, we calibrated a molecular clock for 1425bp of the 16S and rhodopsin genes. We applied this clock to date speciation events among brown frogs. Western Palearctic brown frogs underwent a basal post-Messinian radiation about 4 million years ago (mya) into five major clades: three monotypic lineages (Rana dalmatina, Rana latastei, Rana graeca), an Anatolian lineage, and a lineage comprising Rana italica, Rana arvalis, and all Iberian taxa. Polytypic lineages radiated further in concordance with the onset of climatic oscillations ca. 3.2, 2.0, and 1.0-0.6 mya, respectively. The dated fossil record corroborates our paleobiogeographic scenario. We conclude that drastic climatic changes followed by successive temperature oscillations "trapped" most brown frog species in their southern European glacial refugia with enough time to speciate. Substantial dispersal was only possible during extensive interglacial periods of a constant subtropical climate.

  12. A newly identified Rab-GDI paralogue has a role in neural development in amphibia.

    PubMed

    Nazlamova, Liliya; Noble, Anna; Schubert, Frank R; McGeehan, John; Myers, Fiona; Guille, Matt; Scarlett, Garry

    2017-01-30

    Vesicle shuttling is critical for many cellular and organismal processes, including embryonic development. GDI proteins contribute to vesicle shuttling by regulating the activity of Rab GTPases, controlling their cycling between the inactive cytosol and active membrane bound states. While identifying genes controlled by A-form DNA sequences we discovered a previously unknown member of the GDI family, GDI3. The GDI3 gene is found only in amphibians and fish and is developmentally expressed in Xenopus from neurula stages onwards in the neural plate, and subsequently in both dorsal and anterior structures. Depletion or over-expression of the GDI3 protein in Xenopus embryos gives rise to very similar phenotypes, suggesting that strict control of GDI3 protein levels is required for correct embryonic development. Our analysis suggests the evolutionary origins of GDI3 and that it is functionally distinct from GDI1. Predicted structural analysis of GDI3 suggests that the key difference between GDI1 and GDI3 lies in their lipid binding pockets. Crown Copyright © 2016. Published by Elsevier B.V. All rights reserved.

  13. Genetic analysis reveals candidate species in the Scinax catharinae clade (Amphibia: Anura) from Central Brazil

    PubMed Central

    Nogueira, Lídia; Solé, Mirco; Siqueira, Sérgio; Affonso, Paulo Roberto Antunes de Mello; Strüssmann, Christine; Sampaio, Iracilda

    2016-01-01

    Abstract Scinax (Anura: Hylidae) is a species-rich genus of amphibians (113 spp.), divided into five species groups by morphological features. Cladistic analyses however revealed only two monophyletic clades in these groups: Scinax catharinae and Scinax ruber. Most species from the S. catharinae clade are found in Atlantic rainforest, except for Scinax canastrensis,S. centralis, S. luizotavioi, S. machadoi,S. pombali and S. skaios. In the present work, specimens of Scinax collected in Chapada dos Guimarães, central Brazil, were morphologically compatible with species from theS. catharinae group. On the other hand, genetic analysis based on mitochondrial (16S and 12S) and nuclear (rhodopsin) sequences revealed a nucleotide divergence of 6 to 20% between Scinax sp. and other congeners from the Brazilian savannah (Cerrado). Accordingly, Bayesian inference placed Scinax sp. in the S. catharinae clade with high support values. Hence, these findings strongly indicate the presence of a new species in the S. catharinae clade from the southwestern portion of the Brazilian savannah. To be properly validated as a novel species, detailed comparative morphological and bioacustic studies with other taxa from Brazil such asS. canastrensis, S. centralis, S. luizotavioi, S. machadoi, S. pombali and S. skaios are required. PMID:27007898

  14. A new species of Telmatobius (Amphibia, Anura, Telmatobiidae) from the Pacific slopes of the Andes, Peru

    PubMed Central

    Catenazzi, Alessandro; García, Víctor Vargas; Lehr, Edgar

    2015-01-01

    Abstract We describe a new species of Telmatobius from the Pacific slopes of the Andes in central Peru. Specimens were collected at 3900 m elevation near Huaytará, Huancavelica, in the upper drainage of the Pisco river. The new species has a snout–vent length of 52.5 ± 1.1 mm (49.3–55.7 mm, n = 6) in adult females, and 48.5 mm in the single adult male. The new species has bright yellow and orange coloration ventrally and is readily distinguished from all other central Peruvian Andean species of Telmatobius but Telmatobius intermedius by having vomerine teeth but lacking premaxillary and maxillary teeth, and by its slender body shape and long legs. The new species differs from Telmatobius intermedius by its larger size, flatter head, and the absence of cutaneous keratinized spicules (present even in immature females of Telmatobius intermedius), and in males by the presence of minute, densely packed nuptial spines on dorsal and medial surfaces of thumbs (large, sparsely packed nuptial spines in Telmatobius intermedius). The hyper-arid coastal valleys of Peru generally support low species richness, particularly for groups such as aquatic breeding amphibians. The discovery of a new species in this environment, and along a major highway crossing the Andes, shows that much remains to be done to document amphibian diversity in Peru. PMID:25685025

  15. The tadpole of Scinax melanodactylus (Lourenço, Luna & Pombal Jr, 2014) (Amphibia, Anura, Hylidae).

    PubMed

    Abreu, Rafael Oliveira De; Napoli, Marcelo Felgueiras; Trevisan, Camila Costa; Camardelli, Milena; Dória, Thais Andrade Ferreira; Silva, Lucas Menezes

    2015-07-06

    Scinax melanodactylus is a small treefrog distributed within the Tropical Atlantic morphoclimatic domain (see Ab'Sáber 1977 for South American morphoclimatic domains), from northern Espírito Santo state to Sergipe state in Brazil (Lourenço et al. 2014). The species is usually found inhabiting herbaceous and shrubby xerophytic vegetation (e.g. terrestrial tank-bromeliads) from sandy plains of beach ridges known in Brazil as Restingas (see Rocha et al. 2007 for a Restinga definition), and also the edge of forest areas with temporary ponds and/or permanent lakes and streams near these environments (Bastazini et al. 2007, as Scinax agilis; Lourenço et al. 2014). Scinax melanodactylus is currently placed in the S. catharinae species group (Lourenço et al. 2014), which in turn is included in the S. catharinae clade (sensu Faivovich et al. 2005). The S. catharinae clade is currently comprised of 46 species, 33 placed in the catharinae group and 13 in the perpusillus group (Faivovich et al. 2010, Silva & Alves-da-Silva 2011, Lourenço et al. 2014, Frost 2015). From these, 32 species have tadpoles with external morphology and oral disc formerly described. Here, we describe the external morphology, oral disc and color patterns of the previously unknown tadpole of S. melanodactylus.

  16. 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.

  17. The identity of the South African toad Sclerophrys capensis Tschudi, 1838 (Amphibia, Anura)

    PubMed Central

    Dubois, Alain

    2016-01-01

    The toad species Sclerophrys capensis Tschudi, 1838 was erected for a single specimen from South Africa which has never been properly studied and allocated to a known species. A morphometrical and morphological analysis of this specimen and its comparison with 75 toad specimens referred to five South African toad species allowed to allocate this specimen to the species currently known as Amietophrynus rangeri. In consequence, the nomen Sclerophrys must replace Amietophrynus as the valid nomen of the genus, and capensis as the valid nomen of the species. This work stresses the usefulness of natural history collections for solving taxonomic and nomenclatural problems. PMID:26788431

  18. Rhinella marina (Amphibia: Bufonidae) Versus Rhabdias paraensis (Nematoda: Rhabdiasidae): Expanding the View on a Natural Infection.

    PubMed

    Santos, Jeannie Nascimento Dos; da Silva, Djane Clarys Baia; Feitosa, Lucas Aristóteles das Neves; Furtado, Adriano Penha; Giese, Elane Guerreiro; de Vasconcelos Melo, Francisco Tiago

    2016-06-01

    Amphibian and reptile lungs are frequently infected with Rhabdias parasites, and this condition ultimately leads to reduced survival, performance, and growth because of granulomatous inflammation, nodule formation, and nematodal pneumonia onset. Here we investigate the histopathological features of naturally infected Rhinella marina by the lung nematode Rhabdias paraensis. A total of 10 host animals were captured in peridomiciliar areas in the eastern Brazilian Amazon, and anatomic-histological analyses were performed on both the infected and non-infected lungs of these amphibians. Helminths were usually found within the secondary and primary septa of infected lungs whereas parasites were not detected within vessels or adhering to tissues. In addition, we observed discrete erythrocytes, diapedesis foci, few granulocytes and erythrocytes in the interseptal spaces, discrete cell infiltration, and a small number of melanomacrophages, and no granulomas or cysts were observed. New aspects related to changes in tissue and helminth-host interactions are discussed for the relationship of R. paraensis × Rhi. marina from the Amazon region.

  19. An Examination of Morphometric Variations in a Neotropical Toad Population (Proceratophrys cristiceps, Amphibia, Anura, Cycloramphidae)

    PubMed Central

    Vieira, Kleber S.; Arzabe, Cristina; Hernández, Malva I. M.; Vieira, Washington L. S.

    2008-01-01

    The species Proceratophrys cristiceps belongs to the genus Proceratophrys within the family Cycloramphidae. These amphibians are found exclusively in South America in the morphoclimatic domain of the semi-arid depression zones in northeastern Brazil known as the Caatinga. We examined intrapopulational variation using univariate and multivariate statistics with traditional and geometric morphometrics, which supported the existence of two morphotypes of this species. Our results indicated significant degrees of variation in skeletal characteristics between some natural populations of this species. Careful analyses of variability levels are fundamental to avoid taxonomic errors, principally in populations that demonstrate characteristics intimately associated with their area of occurrence, as is the case of Proceratophrys cristiceps. PMID:19088855

  20. A Molecular Assessment of Phylogenetic Relationships and LineageDiversification Within the Family Salamandridae (Amphibia, Caudata)

    SciTech Connect

    Weisrock, David W.; Papenfuss, Theodore J.; Macey, J. Robert; Litvinchuk, Spartak N.; Polymeni, Rosa; Ugurtas, Ismail H.; Zhao, Ermi; Larson, Allan

    2005-08-08

    Phylogenetic relationships among species of the salamanderfamily Salamandridae are investigated using nearly 3000 nucleotide basesof newly reported mitochondrial DNA sequence data from the mtDNA genicregion spanning the genes tRNALeu-COI. This study uses nearlycomprehensive species-level sampling to provide the first completephylogeny for the Salamandridae. Deep phylogenetic relationships amongthe three most divergent lineages in the family Salamandrina terdigitata,a clade comprising the "True" salamanders, and a clade comprising allnewts except S. terdigitata are difficult to resolve. However, mostrelationships within the latter two lineages are resolved with robustlevels of branch support. The genera Euproctus and Triturus arestatistically shown to be nonmonophyletic, instead each contains adiverse set of lineages positioned within the large newt clade. The genusParamesotriton is also resolve as a nonmonophyletic group, with the newlydescribed species P. laoensis constituting a divergent lineage placed ina sister position to clade containing all Pachytriton species and allremaining Paramesotriton species. Sequence divergences between P.laoensis and other Paramesotriton species are as great as those comparingP. laoensis and species of the genera Cynops and Pachytriton. Analyses oflineage diversification across the Salamandridae indicate that, despiteits exceptional diversity, lineage accumulation appears to have beenconstant across time, indicating that it does not represent a truespecies radiation.

  1. The skull structure of six species of Mesoamerican plethodontid salamanders (Amphibia, Urodela).

    PubMed

    Ehmcke, Jens; Clemen, Günter

    2003-06-01

    The skulls of six species of plethodontid salamanders of the genus Bolitoglossa from Costa Rica and Panama, Bolitoglossa colonnea, B. dofleini, B. lignicolor, B. marmorea, B. schizodactyla and B. striatula are comparatively analysed. All species are terrestrial or slightly arboreal and show no life-mode-dependent skull characteristics. Heads cleared by transparent preparation and stained in toto were used for examination of the skull structure and paraffin sections of the gonads were prepared to confirm sexual maturity of each individual. Focussing on the size of the premaxillary pars dentalis, the degree of fusion of the processus dorsales praemaxillares and the presence or absence of the paired prefrontals we state that B. dofleini and B. striatula possess more ancestral characteristics, B. marmorea is situated in an intermediate position and B. colonnea, B. lignicolor and B. schizodactyla show more advanced characteristics.

  2. Two new Salamanders of the genus Onychodactylus from Eastern Honshu, Japan (Amphibia, Caudata, Hynobiidae).

    PubMed

    Yoshikawa, Natsuhiko; Matsui, Masafumi

    2014-09-22

    We describe two new species of hynobiid salamanders in the genus Onychodactylus from eastern Honshu, Japan, based on the morphological and genetic evidence. Onychodactylus intermedius sp. nov. is distributed in southern part of Tohoku District and northern Ibaraki and Niigata Prefectures, and was previously reported as S-Tohoku group. Onychodactylus intermedius belongs to the O. japonicus species complex, and differs from the other congeners in having relatively long tail, narrow head, short snout, 18 presacral vertebrae, and distinctly curved vomerine tooth series without gap. Onychodactylus fuscus sp. nov. is known from only four localities in Fukushima and Niigata Prefectures of Tohoku and Hokuriku Districts. It also belongs to the O. japonicus complex, but lacks the dorsal stripe, which is a diagnostic character of the species complex. In other characteristics, O. fuscus differs from the other congeners in having comparatively long tail, wide head and internarial space, shallowly curved vomerine tooth series with gap, and relatively few vomerine teeth. Both species described here breed in winter. Phylogenetically, the two new species are closely related to each other, forming a well-supported clade with O. tsukubaensis as their sister species. Onychodactylus intermedius sp. nov. is known to be parapatric with O. japonicus and O. nipponoborealis without hybridization, whereas O. fuscus sp. nov. is sympatric with O. japonicus at least in a single known locality, and analysis of microsatellite loci indicates they are reproductively isolated.

  3. Two new species of Salamanders, Genus Bolitoglossa (Amphibia: Plethodontidae), from the Eastern Colombian Andes.

    PubMed

    Acevedo, Aldemar A; Wake, David B; Márquez, Roberto; Silva, Karen; Franco, Rosmery; Amézquita, Adolfo

    2013-01-25

    The salamander fauna of Colombia is very poorly known, probably because most research efforts have been devoted to anurans during the last two decades. Here, we describe two new species of the genus Bolitoglossa (Eladinea) from the eastern flank of the Eastern Colombian Andes (Cordillera Oriental), near the border with Venezuela. Bolitoglossa tamaense sp. nov. is distributed between 2000 to 2700 m.a.s.l. and Bolitoglossa leandrae sp. nov. is distributed in the low-lands at about 600 m. The new species are diagnosed by a combination of molecular (16S rRNA sequences), coloration, body size, and morphometric (number of maxillary and vomerine teeth and differences in foot webbing) characters. Both species face threats such as chytridiomycosis infections and habitat fragmentation that have already affected other sala-manders in the country. Thus, intensive field and museum work is needed to better document and perhaps protect the local salamander diversity.

  4. Three new species of the salamander genus Hynobius (Amphibia, Urodela, Hynobiidae) from Kyushu, Japan.

    PubMed

    Nishikawa, Kanto; Matsui, Masafumi

    2014-08-14

    Three new species of lotic breeding Hynobius, formerly assigned to H. boulengeri, are described from the Kyushu region, southwestern Japan. They differ from all the known congeners by a unique combination of body size, character ratios, coloration, mtDNA, and allozymic characteristics. Together with H. stejnegeri they form a clade, which is not a sister group of H. boulengeri, and their speciation in Kyushu is surmised to have occurred at the end of Miocene, accompanied by differentiations in larval period and metamorphosing size. Measures of conservation of these new species are discussed briefly. 

  5. Gender-dependent dimorphic teeth in four species of Mesoamerican plethodontid salamanders (Urodela, Amphibia).

    PubMed

    Ehmcke, Jens; Wistuba, Joachim; Clemen, Günter

    2004-06-01

    The tooth shapes of premaxillary and maxillary teeth of adults of four Mesoamerican salamander species (Urodela, Plethodontidae) were examined. Using scanning electron microscopy we determined whether the monocuspid teeth that are present only on the premaxillary of sexually mature males belong to the conical, unbladed, monocuspid tooth type found in urodele larvae or whether they represent morphological variations of the typical, bladed, bicuspid teeth of metamorphosed individuals. The teeth of some studied species are, in fact, unbladed and in some cases show one very reduced tip. But none of the studied teeth is per definitionem monocuspid and no tooth shows an enameloid layer between dentine shaft and enamel cap, which is always present in the teeth of early urodele larvae. The "monocuspid" teeth of adult males of Mesoamerican plethodontid salamanders have to be considered a morphological variation of the metamorphosed, bicuspid tooth type typical for metamorphosed urodeles.

  6. A comparative study of the hyobranchial apparatus in Hynobiidae (Amphibia: Urodela).

    PubMed

    Xiong, Jian-li; Sun, Ping; Zhang, Ji-liang; Liu, Xiu-ying

    2013-04-01

    The morphology of the adult hyobranchial apparatus has played an important role in understanding the systematics and evolution of urodeles, but the hyobranchial apparatus of hynobiid salamanders has received little attention so far. In this study, the hyobranchial apparatus of eight hynobiid salamanders (Hynobius leechii, Onychodactylus zhangyapingi, Ranodon sibiricus, Batrachuperus pinchonii, Salamandrella keyserlingii, Liua shihi, Pachyhynobius shangchengensis and Pseudohynobius flavomaculatus) is described and compared based on the clearing and double-staining method. The basic elements of the hyobranchial apparatus of the eight species are similar, including one basibranchial, cornua, one pair of radial loops, one pair of ceratohyals, one pair of hypobranchials II, one pair of ceratobranchials II, one urohyal (absent in O. zhangyapingi), one pair of the complex of hypobranchial I and ceratobranchial I (separated in certain species). Although the hyobranchial apparatus is similar among hynobiid salamanders and shows a unique morphological pattern, there are also certain species-specific distinctions that may be used for specific or generic diagnosis. The results of an ancestral state reconstruction of five traits showed that the ossified basibranchial, the presence of a separated hypobranchial I and ceratobranchial I, the absence of a urohyal, the ossified hypobranchial I and the partially ossified ceratohyal are derived traits. The state shown by the traits of each species is consistent with the phylogenetic position of each species. Compared with other Urodela, the hyobranchial apparatus of this group shows certain distinctive features that may represent the diagnostic characters of the family Hynobiidae. The partially ossified ceratohyal is correlated with the habitat and represents an ecological adaptation.

  7. Helminth parasites of the leopard frog Lithobates sp. Colima (Amphibia: Ranidae) from Colima, Mexico.

    PubMed

    Cabrera-Guzmán, Elisa; Garrido-Olvera, Lorena; León-Règagnon, Virginia

    2010-08-01

    The helminth fauna inhabiting Lithobates sp. Colima from Ticuizitán, Colima, Mexico, comprises 10 species: 4 digeneans ( Clinostomum sp., Glypthelmins quieta , Haematoloechus sp., and Langeronia macrocirra ), 5 nematodes ( Aplectana itzocanensis , Cosmocerca podicipinus , Foleyellides striatus , Oswaldocruzia subauricularis , and Rhabdias sp.), and 1 cestode (Cyclophyllidea). Glypthelmins quieta , L. macrocirra , and A. itzocanensis represent new host records. These observations, added to previous records from Acapulco, Guerrero, Mexico, indicate that the helminth fauna of Lithobates sp. from Colima comprises 25 taxa. Frogs are being parasitized by 3 infection routes: ingestion of intermediate host, skin penetration by larval forms, and transmission by vectors. Species of Aplectana , Cosmocerca , Foleyellides , and Oswaldocruzia occurred in high prevalence in Colima, similar to a previous study on the same frog species from Guerrero. In Colima, Glypthelmins , Haematoloechus , and Rhabdias also occurred in high prevalence. Haematoloechus species reached the highest mean intensity in both localities. The semiaquatic habits of this species of frog and the availability of particular feeding resources appear to determine the helminth composition and infection levels; however, co-speciation events also play an important role structuring these helminth communities.

  8. Unmasking Rana okinavana Boettger, 1895 from the Ryukyus, Japan (Amphibia: Anura: Ranidae).

    PubMed

    Matsui, Masafumi

    2007-02-01

    Examination of the lectotype and a paralectotype of Rana okinavana Boettger, 1895 revealed that the species is not a brown frog of the subgenus Rana, occurring in the middle group of the Ryukyu Archipelago, but is identical with a frog of the subgenus Nidirana from the southern group of the Archipelago and Taiwan, now called R. psaltes Kuramoto, 1985. The type locality of R. okinavana given in the original description, Okinawa of the middle Ryukyus, is highly doubtful and should be somewhere in the Yaeyama Islands of the southern Ryukyus. The name R. psaltes is relegated to a subjective junior synonym of R. okinavana Boettger, 1895, while the brown frog of the subgenus Rana from the northern Ryukyus requires a replacement name.

  9. Effects of developmental and growth history on metamorphosis in the gray treefrog, Hyla versicolor (Amphibia, Anura).

    PubMed

    Beachy, C K; Surges, T H; Reyes, M

    1999-05-01

    In ecological models, the timing of amphibian metamorphosis is dependent upon rate of larval growth, e.g., tadpoles that experience a decrease in growth rate can initiate metamorphosis early. Recent authors have suggested that this plasticity may be lost at some point during the larval period. We tested this hypothesis by exposing groups of tadpoles of the gray treefrog, Hyla versicolor, to different growth schedules. In endocrine models, metamorphosis is dependent on thyroxine levels and thyroxine is antagonized by prolactin (amphibian larval growth hormone), consistent with the idea that a rapidly growing tadpole can delay metamorphosis. Thus, we also manipulated the rate of development by supplementing or maintaining natural thyroxine levels for half of the tadpoles in each growth treatment. All tadpoles that received thyroxine supplements metamorphosed at the same time regardless of growth history. They also metamorphosed earlier than tadpoles not treated with thyroxine. Tadpoles not given thyroxine supplements metamorphosed at different times: those growing rapidly during day 15-34 metamorphosed earlier than tadpoles growing slowly. Growth rate before day 15 and after day 34 had no effect on metamorphic timing. The difference in larval period between these rapidly growing tadpoles and their sisters given thyroxine treatments was less than the same comparison for tadpoles that grew slowly during the same period. This apparent prolactin/thyroxine antagonism did not exist after day 34. These results are consistent with the hypothesis of a loss of plasticity in metamorphic timing.

  10. The complete mitochondrial genome sequence of the Dark-spotted frog Pelophylax nigromaculatus (Amphibia, Anura, Ranidae).

    PubMed

    Jiang, Lichun; Zhao, Li; Liu, Yabin; Leng, Zheng; Zhao, Liping; Ruan, Qiping

    2017-03-01

    The dark-spotted frog (Pelophylax nigromaculatus) belongs to Ranidae. This species is known from the Russian Far East, central, northern and north-eastern China, the Democratic People's Republic of Korea, the Republic of Korea, and Japan. In this study, the complete mitochondrial genome of P. nigromaculatus was sequenced. The mitogenome was 17 567 bp in length, consisting of 13 protein-coding genes, 22 transfer RNA (tRNA) genes, 2 ribosomal RNA (rRNA) genes, and a non-coding control region. As in other vertebrates, most mitochondrial genes are encoded on the heavy strand, except for ND6 and eight tRNA genes which are encoded on the light strand. The overall base composition of the P. nigromaculatus is 29.2% A, 27.4% T, 28.4% C, and 15.0% G. Phylogenetic analysis showed P. nigromaculatus was closely related to P. plancyi and P. chosenicus. The complete mitogenome of P. nigromaculatus can provide important data for the studies on phylogenetic relationship and population genetics to further explore the taxonomic status of this species.

  11. A new species of tree frog genus Rhacophorus from Sumatra, Indonesia Amphibia, Anura).

    PubMed

    Hamidy, Amir; Kurniati, Hellen

    2015-04-14

    A small-sized tree frog of the genus Rhacophorus is described on the basis of 18 specimens collected from three different localities on Sumatra Island, Indonesia. Rhacophorus indonesiensis sp. nov. is divergent from all other Rhacophorus species genetically and morphologically. The new species is distinguished from its congeners by a combination of: the presence of black spots on the ventral surfaces of the hand and foot webbing, an absence of vomerine teeth, a venter with a white kite-shaped marking, raised white spots on the dorsum or on the head, and a reddish brown dorsum with irregular dark brown blotches and distinct black dots. With the addition of this new species, fifteen species of Rhacophorus are now known from Sumatra, the highest number of species of this genus in the Sundaland region. However, with the increasing conversion of forest to oil palm cultivation or mining, the possibility of the extinction of newly described or as yet undiscovered species is of great concern.

  12. A new species of Meristogenys (Amphibia, Anura, Ranidae) from Sabah, Borneo.

    PubMed

    Matsui, Masafumi; Shimada, Tomohiko; Sudin, Ahmad

    2010-01-01

    We describe a new species of torrent-dwelling ranid frog of the genus Meristogenys from the Crocker Range, western Sabah, northern Borneo. The new species, Meristogenys maryatiae, differs from congeners by the combination of: small body, males 31-37 mm and females 65-66 mm in snout-vent length; head narrower than long; eyes moderate, diameter subequal to snout; iris unicolored; legs long; ventral surface of tibia without heavy pigmentation; rear of thigh blotched dark brown and cream; toes fully webbed; outer metatarsal tubercle present; larval dental formula 7(4-7)/6(1).

  13. Molecular phylogeny and diversification of the genus Odorrana (Amphibia, Anura, Ranidae) inferred from two mitochondrial genes.

    PubMed

    Chen, Xiaohong; Chen, Zhuo; Jiang, Jianping; Qiao, Liang; Lu, Youqiang; Zhou, Kaiya; Zheng, Guangmei; Zhai, Xiaofei; Liu, Jianxin

    2013-12-01

    A diversity of hypotheses have been proposed for phylogenetic relationships and taxonomy within the genus Odorrana, and great progress has been made over the past several decades. However, there is still some controversy concerning relationships among Odorrana species. Here, we used many paratypes and topotypes and utilized 1.81 kb of mitochondrial sequence data to generate a phylogeny for approximately 4/5 of Odorrana species, and Odorrana haplotypes form a strongly supported monophyletic group relative to the other genera sampled. The deepest phylogenetic divergences within Odorrana separate 3 lineages whose interrelationships are not recovered with strong support. These lineages include the ancestral lineage of O. chapaensis, the ancestral lineage of a strongly supported clade comprising many western species, and the ancestral lineage of a strongly supported clade comprising all other Odorrana sampled. Within the latter clade, the first phylogenetic split separates O. ishikawae from a well-supported clade comprising its other species. These divergences likely occurred in the middle Miocene, approximately 12-15 million years ago. Separation of the ancestral lineage of Odorrana from its closest relative, Babina in our study, likely occurred in the early Miocene or possibly late Oligocene. Rates of lineage accumulation remained high from the middle Miocene through the Pleistocene. Copyright © 2013 Elsevier Inc. All rights reserved.

  14. Galanin: presence and distribution in the brain and pituitary of Rhinella arenarum (Amphibia: Anura) during development.

    PubMed

    Heer, T; Yovanovich, C A; Pozzi, A G; Paz, D A

    2008-10-01

    The immunohistochemical distribution of galanin (Gal) in the brain and pituitary of Rhinella arenarum was studied during development. Gal-immunoreactivity was first observed in the brain just after hatching in anterior preoptic area, infundibular area, median eminence and pars distalis of the pituitary as well as in the olfactory epithelium. At the beginning of prometamorphosis new Gal-immunoreactive (ir) cells were observed in the olfactory nerve and bulb. Later in prometamorphosis new Gal-ir cells were observed in the telencephalon, suprachiasmatic nucleus, rostral rhombencephalon and in the pars nervosa of the pituitary. The most numerous accumulations of Gal-ir neurons throughout the larval development were observed in the ventral hyphothalamus where numerous Gal-ir cells of cerebrospinal fluid-contacting type were found. During metamorphic climax and soon after we did not detect Gal-ir neurons in the pallium, medial or pretectal dorsal thalamus. In the median eminence and pars distalis of the pituitary many Gal-ir fibers were found during development indicating that Gal may play a role in the modulation of hypophyseal secretion. Furthermore, the distribution of Gal-ir elements observed throughout larvae development indicates that galaninergic system maturation continues until sexual maturity.

  15. Organophosphorus pesticides effect on early stages of the axolotl Ambystoma mexicanum (Amphibia: Caudata).

    PubMed

    Robles-Mendoza, C; García-Basilio, C; Cram-Heydrich, S; Hernández-Quiroz, M; Vanegas-Pérez, C

    2009-02-01

    Ambystoma mexicanum is an endemic salamander of Xochimilco, a wetland of the basin of Mexico valley. Nowadays, axolotl populations are decreasing due environmental stressors. Particularly, studies about organophosphorus pesticides (OPPs; i.e. chlorpyrifos and malathion) toxicity are of great importance due to their intensive use in agricultural activities in Xochimilco. Thus, the aim of this study was to evaluate under controlled conditions the toxicity of chlorpyrifos (CPF) and malathion (MLT) on embryos and larvae (stage 44 and 54) of A. mexicanum. Embryos and larvae were exposure 96h from 0.5 to 3mg CPFL(-1) and from 10 to 30mg MLTL(-1) in independent tests. Embryos at the end of this period were maintained 9d without pesticide in order to identify possible recuperation. Differences obtained in mortality, hatching success, development, morphological abnormalities, behaviour and activity, suggest that toxicity of CPF and MLT differs in embryos and larval stages. Embryos were less sensitive to OPPs acute exposure than axolotl larvae; additionally, toxicity of CPF in larval stages was greater than MLT. On the other hand, data obtained in axolotl embryos during the period of recuperation to CPF in particular as delay and inhibition of development, malformations and success of hatching, indicated that these responses turned out more sensitive than mortality. This study allowed to identify the toxicological potential of OPPs on early developmental stages of A. mexicanum and it is a valuable contribution for the future management of the axolotl wild population.

  16. Intergenomic translocations in unisexual salamanders of the genus Ambystoma (Amphibia, Caudata).

    PubMed

    Bi, K; Bogart, J P; Fu, J

    2007-01-01

    Intergenomic interactions that include homoeologous recombinations and intergenomic translocations are commonly observed in plant allopolyploids. Homoeologous recombinations have recently been documented in unisexual salamanders in the genus Ambystoma and revealed exchanged chromosomal segments between A. laterale and A.jeffersonianum genomes in individual unisexuals. We discovered intergenomic translocations in two widespread unisexual triploids A.laterale--2 jeffersonianum (or LJJ) and its tetraploid derivative A.laterale--3 jeffersonianum (or LJJJ) by genomic in situ hybridization (GISH). Two different types of intergenomic translocations were observed in two unisexual populations and one contained novel chromosomes generated by an intergenomic reciprocal translocation. We also observed chromosome deletions in several individuals and these chromosome fragmentations were all derived from the A. jeffersonianum genome. These observed intergenomic reciprocal translocations are believed to be caused by non-homologous pairing during meiosis followed by breakage-rejoining events. Genomes of unisexual Ambystoma undergo complicated structural changes that include various intergenomic exchanges that offer unisexuals genetic and phenotypic complexity to escape their evolutionary demise. Unisexual Ambystoma have persisted as natural nuclear genomic hybrids for about four million years. These unisexuals provide a vertebrate model system to examine the interaction of distinct genomes and to evaluate the corresponding genetic, developmental and evolutionary implications of intergenomic exchanges. Intergenomic translocations and homoeologous recombinations appear to be frequent chromosome reconstruction events among unisexual Ambystoma.

  17. The testicular sperm ducts and genital kidney of male Ambystoma maculatum (Amphibia, Urodela, Ambystomatidae).

    PubMed

    Siegel, Dustin S; Aldridge, Robert D; Rheubert, Justin L; Gribbins, Kevin M; Sever, David M; Trauth, Stanley E

    2013-03-01

    The ducts associated with sperm transport from the testicular lobules to the Wolffian ducts in Ambystoma maculatum were examined with transmission electron microscopy. Based on the ultrastructure and historical precedence, new terminology for this network of ducts is proposed that better represents primary hypotheses of homology. Furthermore, the terminology proposed better characterizes the distinct regions of the sperm transport ducts in salamanders based on anatomy and should, therefore, lead to more accurate comparisons in the future. While developing the above ontology, we also tested the hypothesis that nephrons from the genital kidney are modified from those of the pelvic kidney due to the fact that the former nephrons function in sperm transport. Our ultrastructural analysis of the genital kidney supports this hypothesis, as the basal plasma membrane of distinct functional regions of the nephron (proximal convoluted tubule, distal convoluted tubule, and collecting tubule) appear less folded (indicating decreased surface area and reduced reabsorption efficiency) and the proximal convoluted tubule possesses ciliated epithelial cells along its entire length. Furthermore, visible luminal filtrate is absent from the nephrons of the genital kidney throughout their entire length. Thus, it appears that the nephrons of the genital kidney have reduced reabsorptive capacity and ciliated cells of the proximal convoluted tubule may increase the movement of immature sperm through the sperm transport ducts or aid in the mixing of seminal fluids within the ducts.

  18. Plasma retinoids concentration in Leptodactylus chaquensis (Amphibia: Leptodactylidae) from rice agroecosystems, Santa Fe province, Argentina.

    PubMed

    Teglia, Carla M; Attademo, Andrés M; Peltzer, Paola M; Goicoechea, Héctor C; Lajmanovich, Rafael C

    2015-09-01

    Retinoids are known to regulate important processes such as differentiation, development, and embryogenesis of vertebrates: Alteration in endogenous retinoids concentration is linked with teratogenic effects. Retinol (ROH), retinoid acid (RA), and isoform 13-Cis-retinoic acid (13-Cis-RA), in plasma of a native adults frog, Leptodactylus chaquensis from a rice field (RF) and a forest (reference site; RS) were measured. ROH did not vary between treatment sites. RA and 13-Cis-RA activities were higher (93.7±8.6 μg mL(-1) and 131.7±11.4 μg mL(-1), respectively) in individuals collected from RF than in those from RS (65.5±8.6 μg mL(-1) and 92.2±10.2 μg mL(-1), respectively). The ratios retinoic acid-retinol (RA/ROH) and 13-Cis-RA/ROH revealed significantly higher values in RF than in RS. RA and 13-Cis-RA concentrations in plasma on wild amphibian's species such as L. chaquensis would be suitable biomarkers of pesticide exposure in field monitoring. Finally, the mechanism of alteration in retinoid metabolites alteration should be further explored both in larvae and adult, considering that the potential exposition and uptake contaminants vary between the double lives of these vertebrates.

  19. A new species of Telmatobius (Amphibia, Anura, Telmatobiidae) from the Pacific slopes of the Andes, Peru.

    PubMed

    Catenazzi, Alessandro; García, Víctor Vargas; Lehr, Edgar

    2015-01-01

    We describe a new species of Telmatobius from the Pacific slopes of the Andes in central Peru. Specimens were collected at 3900 m elevation near Huaytará, Huancavelica, in the upper drainage of the Pisco river. The new species has a snout-vent length of 52.5 ± 1.1 mm (49.3-55.7 mm, n = 6) in adult females, and 48.5 mm in the single adult male. The new species has bright yellow and orange coloration ventrally and is readily distinguished from all other central Peruvian Andean species of Telmatobius but Telmatobiusintermedius by having vomerine teeth but lacking premaxillary and maxillary teeth, and by its slender body shape and long legs. The new species differs from Telmatobiusintermedius by its larger size, flatter head, and the absence of cutaneous keratinized spicules (present even in immature females of Telmatobiusintermedius), and in males by the presence of minute, densely packed nuptial spines on dorsal and medial surfaces of thumbs (large, sparsely packed nuptial spines in Telmatobiusintermedius). The hyper-arid coastal valleys of Peru generally support low species richness, particularly for groups such as aquatic breeding amphibians. The discovery of a new species in this environment, and along a major highway crossing the Andes, shows that much remains to be done to document amphibian diversity in Peru.

  20. Histology and ultrastructure of the gut epithelium of the neotenic cave salamander, Proteus anguinus (Amphibia, Caudata).

    PubMed

    Bizjak Mali, Lilijana; Bulog, Boris

    2004-01-01

    Histological, histochemical, and ultrastructural features of the gut of the European endemic cave salamander Proteus anguinus were studied. The gut is a relatively undifferentiated muscular tube lined with a simple columnar epithelium containing numerous goblet cells. The mucosa and underlying lamina propria/submucosa are elevated into a number of high longitudinal folds projecting into the lumen. The enterocytes are covered apically with uniform microvilli. Irregularity in the arrangement of microvilli was observed. Occasionally, irregular protrusions of the cytoplasm appear between groups of microvilli. Pinocytotic activity occurs at the bases of the intermicrovillous space. Mitochondria are numerous in the apical cytoplasm and basally beneath the nuclei. The supranuclear cytoplasm contains most of the cell organelles. The lateral plasma membranes of adjacent cells interdigitate and are joined by junctional complexes. The periodic acid-Schiff (PAS) reaction, indicating neutral mucosubstances, is positive only in the apical brush border of enterocytes and in goblet cells. The goblet cells also stained with Alcian blue (AB), at pH 2.5, thus revealing the presence of carboxylated glycosaminoglycans. Compact aggregations of AB- and PAS-negative cells are situated directly below the epithelium. Mitotic figures are present in individual clusters of cells. The fine structure of cells in these clusters indicated that these cells could be responsible for renewal of intestinal epithelium. Numerous endocrine-like cells could also be seen. The closely packed smooth muscle cells and amorphous extracellular material with collagen fibrils constitute a net-like structure under the basal lamina that is very closely associated with the epithelium. There are numerous acidophilic granular cells between epithelial cells, in the lamina propria/submucosa, and between cells aggregations. They seem to be associated with nematode infections and possibly constitute a humoral defense mechanism. Copyright 2003 Wiley-Liss, Inc.

  1. Developmental and acute toxicity of cetylpyridinium chloride in Bombina orientalis (Amphibia: Anura).

    PubMed

    Park, Chan Jin; Song, Sang Ha; Kim, Dae Han; Gye, Myung Chan

    2016-08-01

    In an effort to evaluate the toxicity of cetylpyridinium chloride (CPC), a cationic surfactant in amphibians, we examined the developmental and acute toxicity of CPC in Bombina orientalis embryos and tadpoles. Embryonic exposure to 2.0μM (0.72mg/l) CPC for 7 days significantly decreased the survival rates and increased DNA damage in the intestine of developed tadpoles. Exposure to 1.5μM (0.54mg/l) CPC significantly decreased the growth of embryos and increased developmental abnormalities. The 168-h LC50 and EC50 values of CPC were 1.95μM (0.697mg/l) and 1.48μM (0.531mg/l) in embryos, respectively. In an extended acute toxicity test using tadpoles, the 168-h LC50 value of CPC was 5.07μM (1.82mg/l). In terms of survival and growth rates, the lowest observed effective concentration of CPC was 1.5μM. At sub-lethal concentrations (1.0 and 2.0μM) CPC treatment to embryos increased lipid peroxidation in the intestine and gills of developed tadpoles, indicating that CPC can impose oxidative stress. At 2.0μM CPC, pro-apoptotic Bax and Bak mRNA levels were significantly increased together with DNA fragmentation, indicative of apoptotic cell death. CPC in freshwater system may threaten the normal development of amphibian embryos.

  2. Temporal changes in cutaneous bacterial communities of terrestrial- and aquatic-phase newts (Amphibia).

    PubMed

    Sabino-Pinto, Joana; Galán, Pedro; Rodríguez, Silvia; Bletz, Molly C; Bhuju, Sabin; Geffers, Robert; Jarek, Michael; Vences, Miguel

    2017-08-01

    Animal-associated bacterial communities play essential roles for their host's ecology, physiology and health. Temporal dynamics of these communities are poorly understood, but might be of high relevance for amphibians with a well-expressed biphasic biology of adults where the structure of their skin changes drastically between the aquatic and terrestrial phases. Here, we investigated the temporal dynamics of cutaneous bacterial communities of Lissotriton boscai and Triturus marmoratus by monthly sampling populations from a pond and surrounding terrestrial habitats near A Coruña, Spain. These communities were characterized by 16S rRNA gene amplicons from DNA isolated from skin swabs. Newt bacterial communities displayed variation at three levels: between larvae and aquatic adults, between adult life phases (terrestrial versus aquatic), and temporally within life phases. The skin bacterial communities tended to differ to a lesser extent temporally and between larvae and adults, and more strongly between life phases. Larvae had a higher proportion of reads associated with antifungal taxa compared with adults, while no differences were found among adult life phases. Terrestrial specimens exhibited the highest community diversity. The regular transitions of adult newts between aquatic and terrestrial environments might contribute to the diversity of their skin microbiota and could increase disease resistance. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

  3. Sperm storage in the spermatheca of the red-back salamander, Plethodon cinereus (Amphibia: Plethodontidae).

    PubMed

    Sever, D M

    1997-11-01

    In northern Indiana, the mating season of Plethodon cinereus occurs after hibernation from March until June, when oviposition begins. During the mating season, a female stores sperm in its spermatheca, a compound tubular gland in the roof of the cloaca. The apical cytoplasm of the spermathecal epithelium is filled with large secretory vacuoles whose product is released while sperm are stored. Females induced to oviposit in June and July by injections of human chorionic gonadotropin (hCG) still retain much sperm 1 month after oviposition, but secretory vacuoles are absent in all specimens sacrificed in July and August. Instead, some sperm are embedded in the spermathecal epithelium with resultant spermiophagy involving lysosomes. A female sacrificed in September 2 months after oviposition possesses scant sperm, but spermiophagy alone does not seem extensive enough to account for the decrease in sperm numbers. Females sacrificed in October prior to hibernation lack sperm in their spermathecae; some secretory vacuoles are present, but they are not as numerous or as enlarged as in specimens collected in March and May. Inter- and intrafamilial differences in the cytology of sperm storage may not be phyletically informative at the family level but related to species-specific reproductive adaptations.

  4. DNA barcoding and the identification of tree frogs (Amphibia: Anura: Rhacophoridae).

    PubMed

    Dang, Ning-Xin; Sun, Feng-Hui; Lv, Yun-Yun; Zhao, Bo-Han; Wang, Ji-Chao; Murphy, Robert W; Wang, Wen-Zhi; Li, Jia-Tang

    2016-07-01

    The DNA barcoding gene COI (cytochrome c oxidase subunit I) effectively identifies many species. Herein, we barcoded 172 individuals from 37 species belonging to nine genera in Rhacophoridae to test if the gene serves equally well to identify species of tree frogs. Phenetic neighbor joining and phylogenetic Bayesian inference were used to construct phylogenetic trees, which resolved all nine genera as monophyletic taxa except for Rhacophorus, two new matrilines for Liuixalus, and Polypedates leucomystax species complex. Intraspecific genetic distances ranged from 0.000 to 0.119 and interspecific genetic distances ranged from 0.015 to 0.334. Within Rhacophorus and Kurixalus, the intra- and interspecific genetic distances did not reveal an obvious barcode gap. Notwithstanding, we found that COI sequences unambiguously identified rhacophorid species and helped to discover likely new cryptic species via the synthesis of genealogical relationships and divergence patterns. Our results supported that COI is an effective DNA barcoding marker for Rhacophoridae.

  5. Reconciling molecular phylogeny, morphological divergence and classification of Madagascan narrow-mouthed frogs (Amphibia: Microhylidae).

    PubMed

    Scherz, Mark D; Vences, Miguel; Rakotoarison, Andolalao; Andreone, Franco; Köhler, Jörn; Glaw, Frank; Crottini, Angelica

    2016-07-01

    A recent study clarified several aspects of microhylid phylogeny by combining DNA sequences from Sanger sequencing and anchored phylogenomics, although numerous aspects of tree topology proved highly susceptible to data partition and chosen model. Although the phylogenetic results of the study were in conflict with previous publications, the authors made several changes to the taxonomy of Madagascar's cophyline microhylids. We re-analyzed part of their data together with our own molecular and morphological data. Based on a supermatrix of 11 loci, we propose a new phylogeny of the Cophylinae, and discuss it in the context of a newly generated osteological dataset. We found several sample misidentifications, partially explaining their deviant results, and propose to resurrect the genera Platypelis and Stumpffia from the synonymy of Cophyla and Rhombophryne, respectively. We provide support for the previous genus-level taxonomy of this subfamily, and erect a new genus, Anilany gen. nov., in order to eliminate paraphyly of Stumpffia and to account for the osteological differences observed among these groups. Deep nodes in our phylogeny remain poorly supported, and future works will certainly refine our classification, but we are confident that these will not produce large-scale rearrangements.

  6. Mitochondrial cytochrome B phylogeny and historical biogeography of the Tohoku salamander, Hynobius lichenatus (Amphibia, Caudata).

    PubMed

    Aoki, Gen; Matsui, Masafumi; Nishikawa, Kanto

    2013-03-01

    The Tohoku salamander, Hynobius lichenatus Boulenger, 1883, is a lentic breeding species widespread throughout montane regions of northeastern Japan. To explore intraspecific genetic variation and infer evolutionary history of H. lichenatus, we performed mitochondrial DNA analysis (complete 1141 bp sequences of the mitochondrial cytochrome b gene) using 215 adult and larval individuals collected from 75 localities, encompassing known distributional range of the species. Hynobius lichenatus proved to be monophyletic, including three well-supported and geographically structured clades (Clade I from northern Kanto, Clade II from southern Tohoku, and Clade III from northern Tohoku). These clades, respectively, comprise several subclades, and show genetic distances as large as those seen between different species of Hynobius. Results of population statistic analyses indicate that all clades and most subclades have maintained high genetic diversity and demographic stability over long periods. Molecular dating indicates divergence in H. lichenatus concords with topographic evolution of northeastern Japan from late Miocene to early Pleistocene, suggesting that paleogeographic events in this region, such as orogenesis, sea level change, and volcanic activity, have been crucial for shaping genetic patterns and diversity in this species. Hynobius lichenatus greatly differs from many other animal species from northeastern Japan in its much older periods and the pattern of genetic differentiation, and is suggested as an old faunal element in this region.

  7. Chromosomal evolution in allopatric populations of the Odontophrynus occidentalis group (Amphibia, Anura) from western Argentina.

    PubMed

    Ruiz, I R; Ceis, J M; Beçak, W

    1982-01-01

    A karyological study of some populations of the Odontophrynus occidentalis group (2n = 22) from Argentina is reported. Ammoniacal silver (Ag-AS) and alkaline Giemsa (CBG) staining have been performed on specimens from La Rioja, Mendoza, Malargue, Tamelen, Tapiluque, Valcheta, and Meseta de Somuncura. All populations showed active ribosomal cistrons (NORs) on chromosome 11. Some metaphases of three specimens from Mendoza and five from La Rioja also showed bands on 9. Centromeric and telomeric C-bands were common to all populations, and a block of heterochromatin on both sides of the centromere of 2 was remarkable in all but the La Rioja populations. The specimens from La Rioja showed a similar block of heterochromatin on the short arm of 1. Taxonomic studies of several specimens from these localities revealed differences in larval development, glandular pattern, the size of specimens, etc. As a whole, biological as well as karyological features suggest that the isolated population at La Rioja is a separate entity, at the species level, as described elsewhere.

  8. Neoteny and progenesis as two heterochronic processes involved in paedomorphosis in Triturus alpestris (Amphibia: Caudata).

    PubMed Central

    Denoël, M; Joly, P

    2000-01-01

    Current theories on the evolution of paedomorphosis suppose that several ontogenetic pathways have appeared according to different selective pressures. The aim of this study was to find out whether two distinct processes can lead to paedomorphosis in the Alpine newt, Triturus alpestris. In this respect, we compared age structures of paedomorphic and metamorphic individuals in two newt populations where the two forms lived syntopically. Whereas paedomorphosis resulted in a slower rate of somatic development in one population, it resulted in an acceleration of sexual maturation in the other population. These processes correspond to neoteny and progenesis, respectively. These results suggest that phenotypic plasticity can result from contrasted ontogenetic pathways between two populations of the same species. They give support to models that consider gonadic development as the target of selection under different environmental pressures. PMID:10983835

  9. Two new Phrynobatrachus species (Amphibia: Anura: Phrynobatrachidae) from the Republic of the Congo.

    PubMed

    Rödel, Mark-Oliver; Burger, Marius; Zassi-Boulou, Ange Ghislain; Emmrich, Mike; Penner, Johannes; Barej, Michael F

    2015-10-14

    We describe two new species of puddle frogs, genus Phrynobatrachus, from the south-western Republic of the Congo. One of them, P. horsti sp. nov., occurs also in neighbouring Gabon and is morphologically most similar to the Cameroonian P. ruthbeateae. It differs from the latter species by smaller males with longer thighs and shanks. The new species comprises various colour morphs but always has less conspicuous black borders between flanks and belly than P. ruthbeateae. The distinct and large black axillary blotch of P. ruthbeateae is either much smaller in P. horsti sp. nov., or broken into numerous irregularly shaped smaller dots. Similarly, a black transversal line at the anterior ventral border of thighs and the black face mask is less distinct and irregularly delimitated in P. horsti sp. nov. when compared to P. ruthbeateae. The mean genetic difference in the sampled region of the 16S rRNA gene between P. horsti sp. nov. and 40 other western African congeners range from 3.66-18.10%. The second new species, P. mayokoensis sp. nov., differs from all other known congeners by the combination of a compact and warty body, the absence of a spiny eyelid tubercle and pedal webbing, a conspicuous black triangle on throat and anterior part of the belly, and a distinct large red blotch on the anterior-proximal surface of the thighs. It exhibited a mean genetic difference in the 16S rRNA to 40 other western African congeners ranging from 1.34-16.98%. The genetically most similar sequence stems from a GenBank entry of a Gabonese frog, determined as P. ogoensis. A comparison of the new species with P. ogoensis syntypes confirmed their specific distinctiveness, most convincingly underlined by the absence of pedal webbing in the new species and the pronounced pedal webbing in P. ogoensis. The GenBank entry thus most likely is based on a misidentification and P. mayokoensis sp. nov. may also occur in neighbouring Gabon. The discovery of the two new frog species is further evidence of the huge gap in our knowledge concerning the species richness in the Guineo-Congolian rainforests.

  10. Globuli ossei in the long limb bones of Pleurodeles waltl (Amphibia, Urodela, Salamandridae).

    PubMed

    Quilhac, Alexandra; de Ricqlès, Armand; Lamrous, Hayat; Zylberberg, Louise

    2014-11-01

    To date, little is known about the structure of the cells and the fibrillar matrix of the globuli ossei, globular structures showing histochemical properties of an osseous tissue, sometimes found in the resorption front of the hypertrophied cartilage in many tetrapods, and easily observed in the long bones of the Urodele Pleurodeles waltl. Here, we present the results obtained from the appendicular long bones of metamorphosed juveniles and subadults using histological and histochemical methods and transmission electron microscopy. The distal part of the cone-shaped cartilage contains a heterogeneous cell population composed of the typical "light" hypertrophic chondrocytes and scarce "dark" hypertrophic chondrocytes. The "dark" chondrocytes display ultrastructural characteristics suggesting that they probably undergo degeneration through chondroptosis. However, in the hypertrophic, calcified cartilage close to the erosion front by the marrow, several noninvaded chondrocytic lacunae retained cells that do not show any morphological characteristics of degeneration and that cannot be identified as regular chondrocytes or osteocytes. These modified chondrocytes that have lost their regular morphology, appear to be active in the terminal cartilage and synthesize collagen fibrils of a peculiar diameter intermediate between the Type I collagen found in bone and the Type II collagen characteristic of cartilage. It is suggested that the local occurrence of globuli ossei is linked to a low rate of longitudinal growth as is the case in the long bones of postmetamorphic urodeles.

  11. Chronic Exposure to Cadmium Disrupts the Adrenal Gland Activity of the Newt Triturus carnifex (Amphibia, Urodela)

    PubMed Central

    Gay, Flaminia; Laforgia, Vincenza; Caputo, Ivana; Esposito, Carla; Lepretti, Marilena

    2013-01-01

    We intended to verify the safety of the freshwater values established for cadmium by the European Community and the Italian Ministry of Health in drinking water (5 μg/L) and sewage waters (20 μg/L). Therefore, we chronically exposed the newt Triturus carnifex to 5 μg/L and 20 μg/L doses of cadmium, respectively, during 3 and 9 months and verified the effects on the adrenal gland. We evaluated the serum concentrations of adrenocorticotropic hormone (ACTH), corticosterone, aldosterone, norepinephrine, and epinephrine. During the 3-month exposure, both doses of cadmium decreased ACTH and corticosterone serum levels and increased aldosterone and epinephrine serum levels. During the 9-month exposure, the 5 μg/L dose decreased ACTH and increased aldosterone and epinephrine serum levels; the 20 μg/L dose decreased norepinephrine and epinephrine serum levels, without affecting the other hormones. It was concluded that (1) chronic exposure to the safety values established for cadmium disrupted the adrenal gland activity and (2) the effects of cadmium were related both to the length of exposure and the dose administered. Moreover, our results suggest probable risks to human health, due to the use of water contaminated by cadmium. PMID:23971036

  12. Ultrastructure of previtellogene oocytes in the neotenic cave salamander Proteus anguinus anguinus (Amphibia, Urodela, Proteidae).

    PubMed

    Mali, Lilijana Bizjak; Bulog, Boris

    2010-10-01

    Oogenesis in the neotenic, cave dwelling salamander Proteus anguinus anguinus has not been studied yet, and this study provides a detailed description of the early growth of the oocytes. Early previtellogene oocytes ranging from 100 to 600 µm in diameter were examined by light and transmission electron microscopy. The oocytes were divided into two stages based on size, color, and histology. Stage I oocytes can be identified by their transparent cytoplasm and a homogenous juxtanuclear mass, composed of numerous lipid droplets and mitochondria. Stage II oocytes are no longer transparent and have increased in diameter to 300- 600 µm, and many cortical alveoli differing in size have appeared. The common and most predominant ultrastructural characteristics of both stages of previtellogene oocytes are extensive quantities of smooth membrane, numerous mitochondria, and lipid droplets, as well as abundant free ribosomes. Myeline-like structures and remarkable annulate lamellae of closely packed membrane stacks are also frequently observed. Previtellogenic oocytes are the most predominant oocytes in the ovaries of Proteus, and while they possess certain structural characteristics typical for other amphibians, some features are unique and could result from adaptation to the subterranean environment.

  13. Historical Demography of an Endangered Salamander, Ranodon sibiricus (Amphibia, Urodela, Hynobiidae): A Reassessment.

    PubMed

    Nishikawa, Kanto; Dujsebayeva, Tatjana; Matsui, Masafumi; Yoshikawa, Natsuhiko; Tominaga, Atsushi

    2017-02-01

    Chinese populations of the endangered Siberian salamander Ranodon sibiricus are reported to have diverged only about 120 years ago, and to have the lowest genetic diversity of any amphibian. However, these conclusions require verification, as the main range of the species is in Kazakhstan. Moreover, the generation time used for estimating divergence time has a weak ground. In order to clarify these problems, we investigated the molecular phylogenetic relationship and historical demography of the species covering its whole distribution range using the mitochondrial DNA region reported for Chinese population (1072 bp sequences of the control region), while conducting skeletochronological analysis to estimate accurate generation time. As a result, the range expansion was estimated at 88,000-50,000 YA, based on the generation time of 6-10 years. Degree of intraspecific genetic differentiation is actually very small, but, as a single species, is not so small as had been reported for Chinese population alone.

  14. A new species of the genus Amolops (Amphibia: Ranidae) from southeastern Tibet, China

    PubMed Central

    JIANG, Ke; WANG, Kai; YAN, Fang; XIE, Jiang; ZOU, Da-Hu; LIU, Wu-Lin; JIANG, Jian-Ping; LI, Cheng; CHE, Jing

    2016-01-01

    A new species of the genus Amolops Cope, 1865 is described from Nyingchi, southeastern Tibet, China, based on morphological and molecular data. The new species, Amolops nyingchiensis sp. nov. is assigned to the Amolops monticola group based on its skin smooth, dorsolateral fold distinct, lateral side of head black, upper lip stripe white extending to the shoulder. Amolops nyingchiensis sp. nov. is distinguished from all other species of Amolops by the following combination of characters: (1) medium body size, SVL 48.5-58.3 mm in males, and 57.6-70.7 mm in females; (2) tympanum distinct, slightly larger than one third of the eye diameter; (3) a small tooth-like projection on anteromedial edge of mandible; (4) the absence of white spine on dorsal surface of body; (5) the presence of circummarginal groove on all fingers; (6) the presence of vomerine teeth; (7) background coloration of dorsal surface brown, lateral body gray with yellow; (8) the presence of transverse bands on the dorsal limbs; (9) the presence of nuptial pad on the first finger in males; (10) the absence of vocal sac in males. Taxonomic status of the populations that were previously identified to A. monticola from Tibet is also discussed. PMID:26828032

  15. The phylogenetic position and diversity of the enigmatic mongrel frog Nothophryne Poynton, 1963 (Amphibia, Anura).

    PubMed

    Bittencourt-Silva, Gabriela B; Conradie, Werner; Siu-Ting, Karen; Tolley, Krystal A; Channing, Alan; Cunningham, Michael; Farooq, Harith M; Menegon, Michele; Loader, Simon P

    2016-06-01

    The phylogenetic relationships of the African mongrel frog genus Nothophryne are poorly understood. We provide the first molecular assessment of the phylogenetic position of, and diversity within, this monotypic genus from across its range-the Afromontane regions of Malawi and Mozambique. Our analysis using a two-tiered phylogenetic approach allowed us to place the genus in Pyxicephalidae. Within the family, Nothophryne grouped with Tomopterna, a hypothesis judged significantly better than alternative hypotheses proposed based on morphology. Our analyses of populations across the range of Nothophryne suggest the presence of several cryptic species, at least one species per mountain. Formal recognition of these species is pending but there is a major conservation concern for these narrowly distributed populations in an area impacted by major habitat change. The phylogenetic tree of pyxicephalids is used to examine evolution of life history, ancestral habitat, and biogeography of this group. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Salinity tolerance of eggs of Buergeria japonica (Amphibia, Anura) inhabiting coastal areas.

    PubMed

    Haramura, Takashi

    2007-08-01

    Buergeria japonica is one of a few frogs that breed in coastal areas. To understand why this species can breed in coastal areas, I tested the salinity tolerance of eggs of B. japonica collected from a coastal area of Okinawa Island, Japan. All eggs hatched within four days after oviposition. At 0%. salinity (control), over 94% of eggs hatched normally, and even at 1 per thousand salinity over 85% of eggs hatched. Survival rate of eggs was low at 2, 3, and 4 per thousand, and no eggs hatched at 5 per thousand salinity. These results indicate that low salinity, close to pure water, is necessary for successful egg development, even for populations of B. japonica that breed in coastal areas. Future studies are necessary to examine whether females of B. japonica breeding in coastal areas select appropriate oviposition sites where the environmental salinity level is sufficiently low for eggs.

  17. Development and characterization of 14 microsatellite markers for Buergeria japonica (Amphibia, Anura, Rhacophoridae).

    PubMed

    Komaki, Shohei; Igawa, Takeshi; Nozawa, Masafumi; Lin, Si-Min; Oumi, Shohei; Sumida, Masayuki

    2014-01-01

    Buergeria japonica is a common frog species distributed throughout almost all islands in Ryukyu Archipelago. Because of their exceptionally wide distribution and higher physiological tolerance comparing to the other anurans, their demographic history and formation of distribution are intrinsic topics in the herpetological fauna of Ryukyu. Microsatellite marker is ideal genetic marker for such studies at inter- and intra-population level. We therefore developed microsatellite markers of B. japonica utilizing Ion PGM™ sequencing. As a result of the screening, we developed a total of 14 polymorphic markers. To test availabilities of these markers, we genotyped four island populations. The total number of alleles and expected hetelozygosities per locus ranged from 4 to 21 and 0.00 to 0.864, respectively. The phylogenetic relationship among the four populations based on the genetic distances of these markers was congruent with general divergence pattern of amphibians and reptiles in Ryukyu area. These markers developed in this study are considered to be useful for future studies about phylogeography and demography of this species.

  18. Reduced genetic variation in the Japanese giant salamander, Andrias japonicus (Amphibia: Caudata).

    PubMed

    Matsui, Masafumi; Tominaga, Atsushi; Liu, Wan-zhao; Tanaka-Ueno, Tomoko

    2008-10-01

    The phylogenetic relationships among 46 samples from 27 populations of the Japanese giant salamander, Andriasjaponicus and its congener, A. davidianus from China was investigated, using 3664 bp sequences of the mitochondrial genes NADH1, NADH3, cyt b and CR, partial NADH6 and intervening genes. In phylogenetic trees constructed by MP, ML, and Bayesian methods, the family Cryptobranchidae and the genus Andrias both form monophyletic groups. Japanese A. japonicus and Chinese A. davidianus are sister taxa and can be regarded as separate species despite a small degree of genetic differentiation. Andriasjaponicus is divided into central and western clades, but the phylogenetic relationships within the latter clade are unresolved. As previously reported from allozyme analyses, A. japonicus exhibits little genetic differentiation, in strong contrast to salamanders of the genus Hynobius with which their distributions overlap. This reduced genetic variability in A. japonicus is attributable to a unique mating system of polygyny, delayed sexual maturity, notable longevity, life in a stable aquatic environment, and gigantism, as well as bottleneck effects following habitat fragmentation and extinction of local populations during Quaternary glaciations. The species is thus susceptible to extinction by potential environmental fluctuations, and requires extensive conservation measures.

  19. A new species of nematode (Molineidae) from Rhinella marina (Amphibia: Bufonidae) in Guerrero, México.

    PubMed

    Ruiz-Torres, Nallely; García-Prieto, Luis; Osorio-Sarabia, David; Violante-González, Juan

    2013-06-01

    Oswaldocruzia lamotheargumedoi n. sp., inhabiting the intestine of the cane toad, Rhinella marina (L.), in Laguna de Coyuca, Guerrero, México, is described here. The new species differs from 10 congeners infecting bufonid hosts because it has a type I bursa. In contrast, 7 of these species have type II bursa and 3 more a type III bursa. The species most similar to the species described herein is Oswaldocruzia pipiens Walton, 1929 . These 2 species share traits such as body size, bursa type, presence of cervical alae, and dorsal ray morphology. Nevertheless, both species can be distinguished based on the number of synlophe ridges at mid-body (54-56 for O. lamotheargumedoi vs. 45-48 for O. pipiens) and by the presence of a chitinous support in the long, and well developed, cervical alae of O. pipiens. In the new species, these structures are short, poorly developed, and lack chitinous support. Previous records of species of Oswaldocruzia in México include Oswaldocruzia subauricularis (Rudolphi, 1819) Travassos, 1917 in the Neotropical Realm and O. pipiens in the Nearctic.

  20. Two new species of Amazophrynella (Amphibia: Anura: Bufonidae) from Loreto, Peru.

    PubMed

    Rojas, Rommel R; Carvalho, Vinícius Tadeu De; Ávila, Robson W; Farias, Izeni Pires; Gordo, Marcelo; Hrbek, Tomas

    2015-04-08

    Amazophrynella is a taxonomically poorly known bufonid genus with a pan-Amazonian distribution. A large part of this ambiguity comes from taxonomic uncertainties regarding the type species A. minuta. In this study we compare morphological and molecular data of topotypic specimens of A. minuta with all other nomical congeneric species. Based on these comparisons, we describe two new species. The first species, A. amazonicola sp. nov., differs from other recognized congeners by having a tip of snout with a small triangular protrusion (in dorsal and lateral view), spiculated body and basal webbing on fingers I and II. The second species, A. matses sp. nov., differs from congeners by the smallest snout to vent length of the genus, edges of nasal protrusion dilated and elliptical shape palmar tubercles. The two species are allopatric, where the first species is known to be associated with white sand forests (=campinaranas), while the second inhabits upland (=terra firme) forests. Both species are diagnosable by a series of substitutions in the 16S rDNA, and both species are highly divergent from their sister taxa (p-distances range from 7-14%).

  1. External morphology and oral cavity of the tadpole of Trachycephalus atlas Bokermann, 1966 (Amphibia, Anura, Hylidae).

    PubMed

    Barreto, Gilvana Santos; Ramos, Juliana Conceição; Mercês, Ednei De Almeida; Napoli, Marcelo Felgueiras; Garda, Adrian Antonio; Juncá, Flora Acuña

    2015-07-01

    The Neotropical genus Trachycephalus Tschudi currently comprises 14 species distributed in lowlands of Mexico, Central and South America east of the Andes, south until northern Argentina (Frost 2014) and throughout Brazil (IUCN 2014). Seven species of the genus have tadpoles formerly described: T. coriaceus (Peters) (Schiesari & Moreira 1996; Lescure et al. 1996), T. cunauaru Gordo, Toledo, Suárez, Kawashita-Ribeiro, Ávila, Morais & Nunes (Grillitsch 1992 as Phrynohyas resinifictrix according to Gordo et al. 2013), T. jordani (Stejneger & Test) (McDiarmid & Altig 1989-1990), T. mesophaeus (Hensel) (Lutz 1973; Carvalho-e-Silva et al. 2002; Prado et al. 2003), T. nigromaculatus Tschudi (Wogel et al. 2000), T. resinifictrix (Goeldi) (Hero 1990; Schiesari et al. 1996), and T. typhonius (Linnaeus) (Pyburn 1967; Duellman 1970; Schiesari et al. 1996). The oral cavity is described only for T. cunauaru (Grillitsch 1992), T. resinifictrix (Schiesari et al. 1996), and T. typhonius (Schiesari et al. 1996; Fabrezi & Vera 1997).

  2. Leptodactylus ocellatus (Amphibia): mechanism of defense in the skin and molecular phylogenetic relationships.

    PubMed

    Leite, João Manoel Almeida; Silva, Luciano Paulino; Silva-Leite, Roberta Rocha; Ferrari, Ana Stella; Noronha, Sergio Eustáquio; Silva, Helio Ricardo; Bloch, Carlos; Leite, José Roberto de Souza de Almeida

    2010-01-01

    Amphibian antimicrobial peptides have been known for many decades and several of them have already been isolated. However, the number of species investigated is still small. Herein, we report on the skin secretions of Leptodactylus ocellatus, which were extracted by mild electrical stimulation and its semi-preparative reverse-phase chromatography was resolved in more than 30 fractions. Among these fractions, two novel antimicrobial peptides were isolated and their amino acid sequences determined by de novo sequencing. The ocellatins-5 and -6 (21 and 22 amino acid residues, respectively) are amidated at the C-terminus. Ocellatins inhibited the growth of reference strains of both Gram-negative bacteria (Escherichia coli) and Gram-positive bacteria (Staphylococcus aureus) with minimal inhibition concentration values in the range of 32-128 microg/mL. The amino acid sequence of the peptides shows structural similarity with members of the antimicrobial peptides found in the skin secretion of other leptodactylid frogs. This observation is consistent with the hypothesis that many frog skin antimicrobial peptides are related evolutionarily, having arisen from multiple duplications of an ancestral gene that existed before the radiation of the different species. (c) 2009 Wiley-Liss, Inc.

  3. A new species of Noblella (Amphibia, Anura, Craugastoridae) from the humid montane forests of Cusco, Peru.

    PubMed

    Catenazzi, Alessandro; Uscapi, Vanessa; von May, Rudolf

    2015-01-01

    A new species of Noblella is described from the humid montane forest of the Región Cusco in Peru. Specimens were collected at 2330-2370 m elevation in Madre Selva, near Santa Ana, in the province of La Convención. The new species is readily distinguished from all other species of Noblella by having a broad, irregularly shaped, white mark on black background on chest and belly. The new species further differs from known Peruvian species of Noblella by the combination of the following characters: tympanic membrane absent, small tubercles on the upper eyelid and on dorsum, tarsal tubercles or folds absent, tips of digits not expanded, no circumferential grooves on digits, dark brown facial mask and lateral band extending from the tip of the snout to the inguinal region. The new species has a snout-to-vent length of 15.6 mm in one adult male and 17.6 mm in one adult female. Like other recently described species in the genus, this new Noblella inhabits high-elevation forests in the Andes and likely has a restricted geographic distribution.

  4. Population Genetic Structure of the Endangered Kaiser’s Mountain Newt, Neurergus kaiseri (Amphibia: Salamandridae)

    PubMed Central

    Farasat, Hossein; Akmali, Vahid; Sharifi, Mozafar

    2016-01-01

    Species often exhibit different levels of genetic structuring correlated to their environment. However, understanding how environmental heterogeneity influences genetic variation is difficult because the effects of gene flow, drift and selection are confounded. We investigated the genetic variation and its ecological correlates in an endemic and critically endangered stream breeding mountain newt, Neurergus kaiseri, within its entire range in southwestern Iran. We identified two geographic regions based on phylogenetic relationships using Bayesian inference and maximum likelihood of 779 bp mtDNA (D-loop) in 111 individuals from ten of twelve known breeding populations. This analysis revealed a clear divergence between northern populations, located in more humid habitats at higher elevation, and southern populations, from drier habitats at lower elevations regions. From seven haplotypes found in these populations none was shared between the two regions. Analysis of molecular variance (AMOVA) of N. kaiseri indicates that 94.03% of sequence variation is distributed among newt populations and 5.97% within them. Moreover, a high degree of genetic subdivision, mainly attributable to the existence of significant variance among the two regions is shown (θCT = 0.94, P = 0.002). The positive and significant correlation between geographic and genetic distances (r = 0.61, P = 0.002) following controlling for environmental distance suggests an important influence of geographic divergence of the sites in shaping the genetic variation and may provide tools for a possible conservation based prioritization policy for the endangered species. PMID:26918642

  5. The 100th: An appealing new species of Dendropsophus (Amphibia: Anura: Hylidae) from northeastern Brazil.

    PubMed

    Dias, Iuri Ribeiro; Haddad, Célio Fernando Baptista; Argôlo, Antônio Jorge Suzart; Orrico, Victor Goyannes Dill

    2017-01-01

    We describe a new species of the Dendropsophus leucophyllatus Group from the Atlantic Forest of the southern region of State of Bahia, Brazil. It can be distinguished from all species of the D. leucophyllatus Group on the basis of morphological characters (especially its unique dorsal pattern and snout in dorsal view), advertisement calls and divergence in mitochondrial DNA gene sequences. The inclusion of D. anceps on the group remains controversial but our phylogenetic analyses do not recover the new species as sister to syntopic species of the D. leucophyllatus Group (with or without D. anceps). These results also highlight the palimpsest that is past relation between the Atlantic and Amazon forests.

  6. Descriptions and biological notes on three unusual mantellid tadpoles (Amphibia: Anura: Mantellidae) from southeastern Madagascar

    USGS Publications Warehouse

    Altig, R.; McDiarmid, R.W.

    2006-01-01

    The morphologies of three unusual tadpoles from slow-flowing, sandy-bottomed, rain forest streams in southeastern Madagascar are described. The large oral apparatus of the tadpole of Boophis picturatus Glaw, Vences, Andreone, and Vallan, 2001 lacks all keratinized structures and has an elaborately-folded lower labium with five, radially oriented, flattopped ridges. The tadpole of Mantidactylus guttulatus (Boulenger, 1881) lacks all keratinized mouthparts and has three immense papillae where the upper jaw normally occurs. The tadpole of Mantidactylus lugubris (Dumeril, 1853) has an ornate oral apparatus involving greatly hypertrophied derivatives of jaw serrations and unique structures on the lower labium that resemble labial teeth.

  7. Extreme negative temperatures and body mass loss in the Siberian salamander (Salamandrella keyserlingii, amphibia, hynobiidae).

    PubMed

    Berman, D I; Meshcheryakova, E N; Bulakhova, N A

    2016-05-01

    Frozen Siberian salamander safely tolerates long (45 days) stay at-35°C. Short-term (3 days) cooling down to-50°C was tolerable for 40% of adult individuals; down to-55°C, for 80% of the underyearlings. Generally, the salamanders lose about 28% of the body mass during the pre-hibernating period (before winter, at temperatures as low as 0°C) and during the process of freezing (as low as-5°C). The body weight remained constant upon further cooling (to-35°C). The frozen salamanders have no physiological mechanisms protecting from sublimation.

  8. A new species of lentic breeding Korean salamander of the genus Hynobius (Amphibia, Urodela).

    PubMed

    Kim, Jong-Bum; Min, Mi-Sook; Matsui, Masafumi

    2003-09-01

    A new species of salamander, Hynobius yangi, is described from Kori (=Hyoam-ri), Busan-shi, southeastern Korea. It is a lentic breeder belonging to the H. nebulosus species group, and has long been confused with another Korean species H. leechii. The new species, however, is genetically substantially differentiated from Korean and Japanese relatives. Hynobius yangi is morphologically very similar to H. leechii, but could be differentiated from it by the tail shape, degree of limb separation, shape of vomerine teeth series, shape of egg sac, and dorsal coloration.

  9. A new species of salamander of the genus Hynobius from Central Honshu, Japan (Amphibia, Urodela).

    PubMed

    Matsui, Masafumi; Kokuryo, Yasuhiro; Misawa, Yasuchika; Nishikawa, Kanto

    2004-06-01

    We describe a small salamander from south Central Honshu, Japan, as a new species, Hynobius katoi. The genetic distances between this species and several named species, including sympatric H. kimurae, derived from allozyme data from a starch gel electrophoresis, proved to be sufficiently large to differentiate it at a specific rank. Distribution of this species is confined to the montane regions of Shizuoka and Nagano Prefectures, on the Akaishi Mountains of the Chubu District, central Japan. It is regarded as a member of the naevius group of Hynobius, characterized by small number of large, pigmentless ova. The species differs from the other species of the naevius group by the combination of relatively small body size, nearly spotless body, relatively few vomerine teeth forming moderately shallow series, and unique electrophoretic pattern of isozymes.

  10. A new species of Noblella (Amphibia, Anura, Craugastoridae) from the humid montane forests of Cusco, Peru

    PubMed Central

    Catenazzi, Alessandro; Uscapi, Vanessa; von May, Rudolf

    2015-01-01

    Abstract A new species of Noblella is described from the humid montane forest of the Región Cusco in Peru. Specimens were collected at 2330–2370 m elevation in Madre Selva, near Santa Ana, in the province of La Convención. The new species is readily distinguished from all other species of Noblella by having a broad, irregularly shaped, white mark on black background on chest and belly. The new species further differs from known Peruvian species of Noblella by the combination of the following characters: tympanic membrane absent, small tubercles on the upper eyelid and on dorsum, tarsal tubercles or folds absent, tips of digits not expanded, no circumferential grooves on digits, dark brown facial mask and lateral band extending from the tip of the snout to the inguinal region. The new species has a snout-to-vent length of 15.6 mm in one adult male and 17.6 mm in one adult female. Like other recently described species in the genus, this new Noblella inhabits high-elevation forests in the Andes and likely has a restricted geographic distribution. PMID:26312020

  11. New Material of Beelzebufo, a Hyperossified Frog (Amphibia: Anura) from the Late Cretaceous of Madagascar

    PubMed Central

    Evans, Susan E.; Groenke, Joseph R.; Jones, Marc E. H.; Turner, Alan H.; Krause, David W.

    2014-01-01

    The extant anuran fauna of Madagascar is exceptionally rich and almost completely endemic. In recent years, many new species have been described and understanding of the history and relationships of this fauna has been greatly advanced by molecular studies, but very little is known of the fossil history of frogs on the island. Beelzebufo ampinga, the first named pre-Holocene frog from Madagascar, was described in 2008 on the basis of numerous disarticulated cranial and postcranial elements from the Upper Cretaceous (Maastrichtian) Maevarano Formation of Madagascar. These specimens documented the presence of a hyperossified taxon that differed strikingly from extant Malagasy frogs in its large size and heavy coarse cranial exostosis. Here we describe and analyse new, articulated, and more complete material of the skull, vertebral column, and hind limb, as well as additional isolated elements discovered since 2008. μCT scans allow a detailed understanding of both internal and external morphology and permit a more accurate reconstruction. The new material shows Beelzebufo to have been even more bizarre than originally interpreted, with large posterolateral skull flanges and sculptured vertebral spine tables. The apparent absence of a tympanic membrane, the strong cranial exostosis, and vertebral morphology suggest it may have burrowed during seasonally arid conditions, which have been interpreted for the Maevarano Formation from independent sedimentological and taphonomic evidence. New phylogenetic analyses, incorporating both morphological and molecular data, continue to place Beelzebufo with hyloid rather than ranoid frogs. Within Hyloidea, Beelzebufo still groups with the South American Ceratophryidae thus continuing to pose difficulties with both biogeographic interpretations and prior molecular divergence dates. PMID:24489877

  12. Variability of tetrodotoxin and of its analogues in the red-spotted newt, Notophthalmus viridescens (Amphibia: Urodela: Salamandridae).

    PubMed

    Yotsu-Yamashita, Mari; Gilhen, John; Russell, Ronald W; Krysko, Kenneth L; Melaun, Christian; Kurz, Alexander; Kauferstein, Silke; Kordis, Dusan; Mebs, Dietrich

    2012-02-01

    Efts and adult specimens (n = 142) of the red-spotted newt Notophthalmus viridescens from various locations in Canada and USA were analyzed for the presence of tetrodotoxin (TTX) and of its analogues 6-epitetrodotoxin and 11-oxotetrodotoxin. Considerable individual variations in toxin levels were found within and among populations from New Hampshire, New York, Pennsylvania, and Virginia ranging from non-detectable to 69 μg TTX per g newt. TTX and its analogues were absent in efts and adults from various locations in the Canadian province Nova Scotia, the northernmost distribution of the newt, and in adults from Florida. Newts kept in captivity for several years and reared on toxin-free diet lost their toxicity. Bayesian and maximum likelihood phylogenetic analysis of specimens from the various populations using three phylogenetic markers (COI, ND2 and 16S RNA) revealed that populations from the northern states of the USA and Canada are genetically homogenous, whereas the newts from Florida exhibited a much higher level of genetic divergence. An exogenous source of TTX in the newts either via the food chain or by synthesis of symbiotic bacteria is suggested to explain the high variability and lack of TTX in certain populations.

  13. Why are the prevalence and diversity of helminths in the endemic Pyrenean brook newt Calotriton asper (Amphibia, Salamandridae) so low?

    PubMed

    Comas, M; Ribas, A

    2015-03-01

    A cornerstone in parasitology is why some species or populations are more parasitized than others. Here we examine the influence of host characteristics and habitat on parasite prevalence. We studied the helminths parasitizing the Pyrenean brook newt Calotriton asper (n= 167), paying special attention to the relationship between parasites and ecological factors such as habitat, sex, ontogeny, body size and age of the host. We detected two species of parasites, Megalobatrachonema terdentatum (Nematoda: Kathlaniidae) and Brachycoelium salamandrae (Trematoda: Brachycoeliidae), with a prevalence of 5.99% and 1.2%, respectively. Marginally significant differences were found in the prevalence between sexes, with females being more parasitized than males. The present results show significant differences in the body length of paedomorphic and metamorphic individuals, the former being smaller. Nevertheless, no significant correlations between parasite prevalence and either newt body length, ontogenetic stage or age were found. In comparison with other Salamandridae living in ponds, prevalence and diversity values were low. This may be due to a long hibernation period, the species' lotic habitat and its reophilous lifestyle, which probably do not allow for a high parasite load.

  14. Description of the tadpoles of three rare species of megophryid frogs (Amphibia: Anura: Megophryidae) from Gunung Mulu, Sarawak, Malaysia.

    PubMed

    Oberhummer, Evelyne; Barten, Catherin; Schweizer, Manuel; Das, Indraneil; Haas, Alexander; Hertwig, Stefan T

    2014-07-09

    The megophryid frogs Leptobrachella brevicrus, Leptolalax dringi and Megophrys dringi are species exclusively known  from highly localised areas in isolated mountain ranges on Borneo. The tadpoles and adults in this study were collected at the shared type locality for the three species in Gunung Mulu National Park, Sarawak, Malaysia (Borneo). The species identities of larvae were determined via comparison to syntopic adults using DNA barcoding techniques based on partial 16S rRNA mitochondrial gene sequences. The genetic data supported the status of the three taxa as valid species. Descriptions of colouration in life and after preservation, external morphological features, morphometric measurements and ecological notes in comparison to congeneric species are supplied. The tadpoles of L. brevicrus and L. dringi show similar adaptations to a fossorial lifestyle. These include an elongated, vermiform body, a relatively long tail and small eyes. Both were found in the gravel beds of a small mountain stream. In contrast, the larvae of M. dringi are adapted to occupying and feeding at the surface of pools within the stream. 

  15. Lsh Is Essential for Maintaining Global DNA Methylation Levels in Amphibia and Fish and Interacts Directly with Dnmt1

    PubMed Central

    Dunican, Donncha S.; Pennings, Sari; Meehan, Richard R.

    2015-01-01

    Eukaryotic genomes are methylated at cytosine bases in the context of CpG dinucleotides, a pattern which is maintained through cell division by the DNA methyltransferase Dnmt1. Dramatic methylation losses are observed in plant and mouse cells lacking Lsh (lymphoid specific helicase), predominantly at repetitive sequences and gene promoters. However, the mechanism by which Lsh contributes to the maintenance of DNA methylation is unknown. Here we show that DNA methylation is lost in Lsh depleted frog and fish embryos, both of which exhibit developmental delay. Additionally, we show that both Lsh and Dnmt1 are associated with chromatin and that Lsh knockdown leads to a decreased Dnmt1-chromatin association. Coimmunoprecipitation experiments reveal that Lsh and Dnmt1 are found in the same protein complex, and pulldowns show this interaction is direct. Our data indicate that Lsh is usually diffuse in the nucleus but can be recruited to heterochromatin in a HP1α-dependent manner. These data together (a) show that the role of Lsh in DNA methylation is conserved in plants, amphibian, fish, and mice and (b) support a model in which Lsh contributes to Dnmt1 binding to chromatin, explaining how its loss can potentially lead to perturbations in DNA methylation maintenance. PMID:26491684

  16. Morphological characterization of Eustrongylides sp. larvae (Nematoda, Dioctophymatoidea) parasite of Rhinella marina (Amphibia: Bufonidae) from Eastern Amazonia.

    PubMed

    Melo, Francisco Tiago de Vasconcelos; Melo, Caroline do Socorro Barros; Nascimento, Luciana de Cássia Silva do; Giese, Elane Guerreiro; Furtado, Adriano Penha; Santos, Jeannie Nascimento Dos

    2016-06-07

    Absctract Eustrongylides spp. nematodes have birds as final hosts and uses other vertebrates as intermediate/paratenic host (fish, amphibians and reptiles) and have zoonotic potential. In amphibians, the larvae may be located in the subcutaneous tissues, liver and mesentery, between the muscle fibres, especially in the lower limbs. Rhinella marina, which is widely observed in Brazil, has exhibited complex diversity in its helminth fauna, reflecting the unique habitat of the Amazon biome. For the first time, this study describes the morphological aspects of third-stage larvae of Eustrongylides sp. in Rhinella marina from Santa Cruz do Ararí, Marajó Archipelago, Eastern Amazonia, using light and scanning electron microscopy.

  17. Rhabdias paraensis sp. nov.: a parasite of the lungs of Rhinella marina (Amphibia: Bufonidae) from Brazilian Amazonia.

    PubMed

    Santos, Jeannie Nascimento dos; Melo, Francisco Tiago de Vasconcelos; Nascimento, Luciana de Cássia Silva do; Nascimento, Daisy Esther Batista do; Giese, Elane Guerreiro; Furtado, Adriano Penha

    2011-06-01

    The nematode parasites of Rhinella marina include species of the genus Rhabdias (Rhabdiasidae: Rhabditoidea). The present study describes Rhabdias paraensis sp. nov., which parasitizes the lungs of R. marina in Brazilian Amazonia. Of the more than 70 known species of this genus, 18 are parasites of bufonids, of which, eight are Neotropical. The new species described here is similar to Rhabdias alabialis in the absence of lips is different by the presence of conspicuous cephalic papillae. We describe details of the four rows of pores, which are distributed equally along the whole of the length of the body and connected with hypodermal cells, using histology and scanning electron microscopy. Other histological aspects of the internal structure of this nematode are also described.

  18. Morphological characterization of Eustrongylides sp. larvae (Nematoda, Dioctophymatoidea) parasite of Rhinella marina (Amphibia: Bufonidae) from Eastern Amazonia.

    PubMed

    Melo, Francisco Tiago de Vasconcelos; Melo, Caroline do Socorro Barros; Nascimento, Luciana de Cássia Silva do; Giese, Elane Guerreiro; Furtado, Adriano Penha; Santos, Jeannie Nascimento Dos

    2016-06-07

    Absctract Eustrongylides spp. nematodes have birds as final hosts and uses other vertebrates as intermediate/paratenic host (fish, amphibians and reptiles) and have zoonotic potential. In amphibians, the larvae may be located in the subcutaneous tissues, liver and mesentery, between the muscle fibres, especially in the lower limbs. Rhinella marina, which is widely observed in Brazil, has exhibited complex diversity in its helminth fauna, reflecting the unique habitat of the Amazon biome. For the first time, this study describes the morphological aspects of third-stage larvae of Eustrongylides sp. in Rhinella marina from Santa Cruz do Ararí, Marajó Archipelago, Eastern Amazonia, using light and scanning electron microscopy.

  19. Long bone histology of the stem salamander Kokartus honorarius (Amphibia: Caudata) from the Middle Jurassic of Kyrgyzstan.

    PubMed

    Skutschas, Pavel; Stein, Koen

    2015-04-01

    Kokartus honorarius from the Middle Jurassic (Bathonian) of Kyrgyzstan is one of the oldest salamanders in the fossil record, characterized by a mixture of plesiomorphic morphological features and characters shared with crown-group salamanders. Here we present a detailed histological analysis of its long bones. The analysis of a growth series demonstrates a significant histological maturation during ontogeny, expressed by the progressive appearance of longitudinally oriented primary vascular canals, primary osteons, growth marks, remodelling features in primary bone tissues, as well as progressive resorption of the calcified cartilage, formation of endochondral bone and development of cartilaginous to bony trabeculae in the epiphyses. Apart from the presence of secondary osteons, the long bone histology of Kokartus is very similar to that of miniaturized temnospondyls, other Jurassic stem salamanders, miniaturized seymouriamorphs and modern crown-group salamanders. We propose that the presence of secondary osteons in Kokartus honorarius is a plesiomorphic feature, and the loss of secondary osteons in the long bones of crown-group salamanders as well as in those of miniaturized temnospondyls is the result of miniaturization processes. Hitherto, all stem salamander long bong histology (Kokartus, Marmorerpeton and 'salamander A') has been generally described as having paedomorphic features (i.e. the presence of Katschenko's Line and a layer of calcified cartilage), these taxa were thus most likely neotenic forms. The absence of clear lines of arrested growth and annuli in long bones of Kokartus honorarius suggests that the animals lived in an environment with stable local conditions. © 2015 Anatomical Society.

  20. [Microstructure comparison of jaw sheaths between the Megophryid tadpoles (Amphibia, Anura) by the technology of electron microscope].

    PubMed

    Li, Cheng; Dong, Zhao-xiong; Wang, Yue-zhao

    2010-10-01

    The jaw sheaths morphology of eight megophryid larvae were examined using scanning electron microscope. The morphology of jaw sheaths of Leptobrachiinae and Leptolalaginae larvae was similar. Their jaw sheaths were U-shaped and strong keratinized, the serrations were pyramidal, with broad-based and short pointed. While the jaw sheaths of Megophryinae larvae were less curved and weak keratinized, the serrations were ivory-shaped, with narrow-based and long pointed. It has been found that the relationship between serration's diameter and density was negatively correlated, the changing trend reflected the functional significance of serrations. These distinctions among the jaw sheaths of tadpoles most could be related to their specific ecological habits and to their dietary specializations.

  1. First record of the tree-frog genus Chiromantis from Borneo with the description of a new species (Amphibia: Rhacophoridae).

    PubMed

    Matsui, Masafumi; Shimada, Tomohiko; Sudin, Ahmad

    2014-01-01

    We record a tree frog of the genus Chiromantis for the first time from outside the Southeast Asian continent and describe it as a new species, Chiromantis inexpectatus. The new species from the Malaysian state of Sabah, Borneo, is a small-sized Chiromantis (male snout-vent length ca. 22 mm), and is distinguished from all other members of the genus by the combination of the following morphological characteristics: dark stripes absent, but dark spots present on dorsum; a dark-brown lateral band present from snout tip to half of body, bordered ventrally by white stripe; third and fourth fingers less than half webbed; third finger disk wider than tympanum diameter; and inner metatarsal tubercle present. Significance of findings of this species from Borneo Island, as well as phylogeny and breeding habit of the genus Chiromantis, are briefly discussed.

  2. Development and growth of long bones in European water frogs (Amphibia: Anura: Ranidae), with remarks on age determination.

    PubMed

    Rozenblut, Beata; Ogielska, Maria

    2005-09-01

    Differentiation and development of long bones were studied in European water frogs: Rana lessonae, R. ridibunda, and R. esculenta. The study included premetamorphic larvae (Gosner Stage 40) to frogs that were 5 years old. Femora, metatarsal bones, and proximal phalanges of the hindlimb exhibit the same pattern of periosteal bone differentiation and the same pattern of growth. Longitudinal and radial growth of these bones was studied by examination of the diaphyses and epiphyses, particularly where the edge of periosteal bone is inserted into the epiphysis. The periosteum seems to be responsible for both longitudinal and radial growth. Investigation of the formation, length, and arrangement of lines of arrested growth reveals that the first line is present only in the middle 25-35% of the length of the diaphysis of an adult bone; therefore, only the central portion of the diaphysis should be used for age estimation in skeletochronological studies. Comparison of the shapes and histological structures of epiphyses in the femur, metatarsal bones, and phalanges revealed that epiphyseal cartilages are composed of an inner and outer part. The inner metaphyseal cartilage has distinct zones and plugs the end of the periosteal bone cylinder; its role in longitudinal growth is questioned. The outer epiphyseal cartilage is composed of articular cartilages proper, in addition to lateral articular cartilages. Differences in the symmetry of the lateral articular cartilages of distal epiphyses of the femur and toes may reflect adaptations to different kinds of movements at the knee and in the foot.

  3. Ultrastructure variation in the spermatozoa of Pseudopaludicola frogs (Amphibia, Anura, Leptodactylidae), with brief comments on its phylogenetic relevance.

    PubMed

    dos Santos, Julio Sérgio; Introíni, Gisele Orlandi; Veiga-Menoncello, Ana Cristina Prado; Recco-Pimentel, Shirlei Maria

    2015-12-01

    The taxonomic history of the small frogs of the genus Pseudopaludicola from South America has been controversial. Phylogenetic inferences based on molecular data have identified four Pseudopaludicola clades, correlating with the known variation in karyotypes (2n = 22, 20, 18, and 16). In this study, the ultrastructure of the spermatozoa was analyzed in 12 species of the Pseudopaludicola, with the aim of describing their morphology and identifying characters that may contribute to a better understanding of the phylogenetic relationships. The spermatozoa presented marked differences in tail structures. The tails of the spermatozoa of the species with 2n = 22 chromosomes (Pseudopaludicola sp. 1 [P. pusilla group], Pseudopaludicola falcipes, P. mineira, and Pseudopaludicola saltica), as well as Pseudopaludicola ameghini and Pseudopaludicola ternetzi (2n=20), have juxta-axonemal fibers, undulating membranes and axial fibers. In contrast, in the species with 2n = 18 (P. facureae, P. giarettai, Pseudopaludicola canga, P. atragula, and Pseudopaludicola sp. 2) and 2n = 16 (Pseudopaludicola mystacalis), there are no evident axial or juxta-axonemal fibers, but a paraxonemal rod with a thick undulating membrane, which is shorter than that found among Pseudopaludicola species. The ultrastructural morphological differences observed in the spermatozoa of these species may be phylogenetically informative, given that they coincide with the consensus phylogeny of the group and appear to represent a progressive simplification of the spermatozoon.

  4. [Ploidy and genetic structure of hybrid populations of water frogs Pelophylax esculentus (L., 1758) complex (Amphibia, Ranidae) of Ukraine].

    PubMed

    Mezhzherin, S V; Morozov-Leonov, S Iu; Rostovskaia, O V; Shabanov, D A; Sobolenko, L Iu

    2010-01-01

    The present study of green frog hybrid populations of Ukraine, including analysis of allozyme variability and planimetric analysis oferythrocytes size has confirmed that the unique region in this area is the Severski Donets basin The allopolyploid individuals there are met very frequently (5.7% of all investigated frogs). In other areas of Ukraine only two polyploid hybrids have been recorded. Beside that, one frog was defined as triploid Rana ridibundus. According to our investigations, all triploid hybrids from the Severski Donets basin are identified as P. esculentu (=lessonae)--2 ridibundus males.

  5. A new species of the genus Odorrana (Amphibia: Ranidae) and the first record of Odorrana bacboensis from China.

    PubMed

    Wang, Ying-Yong; Lau, Michael Wai-Neng; Yang, Jian-Huan; Chen, Guo-Ling; Liu, Zu-Yao; Pang, Hong; Liu, Yang

    2015-08-10

    The genus Odorrana currently contains at least 56 recognized species that inhabits montane streams in subtropical and tropical Asia. Twenty new species have been described in the last decade, indicating the potential cryptic species diversity of this genus. We collected several specimens of Odorrana species from Southern China from 2007 to 2014, and on the basis of a combined morphological characters and phylogenetic analysis, we described the new species Odorrana fengkaiensis sp. nov. herein. The new species is very similar to O. hainanensis and O. bacboensis, but can be consistently separated by morphology, and allopatric distribution. It is further reciprocally monophyletic to O. hainanensis in a mitochondrial gene trees with an average genetic divergence of 2.1% (1.9%-2.4%). The new species inhabits in lowland broad streams, rivers, pools and near the riparian areas, but its general ecology remains poorly known. The new species is characterized by its body length of adult females approximately twice as long as adult males (SVL 77.8-111.9 mm in females, 37.4-51.8 mm in males); eye large in males, eye diameter 1.01-1.16 times as long as snout length; tympanum of males large and distinct, extremely close to the eye, 0.7-1.4 mm in tympanum-eye distance; dorsolateral folds absent; dorsal skin shagreened, with several large tubercles in males; flanks with tubercles and scattered larger pustules, 8-10 of which usually arranged in a dorsolateral row; ventral skin smooth, with spines in adult males during the breeding season; the tibio-tarsal articulation stretched forward beyond the tip of snout; relative finger lengths: II < I < IV < III; dorsum brown with irregularly reticulated green markings in males and young females, uniformly brown in some old adult females; males with velvety nuptial pad on thumb, paired gular pouches; mature oocytes almost purely black in life, showed dark grey animal pole and olive vegetative pole in preservative. In addition, we found O. bacboensis, a new country record from China, indicating a range extension from north-central Vietnam to southeast Yunnan and adjacent area in Guangxi.

  6. Thyroid hormones in the skeletogenesis and accessory sources of endogenous hormones in Xenopus laevis (Amphibia; Anura) ontogeny: Experimental evidence.

    PubMed

    Smirnov, S V; Vassilieva, A B

    2014-03-01

    Skeletal development was studied in normal and goitrogen-treated Xenopus laevis tadpoles reared under thyroid hormone (TH) deficiency. Early stages of skeletal development proceed similarly in both groups. Later stages are retarded or completely arrested in goitrogen-treated tadpoles. After goitrogen-treated tadpoles were transferred into pure water or into a medium containing both goitrogen and exogenous TH, tadpoles resumed development. Consequently, late stages of skeletogenesis are TH-dependent and TH-induced. Athyroid X. laevis "giant tadpoles" described in literature differ from goitrogen-arrested tadpoles in that they have features which require TH to appear. The appearance of TH-depended features in giant tadpoles indicates the occurrence of the additional sources of TH other than thyroid gland.

  7. COI is better than 16S rRNA for DNA barcoding Asiatic salamanders (Amphibia: Caudata: Hynobiidae).

    PubMed

    Xia, Yun; Gu, Hai-Feng; Peng, Rui; Chen, Qin; Zheng, Yu-Chi; Murphy, Robert W; Zeng, Xiao-Mao

    2012-01-01

    The 5' region of the mitochondrial DNA (mtDNA) gene cytochrome c oxidase I (COI) is the standard marker for DNA barcoding. However, because COI tends to be highly variable in amphibians, sequencing is often challenging. Consequently, another mtDNA gene, 16S rRNA gene, is often advocated for amphibian barcoding. Herein, we directly compare the usefulness of COI and 16S in discriminating species of hynobiid salamanders using 130 individuals. Species identification and classification of these animals, which are endemic to Asia, are often based on morphology only. Analysis of Kimura 2-parameter genetic distances (K2P) documents the mean intraspecific variation for COI and 16S rRNA genes to be 1.4% and 0.3%, respectively. Whereas COI can always identify species, sometimes 16S cannot. Intra- and interspecific genetic divergences occasionally overlap in both markers, thus reducing the value of a barcoding gap to identify genera. Regardless, COI is the better DNA barcoding marker for hynobiids. In addition to the comparison of two potential markers, high levels of intraspecific divergence in COI (>5%) suggest that both Onychodactylus fischeri and Salamandrella keyserlingii might be composites of cryptic species.

  8. An evaluation of transcriptome-based exon capture for frog phylogenomics across multiple scales of divergence (Class: Amphibia, Order: Anura).

    PubMed

    Portik, Daniel M; Smith, Lydia L; Bi, Ke

    2016-09-01

    Custom sequence capture experiments are becoming an efficient approach for gathering large sets of orthologous markers in nonmodel organisms. Transcriptome-based exon capture utilizes transcript sequences to design capture probes, typically using a reference genome to identify intron-exon boundaries to exclude shorter exons (<200 bp). Here, we test directly using transcript sequences for probe design, which are often composed of multiple exons of varying lengths. Using 1260 orthologous transcripts, we conducted sequence captures across multiple phylogenetic scales for frogs, including outgroups ~100 Myr divergent from the ingroup. We recovered a large phylogenomic data set consisting of sequence alignments for 1047 of the 1260 transcriptome-based loci (~561 000 bp) and a large quantity of highly variable regions flanking the exons in transcripts (~70 000 bp), the latter improving substantially by only including ingroup species (~797 000 bp). We recovered both shorter (<100 bp) and longer exons (>200 bp), with no major reduction in coverage towards the ends of exons. We observed significant differences in the performance of blocking oligos for target enrichment and nontarget depletion during captures, and differences in PCR duplication rates resulting from the number of individuals pooled for capture reactions. We explicitly tested the effects of phylogenetic distance on capture sensitivity, specificity, and missing data, and provide a baseline estimate of expectations for these metrics based on a priori knowledge of nuclear pairwise differences among samples. We provide recommendations for transcriptome-based exon capture design based on our results, cost estimates and offer multiple pipelines for data assembly and analysis.

  9. Correlations of geographic distribution and temperature of embryonic development with the nuclear DNA content in the Salamandridae (Urodela, Amphibia).

    PubMed

    Litvinchuk, Spartak N; Rosanov, Jury M; Borkin, Leo J

    2007-04-01

    We used flow cytometry to measure the nuclear DNA content in erythrocytes of 27 salamandrid species. Across these species, diploid genome size varied more than 2 fold (51.3-104.4 pg). According to genome size and geographic distribution, 3 groups of newt species were recognized: West Palearctics with smaller amounts of nuclear DNA; Nearctic, with intermediate values; and East Asiatic, with higher genome sizes. Viviparous West Palearctic salamanders differed from most of the oviparous West Palearctic newts in possessing larger genome sizes. The nuclear DNA content strongly correlates with species range limits. At the same temperature, embryos of salamandrid species with larger genome sizes have a markedly longer developmental time than those with smaller genomes. We present an analysis of the relationships between the amount of nuclear DNA and water temperature at the breeding sites.

  10. A new golden frog species of the genus Diasporus (Amphibia, Eleutherodactylidae) from the Cordillera Central, western Panama

    PubMed Central

    Hertz, Andreas; Hauenschild, Frank; Lotzkat, Sebastian; Köhler, Gunther

    2012-01-01

    Abstract We describe the frog species Diasporus citrinobapheus sp. n. from the Cordillera Central of western Panama. The new species differs from all other species in its genus in coloration, disk cover and disk pad shape, skin texture, advertisement call, and size. It is most similar to Diasporus tigrillo, from which it differs in dorsal skin texture, relative tibia length, number of vomerine teeth, ventral coloration, dorsal markings, and relative tympanum size, and to Diasporus gularis, from which it can be distinguished by the lack of membranes between the toes, adult size, posterior thigh coloration, and position of the choanae. We provide data on morpho- logy, vocalization, and distribution of the new species, as well as brief information on its natural history. PMID:22679389

  11. Chromosome banding in Amphibia. XXIX. The primitive XY/XX sex chromosomes of Hyla femoralis (Anura, Hylidae).

    PubMed

    Schmid, M; Steinlein, C

    2003-01-01

    The karyotype of the pine woods treefrog, Hyla femoralis, is characterized by primitive XY female/XX male sex chromosomes. The sole difference between the X and the Y is the presence of a nucleolus organizer region (NOR) in the X. Due to a deletion of the NOR in the Y, this chromosome is distinctly smaller than the X. Since no autosomal NORs exist in the karyotype of this species, the NOR deletion in the Y results in a sex-specific difference in the number of ribosomal RNA genes, with a female:male ratio of about 2:1. Interphase nuclei of male animals contain always one silver-stained nucleolus, whereas most nuclei of female specimens exhibit two nucleoli. This is in agreement with the absence of dosage compensation for sex-linked genes in amphibian cells. The consequences of the loss of about 50% of ribosomal RNA genes for the viability of male individuals and spermatogenesis are discussed. Copyright 2003 S. Karger AG, Basel

  12. Highly complex mitochondrial DNA genealogy in an endemic Japanese subterranean breeding brown frog Rana tagoi (Amphibia, Anura, Ranidae).

    PubMed

    Eto, Koshiro; Matsui, Masafumi; Sugahara, Takahiro; Tanaka-Ueno, Tomoko

    2012-10-01

    The endemic Japanese frog Rana tagoi is unique among Holarctic brown frogs in that it breeds in small subterranean streams. Using mitochondrial 16S ribosomal RNA and NADH dehydrogenase subunit 1 genes, we investigated genealogical relationships among geographic samples of this species together with its relative R. sakuraii, which is also a unique stream breeder. These two species together form a monophyletic group, within which both are reciprocally paraphyletic. Rana tagoi is divided into two major clades (Clade A and B) that are composed of 14 genetic groups. Rana sakuraii is included in Clade A and split into two genetic groups, one of which forms a clade (Subclade A-2) with sympatric R. tagoi. This species-level paraphyly appears to be caused by incomplete taxonomy, in addition to introgressive hybridization and/or incomplete lineage sorting. Rana tagoi strongly differs from other Japanese anurans in its geographic pattern of genetic differentiation, most probably in relation to its unique reproductive habits. Taxonomically, R. tagoi surely includes many cryptic species.

  13. [Specific growth rate and the rate of energy metabolism in the ontogenesis of axolotl, Ambystoma mexicanum (Amphibia: Ambystomatidae)].

    PubMed

    Vladimirova, I G; Kleĭmenov, S Iu; Alekseeva, T A; Radzinskaia, L I

    2003-01-01

    Concordant changes in the rate of energy metabolism and specific growth rate of axolotls have been revealed. Several periods of ontogeny are distinguished, which differ in the ratio of energy metabolism to body weight and, therefore, are described by different allometric equations. It is suggested that the specific growth rate of an animal determines the type of dependence of energy metabolism on body weight.

  14. Climate Change and the Distribution of Neotropical Red-Bellied Toads (Melanophryniscus, Anura, Amphibia): How to Prioritize Species and Populations?

    PubMed Central

    Zank, Caroline; Becker, Fernando Gertum; Abadie, Michelle; Baldo, Diego; Maneyro, Raúl; Borges-Martins, Márcio

    2014-01-01

    We used species distribution modeling to investigate the potential effects of climate change on 24 species of Neotropical anurans of the genus Melanophryniscus. These toads are small, have limited mobility, and a high percentage are endangered or present restricted geographical distributions. We looked at the changes in the size of suitable climatic regions and in the numbers of known occurrence sites within the distribution limits of all species. We used the MaxEnt algorithm to project current and future suitable climatic areas (a consensus of IPCC scenarios A2a and B2a for 2020 and 2080) for each species. 40% of the species may lose over 50% of their potential distribution area by 2080, whereas 28% of species may lose less than 10%. Four species had over 40% of the currently known occurrence sites outside the predicted 2080 areas. The effect of climate change (decrease in climatic suitable areas) did not differ according to the present distribution area, major habitat type or phylogenetic group of the studied species. We used the estimated decrease in specific suitable climatic range to set a conservation priority rank for Melanophryniscus species. Four species were set to high conservation priority: M. montevidensis, (100% of its original suitable range and all known occurrence points potentially lost by 2080), M. sp.2, M. cambaraensis, and M. tumifrons. Three species (M. spectabilis, M. stelzneri, and M. sp.3) were set between high to intermediate priority (more than 60% decrease in area predicted by 2080); nine species were ranked as intermediate priority, while eight species were ranked as low conservation priority. We suggest that monitoring and conservation actions should be focused primarily on those species and populations that are likely to lose the largest area of suitable climate and the largest number of known populations in the short-term. PMID:24755937

  15. Comments on the type locality, type series, and geographic distribution of Pseudopaludicola falcipes (Hensel, 1867) (Amphibia, Anura).

    PubMed

    Langone, José A; Lavilla, Esteban O; De Sá, Rafael O; Cardozo, Darío

    2015-12-15

    The genus Pseudopaludicola was erected by Miranda-Ribeiro, 1926 to accommodate Liuperus falcipes Hensel, 1867a. Currently, there are 18 recognized species of Pseudopaludicola, with 45% of the species described since 2003. Although Pseudopaludicola falcipes is the type species, Hensel's description lacked designation of type specimens for that species; furthermore, it was based on a series of 30 individuals (without collection numbers or indication of where were they deposited) from "Provinz S[ão]. Pedro do Rio Grande do Sul" (today Rio Grande do Sul State, Brazil).

  16. Climate change and the distribution of neotropical red-bellied toads (Melanophryniscus, Anura, Amphibia): how to prioritize species and populations?

    PubMed

    Zank, Caroline; Becker, Fernando Gertum; Abadie, Michelle; Baldo, Diego; Maneyro, Raúl; Borges-Martins, Márcio

    2014-01-01

    We used species distribution modeling to investigate the potential effects of climate change on 24 species of Neotropical anurans of the genus Melanophryniscus. These toads are small, have limited mobility, and a high percentage are endangered or present restricted geographical distributions. We looked at the changes in the size of suitable climatic regions and in the numbers of known occurrence sites within the distribution limits of all species. We used the MaxEnt algorithm to project current and future suitable climatic areas (a consensus of IPCC scenarios A2a and B2a for 2020 and 2080) for each species. 40% of the species may lose over 50% of their potential distribution area by 2080, whereas 28% of species may lose less than 10%. Four species had over 40% of the currently known occurrence sites outside the predicted 2080 areas. The effect of climate change (decrease in climatic suitable areas) did not differ according to the present distribution area, major habitat type or phylogenetic group of the studied species. We used the estimated decrease in specific suitable climatic range to set a conservation priority rank for Melanophryniscus species. Four species were set to high conservation priority: M. montevidensis, (100% of its original suitable range and all known occurrence points potentially lost by 2080), M. sp.2, M. cambaraensis, and M. tumifrons. Three species (M. spectabilis, M. stelzneri, and M. sp.3) were set between high to intermediate priority (more than 60% decrease in area predicted by 2080); nine species were ranked as intermediate priority, while eight species were ranked as low conservation priority. We suggest that monitoring and conservation actions should be focused primarily on those species and populations that are likely to lose the largest area of suitable climate and the largest number of known populations in the short-term.

  17. Probing the meiotic mechanism of intergenomic exchanges by genomic in situ hybridization on lampbrush chromosomes of unisexual Ambystoma (Amphibia: Caudata).

    PubMed

    Bi, Ke; Bogart, James P

    2010-04-01

    The meiotic mechanism of unisexual salamanders in the genus Ambystoma was previously explained by observing lampbrush chromosomes (LBCs). In polyploid unisexual females, a pre-meiotic endomitotic event doubles the chromosome number so that, after meiotic reduction, the mature eggs have the same ploidy as the female. It was assumed that synapses during meiotic I prophase, which result in observed bivalents, join duplicated sister chromosomes. Previous studies also found LBC quadrivalents in some oocytes that could be explained by occasional synapses between homologs. The discovery of widespread intergenomic exchanges among unisexual populations has prompted new speculations on this meiotic mechanism. Synapses that involve homeologous chromosomes may be frequent during meiosis and could be responsible for intergenomic exchanges and the high embryonic mortality of unisexuals. Furthermore, LBC quadrivalents may be established by associations between homeologous rather than homologous chromosomes. The present study investigated these two important aspects pertaining to the mechanism of intergenomic exchanges: the frequency of homeologous synapses and the relationship between homeologous associations and meiotic quadrivalents. We applied genomic in situ hybridization (GISH) on LBCs from oocytes of 14 triploid and two tetraploid unisexual females. Homeologous bivalents were not observed, and all 13 LBC quadrivalents that we found were the result of homologous synapses and were not associated with any homeologous or exchanged LBCs. Intergenomic exchanges were used as markers to compare the same chromosomes at meiotic diplotene and mitotic metaphase stages. We conclude that contemporary intergenomic exchanges are very rare, and no direct link exists between intergenomic exchanges and high embryonic mortality. The actual mechanisms and evolutionary implications of intergenomic exchanges appear to be complicated and difficult to assess. The application of GISH-type molecular cytogenetic techniques will help to improve our understanding of the role that intergenomic interactions play in the persistence of unisexual Ambystoma and other unisexual vertebrates.

  18. The pelvic kidney of male Ambystoma maculatum (Amphibia, urodela, ambystomatidae) with special reference to the sexual collecting ducts.

    PubMed

    Siegel, Dustin S; Sever, David M; Aldridge, Robert D

    2010-12-01

    This study details the gross and microscopic anatomy of the pelvic kidney in male Ambystoma maculatum. The nephron of male Ambystoma maculatum is divided into six distinct regions leading sequentially away from a renal corpuscle: (1) neck segment, which communicates with the coelomic cavity via a ventrally positioned pleuroperitoneal funnel, (2) proximal tubule, (3) intermediate segment, (4) distal tubule, (5) collecting tubule, and (6) collecting duct. The proximal tubule is divided into a vacuolated proximal region and a distal lysosomic region. The basal plasma membrane is modified into intertwining microvillus lamellae. The epithelium of the distal tubule varies little along its length and is demarcated by columns of mitochondria with their long axes oriented perpendicular to the basal lamina. The distal tubule possesses highly interdigitating microvillus lamellae from the lateral membranes and pronounced foot processes of the basal membrane that are not intertwined, but perpendicular to the basal lamina. The collecting tubule is lined by an epithelium with dark and light cells. Light cells are similar to those observed in the distal tuble except with less mitochondria and microvillus lamellae of the lateral and basal plasma membrane. Dark cells possess dark euchromatic nuclei and are filled with numerous small mitochondria. The epithelium of the neck segment, pleuroperitoneal funnel, and intermediate segment is composed entirely of ciliated cells with cilia protruding from only the central portion of the apical plasma membrane. The collecting duct is lined by a highly secretory epithelium that produces numerous membrane bound granules that stain positively for neutral carbohydrates and proteins. Apically positioned ciliated cells are intercalated between secretory cells. The collecting ducts anastomose caudally and unite with the Wolffian duct via a common collecting duct. The Wolffian duct is secretory, but not to the extent of the collecting duct, synthesizes neutral carbohydrates and proteins, and is also lined by apical ciliated cells intercalated between secretory cells. Although functional aspects associated with the morphological variation along the length of the proximal portions of the nephron have been investigated, the role of a highly secretory collecting duct has not. Historical data that implicated secretory activity concordant with mating activity, and similarity of structure and chemistry to sexual segments of the kidneys in other vertebrates, lead us to believe that the collecting duct functions as a secondary sexual organ in Ambystoma maculatum.

  19. Two rare aneutriploids in the unisexual Ambystoma (Amphibia, Caudata) identified by GISH indicating two different types of meiotic errors.

    PubMed

    Bi, K; Bogart, J P; Fu, J

    2007-01-01

    We report two types of aneutriploids in unisexual salamanders Ambystomalaterale-2jeffersonianum (LJJ) and Ambystoma 2 laterale-jeffersonianum (LLJ). One karyotype has 3n = 42: L27 (L8-); J15 (J8p+), and we suggest that it was induced by homoeologous pairing after premeiotic endomitosis followed by an unequal L8;J8 segregation. The second karyotype has 3n = 43: L14 (L10q); J29 (J12+), which can be explained by meiotic nondisjunction followed by unbalanced segregation. These two rare aneutriploids demonstrate two different types of meiotic errors that might help to explain the high mortality observed in this complex. Case one also indicates that contemporary intergenomic exchanges and homoeologous recombinations may occur after a premeiotic chromosome doubling event. Our study provides additional evidence for the extremely flexible reproduction of unisexual Ambystoma.

  20. Osteological Variation among Extreme Morphological Forms in the Mexican Salamander Genus Chiropterotriton (Amphibia: Plethodontidae): Morphological Evolution And Homoplasy

    PubMed Central

    Darda, David M.; Wake, David B.

    2015-01-01

    Osteological variation is recorded among and within four of the most distinctive species of the Mexican salamander genus Chiropterotriton. Analysis of the data is consistent with the monophyletic status of the genus and documents previously unrecorded intraspecific and interspecific variation. Most of the recorded variation involves qualitative and quantitative proportional differences, but four fixed differences constitute autapomorphic states that affirm and diagnose some species (C. dimidiatus, C. magnipes). Osteological variation in 15 characters is analyzed with respect to predictions generated from four hypotheses: 1) phylogeny, 2) adaptation to specific habitats (the four species include cave-dwelling, terrestrial, and arboreal forms), 3) size-free shape, and 4) size. High levels of intraspecific variation suggest that the characters studied are not subject to rigid functional constraints in salamanders, regardless of size. The pattern predicted by the hypothesis based on size differences seen among these four Chiropterotriton species matches most closely the observed pattern of relative skull robustness. Since size change and heterochrony are often associated in plethodontid evolution, it is likely that changes in developmental timing play a role in the morphological transitions among these morphologically diverse taxa. Webbed feet, miniaturization, body shape, and an unusual tarsal arrangement are morphologies exhibited in species of Chiropterotrition that are shown to be homoplastic with other clades of tropical plethodontids. Although extensive homoplasy in salamanders might be seen as a roadblock to unraveling phylogenetic hypotheses, the homologous developmental systems that appear to underlie such homoplasy may reveal common and consistent evolutionary processes at work. PMID:26060996

  1. Modifications of the genital kidney proximal and distal tubules for sperm transport in Notophthalmus viridescens (Amphibia, Urodela, Salamandridae).

    PubMed

    Nicholson, Abbigail E; Siegel, Dustin S

    2014-08-01

    Male salamanders use nephrons from the genital kidney to transport sperm from the testicular lobules to the Wolffian duct. The microstructure of the epithelia of the genital kidney proximal tubule and distal tubule was studied over 1 year in a population of Notophthalmus viridescens from Crawford and Pike counties in central Missouri. Through ultrastructural analysis, we were able to support the hypothesis that the genital kidney nephrons are modified to aid in the transportation of sperm. A lack of folding of the basal plasma membrane, in both the genital kidney proximal and distal tubules when compared to the pelvic kidney proximal and distal tubules, reduces the surface area and thus likely decreases the efficiency of reabsorption in these nephron regions of the genital kidney. Ciliated epithelial cells are also present along the entire length of the genital kidney proximal tubule, but are lacking in the epithelium of the pelvic kidney proximal tubule. The exact function of these cilia remains unknown, but they may aid in mixing of seminal fluids or the transportation of immature sperm through the genital kidney nephrons. Ultrastructural analysis of proximal and distal tubules of the genital kidney revealed no seasonal variation in cellular activity and no mass production of seminal fluids throughout the reproductive cycle. Thus, we failed to support the hypothesis that the cellular activity of the epithelia lining the genital kidney nephrons is correlated to specific events in the reproductive cycle. The cytoplasmic contents and overall structure of the genital and pelvic kidney epithelial cells were similar to recent observations in Ambystoma maculatum, with the absence of abundant dense bodies apically in the epithelial cells lining the genital kidney distal tubule.

  2. On the diagnosis and conservation of the poorly known bromeligenous Scinax arduous Peixoto, 2002 (Amphibia; Anura; Hylidae).

    PubMed

    Lacerda, João Victor A; Ferreira, Rodrigo B; De Souza, Geisa Alves; Da Silva, Hélio Ricardo; Feio, Renato N

    2015-09-28

    Since Scinax arduous description, many other populations belonging to the Scinax perpusillus group have been recorded for the States of Espírito Santo and Minas Gerais, Southeastern Brazil. Both in collections and publications most of these new specimens are identified as S. arduous, Scinax cf. arduous, Scinax cf. perpusillus, Scinax gr. perpusillus, S. perpusillus and S. v-signatus. Such state of affairs may be due to the lack of information on the original description of S. arduous. Only two individuals [the holotype (female) and the paratype (male)] were used in the original description and diagnosis, therefore, information on variation and distribution were not available. Furthermore, in S. arduous description, the section on coloration in life was based only on two juveniles raised in laboratory. Herein we redefine Scinax arduous based on 44 males and 17 females from the type locality, the Municipality of Santa Teresa, in the State of Espírito Santo. In addition, we provide information on its conservation status, distribution, natural history, vocalization, tadpoles, and detailed photographs of both adults and larvae.

  3. A new species of Bolitoglossa (Amphibia, Caudata) from the Sierra de Juárez, Oaxaca, Mexico.

    PubMed

    Rovito, Sean M; Parra-Olea, Gabriela; Lee, Dana; Wake, David B

    2012-01-01

    We describe a new species of Bolitoglossa (Nanotriton) from the Sierra de Juárez and Sierra Mixe of Oaxaca, Mexico. Bolitoglossa chinantecasp. n. is distinguished from the three other species in the subgenus Nanotriton by its more robust body, by having substantial numbers of maxillary teeth and differences in relative head width, foot width, and limb length. The new species occurs in sympatry with Bolitoglossa (Nanotriton) rufescens at the type locality. The description of another species of salamander from the Sierra de Juárez is noteworthy, given the already high plethodontid salamander species richness of the region.

  4. Morphology, Molecular Genetics, and Bioacoustics Support Two New Sympatric Xenophrys Toads (Amphibia: Anura: Megophryidae) in Southeast China

    PubMed Central

    Wang, Yingyong; Zhao, Jian; Yang, Jianhuan; Zhou, Zhixin; Chen, Guoling; Liu, Yang

    2014-01-01

    Given their recent worldwide declines and extinctions, characterization of species-level diversity is of critical importance for large-scale biodiversity assessments and conservation of amphibians. This task is made difficult by the existence of cryptic species complexes, species groups comprising closely related and morphologically analogous species. The combination of morphology, genetic, and bioacoustic analyses permits robust and accurate species identification. Using these methods, we discovered two undescribed Xenophrys species, namely Xenophrys lini sp. nov. and Xenophrys cheni sp. nov. from the middle range of Luoxiao Mountains, southeast China. These two new species can be reliably distinguished from other known congeners by morphological and morphometric differences, distinctness in male advertisement calls, and substantial genetic distances (>3.6%) based on the mitochondrial 16s and 12s rRNA genes. The two new species, together with X. jinggangensis, are sympatric in the middle range of Luoxiao Mountains but may be isolated altitudinally and ecologically. Our study provides a first step to help resolve previously unrecognized cryptic biodiversity and provides insights into the understanding of Xenophrys diversification in the mountain complexes of southeast China. PMID:24714161

  5. Paulanoblella , nomen novum (Radiolaria) replaces Noblella Kozur, Mostler & Repetski, 1996, a homonym of Noblella Barbour, 1930 (Amphibia)

    USGS Publications Warehouse

    Kozur, H.W.; Repetski, John E.

    2002-01-01

    Kozur et al . (1996) reported and described some well-preserved Lower Ordovician (Tremadocian) Radiolariafrom central Nevada and established several new taxa, among them a new genus Noblella , assigned to the Family Protoentactiniidae Kozur, Mostler & Repetski, 1996. Dr J. K. Page kindly informed us that the genus Noblella already was established for an amphibian genus, Family Brachycephalidae, type species N. peruviana (Noble), byBarbour (1930; p. 81). Therefore, the genus name Noblella Kozur, Mostler & Repetski, 1996 non! NoblellaBarbour, 1930, is invalid because of homonymy. We here replace this junior homonym with Paulanoblella Kozur & Repetski, nomennovum.

  6. Extremely Low Genetic Diversity Indicating the Endangered Status of Ranodon sibiricus (Amphibia: Caudata) and Implications for Phylogeography

    PubMed Central

    Wang, Xiu-Ling; Sun, Jian-Yun; Xue, Yan; Zhang, Peng; Zhou, Hui; Qu, Liang-Hu

    2012-01-01

    Background The Siberian salamander (Ranodon sibiricus), distributed in geographically isolated areas of Central Asia, is an ideal alpine species for studies of conservation and phylogeography. However, there are few data regarding the genetic diversity in R. sibiricus populations. Methodology/Principal Findings We used two genetic markers (mtDNA and microsatellites) to survey all six populations of R. sibiricus in China. Both of the markers revealed extreme genetic uniformity among these populations. There were only three haplotypes in the mtDNA, and the overall nucleotide diversity in the mtDNA was 0.00064, ranging from 0.00000 to 0.00091 for the six populations. Although we recovered 70 sequences containing microsatellite repeats, there were only two loci that displayed polymorphism. We used the approximate Bayesian computation (ABC) method to study the demographic history of the populations. This analysis suggested that the extant populations diverged from the ancestral population approximately 120 years ago and that the historical population size was much larger than the present population size; i.e., R. sibiricus has experienced dramatic population declines. Conclusion/Significance Our findings suggest that the genetic diversity in the R. sibiricus populations is the lowest among all investigated amphibians. We conclude that the isolation of R. sibiricus populations occurred recently and was a result of recent human activity and/or climatic changes. The Pleistocene glaciation oscillations may have facilitated intraspecies genetic homogeneity rather than enhanced divergence. A low genomic evolutionary rate and elevated inbreeding frequency may have also contributed to the low genetic variation observed in this species. Our findings indicate the urgency of implementing a protection plan for this endangered species. PMID:22428037

  7. THE POLYTYPIC SPECIES REVISITED: GENETIC DIFFERENTIATION AND MOLECULAR PHYLOGENETICS OF THE TIGER SALAMANDER AMBYSTOMA TIGRINUM (AMPHIBIA: CAUDATA) COMPLEX.

    PubMed

    Shaffer, H Bradley; McKnight, Mark L

    1996-02-01

    We present a phylogenetic analysis of the Ambystoma tigrinum complex, based on approximately 840 base pairs of mitochondrial-DNA sequence from the rapidly evolving D-loop and an adjacent intron. Our samples include populations of the continentally distributed species, A. tigrinum, plus all described species of Mexican ambystomatids. Sequence divergence is low, ranging from 0-8.5%, and most phylogenetic groupings are weakly supported statistically. We identified eight reasonably well-defined clades from the United States and Mexico, with the geographically isolated A. californiense from California as the probable sister group to the remaining taxa. Our sequence data are not capable of resolving the relationships among these clades, although the pattern of transitional-site evolution suggests that these eight lineages diverged during a period of rapid cladogenesis. We roughly calibrate a molecular clock and identify a few lineages that significantly deviate from the slow, baseline rate of 0.5-0.75% per million years. Our data also suggest that species boundaries for several U.S. and Mexican species need to be altered and that the concept of a continentally distributed, polytypic tiger salamander is not valid. © 1996 The Society for the Study of Evolution.

  8. Ultrastructure and immunocytochemistry of the neuroepithelial bodies in the lung of the tiger salamander, Ambystoma tigrinum (Urodela, Amphibia).

    PubMed

    Goniakowska-Witalińska, L; Lauweryns, J M; Zaccone, G; Fasulo, S; Tagliafierro, G

    1992-11-01

    Light and electron microscopy of the lungs of Ambystoma tigrinum (Urodela) revealed a relatively complex pattern of the neuroendocrine (NE) cells. In the apical parts of smaller septa single NE cells not associated with nerve fibres were covered and surrounded by pneumocytes. The larger septa possessed small areas of ciliated epithelium, in which the NE cells were grouped in a form of neuroepithelial bodies (NEB) consisting of 3-5 cells and covered by goblet cells. NE cells possessed a large nucleus with patches of condensed chromatin, clear cytoplasm, and membrane-bound vesicles of variable morphology and size, containing an electron dense interior surrounded by a lucent space. The size of these dense core vesicles (DCV) ranged from 70-140 nm, while rarely the larger ones exhibited a diameter of 300-600 nm. In some NEB a second type of NE cells was observed for the first time in an amphibian species: these cells communicated with the air space and exhibited on their surface microvilli and a single modified cilium with a 8 + 1 microtubule arrangement. Their cytoplasm contained two types of DCV: dense core granules with a diameter of 140-260 nm and vesicles 320-700 nm in diameter with a moderately electron dense interior. The NEB were associated with intracorpuscular, sensory nerve terminals morphologically afferent and efferent. By immunocytochemistry, the NE cells revealed the presence of serotonin, met-enkephalin, and leu-enkephalin. A paracrine and chemoreceptor role is proposed for NEB of Ambystoma tigrinum.

  9. Long bone histology of the stem salamander Kokartus honorarius (Amphibia: Caudata) from the Middle Jurassic of Kyrgyzstan

    PubMed Central

    Skutschas, Pavel; Stein, Koen

    2015-01-01

    Kokartus honorarius from the Middle Jurassic (Bathonian) of Kyrgyzstan is one of the oldest salamanders in the fossil record, characterized by a mixture of plesiomorphic morphological features and characters shared with crown-group salamanders. Here we present a detailed histological analysis of its long bones. The analysis of a growth series demonstrates a significant histological maturation during ontogeny, expressed by the progressive appearance of longitudinally oriented primary vascular canals, primary osteons, growth marks, remodelling features in primary bone tissues, as well as progressive resorption of the calcified cartilage, formation of endochondral bone and development of cartilaginous to bony trabeculae in the epiphyses. Apart from the presence of secondary osteons, the long bone histology of Kokartus is very similar to that of miniaturized temnospondyls, other Jurassic stem salamanders, miniaturized seymouriamorphs and modern crown-group salamanders. We propose that the presence of secondary osteons in Kokartus honorarius is a plesiomorphic feature, and the loss of secondary osteons in the long bones of crown-group salamanders as well as in those of miniaturized temnospondyls is the result of miniaturization processes. Hitherto, all stem salamander long bong histology (Kokartus, Marmorerpeton and ‘salamander A’) has been generally described as having paedomorphic features (i.e. the presence of Katschenko's Line and a layer of calcified cartilage), these taxa were thus most likely neotenic forms. The absence of clear lines of arrested growth and annuli in long bones of Kokartus honorarius suggests that the animals lived in an environment with stable local conditions. PMID:25682890

  10. A new species of the Pristimantis orestes group (Amphibia: Strabomantidae) from the high Andes of Ecuador, Reserva Mazar.

    PubMed

    Guayasamin, Juan M; Arteaga, Alejandro F

    2013-02-21

    We describe a new Pristimantis from La Libertad and Rumiloma, Reserva Mazar, Andes of Southeastern Ecuador, at elevations between 2895-3415 m. This species is assigned to the P. orestes group, from whose members it differs by its small body size (adult males ≤ 18.1 mm; adult females ≤ 23.7 mm), usually reticulated ventral pattern, and visible tympanum. The vocalization of the new species consists of a series of calls; each call is composed by a pulsed, non-modulated note in frequency, and with a dominant frequency of 3122-3171 Hz. A molecular phylogeny based on a fragment of the mitochondrial gene 12S shows that the new species is sister to Pristimantis simonbolivari.

  11. Functional characterization of the vertebrate primary ureter: Structure and ion transport mechanisms of the pronephric duct in axolotl larvae (Amphibia)

    PubMed Central

    2010-01-01

    Background Three kidney systems appear during vertebrate development: the pronephroi, mesonephroi and metanephroi. The pronephric duct is the first or primary ureter of these kidney systems. Its role as a key player in the induction of nephrogenic mesenchyme is well established. Here we investigate whether the duct is involved in urine modification using larvae of the freshwater amphibian Ambystoma mexicanum (axolotl) as model. Results We investigated structural as well as physiological properties of the pronephric duct. The key elements of our methodology were: using histology, light and transmission electron microscopy as well as confocal laser scanning microscopy on fixed tissue and applying the microperfusion technique on isolated pronephric ducts in combination with single cell microelectrode impalements. Our data show that the fully differentiated pronephric duct is composed of a single layered epithelium consisting of one cell type comparable to the principal cell of the renal collecting duct system. The cells are characterized by a prominent basolateral labyrinth and a relatively smooth apical surface with one central cilium. Cellular impalements demonstrate the presence of apical Na+ and K+ conductances, as well as a large K+ conductance in the basolateral cell membrane. Immunolabeling experiments indicate heavy expression of Na+/K+-ATPase in the basolateral labyrinth. Conclusions We propose that the pronephric duct is important for the subsequent modification of urine produced by the pronephros. Our results indicate that it reabsorbs sodium and secretes potassium via channels present in the apical cell membrane with the driving force for ion movement provided by the Na+/K+ pump. This is to our knowledge the first characterization of the pronephric duct, the precursor of the collecting duct system, which provides a model of cell structure and basic mechanisms for ion transport. Such information may be important in understanding the evolution of vertebrate kidney systems and human diseases associated with congenital malformations. PMID:20507566

  12. A new species of Bolitoglossa (Amphibia, Caudata) from the Sierra de Juárez, Oaxaca, Mexico

    PubMed Central

    Rovito, Sean M.; Parra-Olea, Gabriela; Lee, Dana; Wake, David B.

    2012-01-01

    Abstract We describe a new species of Bolitoglossa (Nanotriton) from the Sierra de Juárez and Sierra Mixe of Oaxaca, Mexico. Bolitoglossa chinanteca sp. n. is distinguished from the three other species in the subgenus Nanotriton by its more robust body, by having substantial numbers of maxillary teeth and differences in relative head width, foot width, and limb length. The new species occurs in sympatry with Bolitoglossa (Nanotriton) rufescens at the type locality. The description of another species of salamander from the Sierra de Juárez is noteworthy, given the already high plethodontid salamander species richness of the region. PMID:22577313

  13. Lanfrediella amphicirrus gen. nov. sp. nov. Nematotaeniidae (Cestoda: Cyclophyllidea), a tapeworm parasite of Rhinella marina (Linnaeus, 1758) (Amphibia: Bufonidae).

    PubMed

    Melo, Francisco Tiago de Vasconcelos; Giese, Elane Guerreiro; Furtado, Adriano Penha; Soares, Maurílio José; Gonçalves, Evonnildo Costa; Vallinoto, Antonio Carlos Rosário; Santos, Jeannie Nascimento dos

    2011-09-01

    The family Nematotaeniidae, tapeworms commonly found in the small intestines of amphibians and reptiles, includes 27 recognised species distributed among four genera: Bitegmen Jones, Cylindrotaenia Jewell, Distoichometra Dickey and Nematotaenia Lühe. The taxonomy of these cestodes is poorly defined, due in part to the difficulties of observing many anatomical traits. This study presents and describes a new genus and species of nematotaeniid parasite found in cane toads (Rhinella marina) from eastern Brazilian Amazonia. The cestodes were collected during the necropsy of 20 hosts captured in the urban area of Belém, Pará. The specimens were fixed and processed for light microscopy, scanning electron microscopy (SEM) and three-dimensional (3D) reconstruction. Samples were also collected for molecular analyses. The specimens presented a cylindrical body, two testes and paruterine organs. However, they could not be allocated to any of the four existing nematotaeniid genera due to the presence of two each of dorsal compact medullary testes, cirri, cirrus pouches, genital pores, ovaries and vitelline glands per mature segment. Lanfrediella amphicirrus gen. nov. sp. nov. is the first nematotaeniid studied using Historesin analysis, SEM and 3D reconstruction, and it is the second taxon for which molecular data have been deposited in GenBank.

  14. A new species of salamander of the genus Hynobius (Amphibia, Caudata, Hynobiidae) from South Korea.

    PubMed

    Min, Mi-Sook; Baek, Hae-Jun; Song, Jae-Young; Chang, Min Ho; Poyarkov, Nikolay A Jr

    2016-09-21

    We describe a new species of lentic-breeding Hynobius salamander from the Naro Islands, near the village of Bongrae-myeon, Goheung-gun, Jeollanam-do, South Korea, on the basis of results of morphological, ecological and genetic analyses. Hynobius unisacculus sp. nov. is distinguished from its congeners by a combination of the following morphological attributes: (1) comparatively small size (adult SVL up to 61 mm; range 38.3-60.3 mm in males and 37.5-59.9 mm in females); (2) relatively slender short limbs; tips of fore- and hindlimbs adpressed on body never meeting, but separated by a large gap (gap of -3.0 to -1.5 costal folds in males and -3.5 to -1.5 in females); (3) comparatively short tail (TL/SVL ratio in adult males varying from 0.54-0.98, in adult females from 0.55 to 0.89), tail flattened and with a low dorsal fin extending to the posterior one-third of tail length; (4) usually 11 (occasionally 12) costal grooves; (5) in adults, dark brown dorsum with indistinct bronze or dark copper spots, lighter greyish-white or pinkish belly; (6) well developed fifth toe; (7) comparatively shallow vomerine tooth series with 13-23 vomerine teeth; (8) small, pigmented ova, located in one, occasionally two, strings in a small, curved egg sac with folded envelope, lacking distinct mucous stalks or whiptail-like structures on both ends. The molecular differentiation among Korean Hynobius is high; Hynobius unisacculus sp. nov. is genetically highly divergent from the morphologically similar H. leechii, H. yangi and H. quelpaertensis: pairwise distances are 9.7%, 9.1% and 8.0% of sequence divergence at the COI mtDNA gene respectively, and 10.9%, 10.9% and 9.4% of sequence divergence at the cyt b mtDNA gene, respectively. At present, the new species is known from coastal areas and offshore islands in southeastern part of Jeollanam-do in South Korea. We suggest the species should be considered as Vulnerable (Vu2a) in accordance with IUCN's Red List categories. Our study supports the presence of undiagnosed taxonomic diversity among Korean Hynobius.

  15. Preparation and ultrastructure of spermatozoa from green poison frogs, Dendrobates auratus, following hormonal induced spermiation (Amphibia, Anura, Dendrobatidae).

    PubMed

    Lipke, Christian; Meinecke-Tillmann, Sabine; Meyer, Wilfried; Meinecke, Burkhard

    2009-07-01

    Few ultrastructural studies have been performed on members of the Dendrobatidae, although such investigations can be useful for the understanding of reproductive patterns, as a diagnostic method for males in breeding programs for endangered amphibians and for phylogenetic analysis. The sperm ultrastructure of the Green Poison Frog, Dendrobates auratus, from Panama is described following induced spermiation in living animals. To date only testicular spermatozoa in other dendrobatid frogs have been analysed. Moreover, an electron microscopic preparation method (transmission and scanning electron microscopy) for dendrobatid sperm cells in low concentration is presented. Sperm cells from stimulated frogs (100 IU human chorionic gonadotropin, hCG, twice at an interval of 1h) were recovered via cloaca lavage using 600 microl isotonic phosphate-free amphibian saline (IPS). Centrifuged flushings (5 min, 173 x g) were deposited on microscopic slides. Adherent spermatozoa were treated with Karnovsky fixative (overnight, 4 degrees C). After postfixation (2h, 1% osmium tetroxide), samples were dehydrated in series of ascending acetones (30-100%). For transmission electron microscopy sperm cells were encapsulated using Epon and 1.5% 2,4,6-tris(dimethylaminomethyl)phenol (DMP 30). Ultrathin sections (70 nm) were cut and stained with uranyl acetate (30 min) and lead citrate (5 min). Sperm cells are filiform with a 21.1+/-2.7 microm long and arcuated head and a single tail (35.0+/-4.2 microm length). Their acrosomal complex is located at the anterior portion of the head and consists of the acrosomal vesicle which has low electron density, and the subjacent electron-dense subacrosomal cone. In transverse section, the nucleus is circular (1.9+/-0.2 microm diameter) and conical in longitudinal section. It is surrounded by several groups of mitochondria. The chromatin is highly condensed and electron-dense but shows numerous electron-lucent inclusions. A short midpiece has a mitochondrial collar with a proximal and a distal centriole. The latter gives rise to the axoneme which alone forms the flagellum. The sperm ultrastructure of D. auratus differs from that of other Dendrobatidae because of the absence of a nuclear space and the absence of the undulating membrane associated with an axial fibre. This tail conformation is found in the Ranoidea but not in the Bufonoidea. These results show that the spermatozoa of D. auratus are the first within the Dendrobatidae without accessory tail structures. Methods of using sperm samples from hormonal treated frogs for ultrastructural studies is not only reasonable to examine e.g. amphibian phylogeny without killing frogs threatened with extinction but allows investigations in the field of assisted reproduction and male fertility for example in conservation programs for endangered amphibians.

  16. A new species of Pristimantis (Amphibia, Anura, Craugastoridae) from the foothills of the Andes in Manu National Park, southeastern Peru.

    PubMed

    Shepack, Alexander; von May, Rudolf; Ttito, Alex; Catenazzi, Alessandro

    2016-01-01

    We describe a new species of Pristimantis from the humid sub-montane forest of the Región Cusco in Peru. Pristimantis pluvialis sp. n. was collected in the Kosñipata and Entoro valleys at elevations from 740 to 1110 m a.s.l., near the borders of Manu National Park and within the Huachiperi Haramba Queros Conservation Concession. The new species can be distinguished from other members of the genus Pristimantis by its rostral tubercle, smooth dorsal skin, and by its advertisement call. Pristimantis lacrimosus and Pristimantis waoranii superficially most resemble the new species, but Pristimantis pluvialis sp. n. differs from both species by having a rostral tubercle (absent in Pristimantis waoranii and variable in Pristimantis lacrimosus) and larger size, from Pristimantis lacrimosus by its call emitted at a lower frequency, and from Pristimantis waoranii for its dorsal coloration with dark markings. Two other species have partially overlapping distributions and resemble the new species, Pristimantis mendax and Pristimantis olivaceus, but they produce advertisement calls with much higher dominant frequencies than the advertisement call of the new species. Furthermore, Pristimantis mendax differs from the new species by lacking a rostral tubercle and by having a sigmoid inner tarsal fold, whereas Pristimantis olivaceus differs by being smaller and by having dorsal skin shagreen with scattered tubercles. The new species has snout-vent length of 21.8-26.9 mm in males (n = 12) and 28.8 mm in a single female.

  17. Effect of estradiol on apoptosis, proliferation and steroidogenic enzymes in the testes of the toad Rhinella arenarum (Amphibia, Anura).

    PubMed

    Scaia, María Florencia; Volonteri, María Clara; Czuchlej, Silvia Cristina; Ceballos, Nora Raquel

    2015-09-15

    Estrogens inhibit androgen production and this negative action on amphibian steroidogenesis could be related to the regulation of steroidogenic enzymes. Estrogens are also involved in the regulation of amphibian spermatogenesis by controlling testicular apoptosis and spermatogonial proliferation. The Bidder's organ (BO) is a structure characteristic from the Bufonidae family and in adult males of Rhinella arenarum it is one of the main sources of plasma estradiol (E2). The purpose of this study is to analyze the effect of E2 on testicular steroidogenic enzymes, apoptosis and proliferation in the toad R. arenarum. For this purpose, testicular fragments were treated during 24h with or without 2 or 20nM of E2. After treatments, the activities of cytochrome P450 17α-hydroxylase-C17-20 lyase (CypP450c17) and 3β-hydroxysteroid dehydrogenase/isomerase (3β-HSD/I) were measured by the transformation of radioactive substrates into products, and CypP450c17 expression was determined by Western blot analysis. Apoptosis in testicular sections was detected with a commercial fluorescent kit based on TUNEL method, and proliferation was evaluated by BrdU incorporation. Results indicate that E2 has no effect on CypP450c17 protein levels or enzymatic activity, while it reduces 3β-HSD/I activity during the post reproductive season. Furthermore, although E2 has no effect on apoptosis during the pre and the post reproductive seasons, it stimulates testicular apoptosis during the reproductive season, mostly in spermatocytes. Finally, E2 has no effect on testicular proliferation all year long. Taken together, these results suggest that E2 is involved in the regulation of testicular steroidogenesis and spermatogenesis.

  18. A new species of the genus Pristimantis (Amphibia, Craugastoridae) associated with the moderately elevated massifs of French Guiana.

    PubMed

    Fouquet, Antoine; Martinez, Quentin; Courtois, Elodie A; Dewynter, Maël; Pineau, Kévin; Gaucher, Philippe; Blanc, Michel; Marty, Christian; Kok, Philippe J R

    2013-12-23

    We describe a new Pristimantis from French Guiana, northern South America, which is mainly distinguished from known phenotypically related congeners (i.e. species from the polyphyletic unistrigatus species group) occurring at low and middle elevations in the Guiana Shield by the combination of a distinct tympanum, a lower ratio of tibia vs. hand length, a reddish groin region, and a distinct advertisement call consisting of clusters of generally four short notes. The new species inhabits pristine primary forests on the slopes of isolated massifs reaching more than 400 m elevation, and seems not to occur below ca. 200 m above sea level. Such a sharp altitudinal limit suggests a strong influence of thermal variation on the distribution of the species, and therefore a potential sensitivity to climate change. With only nine isolated populations documented so far, the new species should be prioritized for conservation. Historical climate fluctuations during the Quaternary are likely responsible for the distribution pattern of the new species. 

  19. Two new species of Oswaldocruzia (Nematoda: Trichostrongylina: Molineoidea) parasites of the cane toad Rhinella marina (Amphibia: Anura) from Peru.

    PubMed

    Guerrero, Ricardo

    2013-03-01

    Two new species of Oswaldocruzia, O. manuensis sp. nov., and O. urubambaensis sp. nov. are described and illustrated from Peru, these are parasites of the cane toad Rhinella marina. O. manuensis is characterized by having cervical alae which are not well developed, ridges without chitinous supports, caudal bursa type II and branches of fork of dissimilar length. O. urubambaensis is characterized by a caudal bursa of type I, ridges with chitinous supports, a thin cephalic vesicle and origin of rays 9 in tip of the dorsal trunk.

  20. Apoptosis, proliferation and presence of estradiol receptors in the testes and Bidder's organ of the toad Rhinella arenarum (Amphibia, Anura).

    PubMed

    Scaia, María Florencia; Czuchlej, Silvia Cristina; Cervino, Nadia; Ceballos, Nora Raquel

    2016-04-01

    The dynamic equilibrium between spermatogonial proliferation and testicular apoptosis determines the progression of spermatogenesis in amphibians. Estrogens and their receptors play a central role in regulating spermatogenesis in vertebrates, and in some species of anurans, estradiol (E2 ) is involved in the regulation of spermatogonial proliferation and apoptosis of germ cells. Bidder's organ (BO) is a structure characteristic of Bufonidae that has historically been compared to an undeveloped ovary. In adult Rhinella arenarum males, BO is one of the main sources of plasma E2 . The aim of this study was 1) to describe the seasonal variations in testicular apoptosis, spermatogonial proliferation, and cellular proliferation in BO; and 2) to analyze the presence and localization of estrogen receptor β (ERβ) in the testes and BO of R. arenarum. Testicular fragments and BOs from animals collected during the year were labeled with 5-bromo-2'-deoxyuridine (BrdU) and BrdU incorporation was determined using immunohistochemistry. Apoptosis in testicular sections was detected using the TUNEL method, and ERβ localization was assessed using immunohistochemistry in testes and BOs. The results indicate that spermatogonial proliferation is highest during the reproductive season and that cysts of spermatocytes and spermatids undergo apoptosis during the postreproductive season. Furthermore, the proliferation of follicular cells is highest during the reproductive and postreproductive seasons. ERβ was primarily detected by immunolocalization in Sertoli cells, follicular cells, and oocytes. Taken together, these results suggest that cysts that do not form spermatozoa are removed from testes by apoptosis and that estrogens regulate both spermatogenesis and oogenesis in adult males of R. arenarum. © 2015 Wiley Periodicals, Inc.

  1. Liver histopathology in the cane toad, Rhinella marina (Amphibia: Bufonidae), induced by Ortleppascaris sp. larvae (Nematoda: Ascarididae).

    PubMed

    Silva, Jefferson P E; da Silva, Djane C B; Melo, Francisco T V; Giese, Elane G; Furtado, Adriano P; Santos, Jeannie N

    2013-04-01

    Exposure to parasites is considered to be an important factor in the development of many diseases and histopathologies which are the result of the parasite-host interaction. The present study evaluated the impact of natural infection by larvae of Ortleppascaris sp. (Nematoda: Ascaridida) in the liver of the cane toad Rhinella marina (Linnaeus, 1758). Larvae were encysted in nodules delimited by collagenous fibers and fibroblasts or freely within the hepatic parenchyma, provoking a clear response from the host. The histological examination of the liver revealed viable larvae in a number of different developmental stages, as well as cysts filled with amorphous material and cell residues and surrounded by dense fibrotic tissue. The infection of the liver by these larvae induces a significant increase in the area occupied by melanomacrophages and a reduction or deficit in the vascularization of the liver, hypertrophy of the hepatocytes, vacuolar bodies, and cytoplasmatic granules. Focal concentrations of inflammatory infiltrates were observed enclosing the unencapsulated early-stage larvae. These results indicate that infection by Ortleppascaris sp. induces severe physiological problems and histopathological lesions in the liver of R. marina .

  2. Distribution and morphological variation of Eleutherodactylus mercedesae Lynch & McDiarmid, 1987 (Amphibia, Anura, Leptodactylidae) with first record for Peru

    USGS Publications Warehouse

    Padial, J.M.; McDiarmid, R.; De la Riva, I.

    2006-01-01

    We report new distributional information for Eleutherodactylus mercedesae in Bolivia, and provide the first record for Peru based on an adult female. This species, previously endemic to Bolivia, now ranges across about 1000 km in cloud forests on the Amazonian slopes of the Andes from southern Peru to central Bolivia. We provide the first morphological description of females based on two specimens, compare them with the male type and paratype, add some observations to the original description, and comment on variation in the species.

  3. Osteological Variation among Extreme Morphological Forms in the Mexican Salamander Genus Chiropterotriton (Amphibia: Plethodontidae): Morphological Evolution And Homoplasy.

    PubMed

    Darda, David M; Wake, David B

    2015-01-01

    Osteological variation is recorded among and within four of the most distinctive species of the Mexican salamander genus Chiropterotriton. Analysis of the data is consistent with the monophyletic status of the genus and documents previously unrecorded intraspecific and interspecific variation. Most of the recorded variation involves qualitative and quantitative proportional differences, but four fixed differences constitute autapomorphic states that affirm and diagnose some species (C. dimidiatus, C. magnipes). Osteological variation in 15 characters is analyzed with respect to predictions generated from four hypotheses: 1) phylogeny, 2) adaptation to specific habitats (the four species include cave-dwelling, terrestrial, and arboreal forms), 3) size-free shape, and 4) size. High levels of intraspecific variation suggest that the characters studied are not subject to rigid functional constraints in salamanders, regardless of size. The pattern predicted by the hypothesis based on size differences seen among these four Chiropterotriton species matches most closely the observed pattern of relative skull robustness. Since size change and heterochrony are often associated in plethodontid evolution, it is likely that changes in developmental timing play a role in the morphological transitions among these morphologically diverse taxa. Webbed feet, miniaturization, body shape, and an unusual tarsal arrangement are morphologies exhibited in species of Chiropterotrition that are shown to be homoplastic with other clades of tropical plethodontids. Although extensive homoplasy in salamanders might be seen as a roadblock to unraveling phylogenetic hypotheses, the homologous developmental systems that appear to underlie such homoplasy may reveal common and consistent evolutionary processes at work.

  4. Histology and ultrastructure of the caudal courtship glands of the red-backed salamander, Plethodon cinereus (Amphibia: Plethodontidae).

    PubMed

    Sever, David M; Siegel, Dustin S

    2015-03-01

    Caudal courtship glands (CCGs) are sexually dimorphic glands described in the skin of the dorsal tail base of some male salamanders in the genera Desmognathus, Eurycea, and Plethodon in the family Plethodontidae. These glands are believed to deliver pheromones to females during courtship, when the female rests her chin on the dorsal tail base during the stereotypic tail straddling walk unique to plethodontids. Although CCGs have been studied histologically, no investigations of their ultrastructure have been made. This article presents the first study on the fine structure and seasonal variation of CCGs, using the plethodontid Plethodon cinereus. The CCGs vary seasonally in height and secretory activity. The mature secretory granules observed in males collected in October and April consist of oval, biphasic granules that are eosinophilic and give positive reactions to periodic acid-Schiff for neutral carbohydrates but do not stain for acidic mucosusbtances or proteins with alcian blue and bromphenol blue, respectively. Granular glands, some of which contain mucous demilunes, are twice as large as CCGs, are syncytial (unlike CCGs), and stain for proteins. Mucous glands are similar in size to CCGs, but are basophilic, show no seasonal variation in secretory activity, and stain positive for acidic mucosubstances. CCGs do not resemble cytologically the sexually dimorphic mental glands of some plethodontids, which contain round or oval granules filled with an electron-dense amorphous substance. The CCGs are similar histologically to sexually dimorphic skin glands described in some anurans, but more comparative work is needed.

  5. Description of a New Salamander of the Genus Onychodactylus from Shikoku and Western Honshu, Japan (Amphibia, Caudata, Hynobiidae).

    PubMed

    Yoshikawa, Natsuhiko; Matsui, Masafumi; Tanabe, Shingo; Okayama, Takehito

    2013-01-01

    Recent phylogenetic studies using mtDNA and allozymes clarified the presence of multiple distinct genetic lineages in the Japanese clawed salamander, Onychodactylus japonicus, of which two from northern regions of the country have already been described as new species. Based on morphological analyses of the remaining genetic lineages, we describe the lineage from Shikoku Island and Chugoku Mountains of western Honshu, in western Japan, as a new species, Onychodactylus kinneburi sp. nov. It belongs to the O. japonicus complex and is morphologically similar to O. japonicus (sensu stricto), but is distinguishable from all the other members of the complex by sharply defined yellowish-orange dorsal stripe on black ground color, lack of dark marking on chest, whitish ventrum, comparatively large body size, and relatively narrow head, usually with 19 presacral vertebrae, 13 costal grooves, and relatively smaller number of vomerine tooth series. The new species occurs exclusively in Shikoku Island, but is sympatric with O. japonicus in Chugoku Mountains.

  6. A new species of Pristimantis (Amphibia, Anura, Craugastoridae) from the foothills of the Andes in Manu National Park, southeastern Peru

    PubMed Central

    Shepack, Alexander; von May, Rudolf; Ttito, Alex; Catenazzi, Alessandro

    2016-01-01

    Abstract We describe a new species of Pristimantis from the humid sub-montane forest of the Región Cusco in Peru. Pristimantis pluvialis sp. n. was collected in the Kosñipata and Entoro valleys at elevations from 740 to 1110 m a.s.l., near the borders of Manu National Park and within the Huachiperi Haramba Queros Conservation Concession. The new species can be distinguished from other members of the genus Pristimantis by its rostral tubercle, smooth dorsal skin, and by its advertisement call. Pristimantis lacrimosus and Pristimantis waoranii superficially most resemble the new species, but Pristimantis pluvialis sp. n. differs from both species by having a rostral tubercle (absent in Pristimantis waoranii and variable in Pristimantis lacrimosus) and larger size, from Pristimantis lacrimosus by its call emitted at a lower frequency, and from Pristimantis waoranii for its dorsal coloration with dark markings. Two other species have partially overlapping distributions and resemble the new species, Pristimantis mendax and Pristimantis olivaceus, but they produce advertisement calls with much higher dominant frequencies than the advertisement call of the new species. Furthermore, Pristimantis mendax differs from the new species by lacking a rostral tubercle and by having a sigmoid inner tarsal fold, whereas Pristimantis olivaceus differs by being smaller and by having dorsal skin shagreen with scattered tubercles. The new species has snout-vent length of 21.8–26.9 mm in males (n = 12) and 28.8 mm in a single female. PMID:27408563

  7. A new rainfrog of the Pristimantis myersi Group (Amphibia, Craugastoridae) from Volcán Pichincha, Ecuador.

    PubMed

    Rojas-Runjaic, Fernando J M; C, J Amanda Delgado; Guayasamin, Juan M

    2014-03-20

    A new frog of the Pristimantis myersi Group is described from a bamboo patch within the Reserva Ecológica Verdecocha (0°5'46.9"S, 78°36'15.3"W; 2851 m), located at northwestern flank of the Volcán Pichincha, in the vicinities of Quito, Ecuador. The new species is known from eight adult males, whereas the females remain unknown; it can be readily distinguished from all species of the P. myersi Group that inhabit the highlands of the Ecuadorian Andes by the unique combination of the following characters: body small (adult male SVL 14.9-19.7 mm; females unknown); dorsal skin shagreen, with a barely visible middorsal raphe, scapular and dorsolateral folds; tympanum small but well-defined; upper eyelid with one enlarged tubercle; males with prominent vocal slits, but without nuptial pads on thumbs; fold-like tarsal tubercles. With this new species, the number of Pristimantis assigned to the P. myersi Group raises to 16, of which, 12 are in Ecuador. We provide notes on morphology and color variation, advertisement call, and natural history of the new species.

  8. Trombiculid mites (Hannemania sp.) in Leptodactylus chaquensis (Amphibia: Anura) inhabiting selected soybean and rice agroecosystems of Argentina.

    PubMed

    Attademo, Andrés M; Peltzer, Paola M; Lajmanovich, Rafael C; Junges, Celina; Bassó, Agustín; Cabagna-Zenklusen, Mariana

    2012-09-01

    Trombiculid mites are known to parasitize a variety of amphibian species; however, few comparisons of mite parasitism among sites have been made. Here, Hannemania sp. parasitism in frogs (Leptodactylus chaquensis) inhabiting agroecosystems from mideastern Argentina was described. A total of 40 adult frogs (22 females and 18 males) were analyzed to detect ectoparasite Hannemania spp. larvae. Prevalence and mean abundance of Hannemania sp. were consistently higher in frogs from the agroecosystems (rice and soybean fields) than from two reference sites. Leptodactylus chaquensis might be considered an important host species of Hannemania sp., particularly in agricultural areas.

  9. Regional distribution and migration of proliferating cell populations in the adult brain of Hyla cinerea (Anura, Amphibia)

    PubMed Central

    M.Almli, Lynn; Wilczynski, Walter

    2007-01-01

    We examined the distribution of adult cell proliferation throughout the brain of an anuran amphibian using 5-bromo-2′-deoxyuridine (BrdU). BrdU, a thymidine analog, is a commonly used cellular marker that is incorporated into actively dividing progenitor cells. Adult green treefrogs, Hyla cinerea, received injections of BrdU and were sacrificed 2 hours, 2 days, 2 weeks, or 30 days later. Immunohistochemistry revealed BrdU-immunopositive (BrdU+) cells to be distributed in ventricular zones throughout the brain. The heaviest concentrations of cells were located in the telencephalon, primarily in the ventrolateral region of the lateral ventricles, and the ventricles of olfactory bulbs. Numerous BrdU+ cells were located around the preoptic and hypothalamic recesses and few around the third ventricle in the diencephalon. Proceeding caudally towards the midbrain, there was a marked decrease in BrdU-labeling and few BrdU+ cells were found in the hindbrain. Consistent with previous studies in ectothermic vertebrates, BrdU+ cells were found predominantly in the ventricular zone (VZ) and immediately adjacent to the VZ; at later time points (i.e., 30 days), the cells appeared to have migrated into parenchymal regions. The extent of cellular proliferation in anurans is similar to that of fishes and reptiles and thus is more widespread compared to mammals. PMID:17573049

  10. Conservation genetics of evolutionary lineages of the endangered mountain yellow-legged frog, Rana muscosa (Amphibia: Ranidae), in southern California

    USGS Publications Warehouse

    Schoville, Sean D.; Tustall, Tate S.; Vredenburg, Vance T.; Backlin, Adam R.; Gallegos, Elizabeth; Wood, Dustin A.; Fisher, Robert N.

    2011-01-01

    Severe population declines led to the listing of southern California Rana muscosa (Ranidae) as endangered in 2002. Nine small populations inhabit watersheds in three isolated mountain ranges, the San Gabriel, San Bernardino and San Jacinto. One population from the Dark Canyon tributary in the San Jacinto Mountains has been used to establish a captive breeding population at the San Diego Zoo Institute for Conservation Research. Because these populations may still be declining, it is critical to gather information on how genetic variation is structured in these populations and what historical inter-population connectivity existed between populations. Additionally, it is not clear whether these populations are rapidly losing genetic diversity due to population bottlenecks. Using mitochondrial and microsatellite data, we examine patterns of genetic variation in southern California and one of the last remaining populations of R. muscosa in the southern Sierra Nevada. We find low levels of genetic variation within each population and evidence of genetic bottlenecks. Additionally, substantial population structure is evident, suggesting a high degree of historical isolation within and between mountain ranges. Based on estimates from a multi-population isolation with migration analysis, these populations diversified during glacial episodes of the Pleistocene, with little gene flow during population divergence. Our data demonstrate that unique evolutionary lineages of R. muscosa occupy each mountain range in southern California and should be managed separately. The captive breeding program at Dark Canyon is promising, although mitigating the loss of neutral genetic diversity relative to the natural population might require additional breeding frogs.

  11. A revised taxonomy of crested newts in the Triturus karelinii group (Amphibia: Caudata: Salamandridae), with the description of a new species.

    PubMed

    Wielstra, B; Litvinchuk, S N; Naumov, B; Tzankov, N; Arntzen, J W

    2013-01-01

    We present a taxonomic revision of the crested newt Triturus karelinii sensu lato. Based on the presence of discrete nuclear DNA gene pools, deep genetic divergence of mitochondrial and nuclear DNA, and no indication of gene flow, we interpret this taxon as comprising two species: one covering the southern Caspian Sea shore, the Caucasus and the Crimea, i.e. the eastern part of the total range and another covering northern Asiatic Turkey and western Asiatic Turkey plus the southeastern Balkan Peninsula, i.e. the central and western part of the total range. We acknowledge that the central/western species should likely be further subdivided into a central and a western taxon, but we prefer to await a more detailed genetic analysis of the putative contact zone, positioned in northwestern Asiatic Turkey. The name T. karelinii (Strauch, 1870) applies to the eastern species as the type locality is positioned along the coast of the Gulf of Gorgan, Iran. The name T. arntzeni has been applied to the central/western species with Vrtovać, Serbia as the type locality. We show that not T. karelinii sensu lato but T. macedonicus occurs at Vrtovać. Hence, the name T. arntzeni Litvinchuk, Borkin, Dzukić and Kalezić, 1999 (in Litvinchuk et al., 1999) is a junior synonym of T. macedonicus (Karaman, 1922) and should not be used for the central/western species. We propose the name T. ivanbureschi sp. nov. for the central/western species and provide a formal species description.

  12. Integrative phylogeography of Calotriton newts (Amphibia, Salamandridae), with special remarks on the conservation of the endangered Montseny brook newt (Calotriton arnoldi).

    PubMed

    Valbuena-Ureña, Emilio; Amat, Fèlix; Carranza, Salvador

    2013-01-01

    The genus Calotriton includes two species of newts highly adapted to live in cold and fast-flowing mountain springs. The Pyrenean brook newt (Calotriton asper), restricted to the Pyrenean region, and the Montseny brook newt (Calotriton arnoldi), endemic to the Montseny massif and one of the most endangered amphibian species in Europe. In the present manuscript, we use an integrative approach including species distribution modeling (SDM), molecular analyses of mitochondrial and nuclear DNA sequence data and morphology to unravel the historical processes that have contributed to shaping the biogeography and genetic structure of the genus Calotriton, with special emphasis on the conservation of C. arnoldi. The results of the molecular analyses confirm that, despite having originated recently, being ecologically similar and geographically very close, there is no signal of hybridization between C. asper and C. arnoldi. SDM results suggest that tough environmental conditions on mountains tops during glacial periods, together with subsequent warmer periods could have prevented the contact between the two species. Within the critically endangered C. arnoldi, a high genetic structure is revealed despite its extremely small distribution range compared to C. asper. Haplotype networks, AMOVA and SAMOVA analyses suggest that two distinct groups of populations can be clearly differentiated with absence of gene flow. This is in concordance with morphological differentiation and correlates with its geographical distribution, as the two groups are situated on the eastern and western sides of a river valley that acts as a barrier. The genetic and morphological results are highly important for the ongoing conservation program of C. arnoldi and strongly justify the management of this species into at least two independent evolutionary significant units (eastern and western sectors) to guarantee the long-term population viability.

  13. The advertisement call and comments on the distribution of Eleutherodactylus bilineatus Bokermann, 1975, an endemic frog of Bahia State, Brazil (Amphibia, Anura)

    PubMed Central

    Dias, Iuri Ribeiro; de Mira-Mendes, Caio Vinicius; Souza-Costa, Carlos Augusto; Juncá, Flora Acuña; Solé, Mirco

    2017-01-01

    Abstract Advertisement calls can be used to aid solving taxonomic problems and understanding the evolution of certain groups. In this study, the advertisement call of Eleutherodactylus bilineatus is described. It is composed by two different notes with a total duration of 0.529–4.241 seconds and dominant frequency of 1.72–3.45 kHz. Additionally, new data is provided on the geographical distribution of Eleutherodactylus bilineatus and the most inland record for this species. PMID:28769692

  14. The advertisement call and comments on the distribution of Eleutherodactylus bilineatus Bokermann, 1975, an endemic frog of Bahia State, Brazil (Amphibia, Anura).

    PubMed

    Dias, Iuri Ribeiro; de Mira-Mendes, Caio Vinicius; Souza-Costa, Carlos Augusto; Juncá, Flora Acuña; Solé, Mirco

    2017-01-01

    Advertisement calls can be used to aid solving taxonomic problems and understanding the evolution of certain groups. In this study, the advertisement call of Eleutherodactylus bilineatus is described. It is composed by two different notes with a total duration of 0.529-4.241 seconds and dominant frequency of 1.72-3.45 kHz. Additionally, new data is provided on the geographical distribution of Eleutherodactylus bilineatus and the most inland record for this species.

  15. 3D Bite Modeling and Feeding Mechanics of the Largest Living Amphibian, the Chinese Giant Salamander Andrias davidianus (Amphibia:Urodela)

    PubMed Central

    Fortuny, Josep; Marcé-Nogué, Jordi; Heiss, Egon; Sanchez, Montserrat; Gil, Lluis; Galobart, Àngel

    2015-01-01

    Biting is an integral feature of the feeding mechanism for aquatic and terrestrial salamanders to capture, fix or immobilize elusive or struggling prey. However, little information is available on how it works and the functional implications of this biting system in amphibians although such approaches might be essential to understand feeding systems performed by early tetrapods. Herein, the skull biomechanics of the Chinese giant salamander, Andrias davidianus is investigated using 3D finite element analysis. The results reveal that the prey contact position is crucial for the structural performance of the skull, which is probably related to the lack of a bony bridge between the posterior end of the maxilla and the anterior quadrato-squamosal region. Giant salamanders perform asymmetrical strikes. These strikes are unusual and specialized behavior but might indeed be beneficial in such sit-and-wait or ambush-predators to capture laterally approaching prey. However, once captured by an asymmetrical strike, large, elusive and struggling prey have to be brought to the anterior jaw region to be subdued by a strong bite. Given their basal position within extant salamanders and their “conservative” morphology, cryptobranchids may be useful models to reconstruct the feeding ecology and biomechanics of different members of early tetrapods and amphibians, with similar osteological and myological constraints. PMID:25853557

  16. The karyotypes of five species of the Scinax perpusillus group (Amphibia, Anura, Hylidae) of southeastern Brazil show high levels of chromosomal stabilization in this taxon.

    PubMed

    Peixoto, Marco Antônio Amorim; Lacerda, João Victor Andrade; Coelho-Augusto, Carolina; Feio, Renato Neves; Dergam, Jorge Abdala

    2015-12-01

    Based on morphological, bioacoustics, and morphological traits, the genus Scinax has been subdivided into two major clades: S. catharinae and S. ruber. The first clade includes S. catharinae and S. perpusillus groups, whereas the second clade includes S. rostratus and S. uruguayus groups. Chromosome morphology, NOR and C-banding patterns of variation support these clades. This study aims the cytogenetic characterization of five species currently included in the S. perpusillus group: Scinax sp. (gr. perpusillus), S. arduous, S. belloni, S. cosenzai, and S. v-signatus, including standard cytogenetic techniques and repetitive DNA FISH probes. All species had 2n = 24 chromosomes. Nucleolar organizing regions occurred in chromosome pair 6 in all species, but differed in their locations among some species, suggesting a putative synaponomastic character for the clade. In S. belloni, the first chromosome pair was a metacentric, contrasting with the submetacentric first pair reported in all other species of the genus. Scinax sp. (gr. perpusillus) and S. v-signatus had similar karyotypic formulae, suggesting they are related species. Scinax cosenzai had a divergent C-banding pattern. Repetitive DNA probes hybridized more frequently in chromosomal subtelomeric regions in all species indicating recent cladogenesis in these species. Karyotypic evidence indicates unreported high levels of stabilization within S. perpusillus and in S. catharinae clade, resulting in a wealth of characters potentially informative for higher phylogenetic analyses.

  17. Microhyla laterite sp. nov., A New Species of Microhyla Tschudi, 1838 (Amphibia: Anura: Microhylidae) from a Laterite Rock Formation in South West India

    PubMed Central

    Ravikanth, G.; Vidisha, M. K.; Saurabh, S.; Pratik, M.

    2016-01-01

    In recent times, several new species of amphibians have been described from India. Many of these discoveries are from biodiversity hotspots or from within protected areas. We undertook amphibian surveys in human dominated landscapes outside of protected areas in south western region of India between years 2013–2015. We encountered a new species of Microhyla which is described here as Microhyla laterite sp. nov. It was delimited using molecular, morphometric and bioacoustics comparisons. Microhyla laterite sp. nov. appears to be restricted to areas of the West coast of India dominated by laterite rock formations. The laterite rock formations date as far back as the Cretaceous-Tertiary boundary and are considered to be wastelands in-spite of their intriguing geological history. We identify knowledge gaps in our understanding of the genus Microhyla from the Indian subcontinent and suggest ways to bridge them. PMID:26960208

  18. Three new species of horned frogs, Megophrys (Amphibia: Megophryidae), from northeast India, with a resolution to the identity of Megophrys boettgeri populations reported from the region.

    PubMed

    Mahony, Stephen; Teeling, Emma C; Biju, S D

    2013-01-01

    Northeast India is a well-established region of biological importance but remains poorly understood with regards to the species level identifications of many of its extant amphibians. In this study we examined small sized frogs from the genus Megophrys recently collected from remote and suburban forests in the northeast Indian states of Meghalaya and Arunachal Pradesh, from which we have identified three new species. Megophrys vegrandis sp. nov., Megophrys ancrae sp. nov. and Megophrys oropedion sp. nov. are compared with all known congeners from India and surrounding regions from which they differ based primarily on a combination of morphological characters. Megophrys boettgeri is removed, and Megophrys minor added to the Indian amphibian checklist, through critical review of all literature pertaining to the former species, and the discovery of an overlooked historical report of the latter species. Two of the new species, Megophrys ancrae sp. nov. and Megophrys vegrandis sp. nov. are known from low and mid elevations within two large protected forests in Arunachal Pradesh, both with poorly studied amphibian fauna. Contrastingly, Megophrys oropedion sp. nov. is currently known only from small forested areas on the upper reaches of the Shillong Plateau. The importance of the Shillong Plateau as an area of known high amphibian endemicity is highlighted in the light of the miniscule proportion of its land area afforded government protection, raising concerns about the future conservation of its still poorly known species.

  19. Integrative Phylogeography of Calotriton Newts (Amphibia, Salamandridae), with Special Remarks on the Conservation of the Endangered Montseny Brook Newt (Calotriton arnoldi)

    PubMed Central

    Valbuena-Ureña, Emilio; Amat, Fèlix; Carranza, Salvador

    2013-01-01

    The genus Calotriton includes two species of newts highly adapted to live in cold and fast-flowing mountain springs. The Pyrenean brook newt (Calotriton asper), restricted to the Pyrenean region, and the Montseny brook newt (Calotriton arnoldi), endemic to the Montseny massif and one of the most endangered amphibian species in Europe. In the present manuscript, we use an integrative approach including species distribution modeling (SDM), molecular analyses of mitochondrial and nuclear DNA sequence data and morphology to unravel the historical processes that have contributed to shaping the biogeography and genetic structure of the genus Calotriton, with special emphasis on the conservation of C. arnoldi. The results of the molecular analyses confirm that, despite having originated recently, being ecologically similar and geographically very close, there is no signal of hybridization between C. asper and C. arnoldi. SDM results suggest that tough environmental conditions on mountains tops during glacial periods, together with subsequent warmer periods could have prevented the contact between the two species. Within the critically endangered C. arnoldi, a high genetic structure is revealed despite its extremely small distribution range compared to C. asper. Haplotype networks, AMOVA and SAMOVA analyses suggest that two distinct groups of populations can be clearly differentiated with absence of gene flow. This is in concordance with morphological differentiation and correlates with its geographical distribution, as the two groups are situated on the eastern and western sides of a river valley that acts as a barrier. The genetic and morphological results are highly important for the ongoing conservation program of C. arnoldi and strongly justify the management of this species into at least two independent evolutionary significant units (eastern and western sectors) to guarantee the long-term population viability. PMID:23750201

  20. Changes of erythrocyte-metric parameters in Pelophylax ridibundus (Amphibia: Anura: Ranidae) inhabiting water bodies with different types of anthropogenic pollution in Southern Bulgaria.

    PubMed

    Zhelev, Zhivko; Popgeorgiev, Georgi; Ivanov, Ivan; Boyadzhiev, Peter

    2017-07-01

    The article presents the basic erythrocyte-metric parameters: cell length (EL) and width (EW), EL/EW, erythrocyte size (ES), nucleus length (NL) and width (NW), NL/NW, nucleus size (NS) and nucleocytoplasmic ratio (NS/ES) in the wild populations of marsh frogs Pelophylax ridibundus from five water bodies in Southern Bulgaria (two rivers and three reservoirs) with different degrees and types of anthropogenic pollution (less disrupted water basins, domestic sewage pollution and heavy metal pollution). The changes in erythrocyte-metric parameters depend on concentrations and types of toxicant and, to a lesser extent, on the type of water basin. We found that when P. ridibundus populations live in conditions of domestic sewage pollution, EL, EW and ES increase in comparison with the control samples, with regard to an elongated elliptical cell shape. Simultaneously, NL, NW and NS did not undergo any significant changes when compared with the control samples. The nuclei had elliptical shape. In the populations from the water basins with heavy metal pollution, EL, EW, ES, NL, NW and NS decreased. The cells and nuclei had a circular shape. NS/ES decreased when compared with the control sample, regardless of the type of toxicants.

  1. Evolutionary history and population genetic structure of the endemic tree frog Hyla tsinlingensis (Amphibia: Anura: Hylidae) inferred from mitochondrial gene analysis.

    PubMed

    Zhang, Yan-Hua; Zhao, Yan-Yu; Li, Xue-Ying; Li, Xiao-Chen

    2016-01-01

    The influence of topography and Pleistocenic climatic fluctuations on the population genetic structure of amphibians in the Tsinling-Dabieshan Mountains of China is poorly investigated. Hyla tsinlingensis is a tree frog endemic to the Tsinling-Dabieshan Mountains, with a restricted and patchy distribution that is currently shrinking. We speculated on the evolutionary history of amphibians in this region by studying the population genetic structure of H. tsinlingensis. Using a total of 212 samples, 32 haplotypes and four haplogroups were found in the present study. Population genetic structure showed significant differentiation (F(ST)) between most populations of H. tsinlingensis in the Tsinling-Dabieshan Mountains. An analysis of molecular variance (AMOVA) suggested that most of the observed genetic variation occurs between the two regions (the Tsinling and Dabieshan Mountains). Mantel tests indicated that the genetic divergence was induced through isolation by distance. Using Monmonier's maximum difference algorithm to predict the genetic barrier, two putative barriers in gene flow that separate lineages of H. tsinlingensis were identified. Mismatch distribution and neutrality tests found a sudden population expansion in all haplogroups except the Tsinling population and total population. This population expansion was identified between 0.5 Myr to 0.1 Myr (Quaternary) by Bayesian skyline plot (BSP). Divergence dating indicated the divergence time between the Tsinling population and Dabieshan population to be 3.26 MYA (Pliocene). In conclusion, the topography of the Tsinling and Dabieshan Mountains exerts a significant impact on the population genetic structure of H. tsinlingensis, and climatic oscillations during glacial periods in the Quaternary affected the distribution of H. tsinlingensis.

  2. Taxonomy and distribution of the salamander genus Bolitoglossa Duméril, Bibron & Duméril, 1854 (Amphibia, Caudata, Plethodontidae) in Brazilian Amazonia.

    PubMed

    Brcko, Isabela Carvalho; Hoogmoed, Marinus Steven; Neckel-Oliverira, Selvino

    2013-01-01

    For nearly 40 years Bolitoglossa paraensis has been synonymized with Bolitoglossa altamazonica. This fact has been mainly related to taxonomic ambiguities arising from the morphological similarities between these species and the scarcity of material deposited in collections. However, during the past 30 years new material of Bolitoglossa has been collected in many places throughout the Brazilian Amazonia, including the type locality of B. paraensis, Santa Isabel do Pará. In this article we designate the neotype of B. paraensis based on new material from the type locality, correct misinterpretations about this name. We determined how many species of the genus Bolitoglossa occur in Brazilian Amazonia, described three new species, B. caldwellae sp. nov., B. madeira sp. nov., and B. tapajonica sp. nov., provide a key for identifying Brazilian salamanders. Were analyzed two hundred and seventy eight specimens of Bolitoglossa from the Brazilian states of Acre, Amapá, Amazonas, Pará, and Rondonia; morphological data ofB. altamazonica from Colombia were used for comparison purposes. We confirm the presence of B. altamazonica in extreme western Brazil, and expand the number of species occurring in Brazilian Amazonia to five.

  3. 3D bite modeling and feeding mechanics of the largest living amphibian, the Chinese giant salamander Andrias davidianus (Amphibia:Urodela).

    PubMed

    Fortuny, Josep; Marcé-Nogué, Jordi; Heiss, Egon; Sanchez, Montserrat; Gil, Lluis; Galobart, Àngel

    2015-01-01

    Biting is an integral feature of the feeding mechanism for aquatic and terrestrial salamanders to capture, fix or immobilize elusive or struggling prey. However, little information is available on how it works and the functional implications of this biting system in amphibians although such approaches might be essential to understand feeding systems performed by early tetrapods. Herein, the skull biomechanics of the Chinese giant salamander, Andrias davidianus is investigated using 3D finite element analysis. The results reveal that the prey contact position is crucial for the structural performance of the skull, which is probably related to the lack of a bony bridge between the posterior end of the maxilla and the anterior quadrato-squamosal region. Giant salamanders perform asymmetrical strikes. These strikes are unusual and specialized behavior but might indeed be beneficial in such sit-and-wait or ambush-predators to capture laterally approaching prey. However, once captured by an asymmetrical strike, large, elusive and struggling prey have to be brought to the anterior jaw region to be subdued by a strong bite. Given their basal position within extant salamanders and their "conservative" morphology, cryptobranchids may be useful models to reconstruct the feeding ecology and biomechanics of different members of early tetrapods and amphibians, with similar osteological and myological constraints.

  4. Cytogenetic analyses of eight species in the genus Leptodactylus Fitzinger, 1843 (Amphibia, Anura, Leptodactylidae), including a new diploid number and a karyotype with multiple translocations

    PubMed Central

    2012-01-01

    Background The karyotypes of Leptodactylus species usually consist of 22 bi-armed chromosomes, but morphological variations in some chromosomes and even differences in the 2n have been reported. To better understand the mechanisms responsible for these differences, eight species were analysed using classical and molecular cytogenetic techniques, including replication banding with BrdU incorporation. Results Distinct chromosome numbers were found: 2n = 22 in Leptodactylus chaquensis, L. labyrinthicus, L. pentadactylus, L. petersii, L. podicipinus, and L. rhodomystax; 2n = 20 in Leptodactylus sp. (aff. podicipinus); and 2n = 24 in L. marmoratus. Among the species with 2n = 22, only three had the same basic karyotype. Leptodactylus pentadactylus presented multiple translocations, L. petersii displayed chromosome morphological discrepancy, and L. podicipinus had four pairs of telocentric chromosomes. Replication banding was crucial for characterising this variability and for explaining the reduced 2n in Leptodactylus sp. (aff. podicipinus). Leptodactylus marmoratus had few chromosomes with a similar banding patterns to the 2n = 22 karyotypes. The majority of the species presented a single NOR-bearing pair, which was confirmed using Ag-impregnation and FISH with an rDNA probe. In general, the NOR-bearing chromosomes corresponded to chromosome 8, but NORs were found on chromosome 3 or 4 in some species. Leptodactylus marmoratus had NORs on chromosome pairs 6 and 8. The data from C-banding, fluorochrome staining, and FISH using the telomeric probe helped in characterising the repetitive sequences. Even though hybridisation did occur on the chromosome ends, telomere-like repetitive sequences outside of the telomere region were identified. Metaphase I cells from L. pentadactylus confirmed its complex karyotype constitution because 12 chromosomes appeared as ring-shaped chain in addition to five bivalents. Conclusions Species of Leptodactylus exhibited both major and minor karyotypic differences which were identified by classical and molecular cytogenetic techniques. Replication banding, which is a unique procedure that has been used to obtain longitudinal multiple band patterns in amphibian chromosomes, allowed us to outline the general mechanisms responsible for these karyotype differences. The findings also suggested that L. marmoratus, which was formerly included in the genus Adenomera, may have undergone great chromosomal repatterning. PMID:23268622

  5. Correlations of cranial morphology, ecology, and evolution in Australian suctorial tadpoles of the genera Litoria and Nyctimystes (Amphibia: Anura: Hylidae: Pelodryadinae).

    PubMed

    Haas, A; Richards, S J

    1998-11-01

    Suctorial anuran larvae are highly specialized for living in fast-flowing waters, using their oral disks as adhesive organs to attach to the substrate. The cranial musculoskeletal structure of suctorial larvae of Litoria nannotis, L. rheocola, and Nyctimystes dayi (Hylidae: Pelodryadinae) were compared with congenerics with pond-type larvae (L. caerulea, L. genimaculata, L. xanthomera). Data from two other neobatrachian species with suctorial larvae (Boophis sp., Hyla armata) as well as published descriptions were taken into account. Suctorial tadpoles evolved several times independently in the Neobatrachia and share various features, irrespective of their phylogenetic position. These include the following. Cornua trabeculae are expanded anteriorly and sometimes fused. The lower jaws are robust. The greatest width of the skull is at the level of the jaw articulation. The upper jaw cartilages are partially or fully fused. The palatoquadrate is robust and connected to the skull by a wide commissura quadratocranialis anterior, processus oticus, processus basalis (in some species), and processus ascendens (vestigial or absent in some species). A processus ventralis quadrati provides an extended area of origin for the m. orbitohyoideus. The m. rectus abdominis inserts far anterior and acts on the cranium. The insertion of the epaxial musculature is shifted anteriorly to the anterior parts of the otic capsule. The mm. diaphragmatobranchialis and rectus cervicis cross at their origins. The origin of the m. levator mandibulae anterior has shifted posteriorly. The branchial basket is relatively small and the ceratohyal area is large. Multiple convergent evolution of these features suggests that they may be causally associated with the suctorial mode of larval life. Aside from these characters, however, the suctorial and pond-type neobatrachian species are remarkably similar in their jaw musculature and hyobranchial musculoskeletal composition. In some features, Ascaphus truei differs significantly from the neobatrachian suctorial species, indicating the influence of the historically distant separation of the two taxa. A novel modification of the upper jaw abduction mechanism has evolved in L. nannotis, L. rheocola, and N. dayi. It involves an adrostral cartilage as a pushing-rod element. This mechanism and unique structural similarities of the cartilago labialis superior gives support to the preliminary assumption that the nannotis species group is more closely related to the suctorial Nyctimystes dayi than it is to other Litoria species with pond-type larvae. Suctorial larvae presumably were present in the most recent common ancestor of the Litoria nannotis group and Nyctimystes dayi.

  6. A new synonym for Pristimantis luscombei (Duellman and Mendelson 1995) and the description of a new species of Pristimantis from the upper Amazon basin (Amphibia: Craugastoridae).

    PubMed

    Ortega-Andrade, H Mauricio; Venegas, Pablo J

    2014-12-12

    We consider Pristimantis achuar as junior synonym of P. luscombei, based on morphological and genetic evidence. Paratype specimens of P. luscombei are part of a new species, which lead to taxonomic confusion regarding the identity of P. luscombei. We describe and name this new species as Pristimantis miktos sp. nov. from Juyuintza, Pastaza province, eastern lowlands of Ecuador. Morphological diagnostic characters used to distinguish the new species from other brownish Amazonian Pristimantis are: (1) skin of dorsum shagreen with scattered tubercles or pustules; (2) tympanum prominent; (3) a thick X-shaped scapular dermal ridge in males; and (4) an orange iris in life. Pristimantis miktos is an inhabitant of the lowlands forests of the Pastaza and Napo drainages in eastern Ecuador and northern Loreto in Peru, reaching elevations of up to 350 m; P. luscombei is widely distributed in the upper Amazon Basin of Ecuador, northern Peru and extreme western Brazil, up to 1000 m. Phylogenetic analyses reveals that P. luscombei and the new species are not closest relatives, as also deduced from morphological evidence.

  7. Morphological and ultrastructural characteristics of Myxobolus ridibundae n. sp. (Myxosporea: Bivalvulida) infecting the testicular tissue of the marsh frog Rana ridibunda (Amphibia: Ranidae) in Egypt.

    PubMed

    Abdel-Ghaffar, Fathy; Abdel-Gaber, Rewaida; Maher, Sherein; El Deeb, Nashwa; Kamel, Reem; Al Quraishy, Saleh; Mehlhorn, Heinz

    2017-01-01

    Myxozoans are one of the most economically important groups of protozoan parasites causing many serious diseases of their hosts. In the present study, a total of 60 live adult male specimens of the marsh frog Rana ridibunda have been randomly captured during the period of January-December 2015 in different areas at Kafr El-Sheikh Governorate, Egypt and were examined for infection by myxosporidian parasites. A total of 48 (80.0 %) out of 60 frog specimens were found to be infected with Myxobolus species. Parasitic infection was restricted to the testicular tissue of the examined frogs. Macroscopic cysts (plasmodia) which heavily infested different parts of the testes were recovered. Morphological and ultrastructural characteristics of these myxosporidian species were carried out using light and transmission electron microscopy. Plasmodia measured 0.16-0.53 (0.34 ± 0.01) mm in diameter. Mature spores appeared oval in frontal view, measuring 8.9-11.5 (9.6 ± 0.1) μm in length and 7.5-9.1 (8.4 ± 0.1) μm in width containing 5-6 turns of polar filaments. Morphometric characterization revealed that the very small size of the present Myxobolus species was the most distinctive feature that separates them from all previously described Myxobolus species. Ultrastructural analysis showed that the plasmodia are surrounded by a plasma membrane with numerous pinocytotic protrusions extending toward the host cell. The generative cells and the different developmental stages are arranged at the periphery of the plasmodia, while immature and mature spores are centrally located. Sporogenesis, capsulogenesis, valvogenesis, and spore maturation of the present parasite are also described. The present species is described as Myxobolus ridibundae and represents a new species.

  8. Mud-packing frog: a novel breeding behaviour and parental care in a stream dwelling new species of Nyctibatrachus (Amphibia, Anura, Nyctibatrachidae).

    PubMed

    Gururaja, Kotambylu Vasudeva; Dinesh, K P; Priti, H; Ravikanth, G

    2014-05-16

    Reproductive modes are diverse and unique in anurans. Selective pressures of evolution, ecology and environment are attributed to such diverse reproductive modes. Globally forty different reproductive modes in anurans have been described to date. The genus Nyctibatrachus has been recently revised and belongs to an ancient lineage of frog families in the Western Ghats of India. Species of this genus are known to exhibit mountain associated clade endemism and novel breeding behaviours. The purpose of this study is to present unique reproductive behaviour, oviposition and parental care in a new species Nyctibatrachus kumbara sp. nov. which is described in the paper. Nyctibatrachus kumbara sp. nov. is a medium sized stream dwelling frog. It is distinct from the congeners based on a suite of morphological characters and substantially divergent in DNA sequences of the mitochondrial 16S rRNA gene. Males exhibit parental care by mud packing the egg clutch. Such parental care has so far not been described from any other frog species worldwide. Besides this, we emphasize that three co-occurring congeneric species of Nyctibatrachus, namely N. jog, N. kempholeyensis and Nyctibatrachus kumbara sp. nov. from the study site differ in breeding behaviour, which could represent a case of reproductive character displacement. These three species are distinct in their size, call pattern, reproductive behaviour, maximum number of eggs in a clutch, oviposition and parental care, which was evident from the statistical analysis. The study throws light on the reproductive behaviour of Nyctibatrachus kumbara sp. nov. and associated species to understand the evolution and adaptation of reproductive modes of anurans in general, and Nyctibatrachus in particular from the Western Ghats.

  9. A new species of limestone karst inhabiting forest frog, genus Platymantis (Amphibia: Anura: Ceratobatrachidae: subgenus Lupacolus) from southern Luzon Island, Philippines.

    PubMed

    Brown, Rafe M; De Layola, Louise Abigail; Lorenzo, Antonio; Diesmos, Mae Lowe L; Diesmos, Arvin C

    2015-11-25

    We describe a new species of limestone karst dwelling forest frog of the genus Platymantis from the Quezon Protected Landscape in southeastern Luzon Island, Philippines. We assign Platymantis quezoni, sp. nov., to the diverse assemblage of terrestrial species in the Platymantis dorsalis Group, subgenus Lupacolus on the basis of its body size and proportions, only slightly expanded terminal discs of the fingers and toes, and its terrestrial microhabitat. The new species is distinguished from these and all other Philippine congeners by features of its external morphology, its restriction to a distinctive limestone karst microhabitat, and its advertisement call, which is unique among frogs of the family Ceratobatrachidae. Several distinguishing morphological characters include its moderate body size (22.1-33.9 mm SVL for 16 adult males and 32.4-39.7 mm SVL for five adult females), slightly expanded terminal discs of the fingers and toes, smooth skin with limited dermal tuberculation, and a dorsal color pattern of mottled tan to dark brown with black blotches. The new species is the sixth Philippine Platymantis known to occur exclusively on limestone karst substrates (previously known karst-obligate species include: P. bayani, P. biak, P. insulatus, P. paengi, and P. speleaus). Recently accelerated discovery of limestone karst anurans across the Philippines suggests that numerous additional species may await discovery on the hundreds of scattered karst formations throughout the archipelago. This possibility suggests that a major conservation priority in coming years will be to study, characterize, describe, and preserve the endemic species supported by this patchy, unique and imperiled type of forest ecosystem in the Philippines.

  10. Molecular phylogeny and genetic identification of populations of two species of Feirana frogs (Amphibia: Anura, Ranidae, Dicroglossinae, Paini) endemic to China.

    PubMed

    Wang, Bin; Jiang, Jianping; Xie, Feng; Chen, Xiaohong; Dubois, Alain; Liang, Gang; Wagner, Steven

    2009-07-01

    Using mitochondrial 12S rRNA, 16S rRNA, and ND2 sequences, we investigated phylogenetic relationships among populations of two frog species endemic to China, both referred to the genus Feirana. A sister-group relationship between the two species was supported moderately in a maximum likelihood analysis and significantly in a Bayesian analysis, but not in a maximum parsimony analysis, of combined data for the three genes. Pending resolution of this incongruence, we provisionally maintain these species in the genus Feirana. Two major clades with a deep divergence are concordant with the species F. quadranus and "F." taihangnica. In the present work, some populations from the Qinling Mountains and all those from the Funiu and the Zhongtiao-southern Taihang Mountains are referred to "F." taihangnica rather than F. quadranus, whereas others are referred to F. quadranus. Consequently, the main body of the Qinling Mountains was identified as a large contact zone between these two species. On the basis of phylogenetic relationships and the distribution pattern of populations, we propose a hypothesis for the divergence of "F." taihangnica: the ancestral species might have inhabited the westernmost Qinling Mountains and dispersed to the main Qinling Mountains, and then to the Zhongtiao-southern Taihang and Funiu Mountains. In contrast, two alternative hypotheses are suggested for F. quadranus: if the two species are confirmed as sister groups, F. quadranus might have dispersed from the westernmost Qinling to the Longmen, Qinling, Daba, and northern Wuling Mountains; alternatively, F. quadranus might have come from the northern Wuling Mountains and then dispersed to the Daba, Qinling, and Longmen mountains.

  11. High genetic diversity but low population structure in the frog Pseudopaludicola falcipes (Hensel, 1867) (Amphibia, Anura) from the Pampas of South America.

    PubMed

    Langone, José A; Camargo, Arley; de Sá, Rafael O

    2016-02-01

    Relative to South America's ecoregions, the temperate grasslands of the Pampas have been poorly studied from a phylogeographic perspective. Based on an intermediate biogeographic setting between subtropical forest (Atlantic Forest) and arid ecosystems (Chaco and Patagonia), Pampean species are expected to show unstable demographic histories due to the Quaternary climatic oscillations. Herein, we investigate the phylogenetic relatedness and phylogeographic history of Pseudopaludicola falcipes, a small and common frog that is widely distributed across the Pampean grasslands. First, we use molecular data to assess if P. falcipes represents a single or multiple, separately evolving cryptic lineages. Because P. falcipes is a small-size species (<20mm) with extensive coloration and morphological variation, we suspected that it might represent a complex of cryptic species. In addition, we expected strong genetic and geographic structuring within Pseudopaludicola falcipes due to its large geographic distribution, potentially short dispersal distances, and multiple riverine barriers. We found that P. falcipes is a single evolutionary lineage with poor geographic structuring. Furthermore, current populations of P. falcipes have a large effective population size, maintain ancestral polymorphisms, and have a complex network of gene flow. We conclude that the demographic history of P. falcipes, combined with its ecological attributes and the landscape features of the Pampas, favored a unique combination among anurans of small body size, large population size, high genetic variability, but high cohesiveness of populations over a wide geographic distribution. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. Discordance between mitochondrial DNA genealogy and nuclear DNA genetic structure in the two morphotypes of Rana tagoi tagoi (Amphibia: Anura: Ranidae) in the Kinki Region, Japan.

    PubMed

    Eto, Koshiro; Matsui, Masafumi; Sugahara, Takahiro

    2013-07-01

    Two morphotypes, with a large and small body size, of a brown frog Rana t. tagoi occur sympatrically in the Kinki region, central Honshu of Japan. Previous mitochondrial (mt) DNA genealogical study recognized two main lineages (A and B) and several sublineages in R. tagoi, where the small type was placed in the group A-1b, and the large type in groups A-1a and B-2a. Using haplotype network and structure analysis of three nuclear genes, we examined the discrepancy between morphology and mitochondrial genealogy. The results showed that the small type is reproductively isolated from its co-occurring large type (A-1a or B-2a), and that unlimited gene flow occurred between parapatrically occurring two mtDNA lineages of large types (A-1a and B-2a). Discordant genetic relationships between mtDNA and nuclear DNA results may be caused by the past mitochondrial introgression, and possibly, the incomplete lineage sorting. These results also suggest a heterospecific relationship between the large (A-1a and B-2a) and small types (A-1b). The large type is identified as Rana t. tagoi as it is genetically very close to the topotypes of the nominal subspecies, while the small type remains unnamed.

  13. [Analysis of helminthofauna of common spaedfoot Pelobates fuscus (Laurenti, 1768) and moor frog Rana arvalis Nilsson, 1842 (Amphibia: Anura) at their joint habitation].

    PubMed

    Ruchin, A B; Chikhliaev, I V; Lukiianov, S V

    2009-01-01

    The helminths fauna of common spaedfoot Pelobates fuscus (Laurenti, 1768) and moor frog Rana arvalis Nilsson, 1842 has been studied at their joint habitation. The stuff was collected in 1998-2002, 2004-2006 years in several regions (republic Mordovia, Samara and Saratov areas). The processing of a stuff is conducted by a method of full helmintologic dissecting. The fauna of helminths considerably differs. For common spaedfoot only 13 species of helminths was detected which also parasitized moor frog (for moor frog 23 species) are detected. The index Jaccar demonstrated mean resemblance structure of helminths and varied from 0.25 till 0.69, and the index Morisite--from 44.58 of % till 74.51 of %. The communities of parasites of common spaedfoot was characterized by low values of an index of Shannon, but the high indexes of an index Simpson, whereas for moor frog tracked the return tendence.

  14. Distribution pattern of neuropeptide Y in the brain, pituitary and olfactory system during the larval development of the toad Rhinella arenarum (Amphibia: Anura).

    PubMed

    Heer, T; Pozzi, A G; Yovanovich, C A; Paz, D A

    2009-04-01

    The first NPY-immunoreactivity (ir) in the central nervous system of Rhinella arenarum was obtained just after hatching in the pre-optic area, ventral thalamus and rostral rhombencephalon. During pre-metamorphosis, new NPY-ir cells were observed in other brain areas such as pallium, septum and striatum, infundibulum and pars intermedia of the pituitary. Further maturation continued through pro-metamorphosis with the appearance of cell groups in the diagonal band, amygdala, pre-optic nucleus, dorsal nucleus of the habenula, anterior ventral and dorsal thalamus, suprachiasmatic nucleus, tuberculum posterior, tectum, torus semicircularis, inter-peduncular nucleus and median eminence. During the metamorphic climax and soon after, the relative abundance of NPY-ir fibres decreased in all hypothalamic areas and the staining intensity and number of NPY-ir cells in the pallium also decreased, whereas no cells were found in the striatum, dorsal nucleus of the habenula and tectum. In the olfactory epithelium, nerve or bulb, neither cells nor NPY-ir fibres were found during the stages of development analysed. The ontogeny pattern of the NPY-ir neuronal system in the brain of Rh. arenarum is more similar to the spatiotemporal appearance reported for Rana esculenta than to that reported for Xenopus laevis. Many NPY-ir fibres were found in the median eminence and in the pars intermedia of the pituitary, supporting the idea that this neuropeptide may play a role in the modulation of hypophyseal secretion during development.

  15. Microhyla laterite sp. nov., A New Species of Microhyla Tschudi, 1838 (Amphibia: Anura: Microhylidae) from a Laterite Rock Formation in South West India.

    PubMed

    Seshadri, K S; Singal, Ramit; Priti, H; Ravikanth, G; Vidisha, M K; Saurabh, S; Pratik, M; Gururaja, Kotambylu Vasudeva

    2016-01-01

    In recent times, several new species of amphibians have been described from India. Many of these discoveries are from biodiversity hotspots or from within protected areas. We undertook amphibian surveys in human dominated landscapes outside of protected areas in south western region of India between years 2013-2015. We encountered a new species of Microhyla which is described here as Microhyla laterite sp. nov. It was delimited using molecular, morphometric and bioacoustics comparisons. Microhyla laterite sp. nov. appears to be restricted to areas of the West coast of India dominated by laterite rock formations. The laterite rock formations date as far back as the Cretaceous-Tertiary boundary and are considered to be wastelands in-spite of their intriguing geological history. We identify knowledge gaps in our understanding of the genus Microhyla from the Indian subcontinent and suggest ways to bridge them.

  16. A new species of Foleyellides (Nematoda: Onchocercidae) parasite of Lithobates spp. (Amphibia: Ranidae) from Mexico with a key for the species of the genus.

    PubMed

    Romero-Mayén, Angeles R; León-Règagnon, Virginia

    2016-09-26

    Thirty-six Foleyellides mayenae n. sp. were recovered from the body cavity of Lithobates psilonota (Webb, 2001) and L. pustulosus (Boulenger, 1883) (Ranidae) from Jalisco and Nayarit, respectively. Foleyellides mayenae is the eleventh species described for the genus and the third for Mexican amphibians; it differs from the other species of the genus by the following combined characters: five pairs of caudal papillae, 1 pre-anal, 1 adanal and 3 post-cloacal, and the absence of a preanal plaque.

  17. Spermiogenesis and spermatozoon ultrastructure of Diplodiscus subclavatus (Pallas, 1760) (Paramphistomoidea, Diplodiscidae), an intestinal fluke of the pool frog Rana lessonae (Amphibia, Anura).

    PubMed

    Bakhoum, A J S; Torres, J; Shimalov, V V; Bâ, C T; Miquel, J

    2011-01-01

    Spermiogenesis in Diplodiscus subclavatus begins with the formation of the zone of differentiation presenting two centrioles associated with striated roots and an intercentriolar body. The latter presents seven electron-dense layers with a fine central plate and three plates on both sides. The external pair of these electron-dense layers is formed by a granular row. Each centriole develops into a free flagellum, both of them growing orthogonally in relation to the median cytoplasmic process. After the flagellar rotation and before the proximodistal fusion of both flagella with the median cytoplasmic process four attachment zones were already observed in several cross-sections indicating the area of fusion. Spinelike bodies are also observed in the differentiation zone before the fusion of flagella. Finally, the constriction of the ring of arched membranes gives rise to the young spermatozoon that detaches from the residual cytoplasm. The mature spermatozoon of D. subclavatus shows all the classical characters observed in Digenea spermatozoa such as two axonemes of different length of the 9+"1" trepaxonematan pattern, nucleus, mitochondrion, two bundles of parallel cortical microtubules and granules of glycogen. However, some peculiarities such as a well-developed lateral expansion associated with external ornamentation of the plasma membrane and spinelike bodies combined with their area of appearance distinguish the ultrastructural organization of the sperm cells of D. subclavatus from those of other digeneans.

  18. [The correlation of the ecological niches of the common (Rana temporaria L.) and of the moor (Rana arvalis Nilss.) frogs (Anura, Amphibia)].

    PubMed

    Severtsov, A S; Liapkov, S M; Surova, G S

    1998-01-01

    During 25 years ecology and population dynamic of two brown frog species (Rana temporaria and R. arvalis) were studied in Moscow region, Solovki island and South Ural. We compared life cycles characteristics, namely biotope preferences, diet, migration, enemies, hibernation places using own and available literature data. Then we analyse how these parameters are changed among the species area and ecological niches were compared. We found that these two species do not compete in any stage of life cycle. Ecological niches are very closed and differences are determined generally by abiotic factors. So, R. temporaria prefers more wet biotope and more sensitive to acidity (low pH value). Differences in spawning time do not associate with interference in spawning places. We conclude that interspecific competition did not take place neither in the past nor in present and the reason of differences in ecological niches are determined by separate ways of evolutionary development of these species.

  19. Structural aspects of an unusual choroidal polarized hyaline cartilage in the eyeball of Bufo ictericus and Rana catesbeiana (Amphibia, Anura): morphological and physiological significance.

    PubMed

    de Jesus Santana, Andréa Souza; de Carvalho-E-Silva, Sérgio Potsch; de Brito-Gitirana, Lycia

    2005-01-01

    Amphibian eyes play an important role in vision and in several physiological processes, such as food capture and breathing. To maintain the integrity of the eyeball there is a unique cuplike hyaline cartilage as a supporting tissue. In Bufo ictericus and Rana catesbeiana the cartilage layer is located between the retina and the choroids, being designated as choroidal cartilage, important to visual performance. On the retinal surface, there is no perichondrium, and the pigmented epithelium exhibits an intimate relationship to the cartilage layer.

  20. The role of phytophysiognomies and seasonality on the structure of ground-dwelling anuran (Amphibia) in the Pampa biome, Southern Brazil.

    PubMed

    Maragno, Franciéle P; Santos, Tiago G; Cechin, Sonia Z

    2013-09-01

    Considering that habitat use by amphibians is related both with climate and environmental features, we tested the hypothesis that anuran assemblages found in different phytophysiognomies and in different seasons vary in structure. Additionally, we searched for species which can be indicators of habitat and seasons. The study was conducted in the Pampa biome, southern Brazil. Sampling was done through pitfall traps placed in three phytophysiognomies: grassland, ecotone grassland/forest; and forest. The seasonality factor was created by grouping months in warn and cold seasons. Sixteen species were found and the assemblages were influenced both by phytophysiognomies and climatic seasonality. In a paired comparison, the three phytophysiognomies differed in structure of assemblage from each other. Physalaemus henselii, P. riograndensis, Pseudopaludicola falcipes and Pseudis minuta were indicators of ecotone. Leptodactylus gracilis and Physalaemus biligonigerus were indicators of grassland. None species was indicator of forest. Most of the species were indicators of warm season: Elachistocleis bicolor, Leptodactylus fuscus, L. gracilis, L. latinasus, L. latrans, L. mystacinus, Physalaemus biligonigerus, P. cuvieri and Pseudis minuta. None species was indicator of cold season. We found that even for species of open areas, as Pampa, heterogeneous phytophysiognomies are important for maintaining abundance and constancy of populations of anuran.

  1. Phylogeny and Differentiation of Wide-Ranging Ryukyu Kajika Frog Buergeria japonica (Amphibia: Rhacophoridae): Geographic Genetic Pattern Not Simply Explained by Vicariance Through Strait Formation.

    PubMed

    Tominaga, Atsushi; Matsui, Masafumi; Eto, Koshiro; Ota, Hidetoshi

    2015-06-01

    To investigate geographic genetic structures and taxonomic relationships among isolated populations of Buergeria japonica, occurring very widely in various habitats of the Ryukyu Archipelago and Taiwan, we conducted phylogenetic and demographic analyses among individuals from various localities, representing their entire distributional ranges. Buergeria japonica is genetically greatly differentiated and comprises three major clades (the Southern Taiwan [ST] clade, the Northern Taiwan + Southern Ryukyu [NT/SR] clade, and the Central + Northern Ryukyu [CR/NR] clade), each of which seems to represent independent species. The first divergence in the species is estimated to have occurred in the middle to late Miocene in areas of current Taiwan, then eastern periphery of the Asian continent. Split of the ST and the remaining clades, and subsequent divergence between the NT/SR and the CR/NR clades in the latter, indicate consecutive south to north vicariant diversifications. However, these vicariances are not always associated with formation of significant barriers such as deep straits. Less but still prominently diverged subclades (the Amami + Tokara [AM/TK] and the Okinawa [ON] subclades) in the CR/NR clade were recognized in spite of the absence of an intervening deep strait. Contrariwise, individuals from Amami and Tokara Groups formed the AM/TK subclade in spite of the presence of the intervening Tokara Gap (a long-standing deep tectonic strait). Furthermore, in the AM/TK subclade, low but definite genetic divergence was found between the Northern Amami + Tokara (NAM/TK) lineage and the Southern Amami (SAM) lineage. Estimated divergence time and gene flow rate within the NAM/TK lineage indicate that this species reached northern Tokara from the south by overseas dispersal over the Tokara Gap long after its formation, but not by more recent artificial transportation. This overseas dispersal would have been facilitated by its more frequent occurrence around coastal habitats than other frogs.

  2. Evolutionary origins and genetic variation of the Seychelles treefrog, Tachycnemis seychellensis (Duméril and Bibron, 1841) (Amphibia: Anura: Hyperoliidae)

    PubMed Central

    Maddock, Simon T.; Day, Julia J.; Nussbaum, Ronald A.; Wilkinson, Mark; Gower, David J.

    2014-01-01

    The hyperoliid frog Tachycnemis seychellensis, the only species of its genus, is endemic to the four largest granitic islands of the Seychelles archipelago and is reliant on freshwater bodies for reproduction. Its presence in the Seychelles is thought to be the product of a transoceanic dispersal, diverging from the genus Heterixalus, its closest living relative (currently endemic to Madagascar), between approximately 10–35 Ma. A previous study documented substantial intraspecific morphological variation among island populations and also among populations within the largest island (Mahé). To assess intraspecific genetic variation and to infer the closest living relative(s) of T. seychellensis, DNA sequence data were generated for three mitochondrial and four nuclear markers. These data support a sister-group relationship between T. seychellensis and Heterixalus, with the divergence between the two occurring between approximately 11–19 Ma based on cytb p-distances. Low levels of genetic variation were found among major mitochondrial haplotype clades of T. seychellensis (maximum 0.7% p-distance concatenated mtDNA), and samples from each of the islands (except La Digue) comprised multiple mitochondrial haplotype clades. Two nuclear genes (rag1 and tyr) showed no variation, and the other two (rho and pomc) lacked any notable geographic structuring, counter to patterns observed within presumably more vagile Seychelles taxa such as lizards. The low levels of genetic variation and phylogeographic structure support an interpretation that there is a single but morphologically highly variable species of Seychelles treefrog. The contrasting genetic and morphological intraspecific variation may be attributable to relatively recent admixture during low sea-level stands, ecophenotypic plasticity, local adaptation to different environmental conditions, and/or current and previously small population sizes. Low genetic phylogeographic structure but substantial morphological variation is unusual within anurans. PMID:24555995

  3. A new species of terrestrial-breeding frog (Amphibia, Craugastoridae, Pristimantis) from high elevations of the Pui Pui Protected Forest in central Peru.

    PubMed

    Lehr, Edgar; von May, Rudolf

    2017-01-01

    We describe a new species of Pristimantis from upper montane forests and high Andean grasslands of the Pui Pui Protected Forest and its close surroundings, Región Junín, central Peru. The description of the new species is based on 34 specimens found at elevations between 3400 and 3936 m a.s.l. Pristimantis attenboroughisp. n. is characterized by a snout-vent length of 14.6-19.2 mm in adult males (n = 21), 19.2-23.0 mm in adult females (n = 10), and is compared morphologically and genetically with other taxonomically and biogeographically relevant species of Pristimantis. The new species is characterized by having narrow digits that lack circumferential grooves, irregularly shaped, discontinuous dorsolateral folds, and absence of both tympanic membrane and tympanic annulus. The high similarity in morphology between P. attenboroughisp. n. and members of the Andean genera Phrynopus and Bryophryne provides an example for convergent evolution, and highlights the importance of using molecular data to justify generic assignment. Pristimantis attenboroughisp. n. is most similar to Phrynopus chaparroi from the Región Junín, suggesting that the generic placement of this species needs to be revised. Phylogenetically the new species belongs to the Pristimantis danae species Group, a clade that includes several Pristimantis species distributed in the montane forests of central Peru, including P. albertus, P. aniptopalmatus, P. ornatus, and P. stictogaster.

  4. A review of the biology and conservation of the Cope's giant salamander Dicamptodon copei Nussbaum, 1970 (Amphibia: Caudata: Dicamptodontidae) in the Pacific northwestern region of the USA

    Treesearch

    Alex D. Foster; Deanna H. Olson; Lawrence L.C. Jones

    2015-01-01

    The Cope’s Giant Salamander Dicamptodon copei is a stream dwelling amphibian reliant on cool streams, native to forested areas primarily west of the crest of the Cascade Range in the Pacific Northwest region, USA. Unlike other members of the genus, adult D. copei are most often found in a paedomorphic form, and rarely transforms to a terrestrial stage. As a result,...

  5. A mini review on the antimicrobial peptides isolated from the genus Hylarana (Amphibia: Anura) with a proposed nomenclature for amphibian skin peptides.

    PubMed

    Thomas, Priya; Kumar, T V Vineeth; Reshmy, V; Kumar, K S; George, S

    2012-06-01

    Hylarana is a well established frog genus coming under the family Ranidae. An increasing number of antimicrobial peptides have been isolated and characterized from the skin of frogs of this genus. This review covers the antimicrobial peptides reported so far from the frogs of Hylarana genus and to propose a consistent system of nomenclature for amphibian skin peptides. Multiple sequence alignment of the skin peptides from Hylarana genus has grouped them into six peptide families, and three bioactive peptides. Existing nomenclature of amphibian antimicrobial peptides is species centered with no implication to the genus which can lead to disparities, when frogs with same species name belonging to different genus have to be named. As per the proposed system the peptide should have the parent peptide name (e.g. Brevinin-1) followed by two uppercase letter of the genus, if two genera begin with the same letter-first letter should be the same followed by an appropriate second letter (e.g. HU for Huia and HM for Humenerana). This is succeeded by species name in lower case-orthologous peptides from different species may be characterized by the initial letter of that species, when two species begin with the same initial letter, second letter should be used appropriately (e.g. HLat for Hylarana aurata and HLan for Hylarana aurantiaca). Paralogs belonging to the same peptide family are assigned by numbers.

  6. Seasonal changes of basic erythrocyte-metric parameters in Pelophylaxridibundus (Amphibia: Ranidae) from anthropogenically polluted biotopes in Southern Bulgaria and their role as bioindicators.

    PubMed

    Zhelev, Zhivko M; Mehterov, Nikolay H; Popgeorgiev, Georgi S

    2016-02-01

    The purpose of this research work is to present data that show the seasonal changes (spring-summer-autumn) of basic erythrocyte-metric parameters (ЕL: Erythrocyte length, ЕW: Erythrocyte width, ЕL/ЕW, ES: Erythrocyte size; NL: Nucleus length, NW: Nucleus width, NL/NW; NS: Nucleus size, NS/ES: Nucleus-cytoplasmic ratio) in Pelophylax ridibundus populations from three biotopes located on two rivers in Southern Bulgaria (less disrupted biotope, with domestic sewage pollution and heavy metal pollution). Differences of high statistical significance were found among the different populations. Within the population living in conditions of domestic sewage pollution, for the entire period of the investigation the erythrocytes and their nuclei had an elliptical shape (a slight elongation of ellipses in autumn) and the biggest sizes (EL, EW, ES, NL and NS were constantly higher than the less disrupted biotope), NS/ES, became significantly smaller in autumn. Throughout the period of investigation, the values of all nine cellular and nuclear parameters were statistically-significantly the lowest in the population from the biotope with heavy metal pollution. The parameters: EL, ЕW, NL, NW and ES became significantly lower, progressively and statistically, during seasonal transitions. Cells and nuclei grew ovular in shape in comparison to the populations from the other two biotopes (this process was most pronounced in autumn) and NS/ES numbers were significantly decreased in summer and autumn.

  7. A new hynobiid-like salamander (Amphibia, Urodela) from Inner Mongolia, China, provides a rare case study of developmental features in an Early Cretaceous fossil urodele.

    PubMed

    Jia, Jia; Gao, Ke-Qin

    2016-01-01

    A new fossil salamander, Nuominerpeton aquilonaris (gen. et sp. nov.), is named and described based on specimens from the Lower Cretaceous Guanghua Formation of Inner Mongolia, China. The new discovery documents a far northern occurrence of Early Cretaceous salamanders in China, extending the geographic distribution for the Mesozoic fossil record of the group from the Jehol area (40th-45th parallel north) to near the 49th parallel north. The new salamander is characterized by having the orbitosphenoid semicircular in shape; coracoid plate of the scapulocoracoid greatly expanded with a convex ventral and posterior border; ossification of two centralia in carpus and tarsus; and first digit being about half the length of the second digit in both manus and pes. The new salamander appears to be closely related to hynobiids, although this inferred relationship awaits confirmation by research in progress by us on a morphological and molecular combined analysis of cryptobranchoid relationships. Comparison of adult with larval and postmetamorphic juvenile specimens provides insights into developmental patterns of cranial and postcranial skeletons in this fossil species, especially resorption of the palatine and anterior portions of the palatopterygoid in the palate and the coronoid in the mandible during metamorphosis, and postmetamorphic ossification of the mesopodium in both manus and pes. Thus, this study provides a rare case study of developmental features in a Mesozoic salamander.

  8. PCB accumulation and tissue distribution in cave salamander (Proteus anguinus anguinus, Amphibia, Urodela) in the polluted karstic hinterland of the Krupa River, Slovenia.

    PubMed

    Pezdirc, Marko; Heath, Ester; Bizjak Mali, Lilijana; Bulog, Boris

    2011-08-01

    For over two decades, a manufacturer of electrical capacitors disposed of its waste within the karstic hinterland of the Krupa River (Slovenia) resulting in the surroundings becomming heavily polluted with PCB. Albeit the extent of the contamination has been known since 1983 and the Krupa River has become one of the most PCB polluted river in Europe, the effects on the cave fauna of the region remain unknown. The most famous cave dweller of the Krupa hinterland is the endemic cave salamander Proteus anguinus anguinus. In this study we determine the levels of PCB in the tissues of the Proteus and in river sediments. The total concentration of PCB in individual tissue samples from specimens of the Krupa spring was between 165.59 μg g(-1) and 1560.20 μg g(-1)dry wt, which is at least 28-times higher than those from an unpolluted site. The kidneys contained the lowest concentration, while the highest concentration was in subcutaneous fat and tissues with high lipid contents like visceral fat and liver. Total PCB concentrations in sediment samples from the Krupa River were between 5.47 and 59.20 μg g(-1)dry wt showing that a high burden of PCB still remains in the region. The most abundant PCB congeners in all analyzed samples were di-ortho substituted (PCB #101, #118, #138 and #158), but higher proportion of mono-ortho PCB was present in sediments. The ability of Proteus to survive a high PCB loading in its environment and especially in its tissues is remarkable. Its partial elimination of low chlorinated and mono-ortho substituted congeners is also reported.

  9. [Hematology and blood cell cytochemistry of Rhinella fernandezae (Amphibia: Anura) from Espinal and Delta-Islands of Paraná River, Argentina].

    PubMed

    Cabagna Zenklusen, Mariana C; Lajmanovich, Rafael C; Attademo, Andrés M; Peltzer, Paola M; Junges, Celina M; Fiorenza Biancucci, Gabriela; Bassó, Agustín

    2011-03-01

    The description of amphibian hematology is scarce and most of these studies have been done in species from North America, Asia and Europe. With the purpose to obtain basic hematological information of Rhinella fernandezae, 23 blood samples from Santa Fe and Entre Rios natural reserves were studied. Blood of each individual was extracted by cardiac puncture and hemograms were carried out. Morphological and cytochemical description of blood cells were analyzed in slides and were inspected for extra and intra cellular parasites. Five leucocytes types were observed, being lymphocytes the predominant ones followed by basophiles. Heterophils and eosinophils were positive to PAS, Sudan B and peroxidase. The erythrocytes and its precursors were negative for cytochemical reactions. Micronuclei and nuclear alterations frequencies were scarce. No significant differences (p > 0.05) were observed between sexes neither in hemograms nor in blood cells morphology. Microfilarias were the only hemoparasites found with a relative low prevalence and infection intensity. The hematological characteristics studied were similar to those reported for other amphibians, suggesting that R. fernandezae individuals present optimal nutritional and immunological status.

  10. Chromosome banding in Amphibia. XXVIII. Homomorphic XY sex chromosomes and a derived Y-autosome translocation in Eleutherodactylus riveroi (Anura, Leptodactylidae).

    PubMed

    Schmid, M; Feichtinger, W; Steinlein, C; Visbal García, R; Fernández Badillo, A

    2003-01-01

    Extensive cytogenetic analyses on a population of the leptodactylid frog Eleutherodactylus riveroi in northern Venezuela revealed the existence of multiple XXAA male/XYAA female/XAA(Y) female sex chromosomes. The XAA(Y) karyotype originated by a centric (Robertsonian) fusion between the original, free Y chromosome and an autosome. 46.2% of the male individuals in this population are carriers of this Y-autosome fusion. In male meiosis the XAA(Y) sex chromosomes pair in the expected trivalent configuration. In the same population 53.8% of the male animals still possess the original, free XY sex chromosomes. E. riveroi is only the second vertebrate species discovered in which a derived Y-autosome fusion coexists with the ancestral free XY sex chromosomes. The free XY sex chromosomes, as well as the multiple XA(Y) sex chromosomes are still in a very primitive (homomorphic) stage of differentiation. With no banding technique applied it is possible to distinguish the Y from the X. Various banding techniques and in situ hybridizations have been carried out to characterize the karyotypes. DNA flow cytometric measurements show that the genome size of E. riveroi resembles that of other Eleutherodactylus species. The cytogenetic data obtained in E. riveroi are compared with those of the sole other vertebrate known to possess the extremely rare, multiple XXAA male/XYAA female/XAA(Y) female sex chromosomes. Surprisingly enough, this vertebrate again is a frog belonging to the genus Eleutherodactylus [E. ((maussi) biporcatus] which lives exactly in the same habitat in northern Venezuela as does E. riveroi.

  11. Chromosome banding in Amphibia. XXVI. Coexistence of homomorphic XY sex chromosomes and a derived Y-autosome translocation in Eleutherodactylus maussi (Anura, Leptodactylidae).

    PubMed

    Schmid, M; Feichtinger, W; Steinlein, C; Haaf, T; Schartl, M; Visbal García, R; Manzanilla Pupo, J; Fernández Badillo, A

    2002-01-01

    A 15-year cytogenetic survey on one population of the leaf litter frog Eleutherodactylus maussi in northern Venezuela confirmed the existence of multiple XXAA male symbol /XAA(Y) female symbol sex chromosomes which originated by a centric (Robertsonian) fusion between the original Y chromosome and an autosome. 95% of the male individuals in this population are carriers of this Y-autosome fusion. In male meiosis the XAA(Y) sex chromosomes pair in the expected trivalent configuration. In the same population, 5% of the male animals still possess the original, free XY sex chromosomes. In a second population of E. maussi analyzed, all male specimens are characterized by these ancestral XY chromosomes which form normal bivalents in meiosis. E. maussi apparently represents the first vertebrate species discovered in which a derived Y-autosome fusion still coexists with the ancestral free XY sex chromosomes. The free XY sex chromosomes, as well as the multiple XA(Y) sex chromosomes are still in a very primitive (homomorphic) stage of differentiation. With no banding technique applied it is possible to distinguish the Y from the X. DNA flow cytometric measurements show that the genome of E. maussi is among the largest in the anuran family Leptodactylidae. The present study also supplies further data on differential chromosome banding and fluorescence in situ hybridization experiments in this amphibian species.

  12. Phylogenetic relationships among Hoplobatrachus rugulosus in Thailand as inferred from mitochondrial DNA sequences of the cytochrome-b gene (Amphibia, Anura, Dicroglossidae).

    PubMed

    Pansook, Anusorn; Khonsue, Wichase; Piyapattanakorn, Sanit; Pariyanonth, Putsatee

    2012-01-01

    A fragment (564 bp) of the mitochondrial cytochrome-b (Cyt-b) gene was studied for 73 individual rice field frogs (Hoplobatrachus rugulosus) from 18 geographical locations (populations) within Thailand. Sequence analysis revealed the presence of 12 haplotypes, with five haplotypes being represented in two or more populations, and the other seven being population-distinct haplotypes. Phylogenetic analysis by maximum parsimony, maximum likelihood, and neighbor joining analyses all placed the 12 haplotypes into two distinct and well-separated clades with high bootstrap support, reflecting the high sequence divergences between the clades (25.3-32.3%). The mountain ranges and the Isthmus of Kra are likely to have played important roles in hindering gene flow among H. rugulosus populations in Thailand. From the sequence divergence values, the two clades of H. rugulosus can be classified into two distinct species, and therefore, the strains of H. rugulosus bred in farm stocks should be restricted to a population of one clade so as to avoid cross breeding between the two clades.

  13. Genetic divergence and evolutionary relationships in six species of genera Hoplobatrachus and Euphlyctis (Amphibia: Anura) from Bangladesh and other Asian countries revealed by mitochondrial gene sequences.

    PubMed

    Alam, Mohammad Shafiqul; Igawa, Takeshi; Khan, Md Mukhlesur Rahman; Islam, Mohammed Mafizul; Kuramoto, Mitsuru; Matsui, Masafumi; Kurabayashi, Atsushi; Sumida, Masayuki

    2008-08-01

    To elucidate the species composition, genetic divergence, evolutionary relationships, and divergence time of Hoplobatrachus and Euphlyctis frogs (subfamily Dicroglossinae, family Ranidae) in Bangladesh and other Asian countries, we analyzed the mitochondrial Cyt b, 12S, and 16S rRNA genes of 252 specimens. Our phylogenetic analyses showed 13 major clades corresponding to several cryptic species as well as to nominal species in the two genera. The results suggested monophyly of Asian Hoplobatrachus species, but the position of African Hoplobatrachus occipitalis was not clarified. Nucleotide divergence and phylogenetic data suggested the presence of allopatric cryptic species allied to Euphlyctis hexadactylus in Sundarban, Bangladesh and several parapatric cryptic species in the Western Ghats, India. The presence of at least two allopatric cryptic species among diverged Euphlyctis cyanophlyctis in Bangladesh, India, and Sri Lanka was also suggested. In some cases, our estimated divergence times matched the paleogeological events of South and Southeast Asian regions that may have led to the divergence of Hoplobatrachus and Euphlyctis taxa. Especially, land formation at Bangladesh (15-10Ma) may have allowed the spread of these frog taxa to Southeast Asian areas, and the aridification of central India (5.1-1.6Ma) might have affected the gene flow of widely distributed species. The present study revealed prior underestimation of the richness of the amphibian fauna in this region, indicating the possible occurrence of many cryptic species among these groups.

  14. Predator-prey interactions between Synbranchus marmoratus (Teleostei: Synbranchidae) and Hypsiboas pulchellus tadpoles (Amphibia: Hylidae): importance of lateral line in nocturnal predation and effects of fenitrothion exposure.

    PubMed

    Junges, Celina M; Lajmanovich, Rafael C; Peltzer, Paola M; Attademo, Andres M; Bassó, Agustín

    2010-11-01

    Environmental contaminants can disrupt interactions between aquatic species by altering community structure. We explored predator-prey interactions between marbled swamp juvenile eels (Synbranchus marmoratus; predator) and anuran tadpoles (Hypsiboas pulchellus; prey) in relation to two aspects: the importance of lateral line in the predator and whether the absence of light modifies predation rates; and the effect of a sub-lethal concentration of fenitrothion on both predator and prey. Eels were tested under two sensory conditions (lateral line intact and lateral line blocked by cobalt chloride) in dark conditions. Predation rates were evaluated using different treatments that combined predator and prey exposed or not to insecticide. Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) activities were also measured in muscle samples of eels and tadpoles to explore whether fenitrothion affects predator and prey differentially. Marbled swamp eels were more efficient in feeding on tadpoles during the night than during the day, showing that lateral line makes an important contribution to prey detection and capture. Regarding pesticide effects, short-term (6 h) exposure to an ecologically relevant fenitrothion dose of 2.5 mg L(-1) altered the predator-prey relationship by changing prey behaviour, reducing prey detection and therefore increasing tadpole survival. At this concentration, the outcome of the predator-prey relationship appears biased in favor of the exposed tadpoles, which were released from predation risk, despite their altered behaviour and the higher inhibition percentages of tail BChE (70%) and AChE (51%) than in control individuals. Our study involving these model species and agrochemicals demonstrates that fenitrothion affected the outcome of a predator-prey relationship. Further studies are needed, in these species and other native amphibians, to investigate the nature of the mechanisms responsible for the adverse effects of pesticides on antipredator behaviour and predation efficiency.

  15. Cryptic diversity in the Hypsiboas semilineatus species group (Amphibia, Anura) with the description of a new species from the eastern Guiana Shield.

    PubMed

    Fouquet, Antoine; Martinez, Quentin; Zeidler, Lauren; Courtois, Elodie A; Gaucher, Philippe; Blanc, Michel; Lima, Jucivaldo Dias; Souza, Sergio Marques; Rodrigues, Miguel T; Lima, Jucivaldo Dias; Souza, Sergio Marques; Rodrigues, Miguel T; Kok, Philippe J R

    2016-02-24

    We used molecular and morphological data to investigate the hidden diversity within the Hypsiboas semilineatus species group, and more specifically within H. geographicus, an allegedly widespread species in northern South America. As a result, the identity of H. geographicus was clarified, several candidate species were detected and one of them, from the eastern Guiana Shield, is described herein as a preliminary step to resolve the taxonomy of the group. Hypsiboas diabolicus sp. nov. is mainly distinguished from closely-related species by an acuminate snout in lateral view, well-developed webbing between fingers and toes, and unspotted carmine/crimson colouration on the concealed surfaces of legs, feet and hands in life. The tadpole of the new species is described and is characterized by a large A-2 gap, a mostly single row of large marginal papillae, and a dark brown to black colouration. We also describe the advertisement call of the new species, which is defined as a soft call consisting of short clusters of 2-3 chuckles with a dominant frequency ranging between 1.11-1.19 kHz. Hypsiboas diabolicus sp. nov. is currently known only from the eastern Guiana Shield, and is probably endemic to that region. The new species' range overlaps broadly with another candidate species referred to as H. aff. semilineatus 1. Our preliminary results stress out a high cryptic diversity in that species group and the need for a formal redescription of Hypsiboas geographicus based on more topotypic material than what is currently available  to properly sort out the taxonomic status of several lineages in that clade.

  16. Cryptic diversity in Amazonian frogs: Integrative taxonomy of the genus Anomaloglossus (Amphibia: Anura: Aromobatidae) reveals a unique case of diversification within the Guiana Shield.

    PubMed

    Vacher, Jean-Pierre; Kok, Philippe J R; Rodrigues, Miguel T; Lima, Jucivaldo Dias; Lorenzini, Andy; Martinez, Quentin; Fallet, Manon; Courtois, Elodie A; Blanc, Michel; Gaucher, Philippe; Dewynter, Maël; Jairam, Rawien; Ouboter, Paul; Thébaud, Christophe; Fouquet, Antoine

    2017-07-01

    Lack of resolution on species boundaries and distribution can hamper inferences in many fields of biology, notably biogeography and conservation biology. This is particularly true in megadiverse and under-surveyed regions such as Amazonia, where species richness remains vastly underestimated. Integrative approaches using a combination of phenotypic and molecular evidence have proved extremely successful in reducing knowledge gaps in species boundaries, especially in animal groups displaying high levels of cryptic diversity like amphibians. Here we combine molecular data (mitochondrial 16S rRNA and nuclear TYR, POMC, and RAG1) from 522 specimens of Anomaloglossus, a frog genus endemic to the Guiana Shield, including 16 of the 26 nominal species, with morphometrics, bioacoustics, tadpole development mode, and habitat use to evaluate species delineation in two lowlands species groups. Molecular data reveal the existence of 18 major mtDNA lineages among which only six correspond to described species. Combined with other lines of evidence, we confirm the existence of at least 12 Anomaloglossus species in the Guiana Shield lowlands. Anomaloglossus appears to be the only amphibian genus to have largely diversified within the eastern part of the Guiana Shield. Our results also reveal strikingly different phenotypic evolution among lineages. Within the A. degranvillei group, one subclade displays acoustic and morphological conservatism, while the second subclade displays less molecular divergence but clear phenotypic divergence. In the A. stepheni species group, a complex evolutionary diversification in tadpole development is observed, notably with two closely related lineages each displaying exotrophic and endotrophic tadpoles. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Designation and description of a neotype of Sclerophrys maculata (Hallowell, 1854), and reinstatement of S. pusilla (Mertens, 1937) (Amphibia: Anura: Bufonidae).

    PubMed

    Poynton, John C; Loader, Simon P; Conradie, Werner; Rödel, Mark-Oliver; Liedtke, H Christoph

    2016-04-05

    Molecular analysis indicates that African material previously referred to Amietophrynus maculatus (Hallowell, 1854; now Sclerophrys maculata), is divisible into two distinct clades: a Western Clade from Cameroon westwards and an Eastern Clade from Central African Republic eastwards, and Uganda southwards to South Africa, extending to Angola-Namibia. Preliminary morphological and bioacoustic data support this division. The two clades are recognised here as two separate species. The Western species retains the name S. maculata, with Hallowell's designated type locality of Liberia. The Eastern Clade retains the name published by Mertens (1937), S. pusilla. It is noted that a type specimen of S. maculata cannot be traced and is presumed lost; the so-called syntypes in the Philadelphia Academy of Natural Sciences are not the material described by Hallowell. None of these have been designated as a neotype, consequently a specimen from Liberia in the collection of the Natural History Museum, London, is designated here as the neotype of S. maculata.

  18. Not Good, but Not All Bad: Dehydration Effects on Body Fluids, Organ Masses, and Water Flux through the Skin of Rhinella schneideri (Amphibia, Bufonidae).

    PubMed

    Anderson, Rodolfo C O; Bovo, Rafael P; Eismann, Carlos E; Menegario, Amauri A; Andrade, Denis V

    Because of their permeable skin, terrestrial amphibians are constantly challenged by the potential risk of dehydration. However, some of the physiological consequences associated with dehydration may affect aspects that are themselves relevant to the regulation of water balance. Accordingly, we examined the effects of graded levels of dehydration on the rates of evaporative water loss and water absorption through the skin in the terrestrial Neotropical toad, Rhinella schneideri. Concomitantly, we monitored the effects of dehydration on the mass of visceral organs; hematocrit and hemoglobin content; plasma osmolality; and plasma concentration of urea, sodium, chloride, and potassium. We found that dehydration caused an increase in the concentration of body fluids, as indicated by virtually all the parameters examined. There was a proportional change in the relative masses of visceral organs, except for the liver and kidneys, which exhibited a decrease in their relative masses greater than the whole-body level of dehydration. Changes-or the preservation-of relative organ masses during dehydration may be explained by organ-specific physiological adjustments in response to the functional stress introduced by the dehydration itself. As dehydration progressed, evaporative water loss diminished and water reabsorption increased. In both cases, the increase in body fluid concentration associated with the dehydration provided the osmotic driver for these changes in water flux. Additionally, dehydration-induced alterations on the cutaneous barrier may also have contributed to the decrease in water flux. Dehydration, therefore, while posing a considerable challenge on the water balance regulation of anurans, paradoxically facilitates water conservation and absorption.

  19. Chloromyxum aegypticus n. sp. (Myxozoa: Chloromyxidae) infecting the testicular tissue of the Egyptian toad, Bufo regularis (Amphibia: Bufonidae), and its pathogenicity.

    PubMed

    Reda, Enayat Salem Ahmed

    2010-11-01

    A new myxosporean, Chloromyxum aegypticus n. sp., is described from the testes of the Egyptian toad Bufo regularis, captured from El Mansoura locality. C. aegypticus is identified on the basis of cytology, electron microscopy and histopathology. It is distinguished from all previously reported Chloromyxum spp. by its shape, dimensions of the mature spore (9.1 ± 0.1 (9.0-9.2) μm in length  × 7.9 ± 0.1 (7.8-8.0) μm in width), polar capsules, external ridge, sporoplasm nuclei, undulating suture, locality and host. Accumulation of several hundreds of plasmodia (0.8 ± 0.3 (0.5-1.1) mm in length × 0.5 ± 0.3 (0.2-0.7) mm in width) in the testes causes their enlargement. Parasites cause destruction of the seminiferous tubule cells and complete loss of spermatozoa. Since spermatogenesis stops, this seems to be a form of "parasitic castration". This is the first known record of the genus Chloromyxum in amphibian testes.

  20. A new species of Psychrophrynella (Amphibia, Anura, Craugastoridae) from the humid montane forests of Cusco, eastern slopes of the Peruvian Andes.

    PubMed

    Catenazzi, Alessandro; Ttito, Alex

    2016-01-01

    We describe a new species of Psychrophrynella from the humid montane forest of the Department Cusco in Peru. Specimens were collected at 2,670-3,165 m elevation in the Área de Conservación Privada Ukumari Llakta, Japumayo valley, near Comunidad Campesina de Japu, in the province of Paucartambo. The new species is readily distinguished from all other species of Psychrophrynella but P. bagrecito and P. usurpator by possessing a tubercle on the inner edge of the tarsus, and from these two species by its yellow ventral coloration on abdomen and limbs. Furthermore, the new species is like P. bagrecito and P. usurpator in having an advertisement call composed of multiple notes, whereas other species of Psychrophrynella whose calls are known have a pulsed call (P. teqta) or a short, tonal call composed of a single note. The new species has a snout-vent length of 16.1-24.1 mm in males and 23.3-27.7 mm in females. Like other recently described species in the genus, this new Psychrophrynella inhabits high-elevation forests in the tropical Andes and likely has a restricted geographic distribution.

  1. Genetic divergence and reproductive isolation in the genus Fejervarya (Amphibia: Anura) from Bangladesh inferred from morphological observations, crossing experiments, and molecular analyses.

    PubMed

    Islam, Mohammed Mafizul; Kurose, Naoko; Khan, Mdmukhlesur Rahman; Nishizawa, Toshitaka; Kuramoto, Mitsuru; Alam, Mohammad Shafiqul; Hasan, Mahmudul; Kurniawan, Nia; Nishioka, Midori; Sumida, Masayuki

    2008-11-01

    In the present study, morphological examinations, crossing experiments and molecular analyses were performed to elucidate the degree of genetic divergence and phylogenetic relationships within the genus Fejervarya from Bangladesh and other Asian countries. Morphological characteristics revealed that Fejervarya species from Bangladesh were divided into four distinct groups: large, medium, small, and mangrove types. Crossing experiments indicated the involvement of three reproductive isolating mechanisms: gametic isolation between the large type and mangrove type, hybrid inviability between the large type and two other types, and hybrid sterility between the medium and small types. Experimental results also indicated that these four types of frogs merit the status of individual species of Fejervarya . Molecular analyses based on mtDNA gene sequences showed that the Bangladesh Fejervarya species were largely divided into three groups: the mangrove type, large type, and others, with the last further subdivided into the medium and small types. Comparison with other Asian Fejervarya species revealed that the Bangladesh mangrove type (which resembled F. cancrivora in morphology) was closely related to F. cancrivora from India, Thailand, and the Philippines; the large type belonged to the F. iskandari group and closely resembled F. orissaensis ; the small type was included in the South Asian or Indian group, and was closest to F. syhadrensis from India and Sri Lanka, whereas the medium type was most closely related to F. limnocharis from Myanmar among all described species of this genus.

  2. Revision of the characters of Centrolenidae (Amphibia : Anura : Athesphatanura), with comments on its taxonomy and the description of new taxa of glassfrogs

    USGS Publications Warehouse

    Cisneros-Heredia, D.F.; McDiarmid, Roy W.

    2007-01-01

    Anurans of the family Centrolenidae are a diverse clade of arboreal frogs distributed across tropical America. Knowledge of their taxonomy, systematics, ecology, behavior, morphology, and other evolutionary aspects of their biology is deficient. Relationships among centrolenid species remain largely unresolved, with no satisfactory phylogenetic hypothesis, and none of the current genera has compelling evidence of monophyly. Further, understanding the phylogeny of glassfrogs is constrained by species-level taxonomic problems, including incorrect description of characters, incomplete analyses of intraspecific variation, and lack of appreciation of species diversity. Herein, we define and analyze the 23 characters that are useful, in combination, in diagnosing centrolenid species, and thereby provide a reference for the use of future workers. We propose revised classifications for the parietal and visceral peritoneal pigmentation, liver form and coloration of its associated hepatic peritoneum, nuptial excrescences, and hand ornamentation. We comment on the generic and species-level taxonomy of Centrolenidae, proposing the recognition of a new genus and describing a new species from Ecuador. We treat Hyla ocellifera Boulenger as a synonym of Centrolene prosoblepon (Boettger), Hyalinobatrachium cardiacalyptum McCranie & Wilson as a synonym of Hyalinobatrachium chirripoi (Taylor), and Hyalinobatrachium crybetes McCranie and Wilson as a synonym of Hyalinobatrachium colymbiphyllum (Taylor). We also present an annotated list of the species of glassfrogs from the Republic of Ecuador with some distributional remarks.

  3. A new species of the genus Centrolene (Amphibia : Anura : Centrolenidae) from Ecuador with comments on the taxonomy and biogeography of Glassfrogs

    USGS Publications Warehouse

    Cisneros-Heredia, D.F.; McDiarmid, R.W.

    2006-01-01

    We describe a new species of Glassfrog, Centrolene mariaelenae n. sp., from the Contrafuerte de Tzunantza, southeastern Ecuador. The new species is assigned to the Centrolene gorzulai species group, a clade previously known only from the Guayana Shield region, because the parietal peritoneum is transparent and the hepatic peritoneum is covered by guanophores. We analyze the diversity patterns of Glassfrogs from eastern Ecuador. The distribution of the new species herein described supports previous hypothesis of a biogeographical connection between the Andes and the Guayana Shield for various groups of plants and animals; particularly a relationship between the Guayana Shield and the sandstone outcrops mountain ranges of southeastern Ecuador and northeastern Peru. We also comment on the infrageneric and generic classification of Glassfrogs, and propose the new combinations Centrolene balionotum n. comb., Cochranella antisthenesi n. comb., and Cochranella pulverata n. comb.

  4. Cytogenetic analyses of eight species in the genus Leptodactylus Fitzinger, 1843 (Amphibia, Anura, Leptodactylidae), including a new diploid number and a karyotype with multiple translocations.

    PubMed

    Gazoni, Thiago; Gruber, Simone L; Silva, Ana P Z; Araújo, Olivia G S; Narimatsu, Hideki; Strüssmann, Christine; Haddad, Célio F B; Kasahara, Sanae

    2012-12-26

    The karyotypes of Leptodactylus species usually consist of 22 bi-armed chromosomes, but morphological variations in some chromosomes and even differences in the 2n have been reported. To better understand the mechanisms responsible for these differences, eight species were analysed using classical and molecular cytogenetic techniques, including replication banding with BrdU incorporation. Distinct chromosome numbers were found: 2n = 22 in Leptodactylus chaquensis, L. labyrinthicus, L. pentadactylus, L. petersii, L. podicipinus, and L. rhodomystax; 2n = 20 in Leptodactylus sp. (aff. podicipinus); and 2n = 24 in L. marmoratus. Among the species with 2n = 22, only three had the same basic karyotype. Leptodactylus pentadactylus presented multiple translocations, L. petersii displayed chromosome morphological discrepancy, and L. podicipinus had four pairs of telocentric chromosomes. Replication banding was crucial for characterising this variability and for explaining the reduced 2n in Leptodactylus sp. (aff. podicipinus). Leptodactylus marmoratus had few chromosomes with a similar banding patterns to the 2n = 22 karyotypes. The majority of the species presented a single NOR-bearing pair, which was confirmed using Ag-impregnation and FISH with an rDNA probe. In general, the NOR-bearing chromosomes corresponded to chromosome 8, but NORs were found on chromosome 3 or 4 in some species. Leptodactylus marmoratus had NORs on chromosome pairs 6 and 8. The data from C-banding, fluorochrome staining, and FISH using the telomeric probe helped in characterising the repetitive sequences. Even though hybridisation did occur on the chromosome ends, telomere-like repetitive sequences outside of the telomere region were identified. Metaphase I cells from L. pentadactylus confirmed its complex karyotype constitution because 12 chromosomes appeared as ring-shaped chain in addition to five bivalents. Species of Leptodactylus exhibited both major and minor karyotypic differences which were identified by classical and molecular cytogenetic techniques. Replication banding, which is a unique procedure that has been used to obtain longitudinal multiple band patterns in amphibian chromosomes, allowed us to outline the general mechanisms responsible for these karyotype differences. The findings also suggested that L. marmoratus, which was formerly included in the genus Adenomera, may have undergone great chromosomal repatterning.

  5. A large-scale phylogeny of Amphibia including over 2800 species, and a revised classification of extant frogs, salamanders, and caecilians.

    PubMed

    Pyron, R Alexander; Wiens, John J

    2011-11-01

    The extant amphibians are one of the most diverse radiations of terrestrial vertebrates (>6800 species). Despite much recent focus on their conservation, diversification, and systematics, no previous phylogeny for the group has contained more than 522 species. However, numerous studies with limited taxon sampling have generated large amounts of partially overlapping sequence data for many species. Here, we combine these data and produce a novel estimate of extant amphibian phylogeny, containing 2871 species (∼40% of the known extant species) from 432 genera (∼85% of the ∼500 currently recognized extant genera). Each sampled species contains up to 12,712 bp from 12 genes (three mitochondrial, nine nuclear), with an average of 2563 bp per species. This data set provides strong support for many groups recognized in previous studies, but it also suggests non-monophyly for several currently recognized families, particularly in hyloid frogs (e.g., Ceratophryidae, Cycloramphidae, Leptodactylidae, Strabomantidae). To correct these and other problems, we provide a revised classification of extant amphibians for taxa traditionally delimited at the family and subfamily levels. This new taxonomy includes several families not recognized in current classifications (e.g., Alsodidae, Batrachylidae, Rhinodermatidae, Odontophrynidae, Telmatobiidae), but which are strongly supported and important for avoiding non-monophyly of current families. Finally, this study provides further evidence that the supermatrix approach provides an effective strategy for inferring large-scale phylogenies using the combined results of previous studies, despite many taxa having extensive missing data.

  6. A new species of Psychrophrynella (Amphibia, Anura, Craugastoridae) from the humid montane forests of Cusco, eastern slopes of the Peruvian Andes

    PubMed Central

    Ttito, Alex

    2016-01-01

    We describe a new species of Psychrophrynella from the humid montane forest of the Department Cusco in Peru. Specimens were collected at 2,670–3,165 m elevation in the Área de Conservación Privada Ukumari Llakta, Japumayo valley, near Comunidad Campesina de Japu, in the province of Paucartambo. The new species is readily distinguished from all other species of Psychrophrynella but P. bagrecito and P. usurpator by possessing a tubercle on the inner edge of the tarsus, and from these two species by its yellow ventral coloration on abdomen and limbs. Furthermore, the new species is like P. bagrecito and P. usurpator in having an advertisement call composed of multiple notes, whereas other species of Psychrophrynella whose calls are known have a pulsed call (P. teqta) or a short, tonal call composed of a single note. The new species has a snout-vent length of 16.1–24.1 mm in males and 23.3–27.7 mm in females. Like other recently described species in the genus, this new Psychrophrynella inhabits high-elevation forests in the tropical Andes and likely has a restricted geographic distribution. PMID:26989637

  7. A new hynobiid-like salamander (Amphibia, Urodela) from Inner Mongolia, China, provides a rare case study of developmental features in an Early Cretaceous fossil urodele

    PubMed Central

    Jia, Jia

    2016-01-01

    A new fossil salamander, Nuominerpeton aquilonaris (gen. et sp. nov.), is named and described based on specimens from the Lower Cretaceous Guanghua Formation of Inner Mongolia, China. The new discovery documents a far northern occurrence of Early Cretaceous salamanders in China, extending the geographic distribution for the Mesozoic fossil record of the group from the Jehol area (40th–45th parallel north) to near the 49th parallel north. The new salamander is characterized by having the orbitosphenoid semicircular in shape; coracoid plate of the scapulocoracoid greatly expanded with a convex ventral and posterior border; ossification of two centralia in carpus and tarsus; and first digit being about half the length of the second digit in both manus and pes. The new salamander appears to be closely related to hynobiids, although this inferred relationship awaits confirmation by research in progress by us on a morphological and molecular combined analysis of cryptobranchoid relationships. Comparison of adult with larval and postmetamorphic juvenile specimens provides insights into developmental patterns of cranial and postcranial skeletons in this fossil species, especially resorption of the palatine and anterior portions of the palatopterygoid in the palate and the coronoid in the mandible during metamorphosis, and postmetamorphic ossification of the mesopodium in both manus and pes. Thus, this study provides a rare case study of developmental features in a Mesozoic salamander. PMID:27761316

  8. B-esterase activities and blood cell morphology in the frog Leptodactylus chaquensis (Amphibia: Leptodactylidae) on rice agroecosystems from Santa Fe Province (Argentina).

    PubMed

    Attademo, Andrés M; Cabagna-Zenklusen, Mariana; Lajmanovich, Rafael C; Peltzer, Paola M; Junges, Celina; Bassó, Agustín

    2011-01-01

    Activity of B-esterases (BChE: butyrylcholinesterase and CbE: carboxylesterase using two model substrates: α-naphthyl acetate and 4-nitrophenyl valerate) in a native frog, Leptodactylus chaquensis from rice fields (RF1: methamidophos and RF2: cypermethrin and endosulfan sprayed by aircraft) and non-contaminated area (pristine forest) was measured. The ability of pyridine-2-aldoxime methochloride (2-PAM) to reactivate BChE levels was also explored. In addition, changes in blood cell morphology and parasite infection were determined. Mean values of plasma BChE activities were lower in samples from the two rice fields than in those from the reference site. CbE (4-nitrophenyl valerate) levels varied in the three sites studied, being highest in RF1. Frog plasma from RF1 showed positive reactivation of BChE activity after incubation with 2-PAM. Blood parameters of frogs from RF2 revealed morphological alterations (anisochromasia and immature erythrocytes frequency). Moreover, a major infection of protozoan Trypanosoma sp. in individuals from the two rice fields was detected. We suggest that integrated use of several biomarkers (BChE and CBEs, chemical reactivation of plasma with 2-PAM, and blood cell parameters) may be a promising procedure for use in biomonitoring programmes to diagnose pesticide exposure of wild populations of this frog and other native anuran species in Argentina.

  9. Adaptations of the reed frog Hyperolius viridiflavus (Amphibia, Anura, Hyperoliidae) to its arid environment : I. The skin of Hyperolius viridiflavus nitidulus in wet and dry season conditions.

    PubMed

    Kobelt, Frank; Linsenmair, K E

    1986-03-01

    Hyperolius viridiflavus nitidulus inhabits parts of the seasonally very hot and dry West African savanna. During the long lasting dry season, the small frog is sitting unhidden on mostly dry plants and has to deal with high solar radiation load (SRL), evaporative water loss (EWL) and small energy reserves. It seems to be very badly equipped to survive such harsh climatic conditions (unfavorable surface to volume ratio, very limited capacity to store energy and water). Therefore, it must have developed extraordinary efficient mechanisms to solve the mentioned problems. Some of these mechanisms are to be looked for within the skin of the animal (e.g. protection against fast desiccation, deleterious effects of UV radiation and overheating). The morphology of the wet season skin is, in most aspects, that of a "normal" anuran skin. It differs in the organization of the processes of the melanophores and in the arrangement of the chromatophores in the stratum spongiosum, forming no "Dermal Chromatophore Unit". During the adaptation to dry season conditions the number of iridophores in dorsal and ventral skin is increased 4-6 times compared to wet season skin. This increase is accompanied by a very conspicuous change of the wet season color pattern. Now, at air temperatures below 35° C the color becomes brownish white or grey and changes to a brilliant white at air temperatures near and over 40° C. Thus, in dry season state the frog retains its ability for rapid color change. In wet season state the platelets of the iridophores are irregularly distributed. In dry season state many platelets become arranged almost parallel to the surface. These purine crystals probably act as quarter-wave-length interference reflectors, reducing SRL by reflecting a considerable amount of the radiated energy input.EWL is as low as that of much larger xeric reptilians. The impermeability of the skin seems to be the result of several mechanisms (ground substance, iridophores, lipids, mucus) supplementing each other.The light red skin at the pelvic region and inner sides of the limbs is specialized for rapid uptake of water allowing the frog to replenish the unavoidable EWL by using single drops of dew or rain, available for only very short periods.

  10. [Comparative morphology of the livers in amphibians].

    PubMed

    Inoue, Asuka; Akiyoshi, Hideo; Naitoh, Tomio; Yamashita, Masamichi

    2002-11-01

    Amphibians are divided into three orders: Gymnophiona, Urodela and Anura. We studied on the correlation between the liver structures in the three orders of amphibians by histological technique. Livers of thirty species of amphibian were fixed by perfusion with paraformaldehyde, and observed by light microscopy in special staining for elastic fibers. The cytoskeletal components of the hepatic stellate cells and myofibroblasts were identified by immunohistochemistry for glial fibrillary acidic protein and a-smooth muscle actin. Among the three orders of amphibians, Gymnophiona and Urodela were characterized the development of lymph vessels in liver capsules and Glisson's sheath. The present study indicates that there are differences in the pattern of hepatic histological components in the amphibians examined at this time. We discussed their diverged mode of living that can be categorized into three groups: aquatic, aqua-terrestrial and fully terrestrial group.

  11. First report of Hepatozoon (Apicomplexa: Adeleorina) in caecilians, with description of a new species.

    PubMed

    Harris, D James; Damas-Moreira, Isabel; Maia, João P M C; Perera, Ana

    2014-02-01

    Hepatozoon spp. are identified for the first time in the amphibian order Gymnophiona, or caecilians, from the Seychelles island of Silhouette. Estimate of relationships derived from partial 18S rRNA gene sequences indicate these are not related to Hepatozoon spp. from frogs or to other Hepatozoon spp. from reptiles in the Seychelles. Assessment of mature gamonts from blood smears indicate that these can be recognized as a new species, Hepatozoon seychellensis n. sp.

  12. Altitudinal distribution and advertisement call of Colostethus latinasus (Amphibia: Dendrobatidae), endemic species from eastern Panama and type species of Colostethus , with a molecular assessment of similar sympatric species.

    PubMed

    Ibáñez, Roberto D; Griffith, Edgardo J; Lips, Karen R; Crawford, Andrew J

    2017-04-12

    We conducted a molecular assessment of Colostethus-like frogs along an elevational gradient in the Serranía de Pirre, above Santa Cruz de Cana, eastern Panama, aiming to establish their species identity and to determine the altitudinal distribution of C. latinasus. Our findings confirm the view of C. latinasus as an endemic species restricted to the highlands of this mountain range, i.e., 1350-1475 m.a.s.l., considered to be type locality of this species. We described the advertisement call of C. latinasus that consists of a series of 4-18 single, short and relatively loud "peep"-like notes given in rapid succession, and its spectral and temporal features were compared with calls of congeneric species. For the first time, DNA sequences from C. latinasus were obtained, since previously reported sequences were based on misidentified specimens. This is particularly important because C. latinasus is the type species of Colostethus, a genus considered paraphyletic according to recent phylogenetic analyses based on molecular data.

  13. Phylogenetic relationships and morphology of the Pristimantis leptolophus species group (Amphibia: Anura: Brachycephaloidea), with the recognition of a new species group in Pristimantis Jiménez de la Espada, 1870.

    PubMed

    González-Durán, Gustavo A; Targino, Mariane; Rada, Marco; Grant, Taran

    2017-03-13

    We evaluate the monophyly and phylogenetic relationships of the Pristimantis leptolophus species group and describe its external morphology, osteology, and some myological characteristics. We also compare the P. leptolophus species group to other related species groups. The P. leptolophus group is not monophyletic due to the inclusion of P. acatallelus, formerly believed to be part of the P. devillei group. The revised P. leptolophus group is composed of nine named species and six unnamed species. Based on our results, we recognize a new species group, the P. boulengeri species group, composed of eight species, many of which were previously assigned to the P. lacrimosus species group.

  14. Odorous secretions in anurans: morphological and functional assessment of serous glands as a source of volatile compounds in the skin of the treefrog Hypsiboas pulchellus (Amphibia: Anura: Hylidae).

    PubMed

    Brunetti, Andrés E; Hermida, Gladys N; Iurman, Mariana G; Faivovich, Julián

    2016-03-01

    Serous (granular or venom) glands occur in the skin of almost all species of adult amphibians, and are thought to be the source of a great diversity of chemical compounds. Despite recent advances in their chemistry, odorous volatile substances are compounds that have received less attention, and until now no study has attempted to associate histological data with the presence of these molecules in amphibians, or in any other vertebrate. Given the recent identification of 40 different volatile compounds from the skin secretions of H. pulchellus (a treefrog species that releases a strong odour when handled), we examined the structure, ultrastructure, histochemistry, and distribution of skin glands of this species. Histological analysis from six body regions reveals the presence of two types of glands that differ in their distribution. Mucous glands are homogeneously distributed, whereas serous glands are more numerous in the scapular region. Ultrastructural results indicate that electron-translucent vesicles observed within granules of serous glands are similar to those found in volatile-producing glands from insects and also with lipid vesicles from different organisms. Association among lipids and volatiles is also evidenced from chemical results, which indicate that at least some of the volatile components in H. pulchellus probably originate within the metabolism of fatty acids or the mevalonate pathway. As odorous secretions are often considered to be secreted under stress situations, the release of glandular content was assessed after pharmacological treatments, epinephrine administrated in vivo and on skin explants, and through surface electrical stimulation. Serous glands responded to all treatments, generally through an obvious contraction of myoepithelial cells that surround their secretory portion. No response was observed in mucous glands. Considering these morpho-functional results, along with previous identification of volatiles from H. pulchellus and H. riojanus after electrical stimulation, we suggest that the electron-translucent inclusions found within the granules of serous glands likely are the store sites of volatile compounds and/or their precursors. Histochemical and glandular distribution analyses in five other species of frogs of the hylid tribe Cophomantini, revealed a high lipid content in all the species, whereas a heterogeneous distribution of serous glands is only observed in species of the H. pulchellus group. The distribution pattern of serous glands in members of this species group, and the odorous volatile secretions are probably related to defensive functions. © 2015 Anatomical Society.

  15. Gene expression and tissue distribution of cytoglobin and myoglobin in the Amphibia and Reptilia: possible compensation of myoglobin with cytoglobin in skeletal muscle cells of anurans that lack the myoglobin gene.

    PubMed

    Xi, Yang; Obara, Masanobu; Ishida, Yuji; Ikeda, Shino; Yoshizato, Katsutoshi

    2007-08-15

    Cytoglobin (Cygb), a recently discovered vertebrate cytoplasmic heme-binding globin, is considered to be in a clade with vertebrate myoglobin (Mb), which is exclusively distributed in the cytoplasm of cardiac and skeletal muscles as an oxygen storage protein. GenBank databases (NCBI and JGI) and gene synteny analyses showed the absence of the Mb gene (mb) in two anuran amphibians, Xenopus laevis and X. tropicalis. Here we conducted comparative studies on the gene expression and tissue distribution of Cygb and Mb in anuran and reptilian tissues. Cygb and Mb genes were cloned from a reptile, iguana (Iguana iguana). Two types of cygb (cygb-1 and -2) were cloned, with lengths of 1066 and 1034 bp, and 196 and 193 amino acid residues, respectively. Their nucleotide and amino acid sequence identities were 90 and 87%, respectively. The Mb gene covered 1416 bp with an open reading frame of 465 bp, giving rise to a 154 amino acid protein. The distal ligand-binding histidine at E7, the proximal heme-binding histidine at F8, and the phenylalanine residue at CD1 were conserved in Mb and Cygb. The nucleotide and amino acid sequence identity of I. iguana cygb-1 and cygb-2 against X. laevis cygb were approximately 67% and 65%, respectively. RT-PCR demonstrated that X. laevis cygb was uniquely expressed in the heart and skeletal muscles, and faintly in the liver and spleen, which was quite contrasted with Iguana and the other vertebrates, where mb is exclusively expressed in the heart and skeletal muscles. Immunohistochemical analyses showed the distribution of Cygb in the cytoplasm of skeletal muscle cells. Interestingly, Cygb in the heart was localized in the nuclei. Considering the absence of mb in the Anura, we hypothesize that Cygb in muscle cells of anurans compensates for the lack of Mb for the storage and intracellular transportation of oxygen.

  16. Adaptations of the reed frog Hyperolius viridiflavus (Amphibia, Anura, Hyperoliidae) to its arid environment. VII. The heat budget of Hyperolius viridiflavus nitidulus and the evolution of an optimized body shape.

    PubMed

    Kobelt, F; Linsenmair, K E

    1995-01-01

    Estivating reed frogs of the superspecies Hyperolius viridiflavus are extraordinarily resistant to the highly adverse climatic conditions prevailing in their African savanna habitats during dry season (air temperature up to 45 degrees C, solar radiation load up to 1000 W.m-2, no water replenishment possible for up to 3 months). They are able to withstand such climatic stress at their exposed estivation sites on dry plants without evaporative cooling. We developed a heat budget model to understand the mechanisms of how an anuran can achieve this unique tolerance, and which allows us to predict the anuran's core and surface temperature for a given set of environmental parameters, to within 4% of the measured values. The model makes it possible to quantify some of the adaptive mechanisms for survival in semiarid habitats by comparing H. viridiflavus with anurans (H. tuberilinguis and Rana pipiens) of less stressful habitats. To minimize heat gain and maximize heat loss from the frog, the following points were important with regard to avoiding lethal heat stress during estivation: 1) solar heat load is reduced by an extraordinarily high skin reflectivity for solar radiation of up to 0.65 under laboratory and even higher in the field under dry season conditions. 2) The half-cylindrical body shape of H. viridiflavus seems to be optimized for estivation compared to the hemispheroidal shape usually found for anurans in moist habitats. A half-cylinder can be positioned relative to the sun so that large surface areas for conductive and convective heat loss are shielded by a small area exposed to direct solar radiation. 3) Another important contribution of body shape is a high body surface area to body mass ratio, as found in the estivating subadult H. viridiflavus (snout-vent lengths of 14-20 mm and body weights of 350-750 mg) compared to adult frogs (24-30 mm, 1000-2500 mg) which have never been observed to survive a dry season. 4) These mechanisms strongly couple core temperature to air temperature. The time constant of the core temperature is 29 +/- 10 s. Since air temperature can be 43-45 degrees C, H. viridiflavus must have a very unusual tolerance to transient core temperatures of 43-45 degrees C. 5) If air temperature rises above this lethal limit, the estivating frog would die despite all its optimizations, but moving from an unsuited to a more favorable site during estivation can be extremely costly in terms of unavoidably high evaporative water loss. Therefore, H. viridiflavus must have developed behavioral strategies for reliably choosing estivation sites with air temperature staying on average within the vital range during the whole dry season.

  17. A new species of Pristimantis (Amphibia, Anura, Craugastoridae) from a montane forest of the Pui Pui Protected Forest in central Peru (Región Junín)

    PubMed Central

    Lehr, Edgar; Moravec, Jiří

    2017-01-01

    Abstract A new species of frog of the genus Pristimantis is described from a montane forest between 1700 and 1800 m a.s.l. of the Pui Pui Protected Forest (Región Junín) in central Peru. Pristimantis ashaninka sp. n. is described based on five adult females (snout–vent length 23.1–26.7 mm) and ten juveniles (snout-vent length 10.6–13.4). It differs from its congeners by having the skin on dorsum shagreen with many conical tubercles giving it a spinose appearance, lacking a tympanum, having groin, anterior and posterior surfaces of thighs uniformly grayish brown, and a pale bronze iris with fine black reticulations, a median reddish hint horizontally across iris, and a black narrow vertical streak from pupil across lower and upper half of iris. Among the Peruvian Pristimantis that lack a tympanum, Pristimantis ashaninka sp. n. is morphologically most similar to Pristimantis lirellus, Pristimantis martiae, and Pristimantis rhabdocnemus. However, 16S DNA barcoding revealed clear distinctions between all four species of Pristimantis. PMID:28228669

  18. Genetic structure and origin of a tetraploid toad species Bufo danatensis Pisanetz, 1978 (Amphibia, Bufonidae) from central Asia: Description of biochemical polymorphism and comparison of heterozygosity levels in diploid and tetraploid species

    SciTech Connect

    Mezhzherin, S.V.; Pisanets, E.M.

    1995-01-01

    Comparison of individual variation at 24 biochemical loci in members of the species complex of Palearctic green toads showed that the heterozygosity of the tetraploid species Bufo danatensis (H{sub obs} = 0.45) was significantly higher than that of the diploid species B. viridis, B. sp., and B. raddei (H{sub obs} = 0.009 - 0.103). Such difference can be explained only by a hybrid origin of the tetraploid species. Individual electrophoretic variability of the polyploid toad species is associated with an allelic variation that is manifested in constantly heterozygous spectra as the gene dosage effect. At the population level, this phenomenon found in Pamir toads is caused by irregular meiosis in founders of the population or by directional changes in gene regulation. Genotypic distributions in zones of contact of the diploid and tetraploid taxons demonstrate the possibility of restricted introgressive hybridization.

  19. Terraranans of the Lost World: a new species of Pristimantis (Amphibia, Craugastoridae) from Abakapá-tepui in the Chimantá massif, Venezuelan Guayana, and additions to the knowledge of P. muchimuk.

    PubMed

    Rojas-Runjaic, Fernando J M; Salerno, Patricia E; Señaris, J Celsa; Pauly, Gregory B

    2013-01-01

    A new frog of the genus Pristimantis is named and described from the summit of Abakapá-tepui in the Chimantd massif, south-eastern Venezuela. The new species is known from two adult specimens and is the second craugastorid species described from this massif. It can be readily distinguished from all congeners inhabiting the highlands of the Guiana Shield by the unique combination of the following characters: dorsal skin shagreen and ventral skin coarsely areolate, tympanum small and ill-defined, vocal slits absent in males, finger I shorter than II, thumbs with two whitish and non-spinous nuptial pads in adult males, fingers and toes with broad lateral fringes, basal webbing between all toes, throat and chest nacreous white in life. Also, based on five specimens of Pristimantis muchimuk recently collected from Churi-tepui, we provide new information on this little known species, including an amended diagnosis, notes on morphology, color variation, advertisement calls, and natural history.

  20. The type localities of Anolis aequatorialis Werner, 1894 (Sauria: Iguania: Dactyloidae) and Pristimantis appendiculatus (Werner, 1894) (Amphibia: Anura: Craugastoridae).

    PubMed

    Cisneros-Heredia, Diego F

    2017-01-04

    The eminent Austrian zoologist Franz Werner described several new species of amphibians and reptiles from America, including Anolis aequatorialis Werner, 1894 and Hylodes appendiculatus Werner, 1894. Both species were described based on single specimens, with no more specific type localities than "Ecuador" (Werner 1894a,b). After its description, A. aequatorialis remained unreported until Peters (1967) and Fitch et al. (1976) published information on its distribution and natural history. Anolis aequatorialis is currently known to inhabit low montane and cloud forest on the western slopes of the Andes from extreme southern Colombia to central Ecuador, between 1300 and 2300 m elevation (Ayala-Varela & Velasco 2010; Ayala-Varela et al. 2014; Lynch et al. 2014; D.F. Cisneros-Heredia pers. obs.). Likewise, Hylodes appendiculatus (now Pristimantis appendiculatus) remained only known from its type description until Lynch (1971) and Miyata (1980) provided certain localities and information on its natural history. Pristimantis appendiculatus is currently known to occur in low montane, cloud, and high montane forests on the western slopes of the Andes from extreme southern Colombia to northern Ecuador between 1460 and 2800 m elevation (Lynch 1971; Miyata 1980; Lynch & Burrowes 1990; Lynch & Duellman 1997; Frost 2016). To this date, the type localities of both species remain obscure. The purpose of this paper is to restrict the type localities of Hylodes appendiculatus Werner, 1894 and Anolis aequatorialis Werner, 1894 based on analyses of the travel journals of their original collector.

  1. Teratological research using in vitro systems. V. Nonmammalian model systems.

    PubMed Central

    Collins, T F

    1987-01-01

    In this review of alternative tests to whole-animal rodent studies, the use of sub-mammalian and sub-vertebrate systems is investigated. The history, methodology, known limitations, end points, dose response, and requirements of virus, hydra, planarian, cricket, fish, amphibia, Drosophila, and chicken embryo systems are discussed. PMID:3113934

  2. Molecular characterization and gene expression of the channel catfish Ferritin H subunit after bacterial infection and iron treatment

    USDA-ARS?s Scientific Manuscript database

    Ferritins are the major iron storage protein in the cytoplasm of cells, responsible for regulating levels of intracellular iron. Ferritin genes are widely distributed in both prokaryotes and eukaryotes. In mammals, ferritin molecules are composed of heavy- (H) and light- (L) chain subunits; amphibia...

  3. THE ROLE OF MAMMALIAN DATA IN DETERMINING PHARMACEUTICAL RESPONSES IN AQUATIC ORGANISMS

    EPA Science Inventory

    The limitations surrounding application of pharmaceutical data are restricted to extrapolation of the animal and human data across phyla. Experience dictates that mammalian data are most likely to extrapolate predictably to fish and other aquatic vertebrates (e.g. Amphibia), and ...

  4. Molecular evolution of HoxA13 and the multiple origins of limbless morphologies in amphibians and reptiles.

    PubMed

    Singarete, Marina E; Grizante, Mariana B; Milograna, Sarah R; Nery, Mariana F; Kin, Koryu; Wagner, Günter P; Kohlsdorf, Tiana

    2015-01-01

    Developmental processes and their results, morphological characters, are inherited through transmission of genes regulating development. While there is ample evidence that cis-regulatory elements tend to be modular, with sequence segments dedicated to different roles, the situation for proteins is less clear, being particularly complex for transcription factors with multiple functions. Some motifs mediating protein-protein interactions may be exclusive to particular developmental roles, but it is also possible that motifs are mostly shared among different processes. Here we focus on HoxA13, a protein essential for limb development. We asked whether the HoxA13 amino acid sequence evolved similarly in three limbless clades: Gymnophiona, Amphisbaenia and Serpentes. We explored variation in ω (dN/dS) using a maximum-likelihood framework and HoxA13sequences from 47 species. Comparisons of evolutionary models provided low ω global values and no evidence that HoxA13 experienced relaxed selection in limbless clades. Branch-site models failed to detect evidence for positive selection acting on any site along branches of Amphisbaena and Gymnophiona, while three sites were identified in Serpentes. Examination of alignments did not reveal consistent sequence differences between limbed and limbless species. We conclude that HoxA13 has no modules exclusive to limb development, which may be explained by its involvement in multiple developmental processes.

  5. Molecular evolution of HoxA13 and the multiple origins of limbless morphologies in amphibians and reptiles

    PubMed Central

    Singarete, Marina E.; Grizante, Mariana B.; Milograna, Sarah R.; Nery, Mariana F.; Kin, Koryu; Wagner, Günter P.; Kohlsdorf, Tiana

    2015-01-01

    Developmental processes and their results, morphological characters, are inherited through transmission of genes regulating development. While there is ample evidence that cis-regulatory elements tend to be modular, with sequence segments dedicated to different roles, the situation for proteins is less clear, being particularly complex for transcription factors with multiple functions. Some motifs mediating protein-protein interactions may be exclusive to particular developmental roles, but it is also possible that motifs are mostly shared among different processes. Here we focus on HoxA13, a protein essential for limb development. We asked whether the HoxA13 amino acid sequence evolved similarly in three limbless clades: Gymnophiona, Amphisbaenia and Serpentes. We explored variation in ω (dN/dS) using a maximum-likelihood framework and HoxA13sequences from 47 species. Comparisons of evolutionary models provided low ω global values and no evidence that HoxA13 experienced relaxed selection in limbless clades. Branch-site models failed to detect evidence for positive selection acting on any site along branches of Amphisbaena and Gymnophiona, while three sites were identified in Serpentes. Examination of alignments did not reveal consistent sequence differences between limbed and limbless species. We conclude that HoxA13 has no modules exclusive to limb development, which may be explained by its involvement in multiple developmental processes. PMID:26500429

  6. Heterochronical patterns of evolution in the transitional stages of vertebrate classes.

    PubMed

    Schad, W

    1993-12-01

    Transitional forms of the recent classes of vertebrates are only known in paleontology. The well described examples are: Eusthenopteron foordi (Crossopterygii), Ichthyostega and Acanthostega (Labyrinthodontia) between Osteichthyes and Amphibia, Seymouria baylorensis (Amphibiosaria) between Amphibia and Reptilia, Archaeopteryx lithographica (Archaeornithes) between Reptilia and Aves, and the mammal-like reptiles Pelycosauria, Therapsida and Cynodontia between Reptilia and Aves, and the description of their phylogenetical heterochronies in terms of peramorphosis and paedomorphosis shows the progressive role of the motorial, especially the locomotorial organ systems and their functions in comparison with the retarded evolution of the axial system, especially the skull and central nervous system. The evolution of the Hominidae shows the same rule. The evaluation of these transitional forms in their fossil context reveals them as inhabitants of biotopes situated in the border areas of coastal and shore landscapes of marine, brackish or fresh water. These biotopes have obviously favoured the innovations on the high taxonimic level of macro-evolutionary characteristics.

  7. [Histochemical characteristics of the secretory cells of gastric glands compared].

    PubMed

    Shubich, M G; Mogil'naia, G M; Dudetskiĭ, V I; Bogatyr', L Ia

    1978-02-01

    The work is dedicated to complex histological studies of the secreting cells in the gastric fundal glands, in their comparative aspect. In the representatives of Amphibia, Reptilians and birds, histochemical differentiation of oxyntopeptic cells was demonstrated to be independent on the peculiarities of the animal nutrition. In mammals, histochemical characteristic of the carbohydrate component in the glandular secreting cells depends on the type of nutrition.

  8. In situ monitoring of animal micronuclei before the operation of Daya Bay Nuclear Power Station

    SciTech Connect

    Y.N. Cai; H.Y. He; L.M. Qian; G.C. Sun; J.Y. Zhao

    1994-12-31

    Daya Bay Nuclear Power Station, a newly-built nuclear power station in southern mainland China, started its operation in 1993. We examined micro-nucleated cells of Invertibrate (Bivalves) and Vertibrate (Fish and Amphibia) in different spots within the 50km surroundings of the Power Station during 1986-1993. This paper reports the results of the investigation carried out in Dong Shan, a place 4.7km to the Power Station:Bivalves; Pteria martensil 5.1(1986),4.8(1988),4.8(1991),5,0(1993),Mytilus smardinus 4.7(1987),4.6(1988); Chamys nobilis 4.9(1987);4.9(1991),4.5(1992),4.5(1993). Fish; Therapon jarbua 0.48(1991),0.67(1992),0.47(1993). Amphibia; Bufo melanostictus 0.29 (1987), 0.34(1988),0.39(1992),0.39(1993). These results showed that the environmental situation, estimated by using the frequencies of micronucleated cells, was stable-there was no obvious chromosome damage in the animals studied. It was found that the incidence of micronucleated cells of Bivalves was higher than that of Fish and Amphibia, suggesting the epithelial cells to be more sensitive than peripheral erythrocytes to environmental genotoxic effects. The results of our studies for other spots will be reported afterward. These data can be used as the original background information to monitor the environment when the Nuclear Power Station is in operation.

  9. Contributions to the knowledge of amphibians and reptiles from Volta Grande do Xingu, northern Brazil.

    PubMed

    Vaz-Silva, W; Oliveira, R M; Gonzaga, A F N; Pinto, K C; Poli, F C; Bilce, T M; Penhacek, M; Wronski, L; Martins, J X; Junqueira, T G; Cesca, L C C; Guimarães, V Y; Pinheiro, R D

    2015-08-01

    The region of Volta Grande do Xingu River, in the state of Pará, presents several kinds of land use ranging from extensive cattle farming to agroforestry, and deforestation. Currently, the Belo Monte Hydroelectric Power Plant affects the region. We present a checklist of amphibians and reptiles of the region and discuss information regarding the spatial distribution of the assemblies based on results of Environmental Programmes conducted in the area. We listed 109 amphibian (Anura, Caudata, and Gymnophiona) and 150 reptile (Squamata, Testudines, and Crocodylia) species. The regional species richness is still considered underestimated, considering the taxonomic uncertainty, complexity and cryptic diversity of various species, as observed in other regions of the Amazon biome. Efforts for scientific collection and studies related to integrative taxonomy are needed to elucidate uncertainties and increase levels of knowledge of the local diversity.

  10. THE METAMORPHOSIS OF VISUAL SYSTEMS IN THE SEA LAMPREY

    PubMed Central

    Wald, George

    1957-01-01

    The life cycle of the sea lamprey, Petromyzon marinus, includes two metamorphoses. At the end of a period spent as a blind larva, buried in the mud of streams, a first metamorphosis prepares it to migrate downstream to the sea or a lake for its growth phase. Then, following a second metamorphosis, it migrates upstream as a sexually mature adult to spawn and die. The downstream migrants have a visual system based upon rhodopsin and vitamin A1, whereas that of the upstream migrants is based upon porphyropsin and vitamin A2. The livers contain vitamin A1 at all stages. The sea lamprey therefore exhibits a metamorphosis of visual systems, like those observed earlier among amphibia. The presence of porphyropsin in this member of the most primitive living group of vertebrates, as in fishes and amphibia, supports the notion that porphyropsin may have been the primitive vertebrate visual pigment. Its association with fresh water existence throughout this range of organisms also is consistent with the view that the vertebrate stock originated in fresh water. The observation that in the life cycle of the lamprey rhodopsin precedes porphyropsin is not at variance with the idea that porphyropsin is the more primitive pigment, since this change is part of the second metamorphosis, marking the return to the original environment. The observation that in lampreys, fishes, and amphibia, porphyropsin maintains the same general association with fresh water, and rhodopsin with marine and terrestrial habit, suggests that a single genetic mechanism may govern this association throughout this wide span of organisms. PMID:13439167

  11. Root Transcript Profiling of Two Rorippa Species Reveals Gene Clusters Associated with Extreme Submergence Tolerance1[C][W][OPEN

    PubMed Central

    Sasidharan, Rashmi; Mustroph, Angelika; Boonman, Alex; Akman, Melis; Ammerlaan, Ankie M.H.; Breit, Timo; Schranz, M. Eric; Voesenek, Laurentius A.C.J.; van Tienderen, Peter H.

    2013-01-01

    Complete submergence represses photosynthesis and aerobic respiration, causing rapid mortality in most terrestrial plants. However, some plants have evolved traits allowing them to survive prolonged flooding, such as species of the genus Rorippa, close relatives of Arabidopsis (Arabidopsis thaliana). We studied plant survival, changes in carbohydrate and metabolite concentrations, and transcriptome responses to submergence of two species, Rorippa sylvestris and Rorippa amphibia. We exploited the close relationship between Rorippa species and the model species Arabidopsis by using Arabidopsis GeneChip microarrays for whole-genome transcript profiling of roots of young plants exposed to a 24-h submergence treatment or air. A probe mask was used based on hybridization of genomic DNA of both species to the arrays, so that weak probe signals due to Rorippa species/Arabidopsis mismatches were removed. Furthermore, we compared Rorippa species microarray results with those obtained for roots of submerged Arabidopsis plants. Both Rorippa species could tolerate deep submergence, with R. sylvestris surviving much longer than R. amphibia. Submergence resulted in the induction of genes involved in glycolysis and fermentation and the repression of many energy-consuming pathways, similar to the low-oxygen and submergence response of Arabidopsis and rice (Oryza sativa). The qualitative responses of both Rorippa species to submergence appeared roughly similar but differed quantitatively. Notably, glycolysis and fermentation genes and a gene encoding sucrose synthase were more strongly induced in the less tolerant R. amphibia than in R. sylvestris. A comparison with Arabidopsis microarray studies on submerged roots revealed some interesting differences and potential tolerance-related genes in Rorippa species. PMID:24077074

  12. Variable patterns of total DNA and rDNA methylation in animals.

    PubMed Central

    Bird, A P; Taggart, M H

    1980-01-01

    Restriction endonucleases were used to determine the degree of methylation at the sequences CCGG and GCGC in a wide range of animal DNAs. Both total DNA methylation and ribosomal DNA methylation were studied. Whole DNA methylation was indetectable in arthropods, fractional in other invertebrate phyla, and high in the vertebrates. Ribosomal DNA was predominantly unmethylated in all animals except fish and amphibia, where it was heavily methylated. We discuss the evolutionary and functional implications of these results, and suggest that the large differences between genome types are the result of evolutionary changes in the relative size of heavily methylated and unmethylated compartments. Images PMID:6253937

  13. Phytosphingosine is a characteristic component of the glycolipids in the vertebrate intestine.

    PubMed

    Nishimura, K

    1987-01-01

    Sphingoids in the intestinal lipids of an agnatha, a chondrichthyes, two osteichthyes, three amphibia, three reptiles and two avian species were analyzed by reversed phase high performance liquid chromatography. The glycolipid fraction of all the samples studied contained 4-D-hydroxysphinganine as the major component together with sphingosine and sphinganine. While the trihydroxy base was not found in their sphingomyelin fraction. The trihydroxy base was considered to be a characteristic component of the intestinal glycolipids for the vertebrates in general. Its concentration in the intestinal tissue had little correlation with the food habitat of the animals.

  14. Telocytes in ileum of the Chinese giant salamander: ultrastructural evidence.

    PubMed

    Zhang, Hui; Zhong, Shengwei; Ge, Tingting; Peng, Shasha; Yu, Pengcheng; Zhou, Zuohong; Guo, Xiaoquan

    2016-03-01

    Telocytes (TCs) and their telopodes (Tps) have been found in various organs of many mammals, including in lower animals. However, knowledge of TCs in lower animals is still very limited. This study identified TCs and their Tps in the ileum of the Chinese giant salamander, Andrias davidianus (Amphibia: Caudata), by transmission electron microscopy. The TCs/Tps were found near epithelial cells, glandular cells and unmyelinated nerve fibres. Moreover, exosomes were also found to be present in between TCs/Tps and these cells.

  15. [Toxicity of nitrate-N to freshwater aquatic life and its water quality criteria].

    PubMed

    Zhang, Ling-Song; Wang, Ye-Yao; Meng, Fan-Sheng; Zhou, Yue-Xi; Yu, Hai-Bin

    2013-08-01

    The toxicity sensitivity of different freshwater aquatic organisms was analyzed using the collected toxicity data in this paper. Three methods were used to estimate the criteria of nitrate to protect the freshwater aquatic life. The results showed that the species sensitivity to nitrate followed the order of Arthropoda > Mollusca > Chordata, and Crustacea > Insecta > Gastropoda > Bivalvia > Amphibia > Actinopterygii. Moreover, the output of assessment factor method, species sensitivity distribution method and USEPA's method was significantly different. Finally, criterias of 87.97 mg x L(-1) and 5.17 mg x L(-1) to protect aquatic life from acute and chronic toxicity were proposed using USEPA's method.

  16. Aquatic Plant Control Research Program. Large-Scale Operations Management Test of Use of the White Amur for Control of Problem Aquatic Plants. Reports 2 and 3. First and Second Year Poststocking Results. Volume 5. The Herpetofauna of Lake Conway, Florida: Community Analysis.

    DTIC Science & Technology

    1983-07-01

    AD Al 34 34 1 AQUATIC PLANT CONTROL RESEARCH PROGRAM LARGE-SC ALE Ij OPERATIONS MANAG E MENT . Ul UNIVERSITY OF SOUTH FLORIDA TAMPA DEPT OF BIOLOGY R...TEST CHART NATIONAL BVIREAU OF StANARS-1963- I AQUATIC PLANT CONTROL RESEARCH PROGRAM TECHNICAL REPORT A-78-2 LARGE-SCALE OPERATIONS MANAGEMENT TEST OF...Road, Springfield, Va. 22161. 19. KEY BORDS (Continue.o --- ,.. old. it ,o..0,y And IdentiIy by block -ob) Amphibia Reptiles Aquatic plant control

  17. Cardiovascular physiology and diseases of amphibians.

    PubMed

    Heinz-Taheny, Kathleen M

    2009-01-01

    The class Amphibia includes three orders of amphibians: the anurans (frogs and toads), urodeles (salamanders, axolotls, and newts), and caecilians. The diversity of lifestyles across these three orders has accompanying differences in the cardiovascular anatomy and physiology allowing for adaptations to aquatic or terrestrial habitats, pulmonic or gill respiration, hibernation, and body elongation (in the caecilian). This article provides a review of amphibian cardiovascular anatomy and physiology with discussion of unique species adaptations. In addition, amphibians as cardiovascular animal models and commonly encountered natural diseases are covered.

  18. Histochemistry of glycoconjugates in the gallbladder epithelium of ten animal species.

    PubMed

    Madrid, J F; Ballesta, J; Galera, T; Castells, M T; Pérez-Tomás, R

    1989-01-01

    A battery of seven lectins and several conventional mucin histochemical techniques were used to identify the epithelial mucins of the gallbladder of ten species: man, rabbit (Oryctolagus cuniculus, mammalia), hamster (Mesocricetus auratus, mammalia), chicken (Gallus gallus, bird), sparrow (Passer domesticus, bird), moorish gecko (Tarentola mauritanica, reptilia), ladder snake (Elaphe scalaris, reptilia), lake frog (Rana perezi, amphibia), natterjack toad (Bufo calamita, amphibia) and gilthead sea bream (Sparus auratus, fish). Glycogen was found in the epithelial lining of the reptilian and amphibian gallbladders. Sulphate and carboxyl groups were frequently found in the same species, except in the ladder snake and natterjack toad gallbladders where only sulphate groups were identified. Sialic acid residues were detected in man, rabbit, bird, T. mauritanica, R. perezi and fish gallbladders. ConA binding pattern was similar in the ten species studied. In the human gallbladder only PNA failed to label the luminal surface, while the glands were only unreactive to DBA. The human gallbladder showed a large variety of saccharides. The present results suggest that no relation exists between the composition of the gallbladder mucins and the situation of the species in the phylogenetic scale.

  19. Extreme flooding tolerance in Rorippa.

    PubMed

    Akman, Melis; Bhikharie, Amit; Mustroph, Angelika; Sasidharan, Rashmi

    2014-01-01

    Low oxygen stress imposed by floods creates a strong selection force shaping plant ecosystems in flood-prone areas. Plants inhabiting these environments adopt various adaptations and survival strategies to cope with increasing water depths. Two Rorippa species, R. sylvestris and R. amphibia that grow in naturally flooded areas, have high submergence tolerance achieved by the so-called quiescence and escape strategies, respectively. In order to dissect the molecular mechanisms involved in these strategies, we investigated submergence-induced changes in gene expression in flooded roots of Rorippa species. There was a higher induction of glycolysis and fermentation genes and faster carbohydrate reduction in R. amphibia, indicating a higher demand for energy potentially leading to faster mortality by starvation. Moreover, R. sylvestris showed induction of genes improving submergence tolerance, potentially enhancing survival in prolonged floods. Additionally, we compared transcript profiles of these 2 tolerant species to relatively intolerant Arabidopsis and found that only Rorippa species induced various inorganic pyrophosphate dependent genes, alternatives to ATP demanding pathways, thereby conserving energy, and potentially explaining the difference in flooding survival between Rorippa and Arabidopsis.

  20. Tuberculosis in wildlife in the Ruwenzori National Park, Uganda (Part II).

    PubMed

    Woodford, M H

    1982-08-01

    The results of post-mortem examinations of 90 warthog (Phacochoerus aethiopicus) conducted in the Ruwenzori National Park, Uganda during a survey of tuberculous infection in wildlife are described. Nine per cent of warthog were found to show gross lesions on autopsy and of these organisms which could by typed, Mycobacterium bovis was isolated in 2 of 6 cases and 5 atypical mycobacterial strains were isolated from the remaining 4. The distribution and character of the lesions is described and it is concluded that the route of infection in the warthog is alimentary. A mycobacterial survey of 8 other species of mammals, 7 species of birds, 5 species of fish and 1 species of amphibian is described. None of the mammals (except possibly 1 elephant), birds, fish or amphibia is described. None of the mammals (except possibly 1 elephant), birds, fish or amphibia was found to be infected with M. bovis but several individuals were found to harbour atypical, probably saprophytic, mycobacterial types. The origin of tuberculosis in buffalo and warthog in the Ruwenzori National Park is discussed and is concluded to have been previous contact with domestic cattle.

  1. Extreme flooding tolerance in Rorippa

    PubMed Central

    Akman, Melis; Bhikharie, Amit V; Mustroph, Angelika; Sasidharan, Rashmi

    2014-01-01

    Low oxygen stress imposed by floods creates a strong selection force shaping plant ecosystems in flood-prone areas. Plants inhabiting these environments adopt various adaptations and survival strategies to cope with increasing water depths. Two Rorippa species, R. sylvestris and R. amphibia that grow in naturally flooded areas, have high submergence tolerance achieved by the so-called quiescence and escape strategies, respectively. In order to dissect the molecular mechanisms involved in these strategies, we investigated submergence-induced changes in gene expression in flooded roots of Rorippa species. There was a higher induction of glycolysis and fermentation genes and faster carbohydrate reduction in R. amphibia, indicating a higher demand for energy potentially leading to faster mortality by starvation. Moreover, R. sylvestris showed induction of genes improving submergence tolerance, potentially enhancing survival in prolonged floods. Additionally, we compared transcript profiles of these 2 tolerant species to relatively intolerant Arabidopsis and found that only Rorippa species induced various inorganic pyrophosphate dependent genes, alternatives to ATP demanding pathways, thereby conserving energy, and potentially explaining the difference in flooding survival between Rorippa and Arabidopsis. PMID:24525961

  2. Autoinduction of nuclear hormone receptors during metamorphosis and its significance.

    PubMed

    Tata, J R

    2000-01-01

    Metamorphosis is a most dramatic example of hormonally regulated genetic reprogramming during postembryonic development. The initiation and sustenance of the process are under the control of ecdysteroids in invertebrates and thyroid hormone, 3,3', 5-triiodothyronine, in oviparous vertebrates. Their actions are inhibited or potentiated by other endogenous or exogenous hormones - juvenile hormone in invertebrates and prolactin and glucocorticoids in vertebrates. The nuclear receptors for ecdysteroids and thyroid hormone are the most closely related members of the steroid/retinoid/thyroid hormone receptor supergene family. In many pre-metamorphic amphibia and insects, the onset of natural metamorphosis and the administration of the exogenous hormones to the early larvae are characterized by a substantial and rapid autoinduction of the respective nuclear receptors. This review will largely deal with the phenomenon of receptor autoinduction during amphibian metamorphosis, although many of its features resemble those in insect metamorphosis. In the frog Xenopus, thyroid hormone receptor autoinduction has been shown to be brought about by the direct interaction between the receptor protein and the thyroid-responsive elements in the promoter of its own gene. Three lines of evidence point towards the involvement of receptor autoinduction in the process of initiation of amphibian metamorphosis: (1) a close association between the extent of inhibition or potentiation by prolactin and glucocorticoid, respectively, and metamorphic response in whole tadpoles and in organ and cell cultures; (2) thyroid hormone fails to upregulate the expression of its own receptor in obligatorily neotenic amphibia but does so in facultatively neotenic amphibia; and (3) dominant-negative receptors known to block hormonal response prevent the autoinduction of wild-type Xenopus receptors in vivo and in cell lines. Autoinduction is not restricted to insect and amphibian metamorphic hormones but is

  3. Discovery of a new family of amphibians from northeast India with ancient links to Africa

    PubMed Central

    Kamei, Rachunliu G.; Mauro, Diego San; Gower, David J.; Van Bocxlaer, Ines; Sherratt, Emma; Thomas, Ashish; Babu, Suresh; Bossuyt, Franky; Wilkinson, Mark; Biju, S. D.

    2012-01-01

    The limbless, primarily soil-dwelling and tropical caecilian amphibians (Gymnophiona) comprise the least known order of tetrapods. On the basis of unprecedented extensive fieldwork, we report the discovery of a previously overlooked, ancient lineage and radiation of caecilians from threatened habitats in the underexplored states of northeast India. Molecular phylogenetic analyses of mitogenomic and nuclear DNA sequences, and comparative cranial anatomy indicate an unexpected sister-group relationship with the exclusively African family Herpelidae. Relaxed molecular clock analyses indicate that these lineages diverged in the Early Cretaceous, about 140 Ma. The discovery adds a major branch to the amphibian tree of life and sheds light on both the evolution and biogeography of caecilians and the biotic history of northeast India—an area generally interpreted as a gateway between biodiversity hotspots rather than a distinct biogeographic unit with its own ancient endemics. Because of its distinctive morphology, inferred age and phylogenetic relationships, we recognize the newly discovered caecilian radiation as a new family of modern amphibians. PMID:22357266

  4. AmphiBIO, a global database for amphibian ecological traits.

    PubMed

    Oliveira, Brunno Freire; São-Pedro, Vinícius Avelar; Santos-Barrera, Georgina; Penone, Caterina; Costa, Gabriel C

    2017-09-05

    Current ecological and evolutionary research are increasingly moving from species- to trait-based approaches because traits provide a stronger link to organism's function and fitness. Trait databases covering a large number of species are becoming available, but such data remains scarce for certain groups. Amphibians are among the most diverse vertebrate groups on Earth, and constitute an abundant component of major terrestrial and freshwater ecosystems. They are also facing rapid population declines worldwide, which is likely to affect trait composition in local communities, thereby impacting ecosystem processes and services. In this context, we introduce AmphiBIO, a comprehensive database of natural history traits for amphibians worldwide. The database releases information on 17 traits related to ecology, morphology and reproduction features of amphibians. We compiled data from more than 1,500 literature sources, and for more than 6,500 species of all orders (Anura, Caudata and Gymnophiona), 61 families and 531 genera. This database has the potential to allow unprecedented large-scale analyses in ecology, evolution, and conservation of amphibians.

  5. Initial diversification of living amphibians predated the breakup of Pangaea.

    PubMed

    San Mauro, Diego; Vences, Miguel; Alcobendas, Marina; Zardoya, Rafael; Meyer, Axel

    2005-05-01

    The origin and divergence of the three living orders of amphibians (Anura, Caudata, Gymnophiona) and their main lineages are one of the most hotly debated topics in vertebrate evolution. Here, we present a robust molecular phylogeny based on the nuclear RAG1 gene as well as results from a variety of alternative independent molecular clock calibrations. Our analyses suggest that the origin and early divergence of the three living amphibian orders dates back to the Palaeozoic or early Mesozoic, before the breakup of Pangaea, and soon after the divergence from lobe-finned fishes. The resulting new biogeographic scenario, age estimate, and the inferred rapid divergence of the three lissamphibian orders may account for the lack of fossils that represent plausible ancestors or immediate sister taxa of all three orders and the heretofore paradoxical distribution of some amphibian fossil taxa. Furthermore, the ancient and rapid radiation of the three lissamphibian orders likely explains why branch lengths connecting their early nodes are particularly short, thus rendering phylogenetic inference of implicated relationships especially difficult.

  6. Spatial distribution of Batrachochytrium dendrobatidis in South American caecilians.

    PubMed

    Lambertini, Carolina; Becker, C Guilherme; Bardier, Cecilia; da Silva Leite, Domingos; Toledo, Luís Felipe

    2017-04-20

    The amphibian-killing fungus Batrachochytrium dendrobatidis (Bd) is linked to population declines in anurans and salamanders globally. To date, however, few studies have attempted to screen Bd in live caecilians; Bd-positive caecilians have only been reported in Africa and French Guiana. Here, we performed a retrospective survey of museum preserved specimens to (1) describe spatial patterns of Bd infection in Gymnophiona across South America and (2) test whether areas of low climatic suitability for Bd in anurans predict Bd spatial epidemiology in caecilians. We used quantitative PCR to detect Bd in preserved caecilians collected over a 109 yr period, and performed autologistic regressions to test the effect of bioclimatic metrics of temperature and precipitation, vegetation density, and elevation on the likelihood of Bd occurrence. We detected an overall Bd prevalence of 12.4%, with positive samples spanning the Uruguayan savanna, Brazil's Atlantic Forest, and the Amazon basin. Our autologistic models detected a strong effect of macroclimate, a weaker effect of vegetation density, and no effect of elevation on the likelihood of Bd occurrence. Although most of our Bd-positive records overlapped with reported areas of high climatic suitability for the fungus in the Neotropics, many of our new Bd-positive samples extend far into areas of poor suitability for Bd in anurans. Our results highlight an important gap in the study of amphibian chytridiomycosis: the potential negative impact of Bd on Neotropical caecilians and the hypothetical role of caecilians as Bd reservoirs.

  7. Metabolic and endocrine changes during the reproductive cycle of dermatophagic caecilians in captivity.

    PubMed

    Gomes, Aline D; Navas, Carlos A; Jared, Carlos; Antoniazzi, Marta M; Ceballos, Nora R; Moreira, Renata G

    2013-10-01

    The amphibian order Gymnophiona is poorly known, and studies about their reproduction are mainly comparative and descriptive, focusing on the structure of testes, ovaries and oviducts. However, to understand the reproductive processes, including those of the oviparous dermatophagic species, it is important to know the dynamics of storage and mobilization of energetic substrates to gonads and skin during the reproductive cycle of males and females, as well as the endocrine control associated. For the present study, total lipids and proteins were measured during the annual cycle in the plasma, liver, muscle, testes, ovaries and skin of Siphonops annulatus in captivity. Plasma levels of gonadal steroids (estradiol, testosterone and progesterone) were quantified by radioimmunoassay. Histological analyses of ovaries and testes were performed to classify the maturation stages of the animals during the reproductive cycle. Gonadal maturation in males and females of S. annulatus was accompanied by metabolic changes in reserve tissues, which supported gonadal development and prepared the females' epidermis for skin feeding by the offspring. Even in confinement conditions, females and males synchronized the reproductive period. However, due to the absence of environmental cues in captivity inadequate levels of the hormones responsible for gamete release were triggered, leading to a lack of reproductive success. Copyright © 2013 Elsevier GmbH. All rights reserved.

  8. Comparative histological study of hepatic architecture in the three orders amphibian livers

    PubMed Central

    2012-01-01

    Background This report presents a detailed description of hepatic architecture in 46 amphibian livers by light microscopy, and extensively discusses the phylogenetic viewpoint. Results The 46 amphibian livers showed a variety of histological features, but anurans were the same as in mammalian livers. The hepatocyte-sinusoidal structures of the amphibian livers were classified into three different types: (I) several-cell-thick plate type, (II) two-cell-thick plate type, and (III) one-cell-thick plate type, depending on the percentage extension of sinusoidal areas per unit area, measured by morphometry. Hematopoietic tissue structures were observed in the connective tissue of both the perihepatic subcapsular regions and portal triads in the order Caudata and Gymnophiona, but were not observed in the order Anura (except for the genus Bombina and Xenopus). As phylogenetic relationships are branched from urodeles to anurans, the parenchyma arrangement progressed from the combined several- and two-cell-thick plate type to one-cell-thick plate type as seen in the mammalian liver type. In contrast, hematopoietic tissue structures were exactly the opposite and did not involve anurans. Conclusions This study is the first to investigate amphibian livers phylogenically, and their architectural differences are shown in the route of hepatic ontogenesis. In this process, parenchymal arrangement formation is acquired phylogenically. The occurrence of hematopoietic cells may be related with the development of the systemic immune system in the spleen and bone marrow. PMID:22905994

  9. Discovery of a new family of amphibians from northeast India with ancient links to Africa.

    PubMed

    Kamei, Rachunliu G; San Mauro, Diego; Gower, David J; Van Bocxlaer, Ines; Sherratt, Emma; Thomas, Ashish; Babu, Suresh; Bossuyt, Franky; Wilkinson, Mark; Biju, S D

    2012-06-22

    The limbless, primarily soil-dwelling and tropical caecilian amphibians (Gymnophiona) comprise the least known order of tetrapods. On the basis of unprecedented extensive fieldwork, we report the discovery of a previously overlooked, ancient lineage and radiation of caecilians from threatened habitats in the underexplored states of northeast India. Molecular phylogenetic analyses of mitogenomic and nuclear DNA sequences, and comparative cranial anatomy indicate an unexpected sister-group relationship with the exclusively African family Herpelidae. Relaxed molecular clock analyses indicate that these lineages diverged in the Early Cretaceous, about 140 Ma. The discovery adds a major branch to the amphibian tree of life and sheds light on both the evolution and biogeography of caecilians and the biotic history of northeast India-an area generally interpreted as a gateway between biodiversity hotspots rather than a distinct biogeographic unit with its own ancient endemics. Because of its distinctive morphology, inferred age and phylogenetic relationships, we recognize the newly discovered caecilian radiation as a new family of modern amphibians.

  10. Is solid always best? Cranial performance in solid and fenestrated caecilian skulls.

    PubMed

    Kleinteich, Thomas; Maddin, Hillary C; Herzen, Julia; Beckmann, Felix; Summers, Adam P

    2012-03-01

    Caecilians (Lissamphibia: Gymnophiona) are characterized by a fossorial lifestyle that appears to play a role in the many anatomical specializations in the group. The skull, in particular, has been the focus of previous studies because it is driven into the substrate for burrowing. There are two different types of skulls in caecilians: (1) stegokrotaphic, where the squamosal completely covers the temporal region and the jaw closing muscles, and (2) zygokrotaphic, with incomplete coverage of the temporal region by the squamosal. We used 3-D imaging and modeling techniques to explore the functional consequences of these skull types in an evolutionary context. We digitally converted stegokrotaphic skulls into zygokrotaphic skulls and vice versa. We also generated a third, akinetic skull type that was presumably present in extinct caecilian ancestors. We explored the benefits and costs of the different skull types under frontal loading at different head angles with finite element analysis (FEA). Surprisingly, the differences in stress distributions and bending between the three tested skull types were minimal and not significant. This suggests that the open temporal region in zygokrotaphic skulls does not lead to poorer performance during burrowing. However, the results of the FEA suggest a strong relationship between the head angle and skull performance, implying there is an optimal head angle during burrowing.

  11. Müller glia reactivity follows retinal injury despite the absence of the glial fibrillary acidic protein gene in Xenopus.

    PubMed

    Martinez-De Luna, Reyna I; Ku, Ray Y; Aruck, Alexandria M; Santiago, Francesca; Viczian, Andrea S; San Mauro, Diego; Zuber, Michael E

    2016-03-17

    Intermediate filament proteins are structural components of the cellular cytoskeleton with cell-type specific expression and function. Glial fibrillary acidic protein (GFAP) is a type III intermediate filament protein and is up-regulated in glia of the nervous system in response to injury and during neurodegenerative diseases. In the retina, GFAP levels are dramatically increased in Müller glia and are thought to play a role in the extensive structural changes resulting in Müller cell hypertrophy and glial scar formation. In spite of similar changes to the morphology of Xenopus Müller cells following injury, we found that Xenopus lack a gfap gene. Other type III intermediate filament proteins were, however, significantly induced following rod photoreceptor ablation and retinal ganglion cell axotomy. The recently available X. tropicalis and X. laevis genomes indicate a small deletion most likely resulted in the loss of the gfap gene during anuran evolution. Lastly, a survey of representative species from all three extant amphibian orders including the Anura (frogs, toads), Caudata (salamanders, newts), and Gymnophiona (caecilians) suggests that deletion of the gfap locus occurred in the ancestor of all Anura after its divergence from the Caudata ancestor around 290 million years ago. Our results demonstrate that extensive changes in Müller cell morphology following retinal injury do not require GFAP in Xenopus, and other type III intermediate filament proteins may be involved in the gliotic response.

  12. Myxozoan infections of caecilians demonstrate broad host specificity and indicate a link with human activity.

    PubMed

    Hartigan, Ashlie; Wilkinson, Mark; Gower, David J; Streicher, Jeffrey W; Holzer, Astrid S; Okamura, Beth

    2016-05-01

    Myxozoans are parasitic cnidarians that infect a wide variety of hosts. Vertebrates typically serve as intermediate hosts whereas definitive hosts are invertebrates, including annelids and bryozoans. Myxozoans are known to exploit species in two of the three extant amphibian orders (Anura: frogs and toads; Caudata: newts and salamanders). Here we use museum collections to determine, to our knowledge for the first time, whether myxozoans also exploit the third amphibian order (Gymnophiona: caecilians). Caecilians are a poorly known group of limbless amphibians, the ecologies of which range from aquatic to fully terrestrial. We examined 12 caecilian species in seven families (148 individuals total) characterised by a diversity of ecologies and life histories. Using morphological and molecular surveys, we discovered the presence of the myxozoan Cystodiscus axonis in two South American species (one of seven examined families) of aquatic caecilians - Typhlonectes natans and Typhlonectes compressicauda. All infected caecilians had been maintained in captivity in the United Kingdom prior to their preservation. Cystodiscus axonis is known from several Australian frog species and its presence in caecilians indicates a capacity for infecting highly divergent amphibian hosts. This first known report of myxozoan infections in caecilians provides evidence of a broad geographic and host range. However, the source of these infections remains unknown and could be related to exposure in South America, the U.K. or to conditions in captivity.

  13. Cranial Morphology of the Carboniferous-Permian Tetrapod Brachydectes newberryi (Lepospondyli, Lysorophia): New Data from µCT

    PubMed Central

    Pardo, Jason D.; Anderson, Jason S.

    2016-01-01

    Lysorophians are a group of early tetrapods with extremely elongate trunks, reduced limbs, and highly reduced skulls. Since the first discovery of this group, general similarities in outward appearance between lysorophians and some modern lissamphibian orders (specifically Urodela and Gymnophiona) have been recognized, and sometimes been the basis for hypotheses of lissamphibian origins. We studied the morphology of the skull, with particular emphasis on the neurocranium, of a partial growth series of the lysorophian Brachydectes newberryi using x-ray micro-computed tomography (μCT). Our study reveals similarities between the braincase of Brachydectes and brachystelechid recumbirostrans, corroborating prior work suggesting a close relationship between these taxa. We also describe the morphology of the epipterygoid, stapes, and quadrate in this taxon for the first time. Contra the proposals of some workers, we find no evidence of expected lissamphibian synapomorphies in the skull morphology in Brachydectes newberryi, and instead recognize a number of derived amniote characteristics within the braincase and suspensorium. Morphology previously considered indicative of taxonomic diversity within Lysorophia may reflect ontogenetic rather than taxonomic variation. The highly divergent morphology of lysorophians represents a refinement of morphological and functional trends within recumbirostrans, and is analogous to morphology observed in many modern fossorial reptiles. PMID:27563722

  14. Cold-induced changes in amphibian oocytes

    SciTech Connect

    Angelier, N.; Moreau, N.A.; N'Da, E.A.; Lautredou, N.F. )

    1989-08-01

    Female Pleurodeles waltl newts (Amphibia, urodele), usually raised at 20 degrees C, were submitted to low temperatures; oocytes responded to this cold stress by drastic changes both in lampbrush chromosome structure and in protein pattern. Preexisting lateral loops of lampbrush chromosomes were reduced in size and number, while cold-induced loops which were tremendously developed, occurred on defined bivalents of the oocyte at constant, reproducible sites. A comparison of protein patterns in control and stressed oocytes showed two main differences: in stressed oocytes, overall protein synthesis was reduced, except for a set of polypeptides, the cold-stress proteins; second, there was a striking inversion of the relative amount of beta- and gamma-actin found in the oocyte nucleus before and after cold stress. Whereas beta-actin was the predominant form in control oocytes, gamma-actin became the major form in stressed oocytes.

  15. Effects of sea lamprey (Petromyzon marinus) control in the Great Lakes on aquatic plants, invertebrates and amphibians

    USGS Publications Warehouse

    Gilderhus, P.A.; Johnson, B.G.H.

    1980-01-01

    The chemicals 3-trifluoromethyl-4-nitrophenol (TFM) or a combination of TFM and 2a??,5-dichloro-4a??-nitrosalicylanilide (Bayer 73) have been used to control the sea lamprey (Petromyzon marinus) in the Great Lakes for about 20 yr. These chemicals cause some mortalities of Oligochaeta and Hirudinea, immature forms of Ephemeroptera (Hexagenia sp.), and certain Trichoptera, Simuliidae, and Amphibia (Necturus sp.). The combination of TFM and Bayer 73 may affect some Pelecypoda and Gastropoda, but its overall effects on invertebrates are probably less than those of TFM alone. Granular Bayer 73 is likely to induce mortalities among oligochaetes, microcrustaceans, chironomids, and pelecypods. No evidence exists that the lampricides have caused the catastrophic decline or disappearance of any species. The overall impact of chemical control of sea lampreys on aquatic communities has been minor compared with the benefits derived.

  16. An enkephalin degrading aminopeptidase of human brain preserved during the vertebrate phylogeny.

    PubMed

    de Souza, A N; Bruno, J A; Carvalho, K M

    1991-01-01

    1. A soluble human brain aminopeptidase which hydrolyses the Tyr-Gly bond of Met-enkephalin and Leu-enkephalin was identified in the brains of the following vertebrates: mammals (Callithrix jacchus and Rattus norvegicus), bird (Gallus domesticus), reptile (Tupinambis teguixin), amphibia (Bufo paracnemis), fish (Sarotherdon niloticus) and elasmobranchy (Galeocerdo cuvieri). 2. The properties of this enzyme are: molecular weight near 100,000 Da, isoelectric point near 4.9, optimum pH near 7.5, activation by dithiothreitol, strong inhibition by Cu2+, Zn2+, Ni2+, puromycin and bacitracin, hydrolysis of enkephalins and basic and neutral aminoacid-beta-naphythylamide substrates. 3. The results indicate the preservation of this human brain aminopeptidase during the course of vertebrate phylogeny.

  17. [Biological experiments on "Kosmos-1887"].

    PubMed

    Alpatov, A M; I'lin, E A; Antipov, V V; Tairbekov, M G

    1989-01-01

    In the 13-ray space flight on Kosmos-1887 various experiments in the field of cell biology, genetics, biorhythm, developmental biology and regeneration were performed using bacteria, protozoa, plants, worms, insects, fish and amphibia. Paramecia showed enhanced cell proliferation, spheroidization and diminished protein content. Experiments on fruit-flies, newt oocytes and primate lymphocytes confirmed involvement of the cell genetic apparatus in responses to microgravity. Beetles exhibited a reduction of the length of the spontaneous period of freely running circadian rhythms. Carausius morosus developed latent changes in early embryogenesis which manifested at later stages of ontogenesis. Exposure to microgravity did not prevent recovery of injured tissues; moreover their regeneration may be accelerated after recovery. Biology research programs in future biosatellite flights are discussed.

  18. No observable effect of a glyphosate-based herbicide on two top predators of temporal water bodies.

    PubMed

    Ujszegi, János; Gál, Zoltán; Mikó, Zsanett; Hettyey, Attila

    2015-02-01

    It has been implied that the application of pesticides is involved in the world-wide decline of biodiversity, but little is known about the influence of these chemicals on key predators of temporary wetlands. The direct impacts were examined of a frequently applied glyphosate-based herbicide on larval Aeshna cyanea (Müller, 1764; Odonata, Insecta) and adult male Lissotriton vulgaris (Linnaeus, 1758; Caudata, Amphibia), 2 top predators of Central European ephemeral ponds. The effects of herbicide exposure were measured on survival, behavior, body mass change, and predatory activity in an outdoor mesocosm experiment lasting for 17 d. No significant effects of exposure were observed in either predator species. The results suggest that the herbicide has no immediate effect on the predators studied at environmentally relevant concentrations and that these predators can also fulfill their top-down regulatory role in contaminated ecosystems. © 2014 SETAC.

  19. Oxygen regulation capacity in Discoglossus pictus tadpoles between moderate hyperoxia and acute hypoxia in water.

    PubMed

    Barja de Quiroga, G; Alonso-Bedate, M

    1988-09-01

    The oxygen dependence of aquatic oxygen consumption was measured in active and anesthetized stage XVIII Discoglossus pictus tadpoles (Amphibia, Anura). The active tadpoles are good oxygen regulators in moderate hyperoxia and moderate hypoxia, whereas they are oxygen conformers in acute hypoxia. Critical oxygen pressure was 52 mmHg O2. Anesthetizing the larvae changes them to perfect oxygen conformers between moderate hyperoxia and moderate hypoxia (249-63 mmHg O2). At stage XVIII the aquatic respiratory organs are still capable of producing oxygen regulation when free access to air is denied. The marked capacity for oxygen regulation in D. pictus tadpoles is concordant with the strong hypoxic environments in which these animals usually live in nature.

  20. [Algo-bacterial communities of the Kulunda steppe (Altai region, Russia) soda lakes].

    PubMed

    Samylina, O S; Sapozhnikov, F V; Gaĭnanova, O Iu; Riabova, A V; Nikitin, M A; Sorokin, D Iu

    2015-01-01

    The composition and macroscopic structure of the floating oxygenic phototrophic communities from Kulunda steppe soda lakes (Petukhovskoe sodovoe, Tanatara VI, and Gorchiny 3) was described based on the data of the 2011 and 2012 expeditions (Winogradsky Institute of Microbiology). The algo-bacterial community with a green alga Ctenocladus circinnatus as an edificator was the typical one. Filamentous Geitlerinema sp. and Nodosilinea sp. were the dominant cyanobacteria. Apart from C. circinnatus, the algological component of the community contained unicellular green algae Dunaliella viridis and cf. Chlorella minutissima, as well as diatoms (Anomeoneis sphaerophora, Brchysira brebissonii, Brachysira zellensis, Mastogloia pusilla var. subcapitata, Nitzschia amphibia, Nitzschia communis, and Nitzschia sp.1). The latter have not been previously identified in the lakes under study. In all lakes, a considerable increase in salinity was found to result in changes in the composition and macroscopic structure of algo-bacterial communities.

  1. Maternal control of sex ratio in Rana rugosa: evidence from DNA sexing.

    PubMed

    Sakisaka, Y; Yahara, T; Miura, I; Kasuya, E

    2000-11-01

    Parental control of primary sex ratio has been reported in a mammal (red deer), some birds, and a snake. However, it remains uncertain whether other vertebrates including Amphibia can control sex ratio. In this paper, we examined the possibility in a wild population of the Japanese frog Rana rugosa which has female heterogamety. Sex ratios of their eggs were determined using DNA markers. The eggs were sampled in the field from May to August in 1998. Each egg was then sexed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) using a sex-specific DNA marker. The result showed a male bias early in the season which changed to a female bias later, suggesting that females of R. rugosa can control the primary sex ratio.

  2. Action currents, internodal potentials, and extracellular records of myelinated mammalian nerve fibers derived from node potentials.

    PubMed Central

    Marks, W B; Loeb, G E

    1976-01-01

    The potential distribution within the internodal axon of mammalian nerve fibers is derived by applying known node potential waveforms to the ends of an equivalent circuit model of the internode. The complete spatial/temporal profile of action potentials synthesized from the internodal profiles is used to compute the node current waveforn, and the extracellular action potential around fibers captured within a tubular electrode. For amphibia, the results agreed with empirical values. For mammals, the amplitude of the node currents plotted against conduction velocity was fitted by a straight line. The extracellular potential waveform depended on the location of the nodes within the tube. For tubes of length from 2 to 8 internodes, extracellular wave amplitude (mammals) was about one-third of the product of peak node current and tube resistance (center to ends). The extracellular potentials developed by longitudinal and radial currents in an anisotropic medium (fiber bundle) are compared. PMID:1276389

  3. Composition and phylogenetic analysis of vitellogenin coding sequences in the Indonesian coelacanth Latimeria menadoensis.

    PubMed

    Canapa, Adriana; Olmo, Ettore; Forconi, Mariko; Pallavicini, Alberto; Makapedua, Monica Daisy; Biscotti, Maria Assunta; Barucca, Marco

    2012-07-01

    The coelacanth Latimeria menadoensis, a living fossil, occupies a key phylogenetic position to explore the changes that have affected the genomes of the aquatic vertebrates that colonized dry land. This is the first study to isolate and analyze L. menadoensis mRNA. Three different vitellogenin transcripts were identified and their inferred amino acid sequences compared to those of other known vertebrates. The phylogenetic data suggest that the evolutionary history of this gene family in coelacanths was characterized by a different duplication event than those which occurred in teleosts, amniotes, and amphibia. Comparison of the three sequences highlighted differences in functional sites. Moreover, despite the presence of conserved sites compared with the other oviparous vertebrates, some sites were seen to have changed, others to be similar only to those of teleosts, and others still to resemble only to those of tetrapods.

  4. Exploring the Effect of Asymmetric Mitochondrial DNA Introgression on Estimating Niche Divergence in Morphologically Cryptic Species

    PubMed Central

    Wielstra, Ben; Arntzen, Jan W.

    2014-01-01

    If potential morphologically cryptic species, identified based on differentiated mitochondrial DNA, express ecological divergence, this increases support for their treatment as distinct species. However, mitochondrial DNA introgression hampers the correct estimation of ecological divergence. We test the hypothesis that estimated niche divergence differs when considering nuclear DNA composition or mitochondrial DNA type as representing the true species range. We use empirical data of two crested newt species (Amphibia: Triturus) which possess introgressed mitochondrial DNA from a third species in part of their ranges. We analyze the data in environmental space by determining Fisher distances in a principal component analysis and in geographical space by determining geographical overlap of species distribution models. We find that under mtDNA guidance in one of the two study cases niche divergence is overestimated, whereas in the other it is underestimated. In the light of our results we discuss the role of estimated niche divergence in species delineation. PMID:24743746

  5. Ubiquitous presence of gluconeogenic regulatory enzyme, fructose-1,6-bisphosphatase, within layers of rat retina

    PubMed Central

    Mamczur, Piotr; Mazurek, Jakub

    2010-01-01

    To shed some light on gluconeogenesis in mammalian retina, we have focused on fructose-1,6-bisphosphatase (FBPase), a regulatory enzyme of the process. The abundance of the enzyme within the layers of the rat retina suggests that, in mammals in contrast to amphibia, gluconeogenesis is not restricted to one specific cell of the retina. We propose that FBPase, in addition to its gluconeogenic role, participates in the protection of the retina against reactive oxygen species. Additionally, the nuclear localization of FBPase and of its binding partner, aldolase, in the retinal cells expressing the proliferation marker Ki-67 indicates that these two gluconeogenic enzymes are involved in non-enzymatic nuclear processes. Electronic supplementary material The online version of this article (doi:10.1007/s00441-010-1008-2) contains supplementary material, which is available to authorized users. PMID:20614135

  6. The chemical and evolutionary ecology of tetrodotoxin (TTX) toxicity in terrestrial vertebrates.

    PubMed

    Hanifin, Charles T

    2010-03-10

    Tetrodotoxin (TTX) is widely distributed in marine taxa, however in terrestrial taxa it is limited to a single class of vertebrates (Amphibia). Tetrodotoxin present in the skin and eggs of TTX-bearing amphibians primarily serves as an antipredator defense and these taxa have provided excellent models for the study of the evolution and chemical ecology of TTX toxicity. The origin of TTX present in terrestrial vertebrates is controversial. In marine organisms the accepted hypothesis is that the TTX present in metazoans results from either dietary uptake of bacterially produced TTX or symbiosis with TTX producing bacteria, but this hypothesis may not be applicable to TTX-bearing amphibians. Here I review the taxonomic distribution and evolutionary ecology of TTX in amphibians with some attention to the origin of TTX present in these taxa.

  7. The Chemical and Evolutionary Ecology of Tetrodotoxin (TTX) Toxicity in Terrestrial Vertebrates

    PubMed Central

    Hanifin, Charles T.

    2010-01-01

    Tetrodotoxin (TTX) is widely distributed in marine taxa, however in terrestrial taxa it is limited to a single class of vertebrates (Amphibia). Tetrodotoxin present in the skin and eggs of TTX-bearing amphibians primarily serves as an antipredator defense and these taxa have provided excellent models for the study of the evolution and chemical ecology of TTX toxicity. The origin of TTX present in terrestrial vertebrates is controversial. In marine organisms the accepted hypothesis is that the TTX present in metazoans results from either dietary uptake of bacterially produced TTX or symbiosis with TTX producing bacteria, but this hypothesis may not be applicable to TTX-bearing amphibians. Here I review the taxonomic distribution and evolutionary ecology of TTX in amphibians with some attention to the origin of TTX present in these taxa. PMID:20411116

  8. [Peculiarities of phosphoglycerate kinase-1 pseudogene evolution in Schrenck salamander (Salamandrella schrenckii Strauch, 1870)].

    PubMed

    Malyarchuk, B A; Denisova, G A; Derenko, M V

    2013-07-01

    Processed copies of genes generally evolve in neutral mode as pseudogenes, however, some of them might be important sources of new functional genes. The psiPGK1 pseudogene has been discovered in Schrenck salamander (Salamandrella schrenckii, Amphibia, Caudata, Hynobiidae) via polymerase chain reaction used to amplify the phosphoglycerate kinase 1 gene (PGK1). This pseudogene is an intronless copy of PGK1 gene absent of exon 6. Analysis of psiPGK1 pseudogene polymorphism has demonstrated that it lacks mutations, which results in shifts in the stop codons and reading frames, as well as that the interspecies variation of this pseudogene was inconsistent with the neutral model of evolution. In addition, the pattern of phylogeographic differentiation of the psiPGK1 variants mainly coincides with that observed in mitochondrial DNA. These observations allow it to be suggested that the psiPGK1 pseudogene is a new functional gene in the Schrenck salamander.

  9. BION - A Unique Space Biological Laboratory: Reviews and Outlooks

    NASA Astrophysics Data System (ADS)

    Kazakova, A. E.; Abrashkin, V. I.; Kozlov, V. D.; Nikanorov, V. M.

    2002-01-01

    unique fundamental and applied researches in field of space biology. facilities when launch date, life time, orbital parameters, operation of the onboard equipment are subject to the benefit of the scientific research. of space system optimization prior to flight tests including ground and airplane tests with research hardware and animals involved. new relevant research hardware was also manufactured. influence of space flight on Earth organisms; combined influence of weightlessness and increased radiation on an organism; implementation of artificial gravity as a preventive aid; possibilities of fertilization and fetal growth under space flight conditions. amphibia, tortoises, laboratory rats, monkeys and others were used in space as biological objects. In total, they constituted 37 appellations. of the system. At present Bion S/C is a space facility, which meets scientific requirements and provides full scale of services to Customers.

  10. Effects of endocrine-disrupting contaminants on amphibian oogenesis: methoxychlor inhibits progesterone-induced maturation of Xenopus laevis oocytes in vitro.

    PubMed Central

    Pickford, D B; Morris, I D

    1999-01-01

    There is currently little evidence of pollution-induced endocrine dysfunction in amphibia, in spite of widespread concern over global declines in this ecologically diverse group. Data regarding the potential effects of endocrine-disrupting contaminants (EDCs) on reproductive function in amphibia are particularly lacking. We hypothesized that estrogenic EDCs may disrupt progesterone-induced oocyte maturation in the adult amphibian ovary, and tested this with an in vitro germinal vesicle breakdown assay using defolliculated oocytes from the African clawed frog, Xenopus laevis. While a variety of natural and synthetic estrogens and xenoestrogens were inactive in this system, the proestrogenic pesticide methoxychlor was a surprisingly potent inhibitor of progesterone-induced oocyte maturation (median inhibitive concentration, 72 nM). This inhibitory activity was specific to methoxychlor, rather than to its estrogenic contaminants or metabolites, and was not antagonized by the estrogen receptor antagonist ICI 182,780, suggesting that this activity is not estrogenic per se. The inhibitory activity of methoxychlor was dose dependent, reversible, and early acting. However, washout was unable to reverse the effect of short methoxychlor exposure, and methoxychlor did not competitively displace [3H]progesterone from a specific binding site in the oocyte plasma membrane. Therefore, methoxychlor may exert its action not directly at the site of progesterone action, but downstream on early events in maturational signaling, although the precise mechanism of action is unclear. The activity of methoxychlor in this system indicates that xenobiotics may exert endocrine-disrupting effects through interference with progestin-regulated processes and through mechanisms other than receptor antagonism. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 PMID:10090707

  11. Molecular phylogeny and taxonomic revision of the genus Wittrockiella (Pithophoraceae, Cladophorales), including the descriptions of W. australis sp. nov. and W. zosterae sp. nov.

    PubMed

    Boedeker, Christian; O'Kelly, Charles J; West, John A; Hanyuda, Takeaki; Neale, Adele; Wakana, Isamu; Wilcox, Mike D; Karsten, Ulf; Zuccarello, Giuseppe C

    2017-06-01

    Wittrockiella is a small genus of filamentous green algae that occurs in habitats with reduced or fluctuating salinities. Many aspects of the basic biology of these algae are still unknown and the phylogenetic relationships within the genus have not been fully explored. We provide a phylogeny based on three ribosomal markers (ITS, LSU, and SSU rDNA) of the genus, including broad intraspecific sampling for W. lyallii and W. salina, recommendations for the use of existing names are made, and highlight aspects of their physiology and life cycle. Molecular data indicate that there are five species of Wittrockiella. Two new species, W. australis and W. zosterae, are described, both are endophytes. Although W. lyallii and W. salina can be identified morphologically, there are no diagnostic morphological characters to distinguish between W. amphibia, W. australis, and W. zosterae. A range of low molecular weight carbohydrates were analyzed but proved to not be taxonomically informative. The distribution range of W. salina is extended to the Northern Hemisphere as this species has been found in brackish lakes in Japan. Furthermore, it is shown that there are no grounds to recognize W. salina var. kraftii, which was described as an endemic variety from a freshwater habitat on Lord Howe Island, Australia. Culture experiments indicate that W. australis has a preference for growth in lower salinities over full seawater. For W. amphibia and W. zosterae, sexual reproduction is documented, and the split of these species is possibly attributable to polyploidization. © 2017 Phycological Society of America.

  12. Mapping the Space of Genomic Signatures

    PubMed Central

    Kari, Lila; Hill, Kathleen A.; Sayem, Abu S.; Karamichalis, Rallis; Bryans, Nathaniel; Davis, Katelyn; Dattani, Nikesh S.

    2015-01-01

    We propose a computational method to measure and visualize interrelationships among any number of DNA sequences allowing, for example, the examination of hundreds or thousands of complete mitochondrial genomes. An "image distance" is computed for each pair of graphical representations of DNA sequences, and the distances are visualized as a Molecular Distance Map: Each point on the map represents a DNA sequence, and the spatial proximity between any two points reflects the degree of structural similarity between the corresponding sequences. The graphical representation of DNA sequences utilized, Chaos Game Representation (CGR), is genome- and species-specific and can thus act as a genomic signature. Consequently, Molecular Distance Maps could inform species identification, taxonomic classifications and, to a certain extent, evolutionary history. The image distance employed, Structural Dissimilarity Index (DSSIM), implicitly compares the occurrences of oligomers of length up to k (herein k = 9) in DNA sequences. We computed DSSIM distances for more than 5 million pairs of complete mitochondrial genomes, and used Multi-Dimensional Scaling (MDS) to obtain Molecular Distance Maps that visually display the sequence relatedness in various subsets, at different taxonomic levels. This general-purpose method does not require DNA sequence alignment and can thus be used to compare similar or vastly different DNA sequences, genomic or computer-generated, of the same or different lengths. We illustrate potential uses of this approach by applying it to several taxonomic subsets: phylum Vertebrata, (super)kingdom Protista, classes Amphibia-Insecta-Mammalia, class Amphibia, and order Primates. This analysis of an extensive dataset confirms that the oligomer composition of full mtDNA sequences can be a source of taxonomic information. This method also correctly finds the mtDNA sequences most closely related to that of the anatomically modern human (the Neanderthal, the Denisovan

  13. The evolution from asparagine or threonine to cysteine in position 146 contributes to generation of a more efficient and stable form of muscle creatine kinase in higher vertebrates.

    PubMed

    Zhao, Tong-Jin; Liu, Yang; Chen, Zhao; Yan, Yong-Bin; Zhou, Hai-Meng

    2006-01-01

    Creatine kinase, a key enzyme in vertebrate excitable tissues that require large energy fluxes, catalyzes the reversible transfer of phosphate between adenosine triphosphate and creatine. Sequence alignment indicated that the 146th amino acid is cysteine in the muscle creatine kinase of higher vertebrates including Amphibia, Reptilia, Aves and Mammalia. In fishes, it is cysteine in Agnatha and Chondrichthyes, and asparagine or threonine in Osteichthyes, which is the ancestor of Amphibia, Reptilia, Aves and Mammalia. To explore the structural and functional role of this special residue, a series of site-directed mutants of rabbit muscle creatine kinase were constructed, including C146S, C146N, C146T, C146G, C146A, C146D and C146R. A detailed comparison was made between wild-type creatine kinase and the mutants in catalytic activity, physico-chemical properties and structural stability against thermal inactivation and guanidine hydrochloride denaturation. It was found that except for C146S, the mutants had relatively lower catalytic activity and structural stability than Wt-CK. Wt-CK and C146S were the most stable ones, followed by C146N and C146T, and then C146G and C146A, and C146D and C146R were the least stable mutants. These results suggested that the 146th residue plays a crucial role in maintaining the structural stability of creatine kinase, and that the evolution in this amino acid from asparagine or threonine to cysteine contributes to the generation of a more efficient and more stable form of creatine kinase in higher vertebrates.

  14. On the origin of and phylogenetic relationships among living amphibians

    PubMed Central

    Zardoya, Rafael; Meyer, Axel

    2001-01-01

    The phylogenetic relationships among the three orders of modern amphibians (Caudata, Gymnophiona, and Anura) have been estimated based on both morphological and molecular evidence. Most morphological and paleontological studies of living and fossil amphibians support the hypothesis that salamanders and frogs are sister lineages (the Batrachia hypothesis) and that caecilians are more distantly related. Previous interpretations of molecular data based on nuclear and mitochondrial rRNA sequences suggested that salamanders and caecilians are sister groups to the exclusion of frogs. In an attempt to resolve this apparent conflict, the complete mitochondrial genomes of a salamander (Mertensiella luschani) and a caecilian (Typhlonectes natans) were determined (16,656 and 17,005 bp, respectively) and compared with previously published sequences from a frog (Xenopus laevis) and several other groups of vertebrates. Phylogenetic analyses of the mitochondrial data supported with high bootstrap values the monophyly of living amphibians with respect to other living groups of tetrapods, and a sister group relationship of salamanders and frogs. The lack of phylogenetically informative sites in the previous rRNA data sets (because of its shorter size and higher among-site rate variation) likely explains the discrepancy between our results and those based on previous molecular data. Strong support of the Batrachia hypothesis from both molecule- and morphology-based studies provides a robust phylogenetic framework that will be helpful to comparative studies among the three living orders of amphibians and will permit better understanding of the considerably divergent vertebral, brain, and digit developmental patterns found in frogs and salamanders. PMID:11390961

  15. Studying the evolutionary significance of thermal adaptation in ectotherms: The diversification of amphibians' energetics.

    PubMed

    Nespolo, Roberto F; Figueroa, Julio; Solano-Iguaran, Jaiber J

    2017-08-01

    A fundamental problem in evolutionary biology is the understanding of the factors that promote or constrain adaptive evolution, and assessing the role of natural selection in this process. Here, comparative phylogenetics, that is, using phylogenetic information and traits to infer evolutionary processes has been a major paradigm . In this study, we discuss Ornstein-Uhlenbeck models (OU) in the context of thermal adaptation in ectotherms. We specifically applied this approach to study amphibians's evolution and energy metabolism. It has been hypothesized that amphibians exploit adaptive zones characterized by low energy expenditure, which generate specific predictions in terms of the patterns of diversification in standard metabolic rate (SMR). We complied whole-animal metabolic rates for 122 species of amphibians, and adjusted several models of diversification. According to the adaptive zone hypothesis, we expected: (1) to find "accelerated evolution" in SMR (i.e., diversification above Brownian Motion expectations, BM), (2) that a model assuming evolutionary optima (i.e., an OU model) fits better than a white-noise model and (3) that a model assuming multiple optima (according to the three amphibians's orders) fits better than a model assuming a single optimum. As predicted, we found that the diversification of SMR occurred most of the time, above BM expectations. Also, we found that a model assuming an optimum explained the data in a better way than a white-noise model. However, we did not find evidence that an OU model with multiple optima fits the data better, suggesting a single optimum in SMR for Anura, Caudata and Gymnophiona. These results show how comparative phylogenetics could be applied for testing adaptive hypotheses regarding history and physiological performance in ectotherms. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Caecilian jaw-closing mechanics: integrating two muscle systems.

    PubMed

    Kleinteich, Thomas; Haas, Alexander; Summers, Adam P

    2008-12-06

    Caecilians (Lissamphibia: Gymnophiona) are unique among vertebrates in having two sets of jaw-closing muscles, one on either side of the jaw joint. Using data from high-resolution X-ray radiation computed tomography scans, we modelled the effect of these two muscle groups (mm. levatores mandibulae and m. interhyoideus posterior) on bite force over a range of gape angles, employing a simplified lever arm mechanism that takes into account muscle cross-sectional area and fibre angle. Measurements of lever arm lengths, muscle fibre orientations and physiological cross-sectional area of cranial muscles were available from three caecilian species: Ichthyophis cf. kohtaoensis; Siphonops annulatus; and Typhlonectes natans. The maximal gape of caecilians is restricted by a critical gape angle above which the mm. levatores mandibulae will open the jaw and destabilize the mandibular joint. The presence of destabilizing forces in the caecilian jaw mechanism may be compensated for by a mandibular joint in that the fossa is wrapped around the condyle to resist dislocation. The caecilian skull is streptostylic; the quadrate-squamosal complex moves with respect to the rest of the skull. This increases the leverage of the jaw-closing muscles. We also demonstrate that the unusual jaw joint requires streptostyly because there is a dorsolateral movement of the quadrate-squamosal complex when the jaw closes. The combination of the two jaw-closing systems results in high bite forces over a wide range of gape angles, an important advantage for generalist feeders such as caecilians. The relative sizes and leverage mechanics of the two closing systems allow one to exert more force when the other has a poor mechanical advantage. This effect is seen in all three species we examined. In the aquatic T. natans, with its less well-roofed skull, there is a larger contribution of the mm. levatores mandibulae to total bite force than in the terrestrial I. cf. kohtaoensis and S. annulatus.

  17. The hyal and ventral branchial muscles in caecilian and salamander larvae: homologies and evolution.

    PubMed

    Kleinteich, Thomas; Haas, Alexander

    2011-05-01

    Amphibians (Lissamphibia) are characterized by a bi-phasic life-cycle that comprises an aquatic larval stage and metamorphosis to the adult. The ancestral aquatic feeding behavior of amphibian larvae is suction feeding. The negative pressure that is needed for ingestion of prey is created by depression of the hyobranchial apparatus as a result of hyobranchial muscle action. Understanding the homologies of hyobranchial muscles in amphibian larvae is a crucial step in understanding the evolution of this important character complex. However, the literature mostly focuses on the adult musculature and terms used for hyal and ventral branchial muscles in different amphibians often do not reflect homologies across lissamphibian orders. Here we describe the hyal and ventral branchial musculature in larvae of caecilians (Gymnophiona) and salamanders (Caudata), including juveniles of two permanently aquatic salamander species. Based on previous alternative terminology schemes, we propose a terminology for the hyal and ventral branchial muscles that reflects the homologies of muscles and that is suited for studies on hyobranchial muscle evolution in amphibians. We present a discussion of the hyal and ventral branchial muscles in larvae of the most recent common ancestor of amphibians (i.e. the ground plan of Lissamphibia). Based on our terminology, the hyal and ventral branchial musculature of caecilians and salamanders comprises the following muscles: m. depressor mandibulae, m. depressor mandibulae posterior, m. hyomandibularis, m. branchiohyoideus externus, m. interhyoideus, m. interhyoideus posterior, m. subarcualis rectus I, m. subarcualis obliquus II, m. subarcualis obliquus III, m. subarcualis rectus II-IV, and m. transversus ventralis IV. Except for the m. branchiohyoideus externus, all muscles considered herein can be assigned to the ground plan of the Lissamphibia with certainty. The m. branchiohyoideus externus is either apomorphic for the Batrachia (frogs

  18. On the origin of and phylogenetic relationships among living amphibians.

    PubMed

    Zardoya, R; Meyer, A

    2001-06-19

    The phylogenetic relationships among the three orders of modern amphibians (Caudata, Gymnophiona, and Anura) have been estimated based on both morphological and molecular evidence. Most morphological and paleontological studies of living and fossil amphibians support the hypothesis that salamanders and frogs are sister lineages (the Batrachia hypothesis) and that caecilians are more distantly related. Previous interpretations of molecular data based on nuclear and mitochondrial rRNA sequences suggested that salamanders and caecilians are sister groups to the exclusion of frogs. In an attempt to resolve this apparent conflict, the complete mitochondrial genomes of a salamander (Mertensiella luschani) and a caecilian (Typhlonectes natans) were determined (16,656 and 17,005 bp, respectively) and compared with previously published sequences from a frog (Xenopus laevis) and several other groups of vertebrates. Phylogenetic analyses of the mitochondrial data supported with high bootstrap values the monophyly of living amphibians with respect to other living groups of tetrapods, and a sister group relationship of salamanders and frogs. The lack of phylogenetically informative sites in the previous rRNA data sets (because of its shorter size and higher among-site rate variation) likely explains the discrepancy between our results and those based on previous molecular data. Strong support of the Batrachia hypothesis from both molecule- and morphology-based studies provides a robust phylogenetic framework that will be helpful to comparative studies among the three living orders of amphibians and will permit better understanding of the considerably divergent vertebral, brain, and digit developmental patterns found in frogs and salamanders.

  19. Amphibian biology and husbandry.

    PubMed

    Pough, F Harvey

    2007-01-01

    Extant amphibians comprise three lineages-- salamanders (Urodela or Caudata), frogs and toads (Anura), and caecilians (Gymnophiona, Apoda, or Caecilia)--which contain more than 6,000 species. Fewer than a dozen species of amphibians are commonly maintained in laboratory colonies, and the husbandry requirements for the vast majority of amphibians are poorly known. For these species, a review of basic characteristics of amphibian biology supplemented by inferences drawn from the morphological and physiological characteristics of the species in question provides a basis for decisions about housing and feeding. Amphibians are ectotherms, and their skin is permeable to water, ions, and respiratory gases. Most species are secretive and, in many cases, nocturnal. The essential characteristics of their environment include appropriate levels of humidity, temperature, and lighting as well as retreat sites. Terrestrial and arboreal species require moist substrates, water dishes, and high relative humidity. Because temperature requirements for most species are poorly known, it is advisable to use a temperature mosaic that will allow an animal to find an appropriate temperature within its cage. Photoperiod may affect physiology and behavior (especially reproduction and hibernation), and although the importance of ultraviolet light for calcium metabolism by amphibians is not yet known, ecological observations suggest that it might be important for some species of frogs. Some amphibians are territorial, and some use olfactory cues to mark their territory and to recognize other individuals of their species. All amphibians are carnivorous as adults, and the feeding response of many species is elicited by the movement of prey. Diets should include a mixture of prey species, and it may be advisable to load prey with vitamins and minerals.

  20. Batrachochytrium dendrobatidis in amphibians of Cameroon, including first records for caecilians.

    PubMed

    Doherty-Bone, T M; Gonwouo, N L; Hirschfeld, M; Ohst, T; Weldon, C; Perkins, M; Kouete, M T; Browne, R K; Loader, S P; Gower, D J; Wilkinson, M W; Rödel, M O; Penner, J; Barej, M F; Schmitz, A; Plötner, J; Cunningham, A A

    2013-02-28

    Amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd) has been hypothesised to be an indigenous parasite of African amphibians. In Cameroon, however, previous surveys in one region (in the northwest) failed to detect this pathogen, despite the earliest African Bd having been recorded from a frog in eastern Cameroon, plus one recent record in the far southeast. To reconcile these contrasting results, we present survey data from 12 localities across 6 regions of Cameroon from anurans (n = 1052) and caecilians (n = 85) of ca. 108 species. Bd was detected in 124 amphibian hosts at 7 localities, including Mt. Oku, Mt. Cameroon, Mt. Manengouba and lowland localities in the centre and west of the country. None of the hosts were observed dead or dying. Infected amphibian hosts were not detected in other localities in the south and eastern rainforest belt. Infection occurred in both anurans and caecilians, making this the first reported case of infection in the latter order (Gymnophiona) of amphibians. There was no significant difference between prevalence and infection intensity in frogs and caecilians. We highlight the importance of taking into account the inhibition of diagnostic qPCR in studies on Bd, based on all Bd-positive hosts being undetected when screened without bovine serum albumin in the qPCR mix. The status of Bd as an indigenous, cosmopolitan amphibian parasite in Africa, including Cameroon, is supported by this work. Isolating and sequencing strains of Bd from Cameroon should now be a priority. Longitudinal host population monitoring will be required to determine the effects, if any, of the infection on amphibians in Cameroon.

  1. Evolution of the Schlafen genes, a gene family associated with embryonic lethality, meiotic drive, immune processes and orthopoxvirus virulence.

    PubMed

    Bustos, Olivia; Naik, Saijal; Ayers, Gayle; Casola, Claudio; Perez-Lamigueiro, Maria A; Chippindale, Paul T; Pritham, Ellen J; de la Casa-Esperón, Elena

    2009-11-01

    Genes of the Schlafen family, first discovered in mouse, are expressed in hematopoietic cells and are involved in immune processes. Previous results showed that they are candidate genes for two major phenomena: meiotic drive and embryonic lethality (DDK syndrome). However, these genes remain poorly understood, mostly due to the limitations imposed by their similarity, close location and the potential functional redundancy of the gene family members. Here we use genomic and phylogenetic studies to investigate the evolution and role of this family of genes. Our results show that the Schlafen family is widely distributed in mammals, where we recognize four major clades that experienced lineage-specific expansions or contractions in various orders, including primates and rodents. In addition, we identified members of the Schlafen family in Chondrichthyes and Amphibia, indicating an ancient origin of these genes. We find evidence that positive selection has acted on many Schlafen genes. Moreover, our analyses indicate that a member of the Schlafen family was horizontally transferred from murine rodents to orthopoxviruses, where it is hypothesized to play a role in allowing the virus to survive host immune defense mechanisms. The functional relevance of the viral Schlafen sequences is further underscored by our finding that they are evolving under purifying selection. This is of particular importance, since orthopoxviruses infect mammals and include variola, the causative agent of smallpox, and monkeypox, an emerging virus of great concern for human health.

  2. beta-cyanoalanine production by marine bacteria on cyanide-free medium and its specific inhibitory activity toward cyanobacteria.

    PubMed

    Yoshikawa, K; Adachi, K; Nishijima, M; Takadera, T; Tamaki, S; Harada, K; Mochida, K; Sano, H

    2000-02-01

    In screening the culture broth of marine bacteria collected at Yap (Micronesia), Palau (Belau), and Okinawa (the southwest islands of Japan) for antimicroalgal activity, 37 out of 2,594 bacterial isolates tested were found to produce anticyanobacterial substances against Oscillatoria amphibia NIES-361. One strain, C-979, identified as a Vibrio sp., was selected and cultured in 2.4 liters of marine broth 2216 to identify the bioactive compound produced by the strain. The purified very hydrophilic compound (16.4 mg) was determined to be beta-cyano-L-alanine (L-CNAla) by instrumental analyses and the application of the advanced Marfey method. L-CNAla did not inhibit the growth of bacteria, yeast, or eukaryotic microalgae, but some cyanobacteria were found to be sensitive to L-CNAla at a concentration of 0.4 to 25 microg/ml. The effect of L-CNAla on some other environmental organisms, including invertebrates and a macroalgae, is discussed. CNAla production in marine broth was examined by thin-layer chromatography for the 37 bacterial isolates which produced an anticyanobacterial substance. The broth of 36 of these strains contained CNAla, suggesting the wide distribution of CNAla production by marine bacteria. This is the first report on bacteria that produce CNAla without a supply of the cyanide ion in the medium.

  3. A consistent nomenclature of antimicrobial peptides isolated from frogs of the subfamily Phyllomedusinae.

    PubMed

    Amiche, Mohamed; Ladram, Ali; Nicolas, Pierre

    2008-11-01

    A growing number of cationic antimicrobial peptides have been isolated from the skin of hylid frogs belonging to the Phyllomedusinae subfamily. The amino acid sequences of these peptides are currently located in several databases under identifiers with no consistent system of nomenclature to describe them. In order to provide a workable terminology for antimicrobial peptides from Phyllomedusid frogs, we have made a systematic effort to collect, analyze, and classify all the Phyllomedusid peptide sequences available in databases. We propose that frogs belonging to the Phyllomedusinae subfamily should be described by the species names set out in Amphibian Species of the World: http://research.amnh.org/herpetology/amphibia/index.php, American Museum of Natural History, New York, USA. Multiple alignments analysis of at least 80 antimicrobial peptides isolated from 12 Phyllomedusinae species were distributed in seven distinct peptide families including dermaseptin, phylloseptin, plasticin, dermatoxin, phylloxin, hyposin and orphan peptides, and will be considered as the name of the headgroup of each family. The parent peptide's name should be followed by the first upper letter of the species for orthologous peptides and publication date determines priority. For example, the abbreviation B for bicolor and H for hypochondrialis. When two species begin with the same letter, two letters in upper case should be used (the first letter followed by the second or the third letter and so on). For example, the abbreviation DI for distincta, DU for duellmani, VA for vaillanti and VN for vanzolinii. Paralogous peptides should bear letter(s) in upper case followed by numbers.

  4. Drought, deluge and declines: the impact of precipitation extremes on amphibians in a changing climate

    USGS Publications Warehouse

    Walls, Susan C.; Barichivich, William J.; Brown, Mary E.

    2013-01-01

    The Class Amphibia is one of the most severely impacted taxa in an on-going global biodiversity crisis. Because amphibian reproduction is tightly associated with the presence of water, climatic changes that affect water availability pose a particularly menacing threat to both aquatic and terrestrial-breeding amphibians. We explore the impacts that one facet of climate change—that of extreme variation in precipitation—may have on amphibians. This variation is manifested principally as increases in the incidence and severity of both drought and major storm events. We stress the need to consider not only total precipitation amounts but also the pattern and timing of rainfall events. Such rainfall “pulses” are likely to become increasingly more influential on amphibians, especially in relation to seasonal reproduction. Changes in reproductive phenology can strongly influence the outcome of competitive and predatory interactions, thus potentially altering community dynamics in assemblages of co-existing species. We present a conceptual model to illustrate possible landscape and metapopulation consequences of alternative climate change scenarios for pond-breeding amphibians, using the Mole Salamander, Ambystoma talpoideum, as an example. Although amphibians have evolved a variety of life history strategies that enable them to cope with environmental uncertainty, it is unclear whether adaptations can keep pace with the escalating rate of climate change. Climate change, especially in combination with other stressors, is a daunting challenge for the persistence of amphibians and, thus, the conservation of global biodiversity.

  5. Parathyroid hormone-related protein in lower vertebrates.

    PubMed

    Ingleton, P M

    2002-05-01

    The genes for parathyroid hormone-related protein (PTHrP) have been cloned in two teleost fishes, cDNA of sea bream (Sparus aurata) and genomic DNA of puffer fish (Fugu rubripes). The gene sequences show that there is significant conservation of amino acid identity, with specific domains most highly conserved. The N-terminus, responsible for bone matrix lysis in mammals and chickens, is present in the fish genes with 52% sequence identity to higher vertebrate PTHrP peptides; the nuclear transporter region shares 73% identity, and the RNA-binding sequence is 65% identical. However, the peptides are shorter then mammalian PTHrP, lacking the C-terminus responsible for inhibition of osteoclast lytic activity, but they have an additional inserted sequence between amino acids 38 and 54 that is not present in higher vertebrate PTHrPs. The N-terminus 1-38 Fugu PTHrP proved to be hypercalcaemic in larval Sparus, suggesting that it may be a physiological regulator of calcium homeostasis in fish. Using homologous nucleotide probes for in situ hybridisation and reverse-transcription polymerase chain reaction (RT-PCR) of extracted RNA, PTHrP gene expression has been widely found in both developing and adult fish. Antiserum to the fish insert sequence demonstrated transcription of PTHrP in all stages of Sparus development, and also detected the same epitope in tissues of developing frog (Rana temporaria), indicating that this has been retained during evolution of the amphibia.

  6. Stepwise enrichment of 15N along food chains: Further evidence and the relation between δ 15N and animal age

    NASA Astrophysics Data System (ADS)

    Minagawa, Masao; Wada, Eitaro

    1984-05-01

    The isotopic composition of nitrogen was measured in marine and fresh-water animals from the East China Sea, The Bering Sea, Lake Ashinoko and Usujiri intertidal zone. Primary producers, showed average δ15Nversus atmospheric nitrogen of +5.0%. (+3.4 to +7.5) in the Bering Sea and Lake Ashinoko, and +6.8%. (+6.0 to +7.6) in Usujiri intertidal zone. Blue green algae from the East China Sea show an average -0.55%. (-0.8 to +1.2). All consumers, Zooplankton, fish and bird exhibited Stepwise enrichment of 15N with increasing trophic level. The 15N enrichment at a single feeding process ranged from +1.3 to +5.3 averaging +3.4 ± 1.1%.. This isotopic fractionation seems to be independent of habitat. The effect of age in animals was obtained by analyzing two marine mussels. The soft tissue nitrogen showed +2.0%. enrichment relative to that of primary producers, and the magnitude was almost constant with shell ages ranging from 0 to 8 years. A similar 15N enrichment occurs in all Molluscs, Crustaceans, Insecta, Amphibia, Fish, Ave and Mammal species regardless of the difference in the form of excreted nitrogen and in laboratory cultured fish, brine shrimp and mice (+2.9 to +4.9%.). The excreted ammonia from guppy was sufficiently light to balance the concentration of 15N to animal body.

  7. The 22 S cylinder particles of Xenopus laevis. II. Immunological characterization and localization of their proteins in tissues and cultured cells.

    PubMed

    Hügle, B; Kleinschmidt, J A; Franke, W W

    1983-11-01

    Cylinder-shaped particles of 10 nm diameter were isolated from nuclei of Xenopus laevis oocytes and purified by sucrose gradient centrifugation and DEAE-Sephacel chromatography. Antibodies to protein constituents of these isolated particles were elicited in guinea pigs and examined by immunoblotting and immunoprecipitation techniques as well as by immunofluorescence microscopy. The antibodies reacted with only two out of the 12 constituent polypeptides characteristic for these particles when examined in the denatured state by the immunoblotting technique, including the largest component of Mr 30 000, but were able to precipitate the whole ensemble of these polypeptides in immunoprecipitation experiments, in agreement with the notion that these proteins form the 22 S particle complex. The antibodies displayed a rather narrow range of interspecies cross-reactivity, showing reaction with cells of other amphibia but not with avian and mammalian cells. In oocytes as well as in transcriptionally active somatic cells the antigen was localized in the nucleoplasm, excluding nucleoli, as well as in the cytoplasm, usually suggesting a higher concentration in the nucleoplasm. During mitosis, the proteins were dispersed throughout the cytoplasm whereas the chromosomes were negative. Inactive cells such as mature erythrocytes, spermatids and spermatozoa were negative. These immunolocalization findings support our conclusion based on fractionation studies that the cylindershaped particles and their protein constituents occur both in the nucleoplasm and the cytoplasm of a broad range of cell types.(ABSTRACT TRUNCATED AT 250 WORDS)

  8. β-Cyanoalanine Production by Marine Bacteria on Cyanide-Free Medium and Its Specific Inhibitory Activity toward Cyanobacteria

    PubMed Central

    Yoshikawa, Kazuhiro; Adachi, Kyoko; Nishijima, Miyuki; Takadera, Takahide; Tamaki, Seiji; Harada, Ken-ichi; Mochida, Kenichi; Sano, Hiroshi

    2000-01-01

    In screening the culture broth of marine bacteria collected at Yap (Micronesia), Palau (Belau), and Okinawa (the southwest islands of Japan) for antimicroalgal activity, 37 out of 2,594 bacterial isolates tested were found to produce anticyanobacterial substances against Oscillatoria amphibia NIES-361. One strain, C-979, identified as a Vibrio sp., was selected and cultured in 2.4 liters of marine broth 2216 to identify the bioactive compound produced by the strain. The purified very hydrophilic compound (16.4 mg) was determined to be β-cyano-l-alanine (l-CNAla) by instrumental analyses and the application of the advanced Marfey method. l-CNAla did not inhibit the growth of bacteria, yeast, or eukaryotic microalgae, but some cyanobacteria were found to be sensitive to l-CNAla at a concentration of 0.4 to 25 μg/ml. The effect of l-CNAla on some other environmental organisms, including invertebrates and a macroalgae, is discussed. CNAla production in marine broth was examined by thin-layer chromatography for the 37 bacterial isolates which produced an anticyanobacterial substance. The broth of 36 of these strains contained CNAla, suggesting the wide distribution of CNAla production by marine bacteria. This is the first report on bacteria that produce CNAla without a supply of the cyanide ion in the medium. PMID:10653741

  9. Calcium Binding and Disulfide Bonds Regulate the Stability of Secretagogin towards Thermal and Urea Denaturation

    PubMed Central

    Weiffert, Tanja; Ní Mhurchú, Niamh; O’Connell, David; Linse, Sara

    2016-01-01

    Secretagogin is a calcium-sensor protein with six EF-hands. It is widely expressed in neurons and neuro-endocrine cells of a broad range of vertebrates including mammals, fishes and amphibia. The protein plays a role in secretion and interacts with several vesicle-associated proteins. In this work, we have studied the contribution of calcium binding and disulfide-bond formation to the stability of the secretagogin structure towards thermal and urea denaturation. SDS-PAGE analysis of secretagogin in reducing and non-reducing conditions identified a tendency of the protein to form dimers in a redox-dependent manner. The denaturation of apo and Calcium-loaded secretagogin was studied by circular dichroism and fluorescence spectroscopy under conditions favoring monomer or dimer or a 1:1 monomer: dimer ratio. This analysis reveals significantly higher stability towards urea denaturation of Calcium-loaded secretagogin compared to the apo protein. The secondary and tertiary structure of the Calcium-loaded form is not completely denatured in the presence of 10 M urea. Reduced and Calcium-loaded secretagogin is found to refold reversibly after heating to 95°C, while both oxidized and reduced apo secretagogin is irreversibly denatured at this temperature. Thus, calcium binding greatly stabilizes the structure of secretagogin towards chemical and heat denaturation. PMID:27812162

  10. Reflections on a systematic nomenclature for antimicrobial peptides from the skins of frogs of the family Ranidae.

    PubMed

    Conlon, J Michael

    2008-10-01

    Frogs belonging to the extensive family Ranidae represent a valuable source of antimicrobial peptides with therapeutic potential but there is currently no consistent system of nomenclature to describe these peptides. Terminology based solely on species name does not reflect the evolutionary relationships existing between peptides encoded by orthologous and paralogous genes. On the basis of limited structural similarity, at least 14 well-established peptide families have been identified (brevinin-1, brevinin-2, esculentin-1, esculentin-2, japonicin-1, japonicin-2, nigrocin-2, palustrin-1, palustrin-2, ranacyclin, ranalexin, ranatuerin-1, ranatuerin-2, temporin). It is proposed that terms that are synonymous with these names should no longer be used. Orthologous peptides from different species may be characterized by the initial letter of that species, set in upper case, with paralogs belonging to the same peptide family being assigned letters set in lower case, e.g. brevinin-1Pa, brevinin-1Pb, etc. When two species begin with the same initial letter, two letters may be used, e.g. P for pipiens and PL for palustris. Species names and assignments to genera may be obtained from Amphibian Species of the World Electronic Database, accessible at http://research.amnh.org/herpetology/amphibia/index.php. American Museum of Natural History, New York, USA.

  11. Symbiotic fermentation, digesta passage, and gastrointestinal morphology in bullfrog tadpoles (Rana catesbeiana).

    PubMed

    Pryor, Gregory S; Bjorndal, Karen A

    2005-01-01

    Relative to other herbivorous vertebrates, the nutritional ecology and digestive physiology of anuran larvae remain poorly understood. Our objective was to compare gut structure and inhabitants, digesta passage, and microbial fermentation in bullfrog tadpoles (Rana catesbeiana) to those in other herbivores. Bullfrog tadpole gastrointestinal tracts were long and voluminous, with an enlarged colon that harbored a diverse symbiotic community. The transit time for particulate markers passing through bullfrog tadpoles was 6 h, the median retention time was 8-10 h, and gut clearance was 10-14 h postingestion. Relatively high levels of short-chain fatty acids in the hindgut of tadpoles indicated active microbial fermentation in this gut region. This report represents the first account of gastrointestinal fermentation in the class Amphibia. On the basis of in vitro fermentation assays, we estimated that microbial fermentation in the hindgut provides 20% of the total daily energy requirement of bullfrog tadpoles. These tadpoles also exhibited coprophagy, a practice that provides important nutritive gains in other herbivores. The physiological and behavioral characteristics of these tadpoles are remarkably similar to those of other small-bodied, hindgut-fermenting vertebrates, suggesting convergent digestive strategies among a broad range of herbivorous taxa.

  12. [Articles published in the Archives d'Anatomie, d'Histologie et d'Embryologie from volume 1 (1922) to volume 74 (1991-92)].

    PubMed

    Le Minor, J M

    Three anatomists followed one another as Chief Editor of the Archives: Professor A. Forster (Strasbourg) from volume 1 (1922) to volume 29 (1940), Professor G. Winckler (Lausanne) from volume 40 (1957) to volume 53 (1970), and Professor J. G. Koritké (Strasbourg) from volume 54 (1971) to volume 74 (1991-92). From the outset, the Archives received papers from distinguished French and foreign anatomists. The Archives also constitute, since their origin, one of the preferential organs of expression for the Strasbourgian morphological works. All fields of morphology are represented. All zoological groups are concerned, some Invertebrates, but principally Vertebrates: Fishes, Amphibia, Reptiles, Birds, and Mammals amongst which the human species occupies a priviliged place. A total of 938 papers has been published in the Archives. Most papers are in French (833 i.e. 89.0%). Papers in English (89 i.e. 9.5%) are more numerous in the most recent volumes; other papers are in Italian (11 i.e. 1.0%) and in German (5 i.e. 0.5%).

  13. Evolutionary cytogenetics in salamanders.

    PubMed

    Sessions, Stanley K

    2008-01-01

    Salamanders (Amphibia: Caudata/Urodela) have been the subject of numerous cytogenetic studies, and data on karyotypes and genome sizes are available for most groups. Salamanders show a more-or-less distinct dichotomy between families with large chromosome numbers and interspecific variation in chromosome number, relative size, and shape (i.e. position of the centromere), and those that exhibit very little variation in these karyological features. This dichotomy is the basis of a major model of karyotype evolution in salamanders involving a kind of 'karyotypic orthoselection'. Salamanders are also characterized by extremely large genomes (in terms of absolute mass of nuclear DNA) and extensive variation in genome size (and overall size of the chromosomes), which transcends variation in chromosome number and shape. The biological significance and evolution of chromosome number and shape within the karyotype is not yet understood, but genome size variation has been found to have strong phenotypic, biogeographic, and phylogenetic correlates that reveal information about the biological significance of this cytogenetic variable. Urodeles also present the advantage of only 10 families and less than 600 species, which facilitates the analysis of patterns within the entire order. The purpose of this review is to present a summary of what is currently known about overall patterns of variation in karyology and genome size in salamanders. These patterns are discussed within an evolutionary context.

  14. Genetic analysis of dorsoventral pattern formation in the zebrafish: requirement of a BMP-like ventralizing activity and its dorsal repressor.

    PubMed

    Hammerschmidt, M; Serbedzija, G N; McMahon, A P

    1996-10-01

    According to a model based on embryological studies in amphibia, dorsoventral patterning is regulated by the antagonizing function of ventralizing bone morphogenetic proteins (BMPs) and dorsalizing signals generated by Spemann's organizer. Large-scale mutant screens in the zebrafish, Danio rerio, have led to the isolation of two classes of recessive lethal mutations affecting early dorsoventral pattern formation. dino mutant embryos are ventralized, whereas swirl mutants are dorsalized. We show that at early gastrula stages, dino and swirl mutants display an expanded or reduced Bmp4 expression, respectively. The dino and swirl mutant phenotypes both can be phenocopied and rescued by the modulation of BMP signaling in wild-type and mutant embryos. By suppressing BMP signaling in dino mutants, adult fertile dino -/- fish were generated. These findings, together with results from the analysis of dino-swirl double mutants, indicate that dino fulfills its dorsalizing activity via a suppression of swirl-dependent, BMP-like ventralizing activities. Finally, cell transplantation experiments show that dino is required on the dorsal side of early gastrula embryos and acts in a non-cell-autonomous fashion. Together, these results provide genetic evidence in support of a mechanism of early dorsoventral patterning that is conserved among vertebrate and invertebrate embryos.

  15. Complete nucleotide sequence of the mitochondrial genome of a salamander, Mertensiella luschani.

    PubMed

    Zardoya, Rafael; Malaga-Trillo, Edward; Veith, Michael; Meyer, Axel

    2003-10-23

    The complete nucleotide sequence (16,650 bp) of the mitochondrial genome of the salamander Mertensiella luschani (Caudata, Amphibia) was determined. This molecule conforms to the consensus vertebrate mitochondrial gene order. However, it is characterized by a long non-coding intervening sequence with two 124-bp repeats between the tRNA(Thr) and tRNA(Pro) genes. The new sequence data were used to reconstruct a phylogeny of jawed vertebrates. Phylogenetic analyses of all mitochondrial protein-coding genes at the amino acid level recovered a robust vertebrate tree in which lungfishes are the closest living relatives of tetrapods, salamanders and frogs are grouped together to the exclusion of caecilians (the Batrachia hypothesis) in a monophyletic amphibian clade, turtles show diapsid affinities and are placed as sister group of crocodiles+birds, and the marsupials are grouped together with monotremes and basal to placental mammals. The deduced phylogeny was used to characterize the molecular evolution of vertebrate mitochondrial proteins. Amino acid frequencies were analyzed across the main lineages of jawed vertebrates, and leucine and cysteine were found to be the most and least abundant amino acids in mitochondrial proteins, respectively. Patterns of amino acid replacements were conserved among vertebrates. Overall, cartilaginous fishes showed the least variation in amino acid frequencies and replacements. Constancy of rates of evolution among the main lineages of jawed vertebrates was rejected.

  16. The general ultrastructure of the carotid body of the domestic fowl.

    PubMed

    Hodges, R D; King, A S; King, D Z; French, E I

    1975-10-27

    Electron microscopic studies of the carotid body of the domestic fowl (Gallus gallus domesticus) have shown Type I and Type II cells combined with axons into compact groups. The many Type I cells in the depths of the organ had a body, containing the nucleus, and an elongated, flared process. Some of the Type I cells in the superficial regions tended to be spindle-shaped. Type I cells were characterised by membrane-bound, dense-cored vesicles about 120 nm in diameter. Type II cells invested the Type I cells and had axons embedded in them as in Schwann cells. The fine structure of the carotid body in the domestic fowl resembles that of the Lovebird (Uroloncha domestica) and of various amphibia and mammals. The possibility is discussed that the Type I cells may have a chemoreceptor or a general secretory function, or even both of these axons leading to or from Type I cells. The main role of the Type II cells seems to be to provide a pathway for functions together.

  17. Biogeographical consequences of Cenozoic tectonic events within East Asian margins: a case study of Hynobius biogeography.

    PubMed

    Li, Jun; Fu, Cuizhang; Lei, Guangchun

    2011-01-01

    Few studies have explored the role of Cenozoic tectonic evolution in shaping patterns and processes of extant animal distributions within East Asian margins. We select Hynobius salamanders (Amphibia: Hynobiidae) as a model to examine biogeographical consequences of Cenozoic tectonic events within East Asian margins. First, we use GenBank molecular data to reconstruct phylogenetic interrelationships of Hynobius by bayesian and maximum likelihood analyses. Second, we estimate the divergence time using the bayesian relaxed clock approach and infer dispersal/vicariance histories under the 'dispersal-extinction-cladogenesis' model. Finally, we test whether evolutionary history and biogeographical processes of Hynobius should coincide with the predictions of two major hypotheses (the 'vicariance'/'out of southwestern Japan' hypothesis). The resulting phylogeny confirmed Hynobius as a monophyletic group, which could be divided into nine major clades associated with six geographical areas. Our results show that: (1) the most recent common ancestor of Hynobius was distributed in southwestern Japan and Hokkaido Island, (2) a sister taxon relationship between Hynobius retardatus and all remaining species was the results of a vicariance event between Hokkaido Island and southwestern Japan in the Middle Eocene, (3) ancestral Hynobius in southwestern Japan dispersed into the Taiwan Island, central China, 'Korean Peninsula and northeastern China' as well as northeastern Honshu during the Late Eocene-Late Miocene. Our findings suggest that Cenozoic tectonic evolution plays an important role in shaping disjunctive distributions of extant Hynobius within East Asian margins.

  18. Biogeographical Consequences of Cenozoic Tectonic Events within East Asian Margins: A Case Study of Hynobius Biogeography

    PubMed Central

    Li, Jun; Fu, Cuizhang; Lei, Guangchun

    2011-01-01

    Few studies have explored the role of Cenozoic tectonic evolution in shaping patterns and processes of extant animal distributions within East Asian margins. We select Hynobius salamanders (Amphibia: Hynobiidae) as a model to examine biogeographical consequences of Cenozoic tectonic events within East Asian margins. First, we use GenBank molecular data to reconstruct phylogenetic interrelationships of Hynobius by Bayesian and maximum likelihood analyses. Second, we estimate the divergence time using the Bayesian relaxed clock approach and infer dispersal/vicariance histories under the ‘dispersal–extinction–cladogenesis’ model. Finally, we test whether evolutionary history and biogeographical processes of Hynobius should coincide with the predictions of two major hypotheses (the ‘vicariance’/‘out of southwestern Japan’ hypothesis). The resulting phylogeny confirmed Hynobius as a monophyletic group, which could be divided into nine major clades associated with six geographical areas. Our results show that: (1) the most recent common ancestor of Hynobius was distributed in southwestern Japan and Hokkaido Island, (2) a sister taxon relationship between Hynobius retardatus and all remaining species was the results of a vicariance event between Hokkaido Island and southwestern Japan in the Middle Eocene, (3) ancestral Hynobius in southwestern Japan dispersed into the Taiwan Island, central China, ‘Korean Peninsula and northeastern China’ as well as northeastern Honshu during the Late Eocene–Late Miocene. Our findings suggest that Cenozoic tectonic evolution plays an important role in shaping disjunctive distributions of extant Hynobius within East Asian margins. PMID:21738684

  19. Cenoses of phototrophic algae of ultrasaline lakes in the Kulunda steppe (Altai krai, Russian Federation)

    NASA Astrophysics Data System (ADS)

    Sapozhnikov, Ph. V.; Kalinina, O. Yu.; Nikitin, M. A.; Samylina, O. S.

    2016-01-01

    In 2012, expeditions of the Institute of Microbiology, Russian Academy of Sciences, delivered samples of algo-bacterial mats from Kulunda steppe alkaline lakes (Petukhovskoe alkaline lake, Tanatar VI, and Gorchina III). The filamentous alga Ctenocladus circinnatus (Chlorophyta) acted as an edificator of the mats. The composition of cenoses algocomponents also included chlorophytes Dunaliella viridis and Picocystis salinarum as well as diatoms Anomeoneis sphaerophora, Brachysira brebissonii, B. zellensis, Mastogloia pusilla var. subcapitata, Nitzschia amphibia, N. cf. communis, and Nitzschia sp. 1. The composition and structure of phototrophic algae cenoses (including diatom taxocenes) were described for the investigated lakes for the first time. For the period from 2011 to 2012, the total mineralization significantly increased in lakes. This involved sensible alterations of cenoses. B. zellensis was the most permanent component of diatom taxocenes in both seasons. In the summer of 2011, it was often accompanied by A. sphaerophora and B. brebissonii. In the summer of 2012, A. sphaerophora was found only singularly in Lake Gorchina III, and some biotopes of Lake Tanatar VI were massively inhabited by N. cf. communis, including colonies that had not been previously described for the species. The genetic analysis of three diatoms, which are markedly different from each other in their appearance and were sampled from different lakes but were all determined as Nitzschia cf. communis, showed their complete similarity to each other with the 18S rRNA gene fragment and the highest similarity of all the three diatoms with the species Nitzschia communis.

  20. Introduction of Trojan sex chromosomes to boost population growth.

    PubMed

    Cotton, Samuel; Wedekind, Claus

    2007-11-07

    Conservation programs that deal with small or declining populations often aim at a rapid increase of population size to above-critical levels in order to avoid the negative effects of demographic stochasticity and genetic problems like inbreeding depression, fixation of deleterious alleles, or a general loss of genetic variability and hence of evolutionary potential. In some situations, population growth is determined by the number of females available for reproduction, and manipulation of family sex ratios towards more daughters has beneficial effects. If sex determination is predominantly genetic but environmentally reversible, as is the case in many amphibia, reptiles, and fish, Trojan sex chromosomes could be introduced into populations in order to change sex ratios towards more females. We analyse the possible consequences for the introduction of XX-males (XX individuals that have been changed to phenotypic males in a XY/XX sex determination system) and ZW males, WW males, or WW females (in a ZZ/ZW sex determination system). We find that the introduction of WW individuals can be most effective for an increase of population growth, especially if the induced sex change has little or no effect on viability.

  1. Environmental sex reversal, Trojan sex genes, and sex ratio adjustment: conditions and population consequences.

    PubMed

    Stelkens, Rike B; Wedekind, Claus

    2010-02-01

    The great diversity of sex determination mechanisms in animals and plants ranges from genetic sex determination (GSD, e.g. mammals, birds, and most dioecious plants) to environmental sex determination (ESD, e.g. many reptiles) and includes a mixture of both, for example when an individual's genetically determined sex is environmentally reversed during ontogeny (ESR, environmental sex reversal, e.g. many fish and amphibia). ESD and ESR can lead to widely varying and unstable population sex ratios. Populations exposed to conditions such as endocrine-active substances or temperature shifts may decline over time due to skewed sex ratios, a scenario that may become increasingly relevant with greater anthropogenic interference on watercourses. Continuous exposure of populations to factors causing ESR could lead to the extinction of genetic sex factors and may render a population dependent on the environmental factors that induce the sex change. However, ESR also presents opportunities for population management, especially if the Y or W chromosome is not, or not severely, degenerated. This seems to be the case in many amphibians and fish. Population growth or decline in such species can potentially be controlled through the introduction of so-called Trojan sex genes carriers, individuals that possess sex chromosomes or genes opposite from what their phenotype predicts. Here, we review the conditions for ESR, its prevalence in natural populations, the resulting physiological and reproductive consequences, and how these may become instrumental for population management.

  2. Ecological risk assessment of endocrine disruptors.

    PubMed Central

    Hutchinson, T H; Brown, R; Brugger, K E; Campbell, P M; Holt, M; Länge, R; McCahon, P; Tattersfield, L J; van Egmond, R

    2000-01-01

    The European Centre for Ecotoxicology and Toxicology of Chemicals proposes a tiered approach for the ecological risk assessment of endocrine disruptors, integrating exposure and hazard (effects) characterization. Exposure assessment for endocrine disruptors should direct specific tests for wildlife species, placing hazard data into a risk assessment context. Supplementing the suite of mammalian screens now under Organization for Economic Cooperation and Development (OECD) validation, high priority should be given to developing a fish screening assay for detecting endocrine activity in oviparous species. Taking into account both exposure characterization and alerts from endocrine screening, higher tier tests are also a priority for defining adverse effects. We propose that in vivo mammalian and fish assays provide a comprehensive screening battery for diverse hormonal functions (including androgen, estrogen, and thyroid hormone), whereas Amphibia should be considered at higher tiers if there are exposure concerns. Higher tier endocrine-disruptor testing should include fish development and fish reproduction tests, whereas a full life-cycle test could be subsequently used to refine aquatic risk assessments when necessary. For avian risk assessment, the new OECD Japanese quail reproduction test guideline provides a valuable basis for developing a test to detecting endocrine-mediated reproductive effects; this species could be used, where necessary, for an avian life-cycle test. For aquatic and terrestrial invertebrates, data from existing developmental and reproductive tests remain of high value for ecological risk assessment. High priority should be given to research into comparative endocrine physiology of invertebrates to support data extrapolation to this diverse fauna. PMID:11102288

  3. Phylogenetically-informed priorities for amphibian conservation.

    PubMed

    Isaac, Nick J B; Redding, David W; Meredith, Helen M; Safi, Kamran

    2012-01-01

    The amphibian decline and extinction crisis demands urgent action to prevent further large numbers of species extinctions. Lists of priority species for conservation, based on a combination of species' threat status and unique contribution to phylogenetic diversity, are one tool for the direction and catalyzation of conservation action. We describe the construction of a near-complete species-level phylogeny of 5713 amphibian species, which we use to create a list of evolutionarily distinct and globally endangered species (EDGE list) for the entire class Amphibia. We present sensitivity analyses to test the robustness of our priority list to uncertainty in species' phylogenetic position and threat status. We find that both sources of uncertainty have only minor impacts on our 'top 100' list of priority species, indicating the robustness of the approach. By contrast, our analyses suggest that a large number of Data Deficient species are likely to be high priorities for conservation action from the perspective of their contribution to the evolutionary history.

  4. Variation of osteocyte lacunae size within the tetrapod skeleton: implications for palaeogenomics.

    PubMed

    Montanari, Shaena; Brusatte, Stephen L; De Wolf, Wendy; Norell, Mark A

    2011-10-23

    Recent studies have emphasized the ability to reconstruct genome sizes (C-values) of extinct organisms such as dinosaurs, using correlations between known genome sizes and bone cell (osteocyte lacunae) volumes. Because of the established positive relationship between cell size and genome size in extant vertebrates, osteocyte lacunae volume is a viable proxy for reconstructing C-values in the absence of any viable genetic material. However, intra-skeletal osteocyte lacunae size variation, which could cause error in genome size estimation, has remained unexplored. Here, 11 skeletal elements of one individual from each of four major clades (Mammalia, Amphibia, Aves, Reptilia) were examined histologically. Skeletal elements in all four clades exhibit significant differences in the average sizes of their lacunae. This variation, however, generally does not cause a significant difference in the estimated genome size when common phylogenetic estimation methods are employed. On the other hand, the spread of the estimations illustrates that this method may not be precise. High variance in genome size estimations remains an outstanding problem. Additionally, a suite of new methods is introduced to further automate the measurement of bone cells and other microstructural features on histological thin sections.

  5. Structural diversity of the ordinary and specialized lateral line organs.

    PubMed

    Cernuda-Cernuda, R; García-Fernández, J M

    1996-07-01

    Lateral line organ, a superficial sensory system in amphibia and fish which provides the animal with information about its surrounding environment, is divided classically into two main different types, ordinary and specialized, whose functions are mechanoreceptive and electroreceptive, respectively. Although it has great diversity, the basic sensory unit, which is usually called "neuromast," is composed of sensory cells embedded in accessory cells. The functions of the latter are to support the sensory cells and to secrete the material that covers the organs, forming a cupular structure or filling a canal which enables the organ to communicate with the exterior. Sensory cells of mechanoreceptive neuromasts have a tuft of processes included in the cupular material; these are a kinocilium and a group of stereocilia with a typical staircase arrangement. The displacement of the stereocilia towards or away from the kinocilium produces different stimuli. The electroreceptive organs are more diverse. They include ampullary and tuberous organs. The latter can be subdivided into different types: knollenorgans, mormyromasts, gymnarchomasts, etc. All of these present a great diversity among species, but their morphology is less reported than that of the mechanoreceptive organs. This paper summarizes the structural features of the main different types of lateral line organs, as well as their taxonomic distribution and different patterns of distribution along the surface of the animal.

  6. Proteome analysis of the liver in the Chinese fire-bellied newt Cynops orientalis.

    PubMed

    Zang, X Y; Guo, J L; Geng, X F; Li, P F; Sun, J Y; Wang, Q W; Xu, C S

    2016-08-12

    The Chinese fire-bellied newt, Cynops orientalis, belonging to Amphibia, Caudata, Salamandridae is a species endemic to China. The liver, which is an important digestive gland and the largest amphibian organ, has various functions, including detoxification, glycogen storage, protein synthesis, and hormone production. However, the newt liver has rarely been studied at the molecular level. We performed histomorphology and high-throughput proteomic analysis of the Chinese fire-bellied newt liver, using hematoxylin and eosin (H&E) staining and two-dimensional electrophoresis coupled with mass spectrometry. The H&E staining showed that the newt liver nuclei are large and round, are located in the lateral cytoplasm, and contain a large quantity of lipid droplets. Melanins were abundantly present throughout the hepatic parenchyma. The proteome analysis showed a total of 545 proteins detected in the newt liver. Furthermore, a gene ontology analysis suggested that these proteins were associated with metabolism, immune response, cellular homeostasis, etc. Among these, proteins with metabolic functions were found to be the most abundant and highly expressed. This supports the role of the liver as the metabolic center. The proteomic results provide new insights into the aspects of the liver proteomes of the Chinese fire-bellied newt. The identification of a more global liver proteome in the newt may provide a basis for characterizing and comparing the liver proteomes from other amphibian species.

  7. Drought, deluge and declines: the impact of precipitation extremes on amphibians in a changing climate.

    PubMed

    Walls, Susan C; Barichivich, William J; Brown, Mary E

    2013-03-11

    The Class Amphibia is one of the most severely impacted taxa in an on-going global biodiversity crisis. Because amphibian reproduction is tightly associated with the presence of water, climatic changes that affect water availability pose a particularly menacing threat to both aquatic and terrestrial-breeding amphibians. We explore the impacts that one facet of climate change-that of extreme variation in precipitation-may have on amphibians. This variation is manifested principally as increases in the incidence and severity of both drought and major storm events. We stress the need to consider not only total precipitation amounts but also the pattern and timing of rainfall events. Such rainfall "pulses" are likely to become increasingly more influential on amphibians, especially in relation to seasonal reproduction. Changes in reproductive phenology can strongly influence the outcome of competitive and predatory interactions, thus potentially altering community dynamics in assemblages of co-existing species. We present a conceptual model to illustrate possible landscape and metapopulation consequences of alternative climate change scenarios for pond-breeding amphibians, using the Mole Salamander, Ambystoma talpoideum, as an example. Although amphibians have evolved a variety of life history strategies that enable them to cope with environmental uncertainty, it is unclear whether adaptations can keep pace with the escalating rate of climate change. Climate change, especially in combination with other stressors, is a daunting challenge for the persistence of amphibians and, thus, the conservation of global biodiversity.

  8. Evolution of the Vertebrate Resistin Gene Family.

    PubMed

    Hu, Qingda; Tan, Huanran; Irwin, David M

    2015-01-01

    Resistin (encoded by Retn) was previously identified in rodents as a hormone associated with diabetes; however human resistin is instead linked to inflammation. Resistin is a member of a small gene family that includes the resistin-like peptides (encoded by Retnl genes) in mammals. Genomic searches of available genome sequences of diverse vertebrates and phylogenetic analyses were conducted to determine the size and origin of the resistin-like gene family. Genes encoding peptides similar to resistin were found in Mammalia, Sauria, Amphibia, and Actinistia (coelacanth, a lobe-finned fish), but not in Aves or fish from Actinopterygii, Chondrichthyes, or Agnatha. Retnl originated by duplication and transposition from Retn on the early mammalian lineage after divergence of the platypus, but before the placental and marsupial mammal divergence. The resistin-like gene family illustrates an instance where the locus of origin of duplicated genes can be identified, with Retn continuing to reside at this location. Mammalian species typically have a single copy Retn gene, but are much more variable in their numbers of Retnl genes, ranging from 0 to 9. Since Retn is located at the locus of origin, thus likely retained the ancestral expression pattern, largely maintained its copy number, and did not display accelerated evolution, we suggest that it is more likely to have maintained an ancestral function, while Retnl, which transposed to a new location, displays accelerated evolution, and shows greater variability in gene number, including gene loss, likely evolved new, but potentially lineage-specific, functions.

  9. Kallikrein generates angiotensin II but not bradykinin in the plasma of the urodele, Amphiuma tridactylum.

    PubMed

    Conlon, J M; Yano, K

    1995-03-01

    Incubation of heat-denatured plasma from the urodele, Amphiuma tridactylum (three-toed amphiuma) or from the anurans Rana ridibunda (European green frog) and Rana catesbeiana (American bullfrog) with either glass beads, porcine pancreatic kallikrein or trypsin did not generate bradykinin-like immunoreactivity. However, peptides were generated in kallikrein-treated amphiuma plasma that contracted vascular rings from the bullfrog systemic arch and had a spasmogenic action on the bullfrog urinary bladder. These peptides which were not generated in trypsin-treated plasma, were purified to homogeneity by reverse-phase HPLC and their primary structures established as: Asp-Arg-Val-Tyr-Val-His-Pro-Phe ([Asp1,Val5]angiotensin II) and Asn-Arg-Val-Tyr-Val-His-Pro-Phe ([Asn1,Val5]angiotensin II). Incubation of synthetic [Asn1,Val5]angiotensin II with amphiuma plasma resulted in deamidation to [Asp1,Val5]angiotensin II. The data suggest, therefore that amphiuma plasma contains an L-asparagine amidohydrolase (asparaginase), as previously described for the eel. Although bradykinin-related peptides have been isolated from frog skin, this study provides evidence tha the kallikrein-kinin system may be absent from the blood of amphibia.

  10. The area composita of adhering junctions connecting heart muscle cells of vertebrates. I. Molecular definition in intercalated disks of cardiomyocytes by immunoelectron microscopy of desmosomal proteins.

    PubMed

    Franke, Werner W; Borrmann, Carola M; Grund, Christine; Pieperhoff, Sebastian

    2006-02-01

    Among sarcomeric muscles the cardiac muscle cells are unique by, inter alia, a systemic and extended cell-cell contact structure, the intercalated disk (ID), comprising frequent and closely spaced arrays of plaque-coated cell-cell adhering junctions (AJs). As some of these junctions may look somewhat like desmosomes and others like fasciae adhaerentes, the dogma has emerged in the literature that IDs contain - like epithelial cells - both kinds of AJs formed by - for the most - mutually exclusive molecular ensembles. This, however, is not the case. In comprehensive immunoelectron microscopic studies of mammalian (human, bovine, rat, mouse) and non-mammalian (chicken, amphibia, fishes) heart muscle tissues, we have localized major constituents of the desmosomal plaques of polar epithelia, desmoplakin, plakophilin-2 and plakoglobin, as well as the desmosomal cadherins, desmoglein Dsg2 and desmocollin Dsc2, in both kinds of ID AJs, independent of the specific morphological appearance. The desmosomal molecules are not restricted to the desmosome-like-looking junctions but can also be detected in junctions appearing similar to the zonula or fascia adhaerens structures. These AJs of cardiac ID are therefore subsumed under the collective term area composita. We discuss our results with respect to the importance of ID junction molecules for the formation, maintenance and function of the heart, particularly in relation to recent findings that deletions of - or mutations in - genes encoding such proteins can cause severe, sometimes lethal damages.

  11. A neural network dynamics that resembles protein evolution

    NASA Astrophysics Data System (ADS)

    Ferrán, Edgardo A.; Ferrara, Pascual

    1992-06-01

    We use neutral networks to classify proteins according to their sequence similarities. A network composed by 7 × 7 neurons, was trained with the Kohonen unsupervised learning algorithm using, as inputs, matrix patterns derived from the bipeptide composition of cytochrome c proteins belonging to 76 different species. As a result of the training, the network self-organized the activation of its neurons into topologically ordered maps, wherein phylogenetically related sequences were positioned close to each other. The evolution of the topological map during learning, in a representative computational experiment, roughly resembles the way in which one species evolves into several others. For instance, sequences corresponding to vertebrates, initially grouped together into one neuron, were placed in a contiguous zone of the final neural map, with sequences of fishes, amphibia, reptiles, birds and mammals associated to different neurons. Some apparent wrong classifications are due to the fact that some proteins have a greater degree of sequence identity than the one expected by phylogenetics. In the final neural map, each synaptic vector may be considered as the pattern corresponding to the ancestor of all the proteins that are attached to that neuron. Although it may be also tempting to link real time with learning epochs and to use this relationship to calibrate the molecular evolutionary clock, this is not correct because the evolutionary time schedule obtained with the neural network depends highly on the discrete way in which the winner neighborhood is decreased during learning.

  12. Illumination controls differentiation of dopamine neurons regulating behaviour.

    PubMed

    Dulcis, Davide; Spitzer, Nicholas C

    2008-11-13

    Specification of the appropriate neurotransmitter is a crucial step in neuronal differentiation because it enables signalling among populations of neurons. Experimental manipulations demonstrate that both autonomous and activity-dependent genetic programs contribute to this process during development, but whether natural environmental stimuli specify transmitter expression in a neuronal population is unknown. We investigated neurons of the ventral suprachiasmatic nucleus that regulate neuroendocrine pituitary function in response to light in teleosts, amphibia and primates. Here we show that altering light exposure, which changes the sensory input to the circuit controlling adaptation of skin pigmentation to background, changes the number of neurons expressing dopamine in larvae of the amphibian Xenopus laevis in a circuit-specific and activity-dependent manner. Neurons newly expressing dopamine then regulate changes in camouflage colouration in response to illumination. Thus, physiological activity alters the numbers of behaviourally relevant amine-transmitter-expressing neurons in the brain at postembryonic stages of development. The results may be pertinent to changes in cognitive states that are regulated by biogenic amines.

  13. Response of a phytoplanktonic assemblage to copper and zinc enrichment in microcosm.

    PubMed

    Pandey, Lalit K; Han, T; Gaur, J P

    2015-04-01

    The response of a laboratory-raised phytoplankton assemblage to copper and zinc enrichment was studied. Higher intracellular accumulation of both the test metals caused disappearance of metal sensitive species, loss of diversity and species richness, reduced growth rate, Chl a and biovolume; however, the community could recover after 14 days of incubation. Cyanobacteria showed marked sensitivity to both the test metals besides some diatoms, such as, Cyclotella meneghiniana and Melosira granulata. Metal enrichment enhanced the relative abundance of species like Scenedesmus quadricauda, Oocystis borgei, Achnanthes exigua, Fragilaria capucina and Nitzschia amphibia, and these were apparently metal tolerant. Cu and Zn stress induces formation of lipid bodies (bigger in size as well as in number) and morphological abnormalities in diatoms. Among these two metals, Cu impact was higher than Zn despite the fact that the intracellular accumulation of Zn was higher than Cu. Deformed raphe and mixed deformities in diatoms were exclusively found under heavy metal stress which was well supported by regression analysis. Finally the present study gives new insight for using diatoms as an effective tool for biomonitoring and biofuel production.

  14. Water quality assessment of the Sinchun stream based on epilithic diatom communities.

    PubMed

    Park, Yeon Jeong; Choi, Jae Sin; Kim, Han Soon

    2014-11-01

    Water quality was assessed 11 sites on the Sinchun Stream, in the region of Daegu City (South Korea), from May 2007 to March 2008 using Diatom Assemblage Index to Organic Water Pollution (DAIpo) and Trophic Diatom Index (TDI). The reference sites were unaffected by effluent from a closed mine or treated sewage and had, epilithic diatom communities that were dominated by saproxenous taxa such as Achnanthes convergens and Cocconeisplacentula var. lineata. The water quality of these sites had DAIpo values ranging between 77.5-93.8 and TDI values between 51.3-67.6, indicating β-oligosaprobic and mesotrophic environments, respectively. Study sites affected by effluent from the closed mine had epilithic diatom communities that were dominated by acidobiontic diatoms, such as Eunotia exigua and Achnanthidium minutissimum. The water quality of these sites had DAlpo values of 45.9-70.8, indicating β-mesosaprobic to α-oligosaprobic environments, whereas TDI ranged between 1.7-66.9, indicating an oligotrophic to mesotrophic environment. Downstream sites affected by the influx of mine effluent and treated sewage had many species and a high percentage of saprophilous taxa, including Fragilaria construens var. venter and Nitzschia amphibia. The water quality of these regions had DAIpo values ranging between 21.8-33.1 and TDI values between 67.5-76.7, indicating α-mesosaprobic and eutrophic environments, respectively.

  15. Uncoupling protein 1 in fish uncovers an ancient evolutionary history of mammalian nonshivering thermogenesis.

    PubMed

    Jastroch, Martin; Wuertz, Sven; Kloas, Werner; Klingenspor, Martin

    2005-07-14

    Uncoupling proteins (UCPs) increase proton leakage across the inner mitochondrial membrane. Thereby, UCP1 in brown adipose tissue dissipates proton motive force as heat. This mechanism of nonshivering thermogenesis is considered as a monophyletic trait of endothermic placental mammals that emerged about 140 million years ago and provided a crucial advantage for life in the cold. The paralogues UCP2 and UCP3 are probably not thermogenic proteins but convey mild uncoupling, which may serve to reduce the rate of mitochondrial reactive oxygen species production. Both are present in endotherms (mammals and birds), but so far only UCP2 has been identified in ectothermic vertebrates (fish and amphibia). The evolution of UCPs is of general interest in the search for the origin of mammalian UCP1-mediated nonshivering thermogenesis. We here show the presence of UCP1 and UCP3 in ectothermic teleost fish species using comparative genomics, phylogenetic inference, and gene expression analysis. In the common carp (Cyprinus carpio), UCP1 is predominantly expressed in the liver and strongly diminished in response to cold exposure, thus contrasting the cold-induced expression of mammalian UCP1 in brown adipose tissue. UCP3 mRNA is only found in carp skeletal muscle with expression levels increased fivefold in response to fasting. Our findings disprove the monophyletic nature of UCP1 in placental mammals and demonstrate that all three members of the core UCP family were already present before the divergence of ray-finned and lobe-finned vertebrate lineages about 420 million years ago.

  16. Evolution of the thyroid hormone, retinoic acid, ecdysone and liver X receptors.

    PubMed

    Ollikainen, Noah; Chandsawangbhuwana, Charlie; Baker, Michael E

    2006-12-01

    Ecdysone and thyroid hormone are 2 ligands that have important roles in regulating metamorphosis in animals. Ecdysone is a steroid that regulates molting in insects. Thyroid hormone regulates differentiation and development in fish and amphibia. Although ecdysone and thyroid hormone have different chemical structures, both hormones act by binding to transcription factors that belong to the nuclear receptor family. We investigated the evolution of structure and function in the ecdysone receptor (EcR) and thyroid hormone receptor (TR), and liver X receptor (LXR) and retinoic acid receptor (RAR), which cluster with EcR and TR, respectively (Bertrand S, Brunet FG, Escriva H, Parmentier G, Laudet V, Robinson-Rechavi M. 2004. Mol Biol Evol 21:1923-37), by constructing a multiple alignment of their sequences and calculating ancestral sequences for TR, RAR, EcR, and LXR. These alignments were mapped onto the 3D structures of TR, RAR, EcR, and LXR in the Protein Data Bank to examine the evolution of amino acids involved in the binding of ligands to TR, RAR, EcR, and LXR.

  17. Tyrosine Recombinase Retrotransposons and Transposons.

    PubMed

    Poulter, Russell T M; Butler, Margi I

    2015-04-01

    Retrotransposons carrying tyrosine recombinases (YR) are widespread in eukaryotes. The first described tyrosine recombinase mobile element, DIRS1, is a retroelement from the slime mold Dictyostelium discoideum. The YR elements are bordered by terminal repeats related to their replication via free circular dsDNA intermediates. Site-specific recombination is believed to integrate the circle without creating duplications of the target sites. Recently a large number of YR retrotransposons have been described, including elements from fungi (mucorales and basidiomycetes), plants (green algae) and a wide range of animals including nematodes, insects, sea urchins, fish, amphibia and reptiles. YR retrotransposons can be divided into three major groups: the DIRS elements, PAT-like and the Ngaro elements. The three groups form distinct clades on phylogenetic trees based on alignments of reverse transcriptase/ribonuclease H (RT/RH) and YR sequences, and also having some structural distinctions. A group of eukaryote DNA transposons, cryptons, also carry tyrosine recombinases. These DNA transposons do not encode a reverse transcriptase. They have been detected in several pathogenic fungi and oomycetes. Sequence comparisons suggest that the crypton YRs are related to those of the YR retrotransposons. We suggest that the YR retrotransposons arose from the combination of a crypton-like YR DNA transposon and the RT/RH encoding sequence of a retrotransposon. This acquisition must have occurred at a very early point in the evolution of eukaryotes.

  18. Assessing the Legacy of Red Mud Pollution in a Shallow Freshwater Lake: Arsenic Accumulation and Speciation in Macrophytes.

    PubMed

    Olszewska, Justyna P; Meharg, Andrew A; Heal, Kate V; Carey, Manus; Gunn, Iain D M; Searle, Kate R; Winfield, Ian J; Spears, Bryan M

    2016-09-06

    Little is known about long-term ecological responses in lakes following red mud pollution. Among red mud contaminants, arsenic (As) is of considerable concern. Determination of the species of As accumulated in aquatic organisms provides important information about the biogeochemical cycling of the element and transfer through the aquatic food-web to higher organisms. We used coupled ion chromatography and inductively coupled plasma mass spectrometry (ICP-MS) to assess As speciation in tissues of five macrophyte taxa in Kinghorn Loch, U.K., 30 years following the diversion of red mud pollution from the lake. Toxic inorganic As was the dominant species in the studied macrophytes, with As species concentrations varying with macrophyte taxon and tissue type. The highest As content measured in roots of Persicaria amphibia (L.) Gray (87.2 mg kg(-1)) greatly exceeded the 3-10 mg kg(-1) range suggested as a potential phytotoxic level. Accumulation of toxic As species by plants suggested toxicological risk to higher organisms known to utilize macrophytes as a food source.

  19. [Phytoplankton community structure and eutrophication risk assessment of Beijiang River].

    PubMed

    Gou, Ting; Ma, Qian-Li; Xu, Zhen-Cheng; Wang, Li; Li, Jie; Zhao, Xue-Min

    2015-03-01

    To study the distribution of phytoplankton and water quality of Beijiang River, the community structure of phytoplankton was investigated and analyzed in wet and dry seasons. The results showed that a total of 74 species belonging to six phyla, 29 family and 48 genera of phytoplankton were identified, including 58 species of five phyla, 23 family and 41 genera in wet season and 59 species of six phyla, 26 family and 40 genera in dry season. Phytoplankton community structure in Beijiang River was represented by Bacillariophyta, Chlorophyta and Cyanophyta. Bacillariophyta dominanted the phytoplankton, and the dominant species were Aulacoseira granulate, Fragilaria virescens, Surirella biseriata, Nitzschia amphibia, Navicula simplex, Cyclotella meneghiniana, Synedra ulna, Gomphonema angustatum and Cymbella tumida. There was little difference in phytoplankton density between both seasons with the mean values being 3.54 x 10(5) and 4.87 x 10(5) cells L(-1) in dry and wet seasons, respectively. Based on the RDA results, DO, permanganate index, nitrogen and phosphorus were the important environmental factors affecting the distribution of phytoplankton in Beijiang River. The water quality of Beijiang River was classified as oligo-mesotrophic level even if this river was subjected to nitrogen and phosphorus pollution mainly from agricultural non-point source.

  20. Characterization of a complete immunoglobulin heavy-chain variable region germ-line gene of rainbow trout.

    PubMed

    Matsunaga, T; Chen, T; Törmänen, V

    1990-10-01

    A germ-line heavy-chain variable region (VH) gene (RTVH431) has been isolated from a rainbow trout (Salmo gairdneri) and characterized by complete nucleotide sequencing. It is characteristic of VH, as shown by the conserved octamer and TATA motif in the 5' region, the heptamernonamer recombination signal sequence in the 3' region, and the 18-amino-acid-long hydrophobic leader interrupted by an intron. The 98-amino-acid-long VH coding region has 50-70% nucleotide sequence homology and 40-60% amino acid sequence homology with VHS of various vertebrate species. We have also found unique or species-specific amino acid residues in the VHS of rainbow trout, amphibia (Xenopus), reptile (Caiman), and shark (Heterodontus) in our sequence analyses. The RTVH431 has an unusual amino acid in the conserved 34th position in complementarity-determining region 1 of VH. Southern hybridization results suggest the presence of a large gene family related to RTVH431 in the trout genome. The complex evolution of antibody V genes is discussed.

  1. Characterization of a complete immunoglobulin heavy-chain variable region germ-line gene of rainbow trout.

    PubMed Central

    Matsunaga, T; Chen, T; Törmänen, V

    1990-01-01

    A germ-line heavy-chain variable region (VH) gene (RTVH431) has been isolated from a rainbow trout (Salmo gairdneri) and characterized by complete nucleotide sequencing. It is characteristic of VH, as shown by the conserved octamer and TATA motif in the 5' region, the heptamernonamer recombination signal sequence in the 3' region, and the 18-amino-acid-long hydrophobic leader interrupted by an intron. The 98-amino-acid-long VH coding region has 50-70% nucleotide sequence homology and 40-60% amino acid sequence homology with VHS of various vertebrate species. We have also found unique or species-specific amino acid residues in the VHS of rainbow trout, amphibia (Xenopus), reptile (Caiman), and shark (Heterodontus) in our sequence analyses. The RTVH431 has an unusual amino acid in the conserved 34th position in complementarity-determining region 1 of VH. Southern hybridization results suggest the presence of a large gene family related to RTVH431 in the trout genome. The complex evolution of antibody V genes is discussed. Images PMID:2120708

  2. Serum response factor is essential for mesoderm formation during mouse embryogenesis.

    PubMed Central

    Arsenian, S; Weinhold, B; Oelgeschläger, M; Rüther, U; Nordheim, A

    1998-01-01

    The transcription factor serum response factor (SRF), a phylogenetically conserved nuclear protein, mediates the rapid transcriptional response to extracellular stimuli, e.g. growth and differentiation signals. DNA- protein complexes containing SRF or its homologues function as nuclear targets of the Ras/MAPK signalling network, thereby directing gene activities associated with processes as diverse as pheromone signalling, cell-cycle progression (transitions G0-G1 and G2-M), neuronal synaptic transmission and muscle cell differentiation. So far, the activity of mammalian SRF has been studied exclusively in cultured cells. To study SRF function in a multicellular organism we generated an Srf null allele in mice. SRF-deficient embryos (Srf -/-) have a severe gastrulation defect and do not develop to term. They consist of misfolded ectodermal and endodermal cell layers, do not form a primitive streak or any detectable mesodermal cells and fail to express the developmental marker genes Bra (T), Bmp-2/4 and Shh. Activation of the SRF-regulated immediate early genes Egr-1 and c-fos, as well as the alpha-Actin gene, is severely impaired. Our study identifies SRF as a new and essential regulator of mammalian mesoderm formation. We therefore suggest that in mammals Ras/MAPK signalling contributes to mesoderm induction, as is the case in amphibia. PMID:9799237

  3. Cytological and molecular analysis in the rare discoglossid species, Alytes muletensis (Sanchiz & Adrover 1977) and its bearing on archaeobatrachian phylogeny.

    PubMed

    Odierna, G; Andreone, F; Aprea, G; Arribas, O; Capriglione, T; Vences, M

    2000-01-01

    Cytogenetic and molecular data on Alytes muletensis (Amphibia: Discoglossidae) are compared with other representatives of archaeobatrachian frogs: Bombina variegata pachypus, Pelobates cultripes, Pelodytes punctatus, Xenopus laevis, and Discoglossus. A. muletensis has the karyotype typical for the genus Alytes, 38 elements with either one or two arms, some of which can be considered as 'microchromosomes'. The NORs are located on the telomeres of the tenth chromosome pair which agrees with the state in A. obstetricians but differs from A. cisternasii reflecting phylogenetic affinities. C-banding and staining with DAPI and chromomycin A3 revealed important blocks of telomeric CMA-positive heterochromatin on the smaller chromosomes of Alytes, similar to the state found in Discoglossus. Phylogenetic analysis of 750 bp of fragments of the mitochondrial 16S and 12S rRNA genes corroborated that Discoglossus and Alytes are sister taxa which together probably form the sister group of the Bombinatorinae. Centromeric heterochromatin in Alytes may be responsible for the retention of a plesiomorphic asymmetric karyotype which independently has evolved into a symmetric karyotype through centric fusions in Bombina and Discoglossus. The HindIII satellite DNA family was present in all archaeobatrachians studied but absent in hyloid and ranoid neobatrachians.

  4. A myogenic precursor cell that could contribute to regeneration in zebrafish and its similarity to the satellite cell.

    PubMed

    Siegel, Ashley L; Gurevich, David B; Currie, Peter D

    2013-09-01

    The cellular basis for mammalian muscle regeneration has been an area of intense investigation over recent decades. The consensus is that a specialized self-renewing stem cell, termed the satellite cell, plays a major role during the process of regeneration in amniotes. How broadly this mechanism is deployed within the vertebrate phylogeny remains an open question. A lack of information on the role of cells analogous to the satellite cell in other vertebrate systems is even more unexpected given the fact that satellite cells were first designated in frogs. An intriguing aspect of this debate is that a number of amphibia and many fish species exhibit epimorphic regenerative processes in specific tissues, whereby regeneration occurs by the dedifferentiation of the damaged tissue, without deploying specialized stem cell populations analogous to satellite cells. Hence, it is feasible that a cellular process completely distinct from that deployed during mammalian muscle regeneration could operate in species capable of epimorphic regeneration. In this minireview, we examine the evidence for the broad phylogenetic distribution of satellite cells. We conclude that, in the vertebrates examined so far, epimorphosis does not appear to be deployed during muscle regeneration, and that analogous cells expressing similar marker genes to satellite cells appear to be deployed during the regenerative process. However, the functional definition of these cells as self-renewing muscle stem cells remains a final hurdle to the definition of the satellite cell as a generic vertebrate cell type.

  5. Immunohistochemical localization of S100-like protein in non-mammalian kidney.

    PubMed

    De Girolamo, Paolo; Arcamone, Nadia; Pelagalli, Gaetano Vincenzo; Gargiulo, Giuliana

    2003-04-15

    The immunolocalization of S100-like protein was investigated in the kidney of saltwater fishes (Dicentrarchus labrax; Coris julis; Serranus cabrilla; Scorpaena porcus), amphibia (Rana aesculenta), reptiles (Lacerta viridis), and aves (Gallus domesticus; Strutio camelus). S100-like immunoreactivity was detected in the juxtaglomerular cells of all saltwater fishes studied. No immunoreactivity was observed in other tracts of the nephron or in the interstitial tissue. In frog kidney, S100-like immunoreactive cells were localized in the proximal tubule, singly distributed or placed side by side in clusters of two or three cells. S100-like immunoreactive cells were distributed in the distal and in the collecting tubules in lizard, chicken, and ostrich kidney. In the distal tubule of lizard kidney, S100-like immunoreactive cells were numerous and uniformly distributed. In lizard collecting tubules, S100-like immunoreactive cells showed less intense immunoreactivity than in the distal tubule, except for a cluster of cells at the junction with the initial collecting duct. In chicken and ostrich kidney, S100-like immunoreactive cells of the distal tubules were closely packed together. In the collecting tubules, S100-like immunoreactive cells were alternate to negative cells. These results indicate the high conservation degree of S100 proteins through phylogenesis and suggest a functional role for these proteins in the vertebrate kidney.

  6. Phospholipid transfer activities in toad oocytes and developing embryos. [Bufo arenarum

    SciTech Connect

    Rusinol, A.; Salomon, R.A.; Bloj, B.

    1987-01-01

    The role of lipid transfer proteins during plasma membrane biogenesis was explored. Developing amphibia embryos were used because during their growth an active plasma membrane biosynthesis occurs together with negligible mitochondrial and endoplasmic reticulum proliferation. Sonicated vesicles, containing /sup 14/C-labeled phospholipids and /sup 3/H-labeled triolein, as donor particles and cross-linked erythrocyte ghosts as acceptor particles were used to measure phospholipid transfer activities in unfertilized oocytes and in developing embryos of the toad Bufo arenarum. Phosphatidylcholine transfer activity in pH 5.1 supernatant of unfertilized oocytes was 8-fold higher than the activity found in female toad liver supernatant, but dropped steadily after fertilization. After 20 hr of development, at the stage of late blastula, the phosphatidylcholine transfer activity had dropped 4-fold. Unfertilized oocyte supernatant exhibited phosphatidylinositol and phosphatidylethanolamine transfer activity also, but at the late blastula stage the former had dropped 18-fold and the latter was no longer detectable under our assay conditions. Our results show that fertilization does not trigger a phospholipid transport process catalyzed by lipid transfer proteins. Moreover, they imply that 75% of the phosphatidylcholine transfer activity and more than 95% of the phosphatidylinositol and phosphatidylethanolamine transfer activities present in pH 5.1 supernatants of unfertilized oocytes may not be essential for toad embryo development. Our findings do not rule out, however, that a phosphatidylcholine-specific lipid transfer protein could be required for embryo early growth.

  7. Positive Darwinian selection results in resistance to cardioactive toxins in true toads (Anura: Bufonidae)

    PubMed Central

    Moore, David J.; Halliday, Damien C. T.; Rowell, David M.; Robinson, Anthony J.; Keogh, J. Scott

    2009-01-01

    Members of the Family Bufonidae, true toads, are famous for their endogenously synthesized cardioactive steroids that serve as defensive toxins. Evolution of resistance to these toxins is not understood. We sequenced a key region of the toxin's binding site in the Na+/K+ ATPase for relevant taxa representing Hyloidea (including bufonids), Ranoidea and Archaeobatrachia and tested for positive selection in a phylogenetic context. Bufonidae were distinct from other Hyloidea at 4–6 of 12 sites and, with one exception, had a homologous amino acid sequence. Melanophryniscus stelzneri had a distinct sequence, consistent with other independent evidence for a differentiated toxin. Tests within Bufonidae detected positive selection within the binding region, providing, to our knowledge, the first evidence of this type for positive selection within Amphibia. There was no evidence for positive selection on Bufonidae or M. stelzneri lineages. Sequence change in Leptodactylus ocellatus, a leptodactylid predator of Bufonidae, provides a molecular basis for predator resistance possibly associated with gene duplication. PMID:19465576

  8. Origins of the parasitic habit in the nematoda.

    PubMed

    Clark, W C

    1994-12-01

    Circumstances that probably attended and influenced the adoption and development of the parasitic habit amongst the Nematoda are examined. Features that allowed early terrestrial nematodes to exploit discontinuous habitats such as decomposing organic matter, are considered to have been advantageous to microbivorous Secernentea that became parasites of animals and plants. This development followed the appearance of a land flora and that the Amphibia were the first vertebrate hosts of nematodes. Life cycles involving intermediate hosts were essential in drier environments and in a aquatic ones where intermediate hosts preserve the infective stages; keeps them "in circulation", and makes them attractive to predators. It is concluded that the parasitic habit was adopted repeatedly in both Secernentea and Adenophorea, though the latter did not diversify as much. Convergence is a common feature of nematode evolution, and the typical life history pattern of 5 stadia separated by 4 moults is often greatly modified by suppression, extension and diversification of stages and their roles. There is a need to examine the nematodes, especially of invertebrates in the remaining rain forests of Gondwanaland before they disappear.

  9. Marcello Malpighi and the discovery of the pulmonary capillaries and alveoli.

    PubMed

    West, John B

    2013-03-15

    Marcello Malpighi (1628-1694) was an Italian scientist who made outstanding contributions in many areas, including the anatomical basis of respiration in amphibia, mammals, and insects and also in the very different fields of embryology and botany. He was one of the first biologists to make use of the newly invented microscope and is best known as the discoverer of the pulmonary capillaries and alveoli. However, he also discovered the spiracles and tracheae that enable respiration in insects. His studies of the embryology of the chicken were far ahead of his time; he then turned to the anatomy of plants, where he made important contributions. Indeed, in some articles Malpighi is referred to as the father of embryology and in other publications as one of the fathers of plant anatomy. His work on the lung was chiefly carried out on the frog; he referred to this animal as the "microscope of nature" because it allowed him to see structures that were not visible in larger animals such as mammals. He also argued that nature undertakes its great works in larger animals after a series of attempts in lower animals. For breadth of interest, innovation, and productivity, it is not easy to think of his equal in the field of life sciences.

  10. Angiotensin II receptors in amphibian kidney. [Calyptocephalella caudiverbera

    SciTech Connect

    Tchernitchin, S.M.; Galli, S.M.; Raizada, M.

    1986-03-05

    The localization of Angiotensin II (Ang II) receptors in the Amphibia kidney was investigated by radioautography and binding studies. /sup 125/I-Ang II was injected into the dorsal aorta of anesthetized toads, Calyptocephalella caudiverbera. The kidney excised 2 and 10 min after injection show intense labeling in the glomeruli and a lesser amount in the tubules. Ang II labeling was found in the proximal, distal and collecting tubules. The thin connecting segment (diluting segment) also shows a distinct labeling. Afferent and efferent arterioles and interstitial connective tissue do not show radioautographic granules above the background level. Ang II binding studies of glomerular and tubular membranes show that the binding of /sup 125/I-Ang II is higher in the glomerular than in the tubular membranes with a Kd of 1.9 x 10/sup -9/M and 1.0 x 10/sup -9/M respectively. Their results show that angiotensin II receptors in the amphibian nephron are present in the glomeruli and tubular segments, supporting the hypothesis of the intrarenal action of Ang II in this group of vertebrates.

  11. Drought, Deluge and Declines: The Impact of Precipitation Extremes on Amphibians in a Changing Climate

    PubMed Central

    Walls, Susan C.; Barichivich, William J.; Brown, Mary E.

    2013-01-01

    The Class Amphibia is one of the most severely impacted taxa in an on-going global biodiversity crisis. Because amphibian reproduction is tightly associated with the presence of water, climatic changes that affect water availability pose a particularly menacing threat to both aquatic and terrestrial-breeding amphibians. We explore the impacts that one facet of climate change—that of extreme variation in precipitation—may have on amphibians. This variation is manifested principally as increases in the incidence and severity of both drought and major storm events. We stress the need to consider not only total precipitation amounts but also the pattern and timing of rainfall events. Such rainfall “pulses” are likely to become increasingly more influential on amphibians, especially in relation to seasonal reproduction. Changes in reproductive phenology can strongly influence the outcome of competitive and predatory interactions, thus potentially altering community dynamics in assemblages of co-existing species. We present a conceptual model to illustrate possible landscape and metapopulation consequences of alternative climate change scenarios for pond-breeding amphibians, using the Mole Salamander, Ambystoma talpoideum, as an example. Although amphibians have evolved a variety of life history strategies that enable them to cope with environmental uncertainty, it is unclear whether adaptations can keep pace with the escalating rate of climate change. Climate change, especially in combination with other stressors, is a daunting challenge for the persistence of amphibians and, thus, the conservation of global biodiversity. PMID:24832668

  12. Evidence for urea-induced hypometabolism in isolated organs of dormant ectotherms.

    PubMed

    Muir, Timothy J; Costanzo, Jon P; Lee, Richard E

    2010-01-01

    Many organisms endure extended periods of dormancy by depressing their metabolism, which effectively prolongs the use of their endogenous energy stores. Though the mechanisms of hypometabolism are varied and incompletely understood, recent work suggests that urea accumulation in autumn and early winter contributes to reduced metabolism of hibernating wood frogs (Rana sylvatica). Urea accumulation during dormancy is a widespread phenomenon, and it has long been presumed that numerous species from diverse taxa benefit from its hypometabolic effect. To investigate the phylogenetic prevalence of urea-induced hypometabolism, we studied four species of urea accumulators from the clades Amphibia (Spea bombifrons and Ambystoma tigrinum), Reptilia (Malaclemys terrapin), and Gastropoda (Anguispira alternata), and one amphibian species (R. pipiens) that does not accumulate urea during dormancy. We measured rates of oxygen consumption (VO(2)) of excised organ samples from dormant animals in the presence or absence of physiological concentrations of urea. Three of the four urea-accumulating species had at least one organ whose VO(2) was significantly decreased by urea treatment. However, VO(2) of organs from R. pipiens, the one species tested that does not accumulate urea during dormancy, was not affected by urea treatment. Our results support the hypothesis that urea accumulation can reduce metabolic rate of dormant animals and provide a base for further investigation into the evolution of urea-induced hypometabolism. (c) 2009 Wiley-Liss, Inc.

  13. Suitability of amphibians and reptiles for translocation.

    PubMed

    Germano, Jennifer M; Bishop, Phillip J

    2009-02-01

    Translocations are important tools in the field of conservation. Despite increased use over the last few decades, the appropriateness of translocations for amphibians and reptiles has been debated widely over the past 20 years. To provide a comprehensive evaluation of the suitability of amphibians and reptiles for translocation, we reviewed the results of amphibian and reptile translocation projects published between 1991 and 2006. The success rate of amphibian and reptile translocations reported over this period was twice that reported in an earlier review in 1991. Success and failure rates were independent of the taxonomic class (Amphibia or Reptilia) released. Reptile translocations driven by human-wildlife conflict mitigation had a higher failure rate than those motivated by conservation, and more recent projects of reptile translocations had unknown outcomes. The outcomes of amphibian translocations were significantly related to the number of animals released, with projects releasing over 1000 individuals being most successful. The most common reported causes of translocation failure were homing and migration of introduced individuals out of release sites and poor habitat. The increased success of amphibian and reptile translocations reviewed in this study compared with the 1991 review is encouraging for future conservation projects. Nevertheless, more preparation, monitoring, reporting of results, and experimental testing of techniques and reintroduction questions need to occur to improve translocations of amphibians and reptiles as a whole.

  14. Molecular and Functional Characterization of Thioredoxin 1 from Korean Rose Bitterling (Rhodeus uyekii)

    PubMed Central

    Kim, Julan; Moon, Ji Young; Kim, Woo-Jin; Kim, Dong-Gyun; Nam, Bo-Hye; Kim, Young-Ok; Park, Jung Youn; An, Cheul Min; Kong, Hee Jeong

    2015-01-01

    Thioredoxin is a multifunctional antioxidant enzyme that belongs to the reductase family. In this study, we cloned and characterized thioredoxin 1 cDNA from the Korean rose bitterling Rhodeus uyekii (RuTrx). The full-length RuTrx cDNA consists of 674 bp with a 324 nt open reading frame (ORF) encoding a 107 aa protein. The deduced RuTrx amino acid sequence indicated a characteristic redox active site, 31WCGPC35. Pairwise alignment revealed RuTrx amino acid identity (55.1%–83.2%) with orthologs from various species of mammalia, amphibia, fish and bird. Phylogenetic analysis was conducted to determine the evolutionary position of RuTrx. Expression analysis showed that RuTrx transcripts were present in all of the tissues examined, and was high in the hepatopancreas of R. uyekii. During early development, the expression of RuTrx transcripts was increased. Recombinant RuTrx protein (rRuTrx) was tested for its capacity to serve as an antioxidant enzyme using a metal-catalyzed oxidation (MCO) system. The ability of rRuTrx to protect against supercoiled DNA cleavage due to oxidative nicking increased in a dose-dependent manner. In Raw264.7 cells, Dihydroethidium (DHE) staining for ROS production indicated the antioxidant activity of rRuTrx. Together, these findings suggest that RuTrx may play a role in maintaining the redox state balance in Korean rose bitterling R. uyekii. PMID:26287186

  15. Biostratigraphy and biochronology of the Monte Hermoso Formation (early Pliocene) at its type locality, Buenos Aires Province, Argentina

    NASA Astrophysics Data System (ADS)

    Tomassini, Rodrigo L.; Montalvo, Claudia I.; Deschamps, Cecilia M.; Manera, Teresa

    2013-12-01

    The Monte Hermoso Formation, cropping out at its type locality of Farola Monte Hermoso (Buenos Aires Province), is a classical fossiliferous unit of the South American Neogene, highlighted by the abundance and diversity of its vertebrate remains. However, its biostratigraphy and age have been largely debated, and numerous discrepancies and controversies have been stated. In this regard, the result of the analysis of new materials recovered from the different levels of this formation, following a strict control of stratigraphic provenance, is here reported. As well, the provenance of specimens of previous collections has been evaluated. The studied assemblage consists of Osteichthyes, Amphibia, Reptilia, Aves and Mammalia. These latter are the most numerous and belong to the Didelphimorphia, Polydolopimorphia, Rodentia, Notoungulata, Litopterna and Xenarthra. The recorded taxa suggest no important faunistic variations among the different levels of the Monte Hermoso Formation that would imply significant chronological differences, and hence, justify the recognition of two biostratigraphic units. The analysis of the first and last records as well as the taxa considered as exclusive, does not support the validity of the biozones of Trigodon gaudryi and Neocavia depressidens previously proposed. On this basis, a new scheme for the Monte Hermoso Formation at its type locality is proposed, including a new single biostratigraphic unit. This unit is the Eumysops laeviplicatus Range Zone, which represents the biostratigraphic base for the Montehermosan Stage/Age of the early Pliocene.

  16. The smelling of Hedione results in sex-differentiated human brain activity.

    PubMed

    Wallrabenstein, I; Gerber, J; Rasche, S; Croy, I; Kurtenbach, S; Hummel, T; Hatt, H

    2015-06-01

    A large family of vomeronasal receptors recognizes pheromone cues in many animals including most amphibia, reptiles, rhodents, and other mammals. Humans possess five vomeronasal-type 1 receptor genes (VN1R1-VN1R5), which code for proteins that are functional in recombinant expression systems. We used two different recombinant expression systems and identified Hedione as a ligand for the putative human pheromone receptor VN1R1 expressed in the human olfactory mucosa. Following the ligand identification, we employed functional magnetic resonance imaging (fMRI) in healthy volunteers to characterize the in vivo action of the VN1R1 ligand Hedione. In comparison to a common floral odor (phenylethyl alcohol), Hedione exhibited significantly enhanced activation in limbic areas (amygdala, hippocampus) and elicited a sex-differentiated response in a hypothalamic region that is associated with hormonal release. Utilizing a novel combination of methods, our results indicate that the putative human pheromone receptor VN1R1 is involved in extra-olfactory neuronal activations induced by the odorous substance Hedione. The activation of VN1R1 might play a role in gender-specific modulation of hormonal secretion in humans. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. Insights from the complete genome sequence of Mycobacterium marinum on the evolution of Mycobacterium tuberculosis

    PubMed Central

    Stinear, Timothy P.; Seemann, Torsten; Harrison, Paul F.; Jenkin, Grant A.; Davies, John K.; Johnson, Paul D.R.; Abdellah, Zahra; Arrowsmith, Claire; Chillingworth, Tracey; Churcher, Carol; Clarke, Kay; Cronin, Ann; Davis, Paul; Goodhead, Ian; Holroyd, Nancy; Jagels, Kay; Lord, Angela; Moule, Sharon; Mungall, Karen; Norbertczak, Halina; Quail, Michael A.; Rabbinowitsch, Ester; Walker, Danielle; White, Brian; Whitehead, Sally; Small, Pamela L.C.; Brosch, Roland; Ramakrishnan, Lalita; Fischbach, Michael A.; Parkhill, Julian; Cole, Stewart T.

    2008-01-01

    Mycobacterium marinum, a ubiquitous pathogen of fish and amphibia, is a near relative of Mycobacterium tuberculosis, the etiologic agent of tuberculosis in humans. The genome of the M strain of M. marinum comprises a 6,636,827-bp circular chromosome with 5424 CDS, 10 prophages, and a 23-kb mercury-resistance plasmid. Prominent features are the very large number of genes (57) encoding polyketide synthases (PKSs) and nonribosomal peptide synthases (NRPSs) and the most extensive repertoire yet reported of the mycobacteria-restricted PE and PPE proteins, and related-ESX secretion systems. Some of the NRPS genes comprise a novel family and seem to have been acquired horizontally. M. marinum is used widely as a model organism to study M. tuberculosis pathogenesis, and genome comparisons confirmed the close genetic relationship between these two species, as they share 3000 orthologs with an average amino acid identity of 85%. Comparisons with the more distantly related Mycobacterium avium subspecies paratuberculosis and Mycobacterium smegmatis reveal how an ancestral generalist mycobacterium evolved into M. tuberculosis and M. marinum. M. tuberculosis has undergone genome downsizing and extensive lateral gene transfer to become a specialized pathogen of humans and other primates without retaining an environmental niche. M. marinum has maintained a large genome so as to retain the capacity for environmental survival while becoming a broad host range pathogen that produces disease strikingly similar to M. tuberculosis. The work described herein provides a foundation for using M. marinum to better understand the determinants of pathogenesis of tuberculosis. PMID:18403782

  18. Risks to Colombian amphibian fauna from cultivation of coca (Erythroxylum coca): a geographical analysis.

    PubMed

    Lynch, J D; Arroyo, S B

    2009-01-01

    The Colombian amphibian fauna is among the richest known in the world, with about 20 species of salamanders (order Caudata), 35 of the limbless caecilians (order Gymnophiona), and more than 700 species of frogs and toads (order Anura) recorded from localities within the country. The potential effects of exposure to glyphosate on amphibians arising from production of illegal crops (coca) were examined. The analysis was based on (1) behavior and ecology of species and (2) proximities of actual museum records to localities in which illegal crops are being grown and the subset of those that have been sprayed with glyphosate. Based on data on the location of amphibians collected in Colombia, records were obtained for 193 species (28% of the national diversity) of frogs and toads found in localities within 10 km of areas where coca is grown. Further analyses with ARC MAP software allowed for measurement of the direct distance separating collection locations for frogs, known coca fields, and areas where aerial spraying was being conducted. Records in or near coca fields included data for 11 of 13 families of frogs and toads known to be present in Colombia. Only Ceratophryidae and Pipidae were not reported from these locations and appear not to be at risk. For eight species (Dendrobates truncatus, Craugastor raniformis, Pristimantis gaigeae, Smilisca phaeota, Elachistocleis ovale, Hypsiboas crepitans, Trachycephalus venulosus, and Pseudis paradoxa) selected to represent several habitat preferences and life-cycle strategies, large areas of their distributions lie outside coca production regions and their populations as a whole are at low risk. For a limited number of species that barely enter Colombian territory, the consequences of coca production may be more serious and may have placed several species of frogs at risk. These include Ameerega bilingua, Dendropsophus bifurcus, Pristimantis colomai, P. degener, P. diadematus, P. quaquaversus, P. variabilis, and

  19. Traps of carnivorous pitcher plants as a habitat: composition of the fluid, biodiversity and mutualistic activities

    PubMed Central

    Adlassnig, Wolfram; Peroutka, Marianne; Lendl, Thomas

    2011-01-01

    Background Carnivorous pitcher plants (CPPs) use cone-shaped leaves to trap animals for nutrient supply but are not able to kill all intruders of their traps. Numerous species, ranging from bacteria to vertrebrates, survive and propagate in the otherwise deadly traps. This paper reviews the literature on phytotelmata of CPPs. Pitcher Fluid as a Habitat The volumes of pitchers range from 0·2 mL to 1·5 L. In Nepenthes and Cephalotus, the fluid is secreted by the trap; the other genera collect rain water. The fluid is usually acidic, rich in O2 and contains digestive enzymes. In some taxa, toxins or detergents are found, or the fluid is extremely viscous. In Heliamphora or Sarracenia, the fluid differs little from pure water. Inquiline Diversity Pitcher inquilines comprise bacteria, protozoa, algae, fungi, rotifers, crustaceans, arachnids, insects and amphibia. The dominant groups are protists and Dipteran larvae. The various species of CPPs host different sets of inquilines. Sarracenia purpurea hosts up to 165 species of inquilines, followed by Nepenthes ampullaria with 59 species, compared with only three species from Brocchinia reducta. Reasons for these differences include size, the life span of the pitcher as well as its fluid. Mutualistic Activities Inquilines closely interact with their host. Some live as parasites, but the vast majority are mutualists. Beneficial activities include secretion of enzymes, feeding on the plant's prey and successive excretion of inorganic nutrients, mechanical break up of the prey, removal of excessive prey and assimilation of atmospheric N2. Conclusions There is strong evidence that CPPs influence their phytotelm. Two strategies can be distinguished: (1) Nepenthes and Cephalotus produce acidic, toxic or digestive fluids and host a limited diversity of inquilines. (2) Genera without efficient enzymes such as Sarracenia or Heliamphora host diverse organisms and depend to a large extent on their symbionts for prey utilization

  20. Parallel tagged amplicon sequencing of transcriptome-based genetic markers for Triturus newts with the Ion Torrent next-generation sequencing platform.

    PubMed

    Wielstra, B; Duijm, E; Lagler, P; Lammers, Y; Meilink, W R M; Ziermann, J M; Arntzen, J W

    2014-09-01

    Next-generation sequencing is a fast and cost-effective way to obtain sequence data for nonmodel organisms for many markers and for many individuals. We describe a protocol through which we obtain orthologous markers for the crested newts (Amphibia: Salamandridae: Triturus), suitable for analysis of interspecific hybridization. We use transcriptome data of a single Triturus species and design 96 primer pairs that amplify c. 180 bp fragments positioned in 3-prime untranslated regions. Next, these markers are tested with uniplex PCR for a set of species spanning the taxonomical width of the genus Triturus. The 52 markers that consistently show a single band of expected length at gel electrophoreses for all tested crested newt species are then amplified in five multiplex PCRs (with a plexity of ten or eleven) for 132 individual newts: a set of 84 representing the seven (candidate) species and a set of 48 from a presumed hybrid population. After pooling multiplexes per individual, unique tags are ligated to link amplicons to individuals. Subsequently, individuals are pooled equimolar and sequenced on the Ion Torrent next-generation sequencing platform. A bioinformatics pipeline identifies the alleles and recodes these to a genotypic format. Next, we test the utility of our markers. baps allocates the 84 crested newt individuals representing (candidate) species to their expected (candidate) species, confirming the markers are suitable for species delineation. newhybrids, a hybrid index and hiest confirm the 48 individuals from the presumed hybrid population to be genetically admixed, illustrating the potential of the markers to identify interspecific hybridization. We expect the set of markers we designed to provide a high resolving power for analysis of hybridization in Triturus.

  1. Using catenas for GIS-based mapping of NW Mediterranean littoral habitats

    NASA Astrophysics Data System (ADS)

    Mariani, Simone; Cefalì, Maria Elena; Terradas, Marc; Chappuis, Eglantine; Ballesteros, Enric

    2014-06-01

    Studies aimed at describing habitats and mapping their distributions are pivotal to implementing management plans and to effectively guide conservation measures. We developed a novel approach of data collection and entry (CAT-LIT) to establish a detailed cartography of the littoral habitats found along the Catalan coast (Spain). Field data were recorded using coded, two-digit hierarchical lists (e.g. Aa, Ab, etc.) of horizons found at each point along the coast, called catenas. The horizons were either dominated by species (on the rocky bottoms) or sediment types (on the beaches) and corresponded to LPRE, EUNIS and CORINE habitats. Catenas were transferred into a database and calculations about the extent of bottom types, habitats, and catenas themselves along the coast were carried out with GIS tools. In addition, habitat link richness was calculated and represented using network analysis programs. The application of CAT-LIT to the Catalan coast showed that the habitats dominated by the lichen Verrucaria amphibia and the flattened barnacle Euraphia depressa and those dominated by the barnacle Chthamalus spp. were almost ubiquitous. Those dominated by the red alga Corallina elongata, the mussel Mytilus galloprovincialis and the red alga Rissoella verruculosa were also common. Because of the frequency of their connections, those habitats formed a huge hub of links in the networks. By using catenas, the habitats can be viewed using GIS based programs keeping the catena as the main informational and ecological unit. The catenas allow maximum compactness when vertically distributed habitats are to be shown on a 2D map. The complete cartography and dataset on the spatial distribution of the littoral habitats from Catalonia is valuable for coastal management and conservation to study changes in the habitat distribution and relate such changes to anthropogenic pressures. Furthermore, the CAT-LIT can be easily adapted to shores of other seas and oceans to obtain accurate

  2. Biogeographic analysis reveals ancient continental vicariance and recent oceanic dispersal in amphibians.

    PubMed

    Pyron, R Alexander

    2014-09-01

    Amphibia comprises over 7000 extant species distributed in almost every ecosystem on every continent except Antarctica. Most species also show high specificity for particular habitats, biomes, or climatic niches, seemingly rendering long-distance dispersal unlikely. Indeed, many lineages still seem to show the signature of their Pangaean origin, approximately 300 Ma later. To date, no study has attempted a large-scale historical-biogeographic analysis of the group to understand the distribution of extant lineages. Here, I use an updated chronogram containing 3309 species (∼ 45% of extant diversity) to reconstruct their movement between 12 global ecoregions. I find that Pangaean origin and subsequent Laurasian and Gondwanan fragmentation explain a large proportion of patterns in the distribution of extant species. However, dispersal during the Cenozoic, likely across land bridges or short distances across oceans, has also exerted a strong influence. Finally, there are at least three strongly supported instances of long-distance oceanic dispersal between former Gondwanan landmasses during the Cenozoic. Extinction from intervening areas seems to be a strong factor in shaping present-day distributions. Dispersal and extinction from and between ecoregions are apparently tied to the evolution of extraordinarily adaptive expansion-oriented phenotypes that allow lineages to easily colonize new areas and diversify, or conversely, to extremely specialized phenotypes or heavily relictual climatic niches that result in strong geographic localization and limited diversification. © The Author(s) 2014. Published by Oxford University Press, on behalf of the Society of Systematic Biologists. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  3. The area composita of adhering junctions connecting heart muscle cells of vertebrates. VI. Different precursor structures in non-mammalian species.

    PubMed

    Pieperhoff, Sebastian; Franke, Werner W

    2008-07-01

    Recent studies on the formation and molecular organization of the mammalian heart have emphasized the architectural and functional importance of the adhering junctions (AJs), which are densely clustered in the bipolar end regions (intercalated disks, IDs) connecting the elongated cardiomyocytes of the adult heart. Moreover, we learned from genetic studies of mutated AJ proteins that desmosomal proteins, which for the most part are integral components of ID-specific composite AJs (areae compositae, AC), are essential in heart development and function. Developmental studies have shown that the bipolar concentration of cardiomyocyte AJs in IDs is a rather late process and only completed postnatally. Here we report that in the adult hearts of diverse lower vertebrates (fishes, amphibia, birds) most AJs remain separate and distinct in molecular character, representing either fasciae adhaerentes, maculae adhaerentes (desmosomes) or--less frequently--some form of AC. In the mature hearts of the amphibian and fish species examined a large proportion of the AJs connecting cardiomyocytes is not clustered in the IDs but remains located on the lateral surfaces where they appear either as puncta adhaerentia or as desmosomes. In many places, these puncta connect parallel cardiomyocytes in spectacular ladder-like regular arrays (scalae adhaerentes) correlated with--and connected by--electron-dense plaque-like material to sarcomeric Z-bands. In the avian hearts, on the other hand, most AJs are clustered in the IDs but only a small proportion of the desmosomes appears as AC, compared to the dominance of distinct fasciae adhaerentes. We conclude that the fusion and amalgamation of AJs and desmosomes to ACs is a late process both in ontogenesis and in evolution. The significance and possible functional implications of the specific junctional structures in vertebrate evolution and the class-specific requirements of architectural and molecular assembly adaptation during regeneration

  4. Epilithic diatom assemblages and their relationships with environmental variables in the Nilüfer Stream Basin, Bursa, Turkey.

    PubMed

    Karacaoğlu, Didem; Dalkıran, Nurhayat

    2017-05-01

    Patterns of epilithic diatom species distribution in relation to environmental variables from 12 sampling sites on the main stream and some of its tributaries in the Nilüfer Stream Basin were determined using multivariate statistical techniques. The stream basin has been heavily influenced by anthropogenic effects. The upper part of the basin that is distant from pollution sources mostly has a spring water quality, while the lower part where the stream flows through the urban area and receives domestic and industrial wastewater has a quite low quality. Ordination techniques using both diatom taxa and 21 environmental variables revealed non- to slightly polluted upper basin sites and highly polluted lower basin sites along the stream. The results showed that the stream catchment is polluted gradually from upstream to downstream and that most of the downstream sites have very low water quality especially in summer months. A total of 134 epilithic diatom taxa belonging to 50 genera were recorded for 12 sample sites. Partial CCA results indicated that water temperature (T), discharge (Q), and total phosphorus (TP) were the most important variables affecting the distribution of diatom species. Unpolluted or slightly polluted upper basin sites were dominated by Achnanthidium minutissimum, Cocconeis placentula var. euglypta, Gomphonema olivaceum, and Navicula tripunctata. Highly polluted lower basin sites were characterized by high levels of organic and inorganic matters and low dissolved oxygen (DO) values. Species widespread in the highly polluted lower basin sites such as Nitzschia umbonata, Nitzschia amphibia, Nitzschia capitellata, Nitzschia palea, Nitzschia paleacea, Luticola mutica, and Stephanodiscus niagarae were mostly related to pollution indicator variables such as ammonium nitrogen (NH4(+)-N), sodium (Na(+)), total phosphorus (TP), and total organic matter (TOM).

  5. Effects of bilateral and unilateral ophthalmectomy on plasma melatonin in Rana tadpoles and froglets under various experimental conditions.

    PubMed

    Wright, Mary L; Francisco, Lucy L; Scott, Jessica L; Richardson, Shaun E; Carr, James A; King, Amy B; Noyes, Arielle G; Visconti, Rachael F

    2006-06-01

    The effect of ophthalmectomy (enucleation) on plasma melatonin in Rana tadpoles and froglets was studied under various experimental conditions to determine if ocular melatonin is released into the circulation from the eyes and to study the factors which might affect this process. Where operations occurred in early or mid-photophase on a 12 light:12 dark (12L:12D) cycle (light onset at 08:00 h), sampling in mid-light and mid-dark revealed that scotophase plasma melatonin was reduced at all developmental stages, with the more significant effects occurring before metamorphic climax. Experiments sampling prometamorphic tadpoles six times in a 24h period on 18L:6D, 12L:12D, or 6L:18D five days after enucleation also showed a significant lowering of plasma melatonin in the dark, so that the scotophase peak was virtually eliminated on all the LD cycles. These findings indicated that the reduction in plasma melatonin after bilateral eye removal was independent of the LD cycle and the metamorphic stage, and that it abolished the diel melatonin rhythm at the expense of the scotophase peak. Experiments carried out for 5 weeks suggested that compensatory secretion of melatonin by other organs after eye removal might partially restore the plasma melatonin level over time. Unilateral ophthalmectomy tended to reduce, but not eliminate, the night peak of plasma melatonin, and did not result in a compensatory increase in ocular melatonin in the remaining eye. Ophthalmectomized tadpoles exhibited darkening of the skin after the operation, which was not associated with a significant change in pituitary alpha-melanotropin. The findings overall indicate that the eyes in Rana tadpoles and froglets contribute up to somewhat over one-half of the circulating melatonin, particularly during the scotophase, and provide experimental evidence for ocular secretion into the blood for the first time in the Amphibia.

  6. Assessing Risks to Non-Target Species during Poison Baiting Programs for Feral Cats

    PubMed Central

    Buckmaster, Tony; Dickman, Christopher R.; Johnston, Michael J.

    2014-01-01

    Poison baiting is used frequently to reduce the impacts of pest species of mammals on agricultural and biodiversity interests. However, baiting may not be appropriate if non-target species are at risk of poisoning. Here we use a desktop decision tree approach to assess the risks to non-target vertebrate species in Australia that arise from using poison baits developed to control feral house cats (Felis catus). These baits are presented in the form of sausages with toxicant implanted in the bait medium within an acid-soluble polymer capsule (hard shell delivery vehicle, or HSDV) that disintegrates after ingestion. Using criteria based on body size, diet and feeding behaviour, we assessed 221 of Australia's 3,769 native vertebrate species as likely to consume cat-baits, with 47 of these likely to ingest implanted HSDVs too. Carnivorous marsupials were judged most likely to consume both the baits and HSDVs, with some large-bodied and ground-active birds and reptiles also consuming them. If criteria were relaxed, a further 269 species were assessed as possibly able to consume baits and 343 as possibly able to consume HSDVs; most of these consumers were birds. One threatened species, the Tasmanian devil (Sarcophilus harrisii) was judged as definitely able to consume baits with implanted HSDVs, whereas five threatened species of birds and 21 species of threatened mammals were rated as possible consumers. Amphibia were not considered to be at risk. We conclude that most species of native Australian vertebrates would not consume surface-laid baits during feral cat control programs, and that significantly fewer would be exposed to poisoning if HSDVs were employed. However, risks to susceptible species should be quantified in field or pen trials prior to the implementation of a control program, and minimized further by applying baits at times and in places where non-target species have little access. PMID:25229348

  7. Vertebrate phylogeny of hydrogen sulfide vasoactivity.

    PubMed

    Dombkowski, Ryan A; Russell, Michael J; Schulman, Alexis A; Doellman, Meredith M; Olson, Kenneth R

    2005-01-01

    Hydrogen sulfide (H(2)S) is a recently identified endogenous vasodilator in mammals. In steelhead/rainbow trout (Oncorhynchus mykiss, Osteichthyes), H(2)S produces both dose-dependent dilation and a unique dose-dependent constriction. In this study, we examined H(2)S vasoactivity in all vertebrate classes to determine whether H(2)S is universally vasoactive and to identify phylogenetic and/or environmental trends. H(2)S was generated from NaHS and examined in unstimulated and precontracted systemic and, when applicable, pulmonary arteries (PA) from Pacific hagfish (Eptatretus stouti, Agnatha), sea lamprey (Petromyzon marinus, Agnatha), sandbar shark (Carcharhinus milberti, Chondrichthyes), marine toad (Bufo marinus, Amphibia), American alligator (Alligator mississippiensis, Reptilia), Pekin duck (Anas platyrhynchos domesticus, Aves), and white rat (Rattus rattus, Mammalia). In otherwise unstimulated vessels, NaHS produced 1) a dose-dependent relaxation in Pacific hagfish dorsal aorta; 2) a dose-dependent contraction in sea lamprey dorsal aorta, marine toad aorta, alligator aorta and PA, duck aorta, and rat thoracic aorta; 3) a threshold relaxation in shark ventral aorta, dorsal aorta, and afferent branchial artery; and 4) a multiphasic contraction-relaxation-contraction in the marine toad PA, duck PA, and rat PA. Precontraction of these vessels with another agonist did not affect the general pattern of NaHS vasoactivity with the exception of the rat aorta, where relaxation was now dominant. These results show that H(2)S is a phylogenetically ancient and versatile vasoregulatory molecule that appears to have been opportunistically engaged to suit both organ-specific and species-specific homeostatic requirements.

  8. Ultrastructural study of the egg wall surrounding the developing miracidia of the digenean Prosotocus confusus (Looss, 1894) (Plagiorchiida: Pleurogenidae), with the description of a unique cocoon-like envelope.

    PubMed

    Świderski, Zdzisław; Miquel, Jordi; Torres, Jordi; Conn, David Bruce

    2015-01-01

    Helminth eggs play a critical role in movement of the parasite from definitive to intermediate host. Eggs of the pleurogenid digenean trematode Prosotocus confusus (Looss, 1894), a parasite of naturally infected frogs Pelophylax lessonae (Amphibia: Ranidae) in Europe, are described here for the first time. Particular emphasis is placed on the ultrastructure on the egg wall and on the detailed description of a unique cocoon-like envelope. Each embryonating egg is composed of an early embryo surrounded by a four-layered egg wall: (1) an outer, anucleate layer external to the eggshell, which forms a thick cocoon; (2) the operculate eggshell; (3) not fully formed, a differentiating outer embryonic envelope containing large nuclei of macromeres; and (4) situated below, an undifferentiated layer of the future inner embryonic envelope containing mesomere nuclei. Layers enveloping the egg apparently play an important role in the protection, metabolism, and storage of nutritive reserves for the developing miracidium. The outer anucleate layer, or cocoon, is situated externally to the eggshell and composed of an electron-lucent substance with numerous electron-dense islands attached to its peripheral membrane. A cocoon envelope such as this has never been seen in previous TEM studies of the eggs of parasitic platyhelminths, with the exception of another pleurogenid Brandesia turgida. The origin, formation, functional ultrastructure, and chemical composition of this peculiar layer remain enigmatic, although its function appears to be protective. The thick, electron-dense eggshell resembles that of other trematodes, exhibiting a characteristic fissure zone around the operculum. Numerous lysosome-like structures observed in some eggs may be involved in the autolysis of both the embryonic envelopes (particularly the early degeneration of macromere nuclei of the outer envelope, characteristic for this species) and in the disintegration of several early micromeres. The inner

  9. Distribution, adaptation and physiological meaning of thiols from vertebrate hemoglobins.

    PubMed

    Reischl, Evaldo; Dafre, Alcir Luiz; Franco, Jeferson Luis; Wilhelm Filho, Danilo

    2007-01-01

    In the present review, the sequences of hemoglobins (Hb) of 267 adult vertebrate species belonging to eight major vertebrate taxa are examined for the presence and location of cysteinyl residues in an attempt at correlation with their ecophysiology. Essentially, all vertebrates have surface cysteinyl residues in Hb molecules whereby their thiol groups may become highly reactive. Thiol-rich Hbs may display eight or more thiols per tetramer. In vertebrates so far examined, the cysteinyl residues occur in 44 different sequence positions in alpha chains and 41 positions in beta chains. Most of them are conservatively located and occur in only a few positions in Teleostei, Aves and Mammalia, whereas they are dispersed in Amphibia. The internal cysteinyl residue alpha104 is ubiquitous in vertebrates. Residue beta93 is highly conserved in reptiles, birds and mammals. The number of cysteine residues per tetramer with solvent access varies in vertebrates, mammalians and bony fish having the lowest number of external residues, whereas nearly all external cysteine residues in Aves and Lepidosauria are of the surface crevice type. In cartilaginous fish, amphibians, Crocodylidae and fresh water turtles, a substantial portion of the solvent accessible thiols are of the totally external type. Recent evidence shows that some Hb thiol groups are highly reactive and undergo extensive and reversible S-thiolation, and that they may be implicated in interorgan redox equilibrium processes. Participation of thiol groups in nitric oxide ((*)NO) metabolism has also been proved. The evidence argues for a new physiologically relevant role for Hb via involvement in free radical and antioxidant metabolism.

  10. [Phytoplankton community structure and assessment of water quality in the middle and lower reaches of Fenhe River].

    PubMed

    Wang, Ai-Ai; Feng, Jia; Xie, Shu-Lian

    2014-03-01

    To understand the distribution of phytoplankton and the water quality in the middle and lower reaches of Fenhe River, 18 sampling sites were selected for specimen collection, species identification and data analysis. The results showed that: (1) There were 298 species of phytoplankton under the membership of 8 divisions and 96 genera, among which, Bacillariophyta was the dominant division, with a total of 127 species of 27 genera, followed by Chlorophyta, with 104 species of 41 genera, and Cyanophyta, with 45 species of 20 genera. Only 22 species of 8 genera belonged to Euglenophyta, Cryptophyta, Pyrrophyta, Chrysophyta and Xanthophyta. The number of species in wet season was higher than that in dry season at all sites. Dominant species included Cyclotella meneghiniana, Synedra acus, Navicula cryptocephala, Nitzschia palea of Bacillariophyta, Chlorella vulgaris of Chlorophyta, Oscillatoria tenuis, O. amphibia of Cyanophyta, most of which were indicator species of alpha- and beta-mesosaprobic type. Cell density was higher in wet season and lower in dry season. (2) Shannon-Wieaver species diversity index ranged from 1 to 3 basically. Margalef species richness index ranged from 0.5 to 2. Pielou evenness index ranged 0.3-0.8. (3) During the wet season, most dominant species of Chlorophyta and Euglenophyta had higher correlation with chemical oxygen demand (COD), conductivity and ammonia nitrogen. The dominant species of Cyanophyta were greatly influenced by the contents of water temperature and chromium (Cr). The distribution of dominant species of Bacillariophyta was complicatedly related with environmental factors. During the dry season, there was a higher correlation between the members of Cyanophyta and ammonia nitrogen, total phosphorus, COD. The species of Chlorophyta and Euglenophyta were mainly influenced by the dissolved oxygen and total phosphorus. The bacillariophytes were mainly related with total phosphorus, dissolved oxygen, pH and cadmium (Cd). In

  11. Disentangling Vector-Borne Transmission Networks: A Universal DNA Barcoding Method to Identify Vertebrate Hosts from Arthropod Bloodmeals

    PubMed Central

    Alcaide, Miguel; Rico, Ciro; Ruiz, Santiago; Soriguer, Ramón; Muñoz, Joaquín; Figuerola, Jordi

    2009-01-01

    Emerging infectious diseases represent a challenge for global economies and public health. About one fourth of the last pandemics have been originated by the spread of vector-borne pathogens. In this sense, the advent of modern molecular techniques has enhanced our capabilities to understand vector-host interactions and disease ecology. However, host identification protocols have poorly profited of international DNA barcoding initiatives and/or have focused exclusively on a limited array of vector species. Therefore, ascertaining the potential afforded by DNA barcoding tools in other vector-host systems of human and veterinary importance would represent a major advance in tracking pathogen life cycles and hosts. Here, we show the applicability of a novel and efficient molecular method for the identification of the vertebrate host's DNA contained in the midgut of blood-feeding arthropods. To this end, we designed a eukaryote-universal forward primer and a vertebrate-specific reverse primer to selectively amplify 758 base pairs (bp) of the vertebrate mitochondrial Cytochrome c Oxidase Subunit I (COI) gene. Our method was validated using both extensive sequence surveys from the public domain and Polymerase Chain Reaction (PCR) experiments carried out over specimens from different Classes of vertebrates (Mammalia, Aves, Reptilia and Amphibia) and invertebrate ectoparasites (Arachnida and Insecta). The analysis of mosquito, culicoid, phlebotomie, sucking bugs, and tick bloodmeals revealed up to 40 vertebrate hosts, including 23 avian, 16 mammalian and one reptilian species. Importantly, the inspection and analysis of direct sequencing electropherograms also assisted the resolving of mixed bloodmeals. We therefore provide a universal and high-throughput diagnostic tool for the study of the ecology of haematophagous invertebrates in relation to their vertebrate hosts. Such information is crucial to support the efficient management of initiatives aimed at reducing

  12. Parallel tagged amplicon sequencing of transcriptome-based genetic markers for Triturus newts with the Ion Torrent next-generation sequencing platform

    PubMed Central

    Wielstra, B; Duijm, E; Lagler, P; Lammers, Y; Meilink, W R M; Ziermann, J M; Arntzen, J W

    2014-01-01

    Next-generation sequencing is a fast and cost-effective way to obtain sequence data for nonmodel organisms for many markers and for many individuals. We describe a protocol through which we obtain orthologous markers for the crested newts (Amphibia: Salamandridae: Triturus), suitable for analysis of interspecific hybridization. We use transcriptome data of a single Triturus species and design 96 primer pairs that amplify c. 180 bp fragments positioned in 3-prime untranslated regions. Next, these markers are tested with uniplex PCR for a set of species spanning the taxonomical width of the genus Triturus. The 52 markers that consistently show a single band of expected length at gel electrophoreses for all tested crested newt species are then amplified in five multiplex PCRs (with a plexity of ten or eleven) for 132 individual newts: a set of 84 representing the seven (candidate) species and a set of 48 from a presumed hybrid population. After pooling multiplexes per individual, unique tags are ligated to link amplicons to individuals. Subsequently, individuals are pooled equimolar and sequenced on the Ion Torrent next-generation sequencing platform. A bioinformatics pipeline identifies the alleles and recodes these to a genotypic format. Next, we test the utility of our markers. baps allocates the 84 crested newt individuals representing (candidate) species to their expected (candidate) species, confirming the markers are suitable for species delineation. newhybrids, a hybrid index and hiest confirm the 48 individuals from the presumed hybrid population to be genetically admixed, illustrating the potential of the markers to identify interspecific hybridization. We expect the set of markers we designed to provide a high resolving power for analysis of hybridization in Triturus. PMID:24571307

  13. Trichospirura aethiopica n. sp. (Nematoda: Rhabdochonidae) from Malacomys longipes (Rodentia: Muridae) in Gabon, first record of the genus in the Ethiopian Realm

    PubMed Central

    Bain, Odile; Junker, Kerstin

    2013-01-01

    Trichospirura aethiopica n. sp. is described from unidentified tubular structures (pancreatic ducts?) near the stomach of the murid Malacomys longipes Milne-Edwards, 1877 in Gabon. The extremely long and narrow buccal capsule, posterior position of the vulva, unequal spicules and absence of caudal alae readily identified the specimens as belonging to Trichospirura Smith & Chitwood, 1967, but a combination of several characters distinguished them from the described species in this genus. Males of the new species are characterized by the absence of precloacal papillae, the presence of four pairs of postcloacal papillae and a left spicule length of 165–200 μm. With only five nominal and one unnamed species, the host range of Trichospirura extends into the Neotropical, Indo-Malayan and Ethiopian Realms and comprises three classes of vertebrates, Amphibia, Reptilia and Mammalia, suggesting a larger species diversity than that currently recorded. Detection is difficult as predilection sites are often outside the gut lumen. It was noted that, irrespective of their geographic origin, species from mammals share certain characters (shorter left spicule and absence of precloacal papillae) that oppose them to those from amphibians and reptiles. A hypothesis for the origin of Trichospirura in mammals through a remote host-switching event in tupaiids in southern Asia, likely facilitated by the intermediate hosts, and for their subsequent migration to the Ethiopian and finally Neotropical Realm is proposed. Regarding the two species from anurans and saurians in the Antilles, one or two host-switching events are considered equally possible, based on morphological characters. PMID:23369432

  14. Postglacial Colonization of the Qinling Mountains: Phylogeography of the Swelled Vent Frog (Feirana quadranus)

    PubMed Central

    Wang, Bin; Jiang, Jianping; Xie, Feng; Li, Cheng

    2012-01-01

    Background The influence of Pleistocene climatic fluctuations on intraspecific diversification in the Qinling–Daba Mountains of East Asia remains poorly investigated. We tested hypotheses concerning refugia during the last glacial maximum (LGM) in this region by examining the phylogeography of the swelled vent frog (Feirana quadranus; Dicroglossidae, Anura, Amphibia). Methodology/Principal Findings We obtained complete mitochondrial ND2 gene sequences of 224 individuals from 34 populations of Feirana quadranus for phylogeographic analyses. Additionally, we obtained nuclear tyrosinase gene sequences of 68 F. quadranus, one F. kangxianensis and three F. taihangnica samples to test for mitochondrial introgression among them. Phylogenetic analyses based on all genes revealed no introgression among them. Phylogenetic analyses based on ND2 datasets revealed that F. quadranus was comprised of six lineages which were separated by deep valleys; the sole exception is that the Main Qinling and Micang–Western Qinling lineages overlap in distribution. Analyses of population structure indicated restricted gene flow among lineages. Coalescent simulations and divergence dating indicated that the basal diversification within F. quadranus may be associated with the dramatic uplifts of the Tibetan Plateau during the Pliocene. Coalescent simulations indicated that Wuling, Daba, and Western Qinling–Micang–Longmen Mountains were refugia for F. quadranus during the LGM. Demographic analyses indicated that the Daba lineage experienced population size increase prior to the LGM but the Main Qinling and the Micang–Western Qinling lineages expanded in population size and range after the LGM, and the other lineages almost have stable population size or slight slow population size decline. Conclusions/Significance The Qinling–Daba Mountains hosted three refugia for F. quadranus during the LGM. Populations that originated in the Daba Mountains colonized the Main Qinling Mountains

  15. Assessing risks to non-target species during poison baiting programs for feral cats.

    PubMed

    Buckmaster, Tony; Dickman, Christopher R; Johnston, Michael J

    2014-01-01

    Poison baiting is used frequently to reduce the impacts of pest species of mammals on agricultural and biodiversity interests. However, baiting may not be appropriate if non-target species are at risk of poisoning. Here we use a desktop decision tree approach to assess the risks to non-target vertebrate species in Australia that arise from using poison baits developed to control feral house cats (Felis catus). These baits are presented in the form of sausages with toxicant implanted in the bait medium within an acid-soluble polymer capsule (hard shell delivery vehicle, or HSDV) that disintegrates after ingestion. Using criteria based on body size, diet and feeding behaviour, we assessed 221 of Australia's 3,769 native vertebrate species as likely to consume cat-baits, with 47 of these likely to ingest implanted HSDVs too. Carnivorous marsupials were judged most likely to consume both the baits and HSDVs, with some large-bodied and ground-active birds and reptiles also consuming them. If criteria were relaxed, a further 269 species were assessed as possibly able to consume baits and 343 as possibly able to consume HSDVs; most of these consumers were birds. One threatened species, the Tasmanian devil (Sarcophilus harrisii) was judged as definitely able to consume baits with implanted HSDVs, whereas five threatened species of birds and 21 species of threatened mammals were rated as possible consumers. Amphibia were not considered to be at risk. We conclude that most species of native Australian vertebrates would not consume surface-laid baits during feral cat control programs, and that significantly fewer would be exposed to poisoning if HSDVs were employed. However, risks to susceptible species should be quantified in field or pen trials prior to the implementation of a control program, and minimized further by applying baits at times and in places where non-target species have little access.

  16. Insulin receptor-related receptor as an extracellular pH sensor involved in the regulation of acid-base balance.

    PubMed

    Petrenko, Alexander G; Zozulya, Sergey A; Deyev, Igor E; Eladari, Dominique

    2013-10-01

    Recent studies of insulin receptor-related receptor (IRR) revealed its unusual property to activate upon extracellular application of mildly alkaline media, pH>7.9. The activation of IRR with hydroxyl anion has typical features of ligand-receptor interaction; it is specific, dose-dependent, involves the IRR extracellular domain and is accompanied by a major conformational change. IRR is a member of the insulin receptor minifamily and has been long viewed as an orphan receptor tyrosine kinase since no peptide or protein agonist of IRR was found. In the evolution, IRR is highly conserved since its divergence from the insulin and insulin-like growth factor receptors in amphibia. The latter two cannot be activated by alkali. Another major difference between them is that unlike ubiquitously expressed insulin and insulin-like growth factor receptors, IRR is found in specific sets of cells of only some tissues, most of them being exposed to extracorporeal liquids of extreme pH. In particular, largest concentrations of IRR are in beta-intercalated cells of the kidneys. The primary physiological function of these cells is to excrete excessive alkali as bicarbonate into urine. When IRR is removed genetically, animals loose the property to excrete bicarbonate upon experimentally induced alkalosis. In this review, we will discuss the available in vitro and in vivo data that support the hypothesis of IRR role as a physiological alkali sensor that regulates acid-base balance. This article is part of a Special Issue entitled: Emerging recognition and activation mechanisms of receptor tyrosine kinases. Copyright © 2012 Elsevier B.V. All rights reserved.

  17. "Legal highs"--toxicity in the clinical and medico-legal aspect as exemplified by suicide with bk-MBDB administration.

    PubMed

    Rojek, Sebastian; Kłys, Małgorzata; Strona, Marcin; Maciów, Martyna; Kula, Karol

    2012-10-10

    The easily available "legal highs", which are products containing psychoactive substances, such as cathinones, piperazines and synthetic cannabinoids, are abused by adolescents in Poland and in the world as alternatives to classic drugs, such as amphetamines or marijuana. The majority of these potentially dangerous substances are still legal and they are associated with a risk of severe poisoning or even death, and provide new challenges in clinical and forensic toxicological practice. Investigations in the field of "designer drugs" may be well illustrated by the case of a suicide of a 21-year old male who ingested a specified dose of a preparation called "Amphi-bi-a" that contains bk-MBDB, chemically 2-methylamino-1-(3,4-methylenedioxyphenyl) butan-1-one, which belongs to the cathinone group, as a synthetic euphoric empathogen and psychoactive stimulant that is chemically similar to MDMA. It is one of more common components of "legal highs" examined in Poland and other countries. The documentation of the case includes a clinical assessment of the patient's health status performed during his almost 4-h hospitalization before death, autopsy and histological examinations supported by toxicological findings revealing bk-MBDB at extremely high concentrations (at 20 mg/l in the blood and 33 mg/kg in the liver); hence, this body of evidence contributes to knowledge in the field of "designer drugs". Inventions of designers of new psychoactive xenobiotics, which are much in demand, especially in view of the dynamic Internet marketing, which drums up narcobusiness, must be balanced by a national strategy developed by medical, legal and educational circles in the modern civilized world in order to prevent the spreading of the phenomenon. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  18. Regulator of complement activation (RCA) gene cluster in Xenopus tropicalis.

    PubMed

    Oshiumi, Hiroyuki; Suzuki, Yuzuru; Matsumoto, Misako; Seya, Tsukasa

    2009-05-01

    Genome and expressed sequence tag information of Xenopus tropicalis suggested that short-consensus repeat (SCR)-containing proteins are encoded by three genes that are mapped within a 300-kb downstream of PFKFB2, which is a marker gene for the regulator of complement activation (RCA) loci in human and chicken. Based on this observation, we cloned the three cDNAs of these proteins using 3'- or 5'-RACE technique. Since their primary structures and locations of the proximity to the PFKFB2 locus, we named them amphibian RCA protein (ARC) 1, 2, and 3. Expression in human HEK293 or CHO cells suggested that ARC1 is a soluble protein of Mr approximately 67 kDa, ARC2 is a membrane protein with Mr 44 kDa, and ARC3 a secretary protein with a putative transmembrane region. They were N-glycosylated during maturation. In human and chicken RCA clusters, the order in which genes for soluble, GPI-anchored, and membrane forms of SCR proteins are arranged is from the distant to proximity to the PFKFB2 gene. However, the amphibian ARC1, 2, and 3 resembled one another and did not reflect the same order found in human and chicken RCA genes. This may be due to self-duplication of ARCs to form a family, and it evolved after the amphibia separated from the ancestor of the amniotes, which possessed soluble, GPI-anchored, and membrane forms of SCR protein members. Taken together, frog possesses a RCA locus, but the constitution of the ARC proteins differs from that of the amniotes with a unique self-resemblance.

  19. Dentition and dentigerous bones in juveniles and adults of Polypterus senegalus (Cladistia, Actinopterygii).

    PubMed

    Clemen, G; Bartsch, P; Wacker, K

    1998-06-01

    Tooth types, their arrangement and the mode of tooth replacement were studied in juvenile and adult specimens of Polypterus senegalus by means of scanning electron microscopy of cleared and stained specimens as well as sections. All the dermal bones of the oropharynx are almost completely covered with teeth except for the angulare. The same is true for the branchial apparatus where only the hyoid skeleton is toothless. The teeth are uniformly monocuspid and conical, but can be classified according to shape and size into three types. These types and the mode of tooth replacement are characteristic for each dermal bone. In some of the jaw bones each tooth possesses a lingually situated replacement tooth. This is true for the teeth of the premaxillary, the maxillary, and the dentary which are arranged in a single line, and those of the dermopalatine, the coronoids, and the vomer which are in several lines and graded in size. Replacement teeth of all the other dentigerous elements develop on top of existing pulpal openings, forming an anastomosing common pulpal complex only after resorption of the previous tooth. The tooth plates of the dermal bones of the branchial apparatus are connected by syndesmosis only to the perichondrally ossified and to the cartilaginous or connective tissue material of the elements of the gill-arches. The dentition and its association with the bones of the head in Polypterus senegalus bear resemblances to advanced actinopterygians on the one hand (e.g. differentiation of tooth-types, arrangement), but also some similarities to living Amphibia (anchoring material and mode of replacement) on the other. The accentuation of a single marginal line of large teeth in both, the outer and the inner dental arcade of the jaws is a peculiarity of Polypterus that in a way parallels the derived state of similar monolinear tooth arrangements in Actinopterygii and Tetrapoda.

  20. Non-invasive reproductive and stress endocrinology in amphibian conservation physiology

    PubMed Central

    Narayan, E. J.

    2013-01-01

    Non-invasive endocrinology utilizes non-invasive biological samples (such as faeces, urine, hair, aquatic media, and saliva) for the quantification of hormones in wildlife. Urinary-based enzyme immunoassay (EIA) and radio-immunoassay have enabled the rapid quantification of reproductive and stress hormones in amphibians (Anura: Amphibia). With minimal disturbance, these methods can be used to assess the ovarian and testicular endocrine functions as well as physiological stress in captive and free-living populations. Non-invasive endocrine monitoring has therefore greatly advanced our knowledge of the functioning of the stress endocrine system (the hypothalamo–pituitary–interrenal axis) and the reproductive endocrine system (the hypothalamo–pituitary–gonadal axis) in the amphibian physiological stress response, reproductive ecology, health and welfare, and survival. Biological (physiological) validation is necessary for obtaining the excretory lag time of hormone metabolites. Urinary-based EIA for the major reproductive hormones, estradiol and progesterone in females and testosterone in males, can be used to track the reproductive hormone profiles in relationship to reproductive behaviour and environmental data in free-living anurans. Urinary-based corticosterone metabolite EIA can be used to assess the sublethal impacts of biological stressors (such as invasive species and pathogenic diseases) as well as anthropogenic induced environmental stressors (e.g. extreme temperatures) on free-living populations. Non-invasive endocrine methods can also assist in the diagnosis of success or failure of captive breeding programmes by measuring the longitudinal patterns of changes in reproductive hormones and corticosterone within captive anurans and comparing the endocrine profiles with health records and reproductive behaviour. This review paper focuses on the reproductive and the stress endocrinology of anurans and demonstrates the uses of non-invasive endocrinology

  1. The effect of metapopulation dynamics on the survival and spread of a novel, conspicuous prey.

    PubMed

    Lee, Thomas J; Speed, Michael P

    2010-12-07

    Animals that deploy chemical defences against predators often signal their unprofitability using bright colouration. This pairing of toxicity and conspicuous patterning is known as aposematism. Explaining the evolution and spread of aposematic traits in previously cryptic species has been the focus of much empirical and theoretical work over the last two decades. Existing research concerning the initial evolution of aposematism does not however properly consider that many aposematic species (such as members of the hymenoptera, the lepidoptera, and amphibia) are highly mobile. We argue in this paper that the evolution of aposematic displays is therefore often best understood within a metapopulation framework; hence in this paper we present the first explicit metapopulation model of the evolution of aposematism. Our most general finding is that migration tends to reduce the probability that an aposematic prey can increase from rarity and spread across a large population. Hence, the best case scenarios for the spread of aposematism required fixation of the aposematic form in one or more isolated sub-habitats prior to some event which subsequently enabled migration. We observed that changes in frequency of new aposematic forms within source habitats are likely to be nonmonotonic. First, aposematic prey tend to decline in frequency as they migrate outwards from the source habitat to neighbouring sink habitats, but subsequently they increase in relative abundance in the source, as the descendents of earlier migrants migrate back from newly converted sub-populations. This pattern of initial loss and subsequent gain between new source and neighbouring sink habitats is then repeated as the aposematic form spreads via a moving cline.

  2. Priority areas for anuran conservation using biogeographical data: a comparison of greedy, rarity, and simulated annealing algorithms to define reserve networks in cerrado.

    PubMed

    Diniz-Filho, J A F; Bini, L M; Bastos, R P; Vieira, C M; Vieira, L C G

    2005-05-01

    Spatial patterns in biodiversity variation at a regional scale are rarely taken into account when a natural reserve is to be established, despite many available methods for determining them. In this paper, we used dimensions of occurrence of 105 species of Anura (Amphibia) in the cerrado region of central Brazil to create a regional system of potential areas that preserves all regional diversity, using three different algorithms to establish reserve networks: "greedy", rarity, and simulated annealing algorithms. These generated networks based on complementarity with 10, 12, and 8 regions, respectively, widely distributed in the biome, and encompassing various Brazilian states. Although the purpose of these algorithms is to find a small number of regions for which all species are represented at least once, the results showed that 67.6%, 76.2%, and 69.5% of the species were represented in two or more regions in the three networks. Simulated annealing produced the smallest network, but it left out three species (one endemic). On the other hand, while the greedy algorithm produce a smaller solution, the rarity-based algorithm ensured that more species were represented more than once, which can be advantageous because it takes into consideration the high levels of habitat loss in the cerrado. Although usually coarse, these macro-scale approaches can provide overall guidelines for conservation and are useful in determining the focus for more local and effective conservation efforts, which is especially important when dealing with a taxonomic group such as anurans, for which quick and drastic population declines have been reported throughout the world.

  3. A novel olfactory receptor gene family in teleost fish.

    PubMed

    Saraiva, Luis R; Korsching, Sigrun I

    2007-10-01

    While for two of three mammalian olfactory receptor families (OR and V2R) ortholog teleost families have been identified, the third family (V1R) has been thought to be represented by a single, closely linked gene pair. We identified four further V1R-like genes in every teleost species analyzed (Danio rerio, Gasterosteus aculeatus, Oryzias latipes, Tetraodon nigroviridis, Takifugu rubripes). In the phylogenetic analysis these ora genes (olfactory receptor class A-related) form a single clade, which includes the entire mammalian V1R superfamily. Homologies are much lower in paralogs than in orthologs, indicating that all six family members are evolutionarily much older than the speciation events in the teleost lineage analyzed here. These ora genes are under strong negative selection, as evidenced by very small d(N)/d(S) values in comparisons between orthologs. A pairwise configuration in the phylogenetic tree suggests the existence of three ancestral Ora subclades, one of which has been lost in amphibia, and a further one in mammals. Unexpectedly, two ora genes exhibit a highly conserved multi-exonic structure and four ora genes are organized in closely linked gene pairs across all fish species studied. All ora genes are expressed specifically in the olfactory epithelium of zebrafish, in sparse cells within the sensory surface, consistent with the expectation for olfactory receptors. The ora gene repertoire is highly conserved across teleosts, in striking contrast to the frequent species-specific expansions observed in tetrapod, especially mammalian V1Rs, possibly reflecting a major shift in gene regulation as well as gene function upon the transition to tetrapods.

  4. Assembly of ovarian follicles in the caecilians Ichthyophis tricolor and Gegeneophis ramaswamii: light and transmission electron microscopic study.

    PubMed

    Beyo, R S; Sreejith, P; Divya, L; Oommen, O V; Akbarsha, M A

    2007-08-01

    Though much is known about various aspects of reproductive biology of amphibia, there is little information on the cellular and mechanistic basis of assembly of ovarian follicles in this group. This is especially true of the caecilians. Therefore, taking advantage of the abundant distribution of caecilians in the Western Ghats of India, two species of caecilians, Ichthyophis tricolor and Gegeneophis ramaswamii, were subjected to light and transmission electron microscopic analysis to trace the sequential changes during the assembly of ovarian follicles. The paired ovaries of these caecilians are elongated sac-like structures each including numerous vitellogenic follicles. The follicles are connected by a connective tissue stroma. This stroma contains nests of oogonia, primary oocytes and pregranulosa cells as spatially separated nests. During assembly of follicles the oocytes increase in size and enter the meiotic prophase when the number of nucleoli in the nucleus increases. The mitochondrial cloud or Balbiani vitelline body, initially localized at one pole of the nucleus, disperses through out the cytoplasm subsequently. Synaptonemal complexes are prominent in the pachytene stage oocytes. The pregranulosa cells migrate through the connective tissue fibrils of the stroma and arrive at the vicinity of the meiotic prophase oocytes. On contacting the oocyte, the pregranulosa cells become cuboidal in shape, wrap the diplotene stage oocyte as a discontinuous layer and increase the content of cytoplasmic organelles and inclusions. The oocytes increase in size and are arrested in diplotene when the granulosa cells become flat and form a continuous layer. Soon a perivitelline space appears between the oolemma and granulosa cells, completing the process of assembly of follicles. Thus, the events in the establishment of follicles in the caecilian ovary are described.

  5. Gene structure, transcripts and calciotropic effects of the PTH family of peptides in Xenopus and chicken

    PubMed Central

    2010-01-01

    PTH-L. It is hypothesized that genes of the PTH family appeared at approximately the same time during the vertebrate radiation and evolved via gene duplication/deletion events. PTH-L was lost from the genome of eutherian mammals and PTH, which has a paracrine distribution in lower vertebrates, became the product of a specific endocrine tissue in Amphibia, the parathyroid gland. The PTHrP gene organisation diverged and became more complex in vertebrates and retained its widespread tissue distribution which is congruent with its paracrine nature. PMID:21122104

  6. Spermatogenesis in nonmammalian vertebrates.

    PubMed

    Pudney, J

    1995-12-15

    Spermatogenesis appears to be a fairly conserved process throughout the vertebrate series. Thus, spermatogonia develop into spermatocytes that undergo meiosis to produce spermatids which enter spermiogenesis where they undergo a morphological transformation into spermatozoa. There is, however, variation amongst the vertebrates in how germ cell development and maturation is accomplished. This difference can be broadly divided into two distinct patterns, one present in anamniotes (fish, amphibia) and the other in amniotes (reptiles, birds, mammals). For anamniotes, spermatogenesis occurs in spermatocysts (cysts) which for most species develop within seminiferous lobules. Cysts are produced when a Sertoli cell becomes associated with a primary spermatogonium. Mitotic divisions of the primary spermatogonium produce a cohort of secondary spermatogonia that are enclosed by the Sertoli cell which forms the wall of the cyst. With spermatogenic progression a clone of isogeneic spermatozoa is produced which are released, by rupture of the cyst, into the lumen of the seminiferous lobule. Following spermiation, the Sertoli cell degenerates. For anamniotes, therefore, there is no permanent germinal epithelium since spermatocysts have to be replaced during successive breeding seasons. By contrast, spermatogenesis in amniotes does not occur in cysts but in seminiferous tubules that possess a permanent population of Sertoli cells and spermatogonia which act as a germ cell reservoir for succeeding bouts of spermatogenic activity. There is, in general, a greater variation in the organization of the testis and pattern of spermatogenesis in the anamniotes compared to amniotes. This is primarily due to the fact there is more reproductive diversity in anamniotes ranging from a relatively unspecialized condition where gametes are simply released into the aqueous environment to highly specialized strategies involving internal fertilization. These differences are obviously reflected in the

  7. Asymmetry in the epithalamus of vertebrates

    PubMed Central

    L. CONCHA, MIGUEL; W. WILSON, STEPHEN

    2001-01-01

    The epithalamus is a major subdivision of the diencephalon constituted by the habenular nuclei and pineal complex. Structural asymmetries in this region are widespread amongst vertebrates and involve differences in size, neuronal organisation, neurochemistry and connectivity. In species that possess a photoreceptive parapineal organ, this structure projects asymmetrically to the left habenula, and in teleosts it is also situated on the left side of the brain. Asymmetries in size between the left and right sides of the habenula are often associated with asymmetries in neuronal organisation, although these two types of asymmetry follow different evolutionary courses. While the former is more conspicuous in fishes (with the exception of teleosts), asymmetries in neuronal organisation are more robust in amphibia and reptiles. Connectivity of the parapineal organ with the left habenula is not always coupled with asymmetries in habenular size and/or neuronal organisation suggesting that, at least in some species, assignment of parapineal and habenular asymmetries may be independent events. The evolutionary origins of epithalamic structures are uncertain but asymmetry in this region is likely to have existed at the origin of the vertebrate, perhaps even the chordate, lineage. In at least some extant vertebrate species, epithalamic asymmetries are established early in development, suggesting a genetic regulation of asymmetry. In some cases, epigenetic factors such as hormones also influence the development of sexually dimorphic habenular asymmetries. Although the genetic and developmental mechanisms by which neuroanatomical asymmetries are established remain obscure, some clues regarding the mechanisms underlying laterality decisions have recently come from studies in zebrafish. The Nodal signalling pathway regulates laterality by biasing an otherwise stochastic laterality decision to the left side of the epithalamus. This genetic mechanism ensures a consistency of

  8. The corneal surface of aquatic vertebrates: microstructures with optical and nutritional function?

    PubMed Central

    Collin, H B; Collin, S P

    2000-01-01

    The anterior surface of the mammalian cornea plays an important role in maintaining a smooth optical interface and consequently a sharp retinal image. The smooth surface is produced by a tear film, which adheres to a variety of microprojections, which increase the cell surface area, improve the absorbance of oxygen and nutrients and aid in the movement of metabolic products across the outer cell membrane. However, little is known of the structural adaptations and tear film support provided in other vertebrates from different environments. Using field emission scanning electron microscopy; this study examines the density and surface structure of corneal epithelial cells in representative species of the classes Cephalaspidomorphi, Chondrichthyes, Osteichthyes, Amphibia, Reptilia, Aves and Mammalia, including some Marsupialia. Variations in cell density and the structure and occurrence of microholes, microridges, microplicae and microvilli are described with respect to the demands placed upon the cornea in different aquatic environments such as marine and freshwater. A progressive decrease in epithelial cell density occurs from marine (e.g. 29348 cells mm(-2) in the Dover sole Microstomius pacficus) to estuarine or freshwater (e.g. 5999 cells mm(-2) in the black bream Acanthopagrus butcheri) to terrestrial (e.g. 2126 cells mm(-2) in the Australian koala Phascolarctos cinereus) vertebrates, indicating the reduction in osmotic stress across the corneal surface. The microholes found in the Southern Hemisphere lampreys, namely the pouched lamprey (Geotria australis) and the shorthead lamprey (Mordacia mordax) represent openings for the release of mucus, which may protect the cornea from abrasion during their burrowing phase. Characteristic of marine teleosts, fingerprint-like patterns of corneal microridges are a ubiquitous feature, covering many types of sensory epithelia (including the olfactory epithelium and the oral mucosa). Like microplicae and microvilli

  9. Impact of Natural and Man-Made Factors on Mineral Composition of the Ardon River Water and Hydrophytes

    NASA Astrophysics Data System (ADS)

    Vadim, Ermakov; Elena, Korobova; Alexander, Degtyarev; Nina, Petrunina; Sergey, Tyutikov

    2013-04-01

    The Unal basin located in mountain region of Northern Ossetia (the Caucasus) belongs to Pb-Zn natural province with anthropogenic and natural transformation of the environment leading to risks of ecological damage. Activity of the Misursk Mining Combine and its Arkhon-Khosta tailings caused a significant local increase of Pb, Cd, Cu, Zn content in soils, water and biotic components relative to background values [1-5]. A catastrophic mud flow of 2002 and the later construction of a gas pipeline and a dam for hydroelectric power station changed local landscapes and biota (plants, algae, and amphibia). Biogeochemical studies performed in the area in 2001, 2003 and 2008 showed that in some cases the specified factors might change the structure of landscapes due to enhanced mass migration and the erosion of outcropping rocks which could be followed by corresponding transformation of the chemical composition of draining waters and flood plain soils, and could also change the character of species' invasion. Algae were proved to adapt and to indicate both natural and man-made transformation of the environment [3, 4]. A distinct relation between the particle size of the suspended matter in the Ardon river waters and water mineralization was discovered. However, heavy metals' concentration level in waters of the Ardon river appeared in general to be within the acceptable hygienic standards and therefore ecologically not critical. References 1. Degtyarev V.P., Ermakov V.V. Ecological and geochemical evaluation of the the Ardon river basin (Northern Ossetia). Geokhimiya, 1998, 1, 88-94. 2. Karpova E.A., Krechetova E.V., Degtyarev V.P. Parameters of heavy metal migration in soils of biogeochemical anomalies of the Northern Ossetia. Modern problems of soil contamination, Moscow State University, V. 1, 2007, 106-110. 3. Petrunina N.S., Ermakov V.V., Tuytikov S.F., Karpova E.A., Levkina L.M., Gololobova M.A. Biogeochemical identification of natural and technogenic polymetallic

  10. Spray droplet size, drift potential, and risks to nontarget organisms from aerially applied glyphosate for coca control in Colombia.

    PubMed

    Hewitt, Andrew J; Solomon, Keith R; Marshall, E J P

    2009-01-01

    end of the spray boom as recorded electronically +/-5%) for protection of sensitive plants were 50-120 m for coca spray scenarios and considerably lower for poppy spray scenarios. The equivalent buffer zone for amphibia was 5 m. The low toxicity of glyphosate to humans suggests that these aerial applications are not a concern for human health.

  11. DIRS-1 and the other tyrosine recombinase retrotransposons.

    PubMed

    Poulter, R T M; Goodwin, T J D

    2005-01-01

    wide range of animals including nematodes, insects, sea urchins, fish and amphibia, while remnants of elements related to DIRS-1 occur in the human genome. The complete set of YR retrotransposons can be divided into two major groups, the DIRS elements and the Ngaro elements, the two groups forming distinct clades on phylogenetic trees based on alignments of RT/RH and recombinase sequences, and also having some structural distinctions. A third group of transposable elements, which we call Cryptons, also carry tyrosine recombinases. These elements do not encode a reverse transcriptase and so are believed to be DNA transposons not retrotransposons. They have been detected in several pathogenic fungi, including the basidiomycete Cryptococcus neoformans, and the ascomycetes Coccidioides posadasii and Histoplasma capsulatum. Sequence comparisons suggest that the Crypton YRs are related to those of the YR retrotransposons. We suggest that the YR retrotransposons arose from the combination of a Crypton-like YR DNA transposon and the RT/RH encoding sequence of a retrotransposon.

  12. Distribution of algae in the San Joaquin River, California, in relation to nutrient supply, salinity and other environmental factors

    USGS Publications Warehouse

    Leland, H.V.; Brown, L.R.; Mueller, D.K.

    2001-01-01

    ., were the principal late-summer benthic species upstream in the mainstem and in drainages of the San Joaquin Valley. Many of the other abundant diatoms (Amphora veneta, Bacillaria paxillifer, Navicula symmetrica, Nitzschia amphibia, N. fonticola, N. palea, Pleurosigma salinarum) of late-summer assemblages in these segments also are motile species. While many of these species also were abundant in segments downstream of confluences with rivers draining the Sierra Nevada, the relative abundance of prostrate (Cocconeis placentula var. euglypta, Navicula minima) and erect or stalked (Achnanthidium deflexum, Achnanthes lanceolata, Gomphonema kobayasii, G. parvulum var. lagenula) diatoms and Stigeoclonium sp. was greater in these lower San Joaquin River segments.5. A weighted-averaging regression model, based on salinity and benthic-algal abundance in the San Joaquin River and segments of its major tributaries within the San Joaquin Valley, yielded a highly significant coefficient-of-determination (r2 = 0.84) and low prediction error between salinity inferred from the species and that observed, indicating that salinity tolerance is a primary constraint on growth and assembly of the phytobenthos. The same measures of predictability indicated poor performance of a model based on inorganic nitrogen. However, with a greater representation of tributaries (including segments within the Sierra Nevada foothills) in the sample set, an inorganic nitrogen model also yielded a highly significant coefficient-of-determination (r2 = 0.87) and low prediction error between the species-inferred and the observed concentration. As with the salinity model (r2 = 0.94) for the enlarged data set, a systematic difference (increased deviation of residuals) existed at high inorganic nitrogen concentrations. These results indicate substantial interaction between salinity and inorganic nitrogen as constraints on the structure of benthic-algal communities of the San Joaquin River basin.

  13. Dose rate estimation of the Tohoku hynobiid salamander, Hynobius lichenatus, in Fukushima.

    PubMed

    Fuma, Shoichi; Ihara, Sadao; Kawaguchi, Isao; Ishikawa, Takahiro; Watanabe, Yoshito; Kubota, Yoshihisa; Sato, Youji; Takahashi, Hiroyuki; Aono, Tatsuo; Ishii, Nobuyoshi; Soeda, Haruhi; Matsui, Kumi; Une, Yumi; Minamiya, Yukio; Yoshida, Satoshi

    2015-05-01

    The radiological risks to the Tohoku hynobiid salamanders (class Amphibia), Hynobius lichenatus due to the Fukushima Dai-ichi Nuclear Power Plant accident were assessed in Fukushima Prefecture, including evacuation areas. Aquatic egg clutches (n = 1 for each sampling date and site; n = 4 in total), overwintering larvae (n = 1-5 for each sampling date and site; n = 17 in total), and terrestrial juveniles or adults (n = 1 or 3 for each sampling date and site; n = 12 in total) of H. lichenatus were collected from the end of April 2011 to April 2013. Environmental media such as litter (n = 1-5 for each sampling date and site; n = 30 in total), soil (n = 1-8 for each sampling date and site; n = 31 in total), water (n = 1 for each sampling date and site; n = 17 in total), and sediment (n = 1 for each sampling date and site; n = 17 in total) were also collected. Activity concentrations of (134)Cs + (137)Cs were 1.9-2800, 0.13-320, and 0.51-220 kBq (dry kg) (-1) in the litter, soil, and sediment samples, respectively, and were 0.31-220 and <0.29-40 kBq (wet kg)(-1) in the adult and larval salamanders, respectively. External and internal absorbed dose rates to H. lichenatus were calculated from these activity concentration data, using the ERICA Assessment Tool methodology. External dose rates were also measured in situ with glass dosimeters. There was agreement within a factor of 2 between the calculated and measured external dose rates. In the most severely contaminated habitat of this salamander, a northern part of Abukuma Mountains, the highest total dose rates were estimated to be 50 and 15 μGy h(-1) for the adults and overwintering larvae, respectively. Growth and survival of H. lichenatus was not affected at a dose rate of up to 490 μGy h(-1) in the previous laboratory chronic gamma-irradiation experiment, and thus growth and survival of this salamander would not be affected, even in the most severely contaminated habitat in Fukushima Prefecture. However, further

  14. THE METAMORPHOSIS OF THE ENDOSTYLE (THYROID GLAND) OF AMMOCOETES BRANCHIALIS (LARVAL LAND-LOCKED PETROMYZON MARINUS (JORDAN) OR PETROMYZON DORSATUS (WILDER)).

    PubMed

    Marine, D

    1913-04-01

    The first specimen of Ammocoetes branchialis that showed histologically any atrophic changes in the endostyle was taken on July 16. These changes proceeded relatively rapidly for about a month, after which the endostyle as such was no longer recognized. All specimens examined after August 15 showed in cross section the characteristic ductless follicles more or less completely formed. More gradual and minor changes in the way of further absorption of cell remnants and completion of the follicles continued at least until September 1. Two specimens taken from the creek on September 4, 1911. showed complete follicle formation with some stainable colloid (figures 14 and 15). There was still yellow granular pigment in the fibrous tissue between the follicles. In two specimens taken on October 14, 1909, the pigment was absent and the follicles were more closely set, larger, and contained homogenous colloid. In the twenty-four specimens of ammocoetes studied, there were variations in the time of the onset of metamorphosis. There may also be variations in the rate of progress of the changes in different specimens. There is no evidence that removal of the animals from their native environment to the laboratory either increases or decreases the rate of metamorphosis. Schneider states that he was unable to get specimens kept in the laboratory to undergo metamorphosis. Gage, however, has repeatedly observed the metamorphosis under laboratory conditions, and the six of our specimens kept in the laboratory-some for forty days-remained in excellent condition and the metamorphosis proceeded as well as in those living in the creek. I know of no observations bearing on the question as to whether the metamorphosis may be hastened or delayed as it can be in tadpoles and other amphibia. It is probable, however, that physical conditions greatly influence the transformation. These observations as to the length of time from the inception to the completion of metamorphosis indicate that a