Bruce, A J
An unusual species of the genus Periclimenaeus Borradaile, 1915 (Crustacea: Decapoda: Palaemonidae Pontoniinae) from Heron Island, Queensland, Australia, collected by Dr Niel Bruce in 1979, is described and illustrated. Periclimenaeus denticulodigitus sp. nov., an ascidian associate was collected from coral reef at 7.0 m and presents some interesting new features. It increases to 17 the number of Periclimenaeus known from Heron Island, Queensland, and to 28 the number of species known from Australia. The new species has the second pereiopod fingers minutely denticulate and unique to the genus.
Kim, Sanghee; Kim, Taeho; Choi, Han-Gu; Park, Joong-Ki; Ahn, Dong-Ha; Min, Gi-Sik
We determined a full-length sequence of mitochondrial (mt) genome from Upogebia major. This is the first complete mt genome report for infraorder Thalassinidea in Decapoda, Crustacea. Our result showed that U. major generally followed a typical pancrustacean gene order but some tRNA genes showed a very unique gene arrangement such as duplication or translocation. Since none of the complete mt genome sequences in the infraorder Thalassinidea are available yet, this report will provide additional information in relation to mt genome diversity and evolution of the decapods.
In 1975, a recent member of a large group of Crustacea Decapoda was described as Neoglyphea inopinata Forest & de Saint Laurent, until now only known as fossils and presumed extinct since the Eocene. The only known specimen had been collected in the Philippine waters, in 1908, at a depth of 200 m. During the next years, three oceanographical expeditions gave more adult specimens, allowing complete study of the species. From its morphology, it appeared that the status attributed to glypheids in the past in the classification of Decapoda Crustacea was quite erroneous. This group, until then considered as related to Palinurids (rock lobsters) was in fact much closer to Astacids (lobster, crayfish, etc.). In 1982, N. inopinata was recorded from the other side of Equator, from the Timor Sea. In October 2005, a second living species of glypheid was discovered southwest of New Caledonia. It was named Neoglyphea neocaledonica B. Richer de Forges, 2006. However, important and significant differences set apart the two species, especially the ornamentation of the cephalothorax, the conformation of the cephalic part and the proportions of epistom and thoracic appendages, being much more robust. It seems justified to establish, for the more recently described species, a new genus, Laurentaeglyphea, much closer to fossil forms.
Wardiatno, Yusli; Hakim, Agus Alim; Mashar, Ali; Butet, Nurlisa Alias; Adrianto, Luky; Farajallah, Achmad
Three specimens of Puerulus mesodontus Chan, Ma & Chu, 2013 (Crustacea, Decapoda, Achelata, Palinuridae) were collected from Palabuhanratu Bay, southern Java, Indonesia. There is no previous record on the presence of the species in Indonesia. This finding represents the first record of this species in Java, Indonesia, and confirms that the species is present in the Indian Ocean. The morphological characters of the species are described. This paper contains a new distribution record of a lobster species from Indonesian waters.
Keenan, S.; Alikhan, M.A. )
The purpose of the study reported in this paper was to compare concentrations of lead and cadmium in the sediment and water, as well as in the crayfish, Cambarus Bartoni (Fab.) (Decapoda - Crustacea) trapped from an acidic and a neutral lake in the Sudbury district of Northeastern Ontario. Hepatopancreatic, alimentary canal, tail muscles and exoskeletal concentrations in the crayfish are also examined to determine specific tissue sites for these accumulations.
Meng, Xian-Liang; Jia, Fu-Long; Liu, Ping; Li, Jian
The complete mitochondrial genome (mitogenome) of the blue swimming crab Portunus pelagicus Linnaeus, 1766 (Crustacea: Decapoda: Portunidae) was determined in this study. The full length mitogenome is 16 157 bp in size, and consists of 13 protein-coding genes, 22 tRNA genes, two rRNA genes, and a non-coding control region, with the base composition of 33.70% for A, 18.99% for C, 12.22% for G, and 35.09% for T. The gene order of P. pelagicus mainly retains as the pancrustacean ground pattern, except for a single translocation of tRNA(His) gene. The mitogenome data provide a basis for further studies on population genetics and phylogenetics.
Hakim, Agus Alim; Mashar, Ali; Butet, Nurlisa Alias; Adrianto, Luky; Farajallah, Achmad
Abstract Background Three specimens of Puerulus mesodontus Chan, Ma & Chu, 2013 (Crustacea, Decapoda, Achelata, Palinuridae) were collected from Palabuhanratu Bay, southern Java, Indonesia. There is no previous record on the presence of the species in Indonesia. This finding represents the first record of this species in Java, Indonesia, and confirms that the species is present in the Indian Ocean. The morphological characters of the species are described. New information This paper contains a new distribution record of a lobster species from Indonesian waters. PMID:27099562
Background The evolutionary history and relationships of the mud shrimps (Crustacea: Decapoda: Gebiidea and Axiidea) are contentious, with previous attempts revealing mixed results. The mud shrimps were once classified in the infraorder Thalassinidea. Recent molecular phylogenetic analyses, however, suggest separation of the group into two individual infraorders, Gebiidea and Axiidea. Mitochondrial (mt) genome sequence and structure can be especially powerful in resolving higher systematic relationships that may offer new insights into the phylogeny of the mud shrimps and the other decapod infraorders, and test the hypothesis of dividing the mud shrimps into two infraorders. Results We present the complete mitochondrial genome sequences of five mud shrimps, Austinogebia edulis, Upogebia major, Thalassina kelanang (Gebiidea), Nihonotrypaea thermophilus and Neaxius glyptocercus (Axiidea). All five genomes encode a standard set of 13 protein-coding genes, two ribosomal RNA genes, 22 transfer RNA genes and a putative control region. Except for T. kelanang, mud shrimp mitochondrial genomes exhibited rearrangements and novel patterns compared to the pancrustacean ground pattern. Each of the two Gebiidea species (A. edulis and U. major) and two Axiidea species (N. glyptocercus and N. thermophiles) share unique gene order specific to their infraorders and analyses further suggest these two derived gene orders have evolved independently. Phylogenetic analyses based on the concatenated nucleotide and amino acid sequences of 13 protein-coding genes indicate the possible polyphyly of mud shrimps, supporting the division of the group into two infraorders. However, the infraordinal relationships among the Gebiidea and Axiidea, and other reptants are poorly resolved. The inclusion of mt genome from more taxa, in particular the reptant infraorders Polychelida and Glypheidea is required in further analysis. Conclusions Phylogenetic analyses on the mt genome sequences and the
Lin, Feng-Jiau; Liu, Yuan; Sha, Zhongli; Tsang, Ling Ming; Chu, Ka Hou; Chan, Tin-Yam; Liu, Ruiyu; Cui, Zhaoxia
The evolutionary history and relationships of the mud shrimps (Crustacea: Decapoda: Gebiidea and Axiidea) are contentious, with previous attempts revealing mixed results. The mud shrimps were once classified in the infraorder Thalassinidea. Recent molecular phylogenetic analyses, however, suggest separation of the group into two individual infraorders, Gebiidea and Axiidea. Mitochondrial (mt) genome sequence and structure can be especially powerful in resolving higher systematic relationships that may offer new insights into the phylogeny of the mud shrimps and the other decapod infraorders, and test the hypothesis of dividing the mud shrimps into two infraorders. We present the complete mitochondrial genome sequences of five mud shrimps, Austinogebia edulis, Upogebia major, Thalassina kelanang (Gebiidea), Nihonotrypaea thermophilus and Neaxius glyptocercus (Axiidea). All five genomes encode a standard set of 13 protein-coding genes, two ribosomal RNA genes, 22 transfer RNA genes and a putative control region. Except for T. kelanang, mud shrimp mitochondrial genomes exhibited rearrangements and novel patterns compared to the pancrustacean ground pattern. Each of the two Gebiidea species (A. edulis and U. major) and two Axiidea species (N. glyptocercus and N. thermophiles) share unique gene order specific to their infraorders and analyses further suggest these two derived gene orders have evolved independently. Phylogenetic analyses based on the concatenated nucleotide and amino acid sequences of 13 protein-coding genes indicate the possible polyphyly of mud shrimps, supporting the division of the group into two infraorders. However, the infraordinal relationships among the Gebiidea and Axiidea, and other reptants are poorly resolved. The inclusion of mt genome from more taxa, in particular the reptant infraorders Polychelida and Glypheidea is required in further analysis. Phylogenetic analyses on the mt genome sequences and the distinct gene orders provide further
Yu, Yan-Qin; Yang, Wei-Jun; Yang, Jin-Shu
In this study we determined the complete mitochondrial genome (mitogenome) of the Chinese swamp shrimp Neocaridina denticulata sinensis Kemp, 1918 (Decapoda, Atyidae). The mitogenome consists of 15,561 bp encoding 37 genes that are involved in mitochondrial protein synthesis as well as respiration chain/oxidative phosphorylation. Besides, a 672-bp putative control region was identified between the small subunit ribosomal RNA and tRNA-Ile genes, the size and AT content of which is moderate within the Decapoda. The gene arrangement of the mitogenome follows the pancrustacean ancestral pattern shared by the decapod subfamily Dendrobranchiata, pleocyematan infrafamilies Caridea and Palinura. Our results will provide important data for various levels of phylogeny and further evolution.
Shen, Xin; Li, Xiao; Sha, Zhongli; Yan, Binlun; Xu, Qihua
The complete sequence of the mitochondrial genome of the Japanese snapping shrimp Alpheus japonicus Miers (Crustacea: Decapoda: Caridea) is presented here. A comparative analysis based on the currently available mitochondrial genomic data revealed many previously unknown characteristics of the mitochondrial genomes of caridean shrimps. The A. japonicus mitochondrial genome is 16487 bp long and contains the typical set of 37 metazoan genes. The gene arrangements in the mitochondrial genomes of four previously studied carideans (Macrobrachium rosenbergii, M. nipponense, M. lanchesteri and Halocaridina rubra) were found to be identical to the pancrustacean ground pattern; thus, it was considered that gene rearrangements probably did not occur in the suborder Caridea. In the present study, a translocation of the trnE gene involving inversion was found in Alpheus mitochondrial genomes. This phenomenon has not been reported in any other crustacean mitochondrial genome that has been studied so far; however, the translocation of one transfer RNA gene (trnP or trnT) was reported in the mitochondrial genome of Exopalaemon carinicauda. When the ratios of the nonsynonymous and synonymous substitutions rates (Ka/Ks) for the 13 protein coding genes from two Alpheus species (A. japonicus and A. distinguendus) and three Macrobrachium species (M. rosenbergii, M. nipponense, M. lanchesteri) were calculated, the Ka/Ks values for all the protein coding genes in Alpheus and Macrobrachium mitochondrial genomes were found to be less than 1 (between 0.0048 and 0.2057), indicating that a strong purification selection had occurred. The phylogenetic tree that was constructed based on the mitochondrial protein coding genes in the genomes of nine related species indicated that Palaemonidae and Alpheidae formed a monophyly and shared a statistically significant relationship, (Palaemonidae+Alpheidae)+Atyidae, at the family level.
The fiddler crab Uca formosensis Rathbun, 1921 (Crustacea: Decapoda: Ocypodidae), restricted to the western part of Taiwan and the offshore Penghu (Pescadores) Islands in the Taiwan Strait, has been placed under the subgenus Uca (Gelasimus) Latreille, 1817 (= Uca (Thalassuca) Crane, 1975) based on only less than a dozen specimens, but later suggested under the subgenus Tubuca Bott, 1973 because the similarity of external morphology. A suite of characters of carapace, major cheliped, gastric mill, male first gonopod, and chela handedness, as well as the phylogenic relationships (mitochondrial 16S rDNA and cytochrome oxidase subunit I, and nuclear 28S rDNA), nevertheless support this species belongs to its own subgenus. A new subgenus Uca (Xeruca) subgen. nov. is herein established for U. formosensis.
Capezzuto, Francesca; Maiorano, Porzia; Panza, Michele; Indennidate, Antonella; Sion, Letizia; D'Onghia, Gianfranco
Occurrence and behaviour of Paromola cuvieri (Crustacea, Decapoda) were recorded by means of the MEMO lander equipped with two digital cameras and deployed in the cold-water coral community of the Santa Maria di Leuca (Mediterranean Sea). A total of 14 individuals were observed at depths between 547 and 648 m; 10 in the coral habitat on coral mounds and 4 off the coral habitat on muddy bottoms. Thirteen specimens recorded were females, one male and all were shown to scavenge the bait. All the specimens carried a sponge on their exoskeleton using the fifth pereiopods. The specimens were distinguishable by the size and shape of the carried sponge. The present observations demonstrate both passive covering behaviour and active behaviour of discouraging approach and attack from competitors or predators, respectively. This study represents the first in situ documentation of Paromola cuvieri behaviour interacting with other deep-sea species in the Mediterranean Sea.
Crustacea Decapoda and Stomatopoda are inventoried for the first time in Juan de Nova Island, Iles Eparses, Mozambique channel. In total, 112 species are reported: 69 crabs, 28 anomurans, 11 shrimps, 3 mantis shrimps and 1 lobster. A comparison is made with nearby islands in the Mozambique channel: Glorieuses Islands (157 species), Europa Island (178 species), and Mayotte Island (505 species). The lower species richness at Juan de Nova is explained by the small size of the island and by the difficulties to collect the crustaceans on the reef flat hardly accessible at low tide. The crustaceans are listed by main habitats from land to outer reef (2-20 m). The presence of the coconut crab (Birgus latro), an endangered species vulnerable to human predation, is confirmed.
Yu, Yan-Qin; Ma, Wen-Ming; Yang, Wei-Jun; Yang, Jin-Shu
In this study we sequenced and analyzed the complete mitochondrial genome (mitogenome) of the lined shore crab Pachygrapsus crassipes Randall, 1840 (Crustacea: Grapsidae). The full-length P. crassipes mitogenome is 15,652 bp in size, which encodes the same 37 genes as all metazoan mitogenomes. Both AT contents of the entire molecule as well as putative control region display lowest values among all mitogenomes of the brachyuran crabs determined to date. The mitochondrial gene order follows a classic crab-type arrangement that underwent a unique tRNA translocation from the pancrustacean ancestral pattern. Our results will provide important data for phylogenetic as well as biogeographic studies.
Martínez-Díaz, José Luis; Phillips, George E.; Nyborg, Torrey; Espinosa, Belinda; Távora, Vladimir de Araújo; Centeno-García, Elena; Vega, Francisco J.
The genus Costacopluma (Brachyura: Decapoda: Retroplumidae) had a wide distribution during the early Paleogene and is currently represented by 14 species across the Late Cretaceous and early Paleogene. Described early Paleogene species have a smaller mean body size compared to Campanian-Maastrichtian populations of Africa, northeastern Mexico, and southeastern United States. Originally described from the Paleocene and Eocene of Alabama, Costacopluma grayi Feldmann and Portell, 2007, is now documented from the uppermost Maastrichtian (66.2 Ma) of northeastern Mexico and Mississippi and Lower Paleocene of Arkansas, all representing medium size specimens. The morphological features of latest Maastrichtian (66.2 Ma) individuals are identical to those observed among populations of C. grayi from the Paleogene of Alabama and Arkansas, which have a smaller mean size. This size reduction, or dwarfism, in C. grayi across the K-Pg boundary is an example of the Lilliput effect. Dwarfism has been documented in several invertebrate groups as a response to environmental stress, but this is the first record of the Lilliput effect in brachyuran crustaceans. The stratigraphic and geographic range for Costacopluma mexicana Vega and Perrilliat, 1989, is extended to the upper Campanian in northeastern Mexico and lower Maastrichtian in Mississippi and is suggested as a possible ancestor of C. grayi. Different preservational modes for this species in northeastern Mexico are discussed.
Luquet, Gilles; Fernández, María S.; Badou, Aïcha; Guichard, Nathalie; Roy, Nathalie Le; Corneillat, Marion; Alcaraz, Gérard; Arias, José L.
Crustaceans have to cyclically replace their rigid exoskeleton in order to grow.Most of them harden this skeleton by a calcification process. Some decapods (land crabs, lobsters and crayfish) elaborate calcium storage structures as a reservoir of calcium ions in their stomach wall, as so-called gastroliths. For a better understanding of the cyclic elaboration of these calcium deposits, we studied the ultrastructure of gastroliths from freshwater crayfish by using a combination of microscopic and physical techniques. Because sugars are also molecules putatively involved in the elaboration process of these biomineralizations, we also determined their carbohydrate composition. This study was performed in a comparative perspective on crayfish species belonging to the infra-order Astacidea (Decapoda, Malacostraca): three species from the Astacoidea superfamily and one species from the Parastacoidea superfamily. We observed that all the gastroliths exhibit a similar dense network of protein-chitin fibers, from macro- to nanoscale, within which calcium is precipitated as amorphous calcium carbonate. Nevertheless, they are not very similar at the molecular level, notably as regards their carbohydrate composition. Besides glucosamine, the basic carbohydrate component of chitin, we evidenced the presence of other sugars, some of which are species-specific like rhamnose and galacturonic acid whereas xylose and mannose could be linked to proteoglycan components. PMID:24970155
Gan, Huan You; Gan, Han Ming; Tan, Mun Hua; Lee, Yin Peng; Austin, Christopher M
The complete mitochondrial genome of the hermit crab Clibanarius infraspinatus was recovered by genome skimming using Next-Gen sequencing. The Clibanarius infraspinatus mitogenome has 16,504 base pairs (67.94% A + T content) made up of 13 protein-coding genes, 2 ribosomal subunit genes, 22 transfer RNAs and a putative 1500 bp non-coding AT-rich region. The Clibanarius infraspinatus mitogenome sequence is the first for the family Diogenidae and the second for the superfamily Paguroidea and exhibits a translocation of the ND3 gene not previously reported for the Decapoda.
Gan, Huan You; Gan, Han Ming; Lee, Yin Peng; Austin, Christopher M
The complete mitochondrial genome of the Bass yabby Trypaea australiensis was obtained from a partial genome scan using the MiSeq sequencing system. The T. australiensis mitogenome is 16,821 bp in length (70.25% A + T content) made up of 13 protein-coding genes, 2 ribosomal subunit genes, 22 transfer RNAs and a putative 1977 bp non-coding AT-rich region. This Trypaea mitogenome sequence is the 5th for the family Callianassidae and represents a new gene order for the Decapoda involving protein-coding, rRNA and tRNA genes and the control region.
Matzen da Silva, Joana; Creer, Simon; dos Santos, Antonina; Costa, Ana C.; Cunha, Marina R.; Costa, Filipe O.; Carvalho, Gary R.
Background Decapods are the most recognizable of all crustaceans and comprise a dominant group of benthic invertebrates of the continental shelf and slope, including many species of economic importance. Of the 17635 morphologically described Decapoda species, only 5.4% are represented by COI barcode region sequences. It therefore remains a challenge to compile regional databases that identify and analyse the extent and patterns of decapod diversity throughout the world. Methodology/Principal Findings We contributed 101 decapod species from the North East Atlantic, the Gulf of Cadiz and the Mediterranean Sea, of which 81 species represent novel COI records. Within the newly-generated dataset, 3.6% of the species barcodes conflicted with the assigned morphological taxonomic identification, highlighting both the apparent taxonomic ambiguity among certain groups, and the need for an accelerated and independent taxonomic approach. Using the combined COI barcode projects from the Barcode of Life Database, we provide the most comprehensive COI data set so far examined for the Order (1572 sequences of 528 species, 213 genera, and 67 families). Patterns within families show a general predicted molecular hierarchy, but the scale of divergence at each taxonomic level appears to vary extensively between families. The range values of mean K2P distance observed were: within species 0.285% to 1.375%, within genus 6.376% to 20.924% and within family 11.392% to 25.617%. Nucleotide composition varied greatly across decapods, ranging from 30.8 % to 49.4 % GC content. Conclusions/Significance Decapod biological diversity was quantified by identifying putative cryptic species allowing a rapid assessment of taxon diversity in groups that have until now received limited morphological and systematic examination. We highlight taxonomic groups or species with unusual nucleotide composition or evolutionary rates. Such data are relevant to strategies for conservation of existing decapod
Guinot, Danièle; Tavares, Marcos; Castro, Peter
it is lost in all other raninoid extant members. New evidence shows that the abdominal holding was an early occurrence for a brachyuran crab. The Raninoidea, sister to Palaeocorystoidea, is characterised by gymnopleurity, a condition that results from the lifting of the carapace and thus the exposure of several pleurites. The narrowing of the body and thoracic sternum, almost certainly associated with their burrowing behaviour, is a diagnostic feature of raninoid evolution, in contrast to the widening observed in the remaining Brachyura. The monophyly of Heterotremata is discussed. Although the correct assignment of the coxal male gonopore and sternal female gonopore (vulva) at the base of Decapoda and Eubrachyura, respectively, left no synapomorphies to support the Heterotremata, the group nevertheless should be regarded as the sister group to Thoracotremata. The controversial monophyly of Podotremata is discussed and arguments are presented against the suppression of this taxon. The distinction of Homoloidia from Dromioidia is argued, and a classification of Podotremata, which considers the fossil record whenever possible, is presented. The earliest brachyurans are re-examined, and a new interpretation of the phylogeny of several basal eubrachyuran groups (Dorippoidea, Inachoididae, Palicoidea, Retroplumoidea) is proposed. Stenorhynchus shares a number of characters with the Inachoididae that differentiate them from Inachidae, and also has some distinctive features that warrants its assignment to a separate inachoidid subfamily, Stenorhynchinae, which is resurrected. The concealment strategies among Brachyura are documented and discussed. Podotremes use carrying behaviour, often combined with burying and concealment under substrates, whereas living within a host, burying, and decoration are used by heterotremes, burrowing being essentially a thoracotreme strategy. (ABSTRACT TRUNCATED)
Ecological remarks and re-description of the hermit crab-associated pleustid amphipod Pleusymtes japonica (Gurjanova, 1938) (Crustacea: Amphipoda: Pleustidae: Pleusymtinae) from the Russian coasts of the Sea of Japan.
Ivan, Marin; Sinelnikov, Sergey; Agniya, Sokolova
Numerous specimens of poorly known pleustid amphipod Pleusymtes japonica (Gurjanova, 1938) (Crustacea: Amphipoda: Pleustidae: Pleusymtinae) were found in association with large hermit crab Pagurus ochotensis Brandt, 1851 (Crustacea: Decapoda: Paguridae) near Furugelma Island in the Sea of Japan. This is the first report of the species in association with hermit crabs. Amphipods were found living close to the shell aperture and hermit crab feeding appendages. Color photographs, remarks on ecology and re-description of the species are given.
McGaw, Iain J; Stillman, Jonathon H
The cardiovascular system of majid crabs was mapped using corrosion casting techniques. The general form of the circulatory system was comparable to that of other malacostracan crustaceans, but with distinct differences between several arterial systems. The anterior aorta exited from the anterior surface of the heart supplying hemolymph to the antennae, eyestalks, gastric muscles and brain. This artery was more complex compared with other decapods. The anterolateral arteries exited from the anterior dorsal surface of the heart and supplied hemolymph to the hypodermis, stomach, antennal gland and mandibular muscles. The hepatic arteries were larger and more complex compared with other decapod families, branching profusely within the hepatopancreas and gonads. The small posterior aorta exited from the posterior-ventral surface of the heart. Standard sex-specific differences in this artery were observed. Exiting from the ventral surface of the heart, the sternal artery supplied each pereiopod in a segmental arrangement. The sternal artery arrangement was different to other brachyuran crabs, possibly a symplesiomorphy with segmented ancestors. In accordance with anatomical descriptions of blue crabs and Cancer crabs it would also seem appropriate to classify the circulatory system of the Majidae as one that is "incompletely closed". Crown Copyright © 2010. Published by Elsevier Ltd. All rights reserved.
Bruce, A J
Two specimens of an undescribed species of pontoniine shrimp of the genus Periclimenaeus Borradaile 1915 from Maui Island, Hawaiian Islands, are described and illustrated, raising to three the number of species known from the Hawaiian Islands. The new species is remarkable for the greatly reduced molar process and sharp lateral cutting edge on the major second pereiopod dactyl and most closely resembles P. tchesunovi Ďuriš, 1990. Host animals not identified. Periclimenaeus devaneyi Bruce, 2010 also has its colouration described for the first time.
Tam, Y K; Kornfield, I
Three variable microsatellite loci have been isolated from the American lobster, Homarus americanus. In a population sample from the Gulf of Maine, the effective numbers of alleles (Ne) for the two most variable loci were 16.33 and 13.19, respectively. Reduced variability at all three loci was seen in the European lobster, H. gammarus, for which the maximum Ne was 4.00. The reduction in variability in H. gammarus is consistent with a bottleneck event. Inheritance analysis using H. americanus demonstrated segregation of codominant alleles and the absence of linkage. Null alleles were observed at two loci in inheritance studies. This study demonstrates that microsatellite loci should be useful in studying the population structure of clawed lobsters.
The fossil record of the ghost shrimp genus Balsscallichirus Sakai, 2011 (Crustacea: Decapoda: Callianassidae) is revised. Barnardcallichirus Sakai, 2011 and Tirmizicallichirus Sakai, 2011 are considered subjective synonyms of Balsscallichirus. Based on the examination of extant species it is argued that the morphology of the major cheliped merus, in combination with other hard part morphology characters, is sufficient for assignment of the fossil material into the genus. Main identifying characters are on merus which is keeled along its midline and its lower half is tuberculated; its lower margin possesses broad proximal meral hook continuing into a lobe distally; the entire lower margin is subdivided into numerous irregularly spaced spines. Three species, Callianassa sismondai A. Milne-Edwards, 1860, C. floriana Glaessner, 1928, and Podocallichirus laepaensis Hyžný & Muñiz, 2012, originally described from the Miocene of Italy, Austria and Spain, respectively, are assigned to Balsscallichirus herein. Neocallichirus wellsi Schweitzer, Feldmann & Gingerich, 2004 from the Upper Eocene of Pakistan is tentatively assigned to that genus as well. Spatial and temporal distribution of the genus indicates that at least since the Oligocene, and possibly even sooner (the Late Eocene), the genus has been restricted to the Western Tethys Region. Later, it migrated also into West Atlantic establishing present day communities. PMID:27499568
Hyžný, Matúš; Charbonnier, Sylvain; Merle, Didier; Lashari, Rafique Ahmed; Bartolini, Annachiara; Mètais, Grégoire
A new set of Paleocene and Eocene decapod crustaceans is described from the Kirthar Range of Pakistan. Two new ghost shrimps (Crustacea, Decapoda, Callianassidae) are described: Neocallichirus khadroensis Hyžný & Charbonnier, n. sp. from the Paleocene (Danian, Khadro Formation) of Gawar Band, Ranikot District, and Neocallichirus lakhraensis Hyžný & Charbonnier, n. sp. from the Early Eocene (Ypresian, Lakhra Formation) of Rbod Nala, Jhirak District. Both new species exhibit chelipeds which are morphologically surprisingly close to extant Neocallichirus karumba (Poore & Griffin, 1979) from the Indo-West Pacific. A group of species sharing this same cheliped morphology is provisionally called the "karumba group" based on Neocallichirus karumba, best documented species. The "karumba group" encompasses seven fossil species: the two new Pakistani species, Neocallichirus tuberculatus (Lőrenthey in Lőrenthey & Beurlen, 1929) n. comb. from the Eocene of Hungary, Neocallichirus borensis Beschin, De Angeli, Checchi & Mietto, 2006 from the Eocene of Italy, Neocallichirus birmanicus (Noetling, 1901) n. comb. from the Miocene of Myanmar, Neocallichirus dijki (Martin, 1883) from the Miocene of Java and Philippines, and the subfossil Neocallichirus maximus (A. Milne-Edwards, 1870) from Thailand. Based upon the extant and fossil occurrences, it is difficult to reconstruct migration pattern of the "karumba group". For now, it can be concluded, that at the genus level, a relative homogeneity of the ghost shrimps is observed between the Eastern and the Western Tethyan regions, as already suggested by Merle et al. (2014) for the assemblage of volutid gastropods from the Lakhra Formation.
Sonakowska, Lidia; Włodarczyk, Agnieszka; Poprawa, Izabela; Binkowski, Marcin; Śróbka, Joanna; Kamińska, Karolina; Kszuk-Jendrysik, Michalina; Chajec, Łukasz; Zajusz, Bartłomiej; Rost-Roszkowska, Magdalena Maria
The freshwater shrimp Neocaridina heteropoda (Crustacea, Malacostraca, Decapoda) originates from Asia and is one of the species that is widely available all over the world because it is the most popular shrimp that is bred in aquaria. The structure and the ultrastructure of the midgut have been described using X-ray microtomography, transmission electron microscopy, light and fluorescence microscopes. The endodermal region of the alimentary system in N. heteropoda consists of an intestine and a hepatopancreas. No differences were observed in the structure and ultrastructure of males and females of the shrimp that were examined. The intestine is a tube-shaped organ and the hepatopancreas is composed of two large diverticles that are divided into the blind-end tubules. Hepatopancreatic tubules have three distinct zones - proximal, medial and distal. Among the epithelial cells of the intestine, two types of cells were distinguished - D and E-cells, while three types of cells were observed in the epithelium of the hepatopancreas - F, B and E-cells. Our studies showed that the regionalization in the activity of cells occurs along the length of the hepatopancreatic tubules. The role and ultrastructure of all types of epithelial cells are discussed, with the special emphasis on the function of the E-cells, which are the midgut regenerative cells. Additionally, we present the first report on the existence of an intercellular junction that is connected with the E-cells of Crustacea.
Sonakowska, Lidia; Włodarczyk, Agnieszka; Poprawa, Izabela; Binkowski, Marcin; Śróbka, Joanna; Kamińska, Karolina; Kszuk-Jendrysik, Michalina; Chajec, Łukasz; Zajusz, Bartłomiej; Rost-Roszkowska, Magdalena Maria
The freshwater shrimp Neocaridina heteropoda (Crustacea, Malacostraca, Decapoda) originates from Asia and is one of the species that is widely available all over the world because it is the most popular shrimp that is bred in aquaria. The structure and the ultrastructure of the midgut have been described using X-ray microtomography, transmission electron microscopy, light and fluorescence microscopes. The endodermal region of the alimentary system in N. heteropoda consists of an intestine and a hepatopancreas. No differences were observed in the structure and ultrastructure of males and females of the shrimp that were examined. The intestine is a tube-shaped organ and the hepatopancreas is composed of two large diverticles that are divided into the blind-end tubules. Hepatopancreatic tubules have three distinct zones – proximal, medial and distal. Among the epithelial cells of the intestine, two types of cells were distinguished – D and E-cells, while three types of cells were observed in the epithelium of the hepatopancreas – F, B and E-cells. Our studies showed that the regionalization in the activity of cells occurs along the length of the hepatopancreatic tubules. The role and ultrastructure of all types of epithelial cells are discussed, with the special emphasis on the function of the E-cells, which are the midgut regenerative cells. Additionally, we present the first report on the existence of an intercellular junction that is connected with the E-cells of Crustacea. PMID:25996951
The complete mitochondrial genome of the mantid shrimp Oratosquilla oratoria (Crustacea: Malacostraca: Stomatopoda): Novel non-coding regions features and phylogenetic implications of the Stomatopoda.
Liu, Yuan; Cui, Zhaoxia
The complete mitochondrial (mt) genome sequence of Oratosquilla oratoria (Crustacea: Malacostraca: Stomatopoda) was determined; a circular molecule of 15,783 bp in length. The gene content and arrangement are consistent with the pancrustacean ground pattern. The mt control region of O. oratoria is characterized by no GA-block near the 3' end and different position of [TA(A)]n-blocks compared with other reported Stomatopoda species. The sequence of the second hairpin structure is relative conserved which suggests this region may be a synapomorphic character for the Stomatopoda. In addition, a relative large intergenic spacer (101 bp) with higher A+T content than that in control region was identified between the tRNA(Glu) and tRNA(Phe) genes. Phylogenetic analyses based on the current dataset of complete mt genomes strongly support the Stomatopoda is closely related to Euphausiacea. They in turn cluster with Penaeoidea and Caridea clades while other decapods form a separate group, which rejects the monophyly of Decapoda. This challenges the suitability of Stomatopoda as an outgroup of Decapoda in phylogenetic analyses. The basal position of Stomatopoda within Eumalacostraca according to the morphological characters is also questioned. Copyright 2010 Elsevier Inc. All rights reserved.
Tutman, P; Kapiris, K; Kirinčić, M; Pallaoro, A
The Columbus crab Planes minutus and Arch-fronted swimming crab Liocarcinus navigator, within their distribution ranges in the Mediterranean, were found rafted on plastic macro-litter floating on the open south Adriatic. While P. minutus was recorded from inanimate flotsam outside of the Mediterranean, L. navigator is herein reported for the first time on floating marine litter. The role of floating litter as habitat or as a dispersal agent for marine invertebrates has received quite attention however, records of decapod crabs drifting on litter has been relatively sparse. Our results suggests that vast quantities of floating debris, comprised primarily of non-biodegradable plastic polymers, probably will augment natural floating substrates in the marine environment, potentially facilitating the spread of invasive species. The dispersion of rafting crabs through floating debris should be investigated given the high potential ecological risk of invasion by exotic species due to the increase in waste production (ecological risk assessment). Copyright © 2017 Elsevier Ltd. All rights reserved.
Hyžný, Matúš; Charbonnier, Sylvain; Merle, Didier; Lashari, Rafique Ahmed; Bartolini, Annachiara; Mètais, Grégoire
A new set of Paleocene and Eocene decapod crustaceans is described from the Kirthar Range of Pakistan. Two new ghost shrimps (Crustacea, Decapoda, Callianassidae) are described: Neocallichirus khadroensis Hyžný & Charbonnier, n. sp. from the Paleocene (Danian, Khadro Formation) of Gawar Band, Ranikot District, and Neocallichirus lakhraensis Hyžný & Charbonnier, n. sp. from the Early Eocene (Ypresian, Lakhra Formation) of Rbod Nala, Jhirak District. Both new species exhibit chelipeds which are morphologically surprisingly close to extant Neocallichirus karumba (Poore & Griffin, 1979) from the Indo-West Pacific. A group of species sharing this same cheliped morphology is provisionally called the “karumba group” based on Neocallichirus karumba, best documented species. The “karumba group” encompasses seven fossil species: the two new Pakistani species, Neocallichirus tuberculatus (Lőrenthey in Lőrenthey & Beurlen, 1929) n. comb. from the Eocene of Hungary, Neocallichirus borensis Beschin, De Angeli, Checchi & Mietto, 2006 from the Eocene of Italy, Neocallichirus birmanicus (Noetling, 1901) n. comb. from the Miocene of Myanmar, Neocallichirus dijki (Martin, 1883) from the Miocene of Java and Philippines, and the subfossil Neocallichirus maximus (A. Milne-Edwards, 1870) from Thailand. Based upon the extant and fossil occurrences, it is difficult to reconstruct migration pattern of the “karumba group”. For now, it can be concluded, that at the genus level, a relative homogeneity of the ghost shrimps is observed between the Eastern and the Western Tethyan regions, as already suggested by Merle et al. (2014) for the assemblage of volutid gastropods from the Lakhra Formation. PMID:28255262
Hyžný, Matúš; Gross, Martin
Cenozoic decapod crustaceans housed in the collections of the Universalmuseum Joanneum (Graz, Austria) are reviewed. Previous descriptions, geographic and stratigraphic provenance and collection history are discussed. Altogether 72 specimens are figured, including five holotypes. Taxonomic affinity of previously unpublished material is addressed. Gebiacantha sp. from the middle Miocene of Wetzelsdorf is the first fossil record of the genus from the Paratethys. PMID:28239309
Dissanayake, Awantha; Galloway, Tamara S; Jones, Malcolm B
Using the shore crab Carcinus maenas as a model, this study tested the hypothesis that nutritional status influences susceptibility of adult crabs (>60mm carapace width (CW)) to environmental contamination. In the laboratory, crabs were either starved, given a restricted diet (fed on alternate days) or fully fed (fed each day). In addition, crabs under each feeding regime were exposed to a sublethal concentration (200microgl(-1)) of pyrene (PYR) as a model organic (PAH (polyaromatic hydrocarbon)) contaminant. Various physiological end points were measured after 7 and 14 days. Results indicated that adult shore crab physiology was relatively robust to short-term (7 days) nutritional changes as multivariate analysis (ANOSIM) showed no significant difference in shore crab physiological condition between control and pyrene-exposed crabs, irrespective of dietary feeding regime [Global R=0.018, P (%)=19.2]. After 14 days, however, starved crabs showed significant impacts to physiological condition (as revealed by multivariate analysis) [Global R=0.134, P (%)=0.1], [R=0.209, P (%)=0.1]; starved individuals had significantly lower antioxidant status (F(2,48)=5.35, P<0.01) compared to crabs under both types of feeding regime. Exposure to pyrene resulted in significantly elevated pyrene metabolite concentrations in the urine at 7 and 14 days compared with control individuals (P<0.001), validating contaminant bioavailability, and this was found for all dietary treatments. Also, exposed crabs had significantly increased protein levels (proteinuria) than controls (P<0.001) in their urine after 7 and 14 days, irrespective of dietary regime. After 7 days, pyrene-exposed crabs showed significantly increased antioxidant status (P<0.001) and cellular functioning (increased cellular viability and decreased phagocytosis) (P<0.001) compared to control crabs; however, after 14 days, antioxidant status (P<0.01) and cellular viability (P<0.001) were significantly decreased in pyrene-exposed compared to unexposed crabs. Results indicate that differences in nutritional status of adult crabs result in shore crabs being robust to short-term sublethal (7 days) pyrene exposure. Susceptibility to contaminant exposure, however, was measured after prolonged exposure (14 days) as indicated by reduced ability to combat oxidative stress. These results indicate that ecotoxicological studies need to take into account the nutritional state of the test organism to achieve the full assessment of contaminant impact. In addition, the results highlight that subtle seasonal biotic features of an organism can influence biomarker responses, and these need to be considered when interpreting field data and during the routine application of biological-effects tools in environmental monitoring.
Two specimens representing two hippolytid genera were sampled recently from the Coral Seamount, southwest Indian Ocean, at 732 m water depth. Lebbeus ketophilos sp. nov. and Eualus oreios sp. nov. are described and illustrated and their morphologies are compared with those of previously described species. The new species are closest in morphology to L. indicus Holthuis, 1947 and E. kinzeri Tiefenbacher, 1990 respectively. They are distinguished clearly from these and other species by a suite of morphological features. This record enhances our present knowledge of seamount biodiversity and species richness of decapod crustaceans in the Indian Ocean.
Horká, Ivona; De Grave, Sammy; Fransen, Charles H. J. M.; Petrusek, Adam; Ďuriš, Zdeněk
The majority of the almost 1,000 species of Palaemonidae, the most speciose family of caridean shrimp, largely live in symbioses with marine invertebrates of different phyla. These associations range from weak epibiosis to obligatory endosymbiosis and from restricted commensalism to semi-parasitism, with the specialisation to particular hosts likely playing a role in the diversification of this shrimp group. Our study elucidates the evolutionary history of symbiotic palaemonids based on a phylogenetic analysis of 87 species belonging to 43 genera from the Indo-West Pacific and the Atlantic using two nuclear and two mitochondrial markers. A complementary three-marker analysis including taxa from GenBank raises this number to 107 species from 48 genera. Seven larger clades were recovered in the molecular phylogeny; the basal-most one includes mostly free-living shrimp, albeit with a few symbiotic species. Ancestral state reconstruction revealed that free-living forms likely colonised cnidarian hosts initially, and switching between different host phyla occurred multiple times in palaemonid evolutionary history. In some cases this was likely facilitated by the availability of analogous microhabitats in unrelated but morphologically similar host groups. Host switching and adaptations to newly colonised host groups must have played an important role in the evolution of this diverse shrimp group. PMID:27246395
Duriš, Zdenek; Anker, Arthur
A new species of the alpheid shrimp genus Athanas Leach, 1814 is described based on a single specimen, an ovigerous female from Nha Trang Bay, Vietnam. Athanas manticolus sp. nov. differs from all other species of Athanas by the presence of a small post-rostral tubercle, combined with a minutely toothed rostrum, reduced extra-corneal teeth, and the absence of infra-corneal and supra-corneal teeth. In addition, the new species is characterised by its unique colour pattern, particularly by the red chromatophores disposed in randomly oriented, short, narrow streaks. As its name suggests, A. manticolus sp. nov. is commensally associated with the burrows of the nannosquillid mantis shrimp Bigelowina phalangium (Fabricius, 1798).
De Grave, Sammy; Smith, Kevin G; Adeler, Nils A; Allen, Dave J; Alvarez, Fernando; Anker, Arthur; Cai, Yixiong; Carrizo, Savrina F; Klotz, Werner; Mantelatto, Fernando L; Page, Timothy J; Shy, Jhy-Yun; Villalobos, José Luis; Wowor, Daisy
We present the first global assessment of extinction risk for a major group of freshwater invertebrates, caridean shrimps. The risk of extinction for all 763 species was assessed using the IUCN Red List criteria that include geographic ranges, habitats, ecology and past and present threats. The Indo-Malayan region holds over half of global species diversity, with a peak in Indo-China and southern China. Shrimps primarily inhabit flowing water; however, a significant subterranean component is present, which is more threatened than the surface fauna. Two species are extinct with a further 10 possibly extinct, and almost one third of species are either threatened or Near Threatened (NT). Threats to freshwater shrimps include agricultural and urban pollution impact over two-thirds of threatened and NT species. Invasive species and climate change have the greatest overall impact of all threats (based on combined timing, scope and severity of threats).
Moraes, Juliana Cristina Bertacini; De Siqueira Bueno, Sérgio Luiz
The present paper contains the complete description of the external morphology of the first juvenile stage of Aegla perobae analysed through light microscopy (LM) and scanning electron microscopy (SEM). Newly-hatched juveniles were obtained from ovigerous females kept under laboratory conditions. Hatching is asynchronous, taking 2-4 days for all juveniles of a single brood to hatch. Average carapace dimensions are 1.54 mm wide and 1.69 mm long (rostrum excluded). Morphology of the carapace, of the cephalothoracic appendages (antennule, antenna, mandible, maxillule, maxilla, maxillipeds, and pereopods), of the pleon, and of the tail fan (telson plus uropods) are described in detail. Aegla perobae juveniles can be readily differentiate from the first juveniles of other aeglids species described so far by the upwardly curved condition of the distal region of the rostrum and the distinct groove along the orbital sinus produced the elevated free in this area. Pleopods 2-5 are present as rudimentary digitiform buds. Rudimentary pleopods are still present in adult males of the species, a trait not yet described in freshwater aeglids. This curious condition is compared and discussed in the light of the current knowledge of early postembryonic developmental patterns found in other anomurans.
Tan, Mun Hua; Gan, Han Ming; Lee, Yin Peng; Austin, Christopher M
The mitochondrial genome sequence of the ghost crab, Ocypode ceratophthalmus, is documented (GenBank accession number: LN611669) in this article. This is the first mitogenome for the family Ocypodidae and the second for the order Ocypodoidea. Ocypode ceratophthalmus has a mitogenome of 15,564 base pairs consisting of 13 protein-coding genes, two ribosomal subunit genes, 22 transfer RNAs and a non-coding AT-rich region. The base composition of the O. ceratophthalmus mitogenome is 35.78% for T, 19.36% for C, 33.73% for A and 11.13% for G, with an AT bias of 69.51% and the gene order is the typical arrangement for brachyuran crabs.
Tan, Mun Hua; Gan, Han Ming; Lee, Yin Peng; Austin, Christopher M
The complete mitochondrial genome of the moon crab Ashtoret lunaris was obtained from a partial genome scan using the MiSeq sequencing system. The Ashtoret lunaris mitogenome is 15,807 base pairs in length (70% A + T content) and made up of 13 protein-coding genes, 2 ribosomal subunit genes, 22 transfer RNAs, and a putative 956 bp non-coding AT-rich region. This A. lunaris mitogenome sequence is the first for the genus, as well as the family Matutidae and superfamily Calappoidea.
Poupin, Joseph; Starmer, John
A new crab Liomerinae, Neoliomera moana sp. nov., is described from the Marquesas Islands, based on three specimens collected by hand at the entrance of submarine caves at depths of 6-28 m. Within the genus the new species belongs to a group of six species that have the carapace cristate on the anterolateral margins. It can be recognized by the presence of a double crest on the upper margin of the palm of chela and by its colour pattern, with about twenty red spots on the dorsal surface of the carapace. This new species is considered has a potential endemic form to the Marquesas Islands.
Cheng, Jiao; Jiang, Wei; Shi, Huafeng; Sha, Zhongli
Although the brachyuran nature of Raninoidea is widely accepted, there is no consensus over the precise position of the Raninoidea within Brachyura. Long PCR and primer walking methods are employed to determine the first complete mitochondrial genome (mitogenome) sequence of raninoidian crab, Ranina ranina. It is a circular double-stranded DNA molecule of 15,563 base pairs (bp) in length with a standard set of 22 transfer RNA genes (tRNAs), 2 ribosomal RNA genes (rRNAs), 13 protein-coding genes (PCGs) as well as a putative non-coding control region. The gene order is substantially consistent with that of the pancrustacean ground pattern with the tRNA(His) gene rearrangement. The basal placement of R. ranina in the phylogenetic tree integrated with a similar genomic organization to ancestral pancrustacea confirmed the primitive position of R. ranina in the Brachyura.
Ng, Peter K L; Lin, Chia-Wei
A new species of rhizopine crab, Zehntneriana serrata (Pilumnidae) is described from a coral reef in southern Taiwan. The new species differs from congeners by its smooth and glabrous carapace, prominently serrated anterolateral margins, elongated ambulatory legs with a serrated anterior margin of the merus, and the diagnostic morphology of the male first gonopod.
Anker, Arthur; Ng, Peter K L
Tritodynamia serratipes sp. nov. is described based on a female specimen dredged on soft mud at a depth of 6.3-6.5 m, near Marina East, only a few kilometers from Singapore's city centre. The new species differs from all other species of Tritodynamia Ortmann, 1894 by a unique combination of morphological characters, including the posterior margin of the propodus of the second ambulatory leg armed with a row of particularly strong teeth, and the cutting edges of dactylus and pollex each proximally armed with two stout teeth. Tritodynamia serratipes sp. nov. is the second species of the genus described from tropical Asia.
Thatje, S.; Calcagno, J. A.; Lovrich, G. A.; Sartoris, F. J.; Anger, K.
Temporal pattern of hatching was studied in the subantarctic lithodid crabs Lithodes santolla (Molina) and Paralomis granulosa (Jaquinot) from the Argentine Beagle Channel. In both species, larval hatching occurred in low daily numbers over an extended period of up to several weeks, depending on hatch size. Low daily hatching activity and low oxygen-consumption rates in freshly hatched P. granulosa larvae are discussed as life history adaptations to, and/or physiological constraints by, the environmental conditions of high latitudes.
Vela, María José; González-Gordillo, Juan Ignacio
Abstract For most of the family Porcellanidae, which comprises 283 species, larval development remains to be described. Full development has been only described for 52 species, while part of the larval cycle has been described for 45 species. The importance of knowing the complete larval development of a species goes beyond allowing the identification of larval specimens collected in the plankton. Morphological larval data also constitute a support to cladistic techniques used in the establishment of the phylogenetic status (see Hiller et al. 2006, Marco-Herrero et al. 2013). Nevertheless, the literature on the larval development of this family is old and widely dispersed and in many cases it is difficult to collect the available information on a particular taxon. Towards the aim of facilitating future research, all information available on the larval development of porcellanids has been compiled. Following the taxonomic checklist of Porcellanidae proposed by Osawa and McLaughlin (2010), a checklist has been prepared that reflects the current knowledge about larval development of the group including larval stages and the method used to obtain the larvae, together with references. Those species for which the recognised names have been changed according to Osawa and McLaughlin (2010) are indicated. PMID:27081332
Hendrickx, Michel E
A large series of specimens of Plesionika sanctaecatalinae was obtained during sampling operations off the west coast of the Baja California Peninsula in 2012 and 2014 (TALUD cruises). This material was examined and compared to the original description, the holotype and two paratypes. Although the fresh material fit well with the type material examined, some discrepancies were noted in the illustrations of the original description, particularly regarding scaphocerite and the telson, and new illustrations are provided. The series of sample available from the TALUD cruises allow to increase considerably the number of localities known for this species in the California Current area. A series of unpublished records corresponding to material examined in the original description but not listed in details, allows for further increase of the number of reported localities where P. sanctaecatalinae has been collected. Its vertical distribution in the water column, however, remains unclear due to the fact that no discrete samples are available for this species.
Mccallum, Anna W; Poore, Gary C B
Five new species from the squat lobster family Chirostylidae are described from the continental margin of western Australia: Uroptychus albus sp. nov., Uroptychus bardi sp. nov., Uroptychus jawi sp. nov., Uroptychus taylorae sp. nov., and Uroptychus worrorra sp. nov. New records of Indo-West Pacific species for Australia are: Gastroptychus brachyterus Baba, 2005, Gastroptychus investigatoris Alcock, 1899, Uroptychodes grandirostris (Yokoya, 1933), Uroptychodes inortenseni (Van Dam, 1939), Uroptychus scandens Benedict, 1902, Uroptychus ciliatus (Van Dam, 1933) and Uroptychus vandamae Baba, 1988. New distributional records are given for species previously recorded from Australia: Uroptychus flindersi Ahyong & Poore, 2004, Uroptychus hesperius Ahyong & Poore, 2004, Uroptychusjoloensis Van Dam, 1939, Uroptychus nigricapillis Alcock, 1901, and Uroptychus spinirostris (Ahyong & Poore, 2004). These new records expand the number of chirostylid species in Australia from 34 to 46. Keys to Australian species of the genera Gastroptychus, Uroptychodes and Uroptychus are provided.
Suzuki, Nobuaki; Hoshino, Kouichi; Murakami, Keisuke; Takeyama, Haruko; Chow, Seinen
To clarify the natural diet of phyllosoma larvae of the Japanese spiny lobster Panulirus japonicus, the sources of 18S rDNA clones obtained from the hepatopancreas were investigated. Of a total of 1537 clones examined, 160 had different restriction profiles from the host larvae, in which 21 restriction types were observed. Nucleotide sequences of 16 of 21 restriction types were successfully determined and their assignments were investigated by homology search and phylogenetic analysis. From seven late-stage larvae collected in spring to early summer, eukaryote DNA molecules of Teleostei, Oomycetes, Mycetozoa, and Fungi were identified. Exogenous DNA from four younger phyllosoma larvae collected in late autumn could not be recovered. A previous study identified DNAs of cnidarians and urochordates in late-stage phyllosoma larvae of a closely related species collected in winter. This indicates that the phyllosoma larvae are opportunistic carnivores, whose diets correlate with the relative abundance of prey organisms in the ambient water.
Cieluch, Ude; Anger, Klaus; Aujoulat, Fabien; Buchholz, Friedrich; Charmantier-Daures, Mireille; Charmantie, Guy
The ontogeny of osmoregulation, the development of branchial transporting epithelia and the expression of the enzyme Na+/K+-ATPase were studied in Carcinus maenas (L.) obtained from the North Sea, Germany. Laboratory-reared zoea larvae, megalopae and young crabs were exposed to a wide range of salinities, and hemolymph osmolality was measured after 24 h exposure time (72 h in juveniles). Zoea I larvae slightly hyper-regulated in dilute media (10.2 per thousand and 17.0 per thousand ) and osmoconformed at >17 per thousand. All later zoeal stages (II-IV) osmoconformed in salinities from 10.2 per thousand to 44.3 per thousand. The megalopa hyper-regulated at salinities from 10.2 to 25.5 per thousand. Young crabs hyperregulated at salinities from 5.3 per thousand to 25.5 per thousand, showing an increase in their osmoregulatory capacity. The development of transporting epithelia and the expression of Na+/K+-ATPase were investigated by means of transmission electron microscopy and immunofluorescence microscopy. In the zoea IV, only a very light fluorescence staining was observed in gill buds. Epithelial cells were rather undifferentiated, without showing any features of ionocytes. Gills were present in the megalopa, where Na+/K+-ATPase was located in basal filaments of the posterior gills. In crab I juveniles and adults, Na+/K+-ATPase was noted in the three most posterior pairs of gills, but lacking in anterior gills. Ionocytes could first be recognized in filaments of megalopal posterior gills, persisting through subsequent stages at the same location. Thus, the development of the gills and the expression of Na+/K+-ATPase are closely correlated with the ontogeny of osmoregulatory abilities. The morphological two-step metamorphosis of C. maenas can also be regarded as an osmo-physiological metamorphosis, (i) from the osmoconforming zoeal stages to the weakly regulating megalopa, and (ii) to the effectively hyper-regulating juvenile and adult crabs.
Gan, Han Ming; Tan, Mun Hua; Gan, Huan You; Lee, Yin Peng; Austin, Christopher M
The clawed lobster Nephrops norvegicus is an important commercial species in European waters. We have sequenced the complete mitochondrial genome of the species from a partial genome scan using Next-Gen sequencing. The N. norvegicus has a mitogenome of 16,132 base pairs (71.22% A+ T content) comprising 13 protein-coding genes, 2 ribosomal subunit genes, 21 transfer RNAs, and a putative 1259 bp non-coding AT-rich region. This mitogenome is the second fully characterized for the family Nephropidae and the first for the genus Nephrops. The mitogenome gene order is identical to the Maine lobster, Homarus americanus with the exception of the possible loss of the trnI gene.
Austin, Christopher M; Tan, Mun Hua; Gan, Huan You; Gan, Han Ming
Next-Gen sequencing was used to recover the complete mitochondrial genome of Cherax tenuimanus. The mitogenome consists of 15,797 base pairs (68.14% A + T content) containing 13 protein-coding genes, two ribosomal subunit genes, 22 transfer RNAs, and a 779 bp non-coding AT-rich region. Mitogenomes have now been recovered for all six species of Cherax native to Western Australia.
Cumillaf, Juan P; Blanc, Johnny; Paschke, Kurt; Gebauer, Paulina; Díaz, Fernando; Re, Denisse; Chimal, María E; Vásquez, Jorge; Rosas, Carlos
Optimum temperatures can be measured through aerobic scope, preferred temperatures or growth. A complete thermal window, including optimum, transition (Pejus) and critical temperatures (CT), can be described if preferred temperatures and CT are defined. The crustacean Hemigrapsus crenulatus was used as a model species to evaluate the effect of acclimation temperature on: (i) thermal preference and width of thermal window, (ii) respiratory metabolism, and (iii) haemolymph proteins. Dependant on acclimation temperature, preferred temperature was between 11.8°C and 25.2°C while CT was found between a minimum of 2.7°C (CTmin) and a maximum of 35.9°C (CTmax). These data and data from tropical and temperate crustaceans were compared to examine the association between environmental temperature and thermal tolerance. Temperate species have a CTmax limit around 35°C that corresponded with the low CTmax limit of tropical species (34-36°C). Tropical species showed a CTmin limit around 9°C similar to the maximum CTmin of temperate species (5-6°C). The maximum CTmin of deep sea species that occur in cold environments (2.5°C) matched the low CTmin values (3.2°C) of temperate species. Results also indicate that the energy required to activate the enzyme complex (Ei) involved in respiratory metabolism of ectotherms changes along the latitudinal gradient of temperature.
Cumillaf, Juan P.; Blanc, Johnny; Paschke, Kurt; Gebauer, Paulina; Díaz, Fernando; Re, Denisse; Chimal, María E.; Vásquez, Jorge; Rosas, Carlos
ABSTRACT Optimum temperatures can be measured through aerobic scope, preferred temperatures or growth. A complete thermal window, including optimum, transition (Pejus) and critical temperatures (CT), can be described if preferred temperatures and CT are defined. The crustacean Hemigrapsus crenulatus was used as a model species to evaluate the effect of acclimation temperature on: (i) thermal preference and width of thermal window, (ii) respiratory metabolism, and (iii) haemolymph proteins. Dependant on acclimation temperature, preferred temperature was between 11.8°C and 25.2°C while CT was found between a minimum of 2.7°C (CTmin) and a maximum of 35.9°C (CTmax). These data and data from tropical and temperate crustaceans were compared to examine the association between environmental temperature and thermal tolerance. Temperate species have a CTmax limit around 35°C that corresponded with the low CTmax limit of tropical species (34–36°C). Tropical species showed a CTmin limit around 9°C similar to the maximum CTmin of temperate species (5–6°C). The maximum CTmin of deep sea species that occur in cold environments (2.5°C) matched the low CTmin values (3.2°C) of temperate species. Results also indicate that the energy required to activate the enzyme complex (Ei) involved in respiratory metabolism of ectotherms changes along the latitudinal gradient of temperature. PMID:26879464
Bruce, A J
An undescribed species of pontoniine shrimp of the genus Nippontonia Bruce & Bauer, N. ashmoriensis sp. nov., collected from a sponge from Ashmore Reef, Western Australia, is described and illustrated.
Aleksandrova, E N; Kovacheva, N P
The application of hematological analysis techniques to detecting the physiological status of the economically valued decapods during their culturing, and in monitoring of the condition of their natural populations, is restrained by the incomplete knowledge of these invertebrates circulatory system and its properties. Scarce data on the use of hematological indicators for determining the physiological status of decapods may be found sporadically in published sources; there is shortage of basic standards needed for interpretation of the analytical results. In this regard the paper considers some data on the major properties of hemolymph and its cellular elements; on methods of their examination; and on the results of application of hematological characteristics to assessing the physiological condition of various species of decapods. The hematological indicators suitable for the analysis of live decapods include: time of coagulation and buffer characteristic of hemolymph; concentration of total proteins, copper, calcium, glucose and lactates in it; total number of hemocytes with the consideration of granulocytes share.
We present the first global assessment of extinction risk for a major group of freshwater invertebrates, caridean shrimps. The risk of extinction for all 763 species was assessed using the IUCN Red List criteria that include geographic ranges, habitats, ecology and past and present threats. The Indo-Malayan region holds over half of global species diversity, with a peak in Indo-China and southern China. Shrimps primarily inhabit flowing water; however, a significant subterranean component is present, which is more threatened than the surface fauna. Two species are extinct with a further 10 possibly extinct, and almost one third of species are either threatened or Near Threatened (NT). Threats to freshwater shrimps include agricultural and urban pollution impact over two-thirds of threatened and NT species. Invasive species and climate change have the greatest overall impact of all threats (based on combined timing, scope and severity of threats). PMID:25807292
Felder, Darryl L; Dworschak, Peter C
A recent descriptive account based on material in the Senckenberg Forschungsinstitut und Naturmuseum included descriptions of two new fossorial axiidean shrimp from the northeastern Gulf of Mexico. Both were based on fragmentary immature specimens, and the accompanying illustrations appeared to potentially represent known species. The types were obtained on loan for study in each of our labs. In one case we conclude that erroneous interpretations of a mangled immature specimen of Axianassa arenaria Kensley & Heard, 1990, led to its assignment to the wrong infraorder, and thus its erroneous description as a new genus and species. In the second case, misinterpretations of morphology of four fragmentary juvenile specimens led to assignment of a name for a population already known in literature to be separated genetically and developmentally from Atlantic populations of Callichirus major (Say, 1818) and Gulf of Mexico populations of C. islagrande (Schmitt, 1935). While no diagnostic characters of value were furnished with the description, we nonetheless conclude that the new name must be used.
Christiansen, Bernd; Boetius, Antje
During cruise Meteor 33/1 in the northern Arabian Sea in September/October 1995, large numbers of the portunid crab Charybdis smithii were observed swimming in the open ocean. In a photographic survey at three abyssal stations in the northern Arabian Sea (NAST, WAST, CAST), even higher densities of Charybdis smithii - up to 1 crab m -2 - were found dead on the sea floor. Average sizes of the crabs were around 34-44 mm carapace width, indicating that the animals died prematurely, before returning to the breeding grounds presumable on the shelves of India or Oman. The average weight of the crabs was 10-14 g wet weight. From the photographic quantification it can be deduced that these large food falls represent a significant carbon input of at least 10-30% of the annual flux of POC as measured in sediment traps in this region. The exceptionally high microbial chitinase activity in the surface sediment layers detected at the same stations indicates that this energy is utilized and channelled into the deep-sea benthic food web of the deep Arabian Sea. There are frequent observations of dense Charybdis smithii swarms in the Arabian Sea from different years; however, it is not certain whether such large food falls as observed during M 33/1 are regular seasonal events that repeat each year.
Marra, Annamaria; Mona, Stefano; Sà, Rui M.; D’Onghia, Gianfranco; Maiorano, Porzia
Aristeus antennatus is an ecologically and economically important deep-water species in the Mediterranean Sea. In this study we investigated the genetic variability of A. antennatus sampled from 10 sampling stations in the Western and Central Mediterranean. By comparing our new samples with available data from the Western area, we aim to identify potential genetic stocks of A. antennatus and to reconstruct its historical demography in the Mediterranean. We analyzed two regions of mitochondrial DNA in 319 individuals, namely COI and 16S. We found two main results: i) the genetic diversity values consistent with previous data within the Mediterranean and the absence of barriers to gene flow within the Mediterranean Sea; ii) a constant long-term effective population size in almost all demes but a strong signature of population expansion in the pooled sample about 50,000 years B.P./ago. We propose two explanation for our results. The first is based on the ecology of A. antennatus. We suggest the existence of a complex meta-population structured into two layers: a deeper-dwelling stock, not affected by fishing, which preserves the pattern of historical demography; and genetically homogeneous demes inhabiting the fishing grounds. The larval dispersal, adult migration and continuous movements of individuals from “virgin” deeper grounds not affected by fishing to upper fishing areas support an effective ‘rescue effect’ contributing to the recovery of the exploited stocks and explain their genetic homogeneity throughout the Mediterranean Sea. The second is based on the reproduction model of this shrimp: the high variance in offspring production calls for a careful interpretation of the data observed under classical population genetics and Kingman’s coalescent. In both cases, management policies for A. antennatus will therefore require careful evaluation of the meta-population dynamics of all stocks in the Mediterranean. In the future, it will be particularly relevant to sample the deepest ones directly. PMID:25775363
Johnson, Magnus L.; De Grave, Sammy
Morphometric differences in the optical morphology of symbiotic palaemonid shrimps can be observed among species symbiotic with different host organisms. Discriminant functional analysis revealed three distinct groups within the species examined. Of these, bivalve symbionts appear to have an eye design that is solely unique to this host-symbiont grouping, a design that spans across multiple genera of phylogenetically unrelated animals. Although some taxonomic effects may be evident, this does not explain the difference and similarities in eye morphology that are seen within these shrimps. Therefore evolutionary pressures from their host environments are having an impact on the optical morphology of their eyes however, as indicated by host-hopping events there ecological adaptations occur post host invasion. PMID:27168962
Kim, Sung-Tae; Kim, Gyungryul; Yoon, Tae-Ho; Kim, Ah-Ran; Kim, Hak Jun; Kim, Hyun-Woo
We determined the complete mitochondrial genome of Palaemon gravieri (Yu, 1930), which is collected from East China Sea (124°E and 33.5°N). Total mitochondrial genome length of P. gravieri was 15 740 bp, in which 13 proteins, 2 ribosomal RNAs, 22 transfer RNAs, and a putative control region were encoded. Nine and four protein-coding genes are encoded on the H-strand and on the L-strand, respectively. According to the phylogenetic analysis, P. gravieri was most closely related to Exopalaemon carinicauda among the compared five species belonging to Palaemonidae. Although overall gene organization was same, the putative control region (between SrRNA gene and tRNA(Ilel)) is least similar to one another among mitochondrial genomes from the compared 5 species belonging to Palaemonidae.
Matozzo, Valerio; Gallo, Chiara; Marin, Maria Gabriella
The effects of temperature on cellular and biochemical parameters of the crab Carcinus aestuarii were evaluated. Crabs were kept for 7 days at 4, 17 (reference value) and 30 °C (salinity of 35 psu), and total haemocyte count (THC), haemocyte volume, haemocyte proliferation, phenoloxidase (PO) activity in both haemocyte lysate (HL) and cell-free haemolymph (CFH), CFH total protein and glucose levels, superoxide dismutase (SOD) and catalase (CAT) activities in both gills and digestive gland were evaluated. The lowest and the highest temperature significantly decreased THC, whereas haemocyte volume and haemolymph glucose concentration did not differ significantly among experimental conditions. Haemolymph protein concentration significantly reduced in crabs maintained at 30 °C, when compared with that of animals kept at 4 and 17 °C. Haemocyte proliferation increased significantly in crabs kept at 4 and 30 °C, when compared with that of crabs held at 17 °C. Likewise, a significantly higher PO activity was recorded in CFH from crabs kept at 4 and 30 °C, than in control crabs. Conversely, PO activity did not vary significantly in HL. With regard to antioxidant enzyme activities, a significant decrease in CAT activity was observed in gills from crabs kept at 4 °C, when compared to that of crabs kept at 17 °C and 30 °C. Results obtained demonstrated that the highest and lowest temperature tested influenced crab biological responses, and indicated that C. aestuarii modulated its cellular and biochemical parameters (mainly haemocyte proliferation, CFH protein concentrations and CFH PO activity) in order to cope with temperature. Copyright © 2011 Elsevier Ltd. All rights reserved.
Dong, Chao; Li, Xinzheng
The present paper reports five species of squat lobster, genus Agononida Baba and de Saint Laurent, 1996, of which A. squamosa (Henderson, 1885) and A. cf. variabilis (Baba, 1988) were not previously reported in Chinese waters. All the specimens are kept in the Marine Biological Museum collection in the Institute of Oceanology, Chinese Academy of Sciences, Qingdao. To date, there have been 11 species of this genus recorded from China's seas. A key to those species is provided in this paper.
Dong, Dong; Li, Xinzheng; Zhou, Yadong; Wang, Chunsheng
A new species, Munidopsis militaris n. sp., from the Carlsberg Ridge, Northwest Indian Ocean Ridge is described herein. The species belongs to a group of species having a pair of epigastric spines, mesial and lateral eye-spines, abdominal tergites unarmed, five or six spines on the lateral margin of the carapace, and a denticulate carina on the distolateral margin of the P1 fixed finger. It can be distinguished from its relatives by the spinous lateral margin of the palm and dorsal carinae on the P2-4 propodus. The Munidopsis fauna of the Indian Ocean Ridge is seldom reported on; this new species is the sixth member of this genus found inhabiting the Indian Ocean Ridge.
Tsang, Ling Ming; Schubart, Christoph D; Ahyong, Shane T; Lai, Joelle C Y; Au, Eugene Y C; Chan, Tin-Yam; Ng, Peter K L; Chu, Ka Hou
Crabs of the infra-order Brachyura are one of the most diverse groups of crustaceans with approximately 7,000 described species in 98 families, occurring in marine, freshwater, and terrestrial habitats. The relationships among the brachyuran families are poorly understood due to the high morphological complexity of the group. Here, we reconstruct the most comprehensive phylogeny of Brachyura to date using sequence data of six nuclear protein-coding genes and two mitochondrial rRNA genes from more than 140 species belonging to 58 families. The gene tree confirms that the "Podotremata," are paraphyletic. Within the monophyletic Eubrachyura, the reciprocal monophyly of the two subsections, Heterotremata and Thoracotremata, is supported. Monophyly of many superfamilies, however, is not recovered, indicating the prevalence of morphological convergence and the need for further taxonomic studies. Freshwater crabs were derived early in the evolution of Eubrachyura and are shown to have at least two independent origins. Bayesian relaxed molecular methods estimate that freshwater crabs separated from their closest marine sister taxa ~135 Ma, that is, after the break up of Pangaea (∼200 Ma) and that a Gondwanan origin of these freshwater representatives is untenable. Most extant families and superfamilies arose during the late Cretaceous and early Tertiary.
Dobson, Nicola C.; De Grave, Sammy; Johnson, Magnus L.
Symbiosis is prevalent in the marine environment with many studies examining the effects of such interactions between host and symbiont. Pontoniine shrimps are a group whose ecology is characterised by symbiotic interactions. This investigation examines the gross morphology of Pontoniinae compound eyes and superficial optical parameters with reference to their symbiotic relationship or lifestyle category; free-living, ectosymbiont, endosymbiont (bivalves) or endosymbiont (non-bivalves). The eye morphologies of free-living and ectosymbiotic species are very similar, yet differ from both forms of endosymbiotic species. Endosymbionts have significantly smaller and simpler eyes with larger facets and bigger interommatidial angles and eye parameters for increased sensitivity levels. However bivalve endosymbionts form an intermediary group between non-bivalve endosymbionts and ectosymbionts as a result of their more active lifestyle. The accessory eye or “nebenauge”, although of uncertain function, commonly occurs in free-living Pontoniinae species but rarely in endosymbionts apart from in more primitive species. The variation in morphology reflects tensions between functional requirements and ecological pressures that have strongly influenced eye design in Pontoniinae. PMID:24950292
Hertzler, Philip L; Freas, William R
Penaeoidean shrimp pleonal muscle is a valuable economic resource worldwide, but little is known of its development during larval stages. The development of pleonal muscle in Penaeus (Litopenaeus) vannamei was studied by rhodamine-phalloidin staining and laser-scanning confocal microscopy. Dorsal pleonal muscle was first evident at the protozoea I stage while ventral pleonal muscle was present by the protozoea II stage. Identifiable ventral pleonal muscles were evident by the protozoea III stage and all ventral muscle types were present in the mysis I. The tail flex response began at the mysis stage and growth of existing pleonal muscles continued. The pleopods formed during the mysis stages, with coxal and basis muscles developed by mysis III. The pleopods became functional beginning with the first post-larval stage. We conclude that the pleonal muscle pattern of P. vannamei larvae is similar to that of adult Penaeus setiferus, and that homologous muscles are present. The major formation of dorsal pleonal muscles occurs during the protozoea II stage, while significant development of ventral pleonal muscles occurs during the protozoea III stage.
Bolla, Eduardo A; Fransozo, Vivian; Negreiros-Fransozo, Maria Lucia
The juvenile development of Callinectes danae was investigated from megalopae obtained in neuston samples at Ubatuba, São Paulo, Brazil. The individuals were raised in the laboratory under constant temperature (25 ± 1°C), filtered sea water from the collection location (35‰), and natural photoperiod. Newly hatched Artemia sp. nauplii were offered as food on a daily basis and ornamental-fish food was also provided for the juveniles from the 4th stage on. Twelve stages of the juvenile phase were obtained. The main morphological features that allowed recognition of the first juvenile stage were drawn and described. All the subsequent stages obtained were examined and measured, and the main changes in relation to the first stage were recorded. Sexual dimorphism becomes apparent from the fourth juvenile stage onwards. Some appendages and morphological features proved to be of great importance in the identification of species, including the number of segments of the antennal flagellum and the number of setae on the maxilla and on the 1st, 2nd and 3rd maxillipeds. These can probably be used for future comparisons and species identifications.
Erkan, M; Sousa, M; Carvalho, E; Oliveira, E; Baldaia, L
In previtellogenic oocytes, nucleoli showed segregated components, with the dense fibrillar component (DFC) appearing highly developed and presenting several fibrillar centers (FC). The granular component (GC) was less developed and formed a wide-spaced reticulum. Only the DFC appeared stained by silver, with higher intensities being found at its periphery. During early vitellogenesis, the nucleolar components were kept segregated but both the DFC and the GC enlarged, without evident changes being noticed in the silver staining pattern. In mid and late vitellogenesis, the nucleoli showed integrated components, with the DFC being intermeshed with the GC. Both nucleolar components were highly developed, no evident FC were noticed, and silver stained the DFC in a heterogeneous pattern. During cortical vesicle formation, the nuclear chromatin condensed and nucleoli appeared disintegrated, showing high levels of accelerated exportation of silver stained materials. Results suggest that the size of the DFC is kept high and the size of the GC kept low (low rDNA transcription levels and RNP exportation accelerated), in the segregated nucleoli of the previtellogenic oocyte, as the cell stores nuages but shows absence of rough endoplasmic reticulum and thus low protein svnthesis; that the size of the DFC and of the GC is increased in the segregated nucleoli of early vitellogenic oocytes (intermediate levels of rDNA transcription and of protein synthesis), which is in accordance with the appearance of the rough endoplasmic reticulum and of yolk vesicles formed with endogenous and exogenous sources; that during mid and late vitellogenesis the DFC and the GC appear highly developed and integrated (high levels of rDNA transcription and of protein synthesis) as the rough endoplasmic reticulum expands and the large yolk vesicles grow by endogenous synthesis; and that chromatin condense and nucleoli disintegrate (very low levels of rDNA transcription with accelerated RNP exportation) when cortical vesicles are formed.
Kim, Jung Nyun; Choi, Jung Hwa; Jo, Hyun-su
A single specimen of the pelagic shrimps, Pasiphaea japonica Omori, 1976 (Pasiphaeidae) collected in the southeastern waters of Korea is described and illustrated. Although this species occurs widely in the Indo-West Pacific including the Japanese coast of the East/Japan Sea and the middle and southern parts of the East China Sea, this is the first record of the species and the genus in Korean waters. The species is distinguished from other congeners by the following combination of characteristics: non-carinate dorsal sixth abdominal somite with a terminal tooth, rudimentary pleurobranch on the eighth thoracic somite, merus of the first pereopod with more than eight spines, and almost entirely transparent white color.
Hyžný, Matúš; Gross, Martin
Cenozoic decapod crustaceans housed in the collections of the Universalmuseum Joanneum (Graz, Austria) are reviewed. Previous descriptions, geographic and stratigraphic provenance and collection history are discussed. Altogether 72 specimens are figured, including five holotypes. Taxonomic affinity of previously unpublished material is addressed. Gebiacantha sp. from the middle Miocene of Wetzelsdorf is the first fossil record of the genus from the Paratethys.
Dambach, Johannes; Thatje, Sven; Rödder, Dennis; Basher, Zeenatul; Raupach, Michael J
Marine invertebrates inhabiting the high Antarctic continental shelves are challenged by disturbance of the seafloor by grounded ice, low but stable water temperatures and variable food availability in response to seasonal sea-ice cover. Though a high diversity of life has successfully adapted to such conditions, it is generally agreed that during the Last Glacial Maximum (LGM) the large-scale cover of the Southern Ocean by multi-annual sea ice and the advance of the continental ice sheets across the shelf faced life with conditions, exceeding those seen today by an order of magnitude. Conditions prevailing at the LGM may have therefore acted as a bottleneck event to both the ecology as well as genetic diversity of today's fauna. Here, we use for the first time specific Species Distribution Models (SDMs) for marine arthropods of the Southern Ocean to assess effects of habitat contraction during the LGM on the three most common benthic caridean shrimp species that exhibit a strong depth zonation on the Antarctic continental shelf. While the shallow-water species Chorismus antarcticus and Notocrangon antarcticus were limited to a drastically reduced habitat during the LGM, the deep-water shrimp Nematocarcinus lanceopes found refuge in the Southern Ocean deep sea. The modeling results are in accordance with genetic diversity patterns available for C. antarcticus and N. lanceopes and support the hypothesis that habitat contraction at the LGM resulted in a loss of genetic diversity in shallow water benthos.
Lee, Yin Peng; Gan, Han Ming; Tan, Mun Hua; Lys, Isabelle; Page, Rachel; Dias Wanigasekera, Beatrice; Austin, Christopher M
The mitogenome of Paranephrops planifrons, was obtained by next generation sequencing. This crayfish has a mitochondrial genome of 16,174 base pairs with 13 protein-coding genes, 2 ribosomal subunit genes, 22 transfer RNAs (tRNA), and a non-coding AT-rich region of 771 bp. The P. planifrons nucleotide composition is: 33.63% for T, 21.92% for C, 34.46% for A, and 9.98% for G and has a 68.09% AT bias. While the mitogenome gene order for this species is consistent with aspects of the highly distinctive parastacid crayfish mitogenome gene arrangement, it has a novel gene order involving the rearrangements of a protein coding and several tRNA genes.
Fransen, Charles H.J.M.; Page, Timothy J.
In recent years the systematic position of genera in the shrimp families Gnathophyllidae and Hymenoceridae has been under debate, with phylogenetic studies suggesting the families are not real family level units. Here, we review the molecular evidence as well as the morphological characters used to distinguish both families, leading to the conclusion that neither family is valid. Further, we studied the structural details of the single morphological character which distinguishes the two subfamilies (Palaemoninae, Pontoniinae) in Palaemonidae, as well as their phylogenetic relationship. As the supposed character distinction plainly does not hold true and supported by the phylogenetic results, the recognition of subfamilies in Palaemonidae is not warranted. As a consequence, all three supra-generic taxa (Gnathophyllidae, Hymenoceridae, Pontoniinae) are thus herein formally synonymised with Palaemonidae. PMID:26339545
Horká, Ivona; De Grave, Sammy; Fransen, Charles H J M; Petrusek, Adam; Ďuriš, Zdeněk
The majority of the almost 1,000 species of Palaemonidae, the most speciose family of caridean shrimp, largely live in symbioses with marine invertebrates of different phyla. These associations range from weak epibiosis to obligatory endosymbiosis and from restricted commensalism to semi-parasitism, with the specialisation to particular hosts likely playing a role in the diversification of this shrimp group. Our study elucidates the evolutionary history of symbiotic palaemonids based on a phylogenetic analysis of 87 species belonging to 43 genera from the Indo-West Pacific and the Atlantic using two nuclear and two mitochondrial markers. A complementary three-marker analysis including taxa from GenBank raises this number to 107 species from 48 genera. Seven larger clades were recovered in the molecular phylogeny; the basal-most one includes mostly free-living shrimp, albeit with a few symbiotic species. Ancestral state reconstruction revealed that free-living forms likely colonised cnidarian hosts initially, and switching between different host phyla occurred multiple times in palaemonid evolutionary history. In some cases this was likely facilitated by the availability of analogous microhabitats in unrelated but morphologically similar host groups. Host switching and adaptations to newly colonised host groups must have played an important role in the evolution of this diverse shrimp group.
Sousa, Liliana; Petriella, Ana María
This work describes the morphology and histology of the P. argentinus digestive tract. The foregut comprises the mouth, oesophagus, and stomach and is lined by a simple cylindrical epithelium overlain by cuticle. There are tegumental glands in the oral region and in the first portion of the oesophagus and of the hindgut. The cardiac stomach is an oval dorsal sac in the cephalothorax and has no calcified structures. The pyloric stomach comprises an upper chamber and a lower gland filter. The filter consists of an outer row of elongated setae and an inner row of dorsally curved setae forming longitudinal channels 16-18 microm wide. The midgut runs from the dorsal chamber of the pyloric stomach to the sixth abdominal somite without caeca. The hindgut runs from the sixth abdominal somite to the ventral anus. The mid-gut epithelium comprises dominant cylindrical cells and small undifferentiated cells in the first portion. The hindgut wall presents longitudinal folds, conspicuous muscular bundles, and a folded cuticle. The digestive tract of P. argentinus is basically similar to that of most of decapods. The absence of calcified structures in the stomach and the width of the longitudinal channels in the filter are related to the predominantly detritivorous diet.
Khodabandeh, S; Charmantier, G; Blasco, C; Grousset, E; Charmantier-Daures, M
The ontogeny of the antennal glands was studied during the embryonic and post-embryonic development of Astacus leptodactylus. The future glands arising from undifferentiated columnar cells were detectable at the metanauplius stage EI 150 microm (EI: eye index; approximately 440 microm at hatching). The tubule and labyrinth differentiated in embryos at EI 190 microm, and the bladder and coelomosac at EI 250 microm. At EI 350 microm, the tubule lengthened and divided into proximal and distal sub-regions. In later stages, the gland retained the same morpho-anatomy but the differentiation and size of each part increased. The cells of the coelomosac displayed the cytological features of podocytes in late embryonic development at EI 440 microm. Only small apical microvilli and a few mitochondria were observable in the labyrinth cells at EI 250 microm; by EI 440 microm, these cells presented well-shaped apical microvilli, formed bodies, basal infoldings and mitochondria. In the cells of the tubules and bladder, mitochondria and basal infoldings occurred at EI 440 microm and EI 250 microm, respectively. The differentiation of the tubules and bladder cells suggested that they were involved in active transport at EI 440 microm. Following hatching, the differentiation of the cells and the size of the glands increased. The ontogeny of the antennal glands thus starts in early embryos, the specific cellular functional features being differentiated in the various parts of the glands by EI 440 microm. The antennal glands are probably functional just before hatching, i.e., before the juveniles are confronted with the low osmolality of freshwater.
VanMaurik, Lauren N.; Wortham, Jennifer L.
Abstract The giant freshwater prawn, Macrobrachium rosenbergii, is a large shrimp extensively used in aquaculture whose grooming behaviors were analyzed in this study. Macrobrachium rosenbergii exhibits three unique male morphotypes that differ in their behavior, morphology and physiology: small-clawed males (SM), orange-clawed males (OC) and blue-clawed males (BC). The largest and most dominant males, BC males, are predicted to have significantly different grooming behaviors compared to females and the other two male morphotypes. These BC males may be too large and bulky to efficiently groom and may dedicate more time to mating and agonistic interactions than grooming behaviors. Observations were conducted to look at the prevalence of grooming behaviors in the absence and presence of conspecifics and to determine if any differences in grooming behavior exist among the sexes and male morphotypes. Significant differences in the grooming behaviors of all individuals (females and male morphotypes) were found. BC males tended to have the highest grooming time budget (percent of time spent grooming) while SM males had a relatively low grooming time budget. The grooming behaviors of the male morphotypes differed, indicating while these males play distinct, separate roles in the social hierarchy, they also have different grooming priorities. The conditions in which Macrobrachium rosenbergii are cultured may result in increased body fouling, which may vary, depending on the grooming efficiencies and priorities of these male morphotypes. Overall, grooming behaviors were found to be a secondary behavior which only occurred when primary behaviors such as mating, feeding or fighting were not present. PMID:25561831
Bracken-Grissom, Heather D; Robles, Rafael; Felder, Darryl L
Widely distributed populations of the snapping shrimp, Alpheus floridanus Kinglsey, 1878, from the eastern Pacific and western and eastern Atlantic Ocean have long been suspected to represent different species due to extreme morphological variation among conspecifics. A companion study (Bracken-Grissom & Felder 2014) contains redescriptions of two western Atlantic species (A. floridanus Kingsley 1878 sensu stricto and A. platycheirus Boone, 1927), assignments of the original syntypes for A. floridanus, descriptions of three new species from the Atlantic and eastern Pacific (A. hephaestus Bracken-Grissom & Felder, 2014; A. roblesi Bracken-Grissom & Felder, 2014; A. ulalae Bracken-Grissom & Felder, 2014), and discussion of the relationship of the eastern Atlantic A. floridanus africanus Balss, 1916. The present study underpins all these findings by application of molecular phylogenetic techniques. Analysis of partial sequences of the 16S, 12S, and COI mitochondrial genes separate species throughout the eastern Pacific and the eastern and western Atlantic. Morphological comparisons suggested that the two syntypes of A. floridanus belong to different species, and molecular results in this study confirm this separation. Genetic data suggest a strong affinity between the western Atlantic A. platycheirus and the eastern Pacific A. hephaestus. Close relationships are evident between trans-Atlantic species, A. floridanus africanus and A. floridanus, a pattern also seen for other cryptic and pseudocryptic species of Alpheus. Alpheus roblesi and A. ulalae represent early-branching lineages within the complex. In some cases, molecular phylogenetic relationships between members of the A. floridanus complex can be reconciled with postulated biogeographic history.
De Grave, Sammy
A new species of crinoid associated Periclimenes, P. rincewindi sp. nov. is described from the Bay Islands (Honduras) in the Caribbean. The species associates with the swimming crinoid, Analcidometra armata and displays a unique colour pattern. Morphologically, the new species is closely related to the other known crinoid associates in the Caribbean, specifically Periclimenes crinoidalis, from which it can be distinguished by a suite of relatively minor morphological features.
Shuhaimi-Othman, Mohammad; Yakub, Nadzifah; Ramle, Nur-Amalina; Abas, Ahmad
Adult Macrobrachium lanchesteri were exposed for a 4-day period in laboratory conditions to a range of copper (Cu), cadmium (Cd), zinc (Zn) and lead (Pb) concentrations. Mortality was assessed and median lethal times (LT₅₀) and concentrations (LC₅₀) were calculated. At the end of the 4-day period, live prawns were used to determine bioconcentration of the metals. LT₅₀ and LC₅₀ increased with the decrease in mean exposure concentrations and times, respectively, for all metals. LC₅₀s for 96 hours for Cu, Cd, Zn and Pb were 32.3, 7.0, 525.1 and 35.0 µg/L, respectively. Cu, Cd, Zn and Pb bioconcentration in M. lanchesteri increases with exposure to increasing concentrations and Cd was the most toxic to M. lanchesteri, followed by Pb, Cu and Zn. Comparison of LC₅₀ values for metals for this species with those for other freshwater crustacean organisms reveals that M. lanchesteri is equally or more sensitive to heavy metals than most other tested crustaceans.
Casas-Sánchez, R; Vaillard-Nava, Y; Re-Araujo, A D
Juvenile prawn Macrobrachium carcinus were fed two different diets: restaurant by-products (diet I) and fish and vegetable market by-products (diet II). These diets were evaluated by proximal analysis, assimilation efficiency and the factor conversion rate (FCR). Diet I registered a higher efficiency, but there was no difference in the growth rate. The growth mean (G. L.) for three months was 0.254 +/- 0.13 cm (diet I) and 0.191 +/- 0.1 cm (diet II). The conversion rate was good for both, suggesting that 6 to 7 kg of food are needed to obtain 1 kg of prawn. Survival was 76% and 100% for diets I and II, respectively.
Keiler, Jonas; Richter, Stefan; Wirkner, Christian S
The morphological transformation of hermit crabs into crab-like king crabs in the evolution of decapod crustaceans represents a remarkable case of carcinization or evolutionary shaping into a crab-like form. In this study, we focus on internal organs such as the hemolymph vascular system and adjacent anatomical structures of several Recent hermit crab (Paguridae) and king crab (Lithodidae) species. There are various correspondences in the morphology of the arterial systems in the dorsal cephalothorax of the two taxa, especially with regard to the anterior aorta, anterior lateral arteries, and hepatic arteries. In the pleon, the posterior aorta in both taxa displays a proximal bifurcation and follows an asymmetrical course. The ventral vessel system, on the other hand, which mainly supplies the limbs, differs significantly between the taxa, with pagurids displaying the plesiomorphic condition. The pattern of the ventral vessel system in Lithodidae is influenced by morphological transformations of integumental structures during carcinization. One of these transformations was the broadening of the sternites, which resulted in a widening of the space between the endosternites. In addition, changes in the morphology of the endophragmal skeleton in Lithodidae led to an increase in the potential for intraspecific variability and interspecific variation in the arterial branching pattern. Copyright © 2013 Wiley Periodicals, Inc.
Komai, Tomoyuki; Reshmi, Rema; Kumar, Appukuttannair Biju
A new species of the hermit crab genus Diogenes Dana, 1851 (Diogenidae), D. canaliculatus, is described and illustrated on the basis of material from off the Kerala State, southern India. It is referred to the D. edwardsii (De Haan, 1849) species group, and compared with D. bicristimanus Alcock, 1905, D. fasciatus Rahayu & Forest, 1995, D. laevicarpus Rahayu, 1996 and D. moosai Rahayu & Forest, 1995. The characteristically sculptured left chela and the unarmed dorsal margins of the propodi of the second and third pereopods distinguish the new species from these congeners.
Komai, T; Osawa, M
A new species of pagurid hermit crab, Pagurus decimbranchiae, is described and illustrated based on 20 specimens collected from shallow waters of the Pacific coast of Japan ranging from Boso Peninsula to Tanegashima Island. It is quite distinctive in having the rudimentary arthrobranch on the third maxilliped represented by a single bud, however close morphological similarity is found between the new species and P. moluccensis Haig and Ball. Comparisons are also made among other species, including P. boriaustraliensis Morgan, P. sp. cf. boriaustraliensis sensu Rahayu and Komai (2000) and the members of the P. anachoretus group. The present generic assignment of the new species should be considered provisional, as more extensive study is needed to investigate phylogenetic relationships of the new species and the other species of Pagurus.
Dambach, Johannes; Thatje, Sven; Rödder, Dennis; Basher, Zeenatul; Raupach, Michael J.
Marine invertebrates inhabiting the high Antarctic continental shelves are challenged by disturbance of the seafloor by grounded ice, low but stable water temperatures and variable food availability in response to seasonal sea-ice cover. Though a high diversity of life has successfully adapted to such conditions, it is generally agreed that during the Last Glacial Maximum (LGM) the large-scale cover of the Southern Ocean by multi-annual sea ice and the advance of the continental ice sheets across the shelf faced life with conditions, exceeding those seen today by an order of magnitude. Conditions prevailing at the LGM may have therefore acted as a bottleneck event to both the ecology as well as genetic diversity of today's fauna. Here, we use for the first time specific Species Distribution Models (SDMs) for marine arthropods of the Southern Ocean to assess effects of habitat contraction during the LGM on the three most common benthic caridean shrimp species that exhibit a strong depth zonation on the Antarctic continental shelf. While the shallow-water species Chorismus antarcticus and Notocrangon antarcticus were limited to a drastically reduced habitat during the LGM, the deep-water shrimp Nematocarcinus lanceopes found refuge in the Southern Ocean deep sea. The modeling results are in accordance with genetic diversity patterns available for C. antarcticus and N. lanceopes and support the hypothesis that habitat contraction at the LGM resulted in a loss of genetic diversity in shallow water benthos. PMID:23029463
Re-Araujo, Ana Denisse; Acosta Ruiz, M de Jesús
The effect of different lecithin sources and presentations on growth, food conversion ratio and survival of P. vannamei (290 mg +/- 0.02) was studied. The bioassay was designed in order to compare different dietary levels and different quality of lecithin. Squid lecithin, crude soybean (7%), deoiled soybean lecithin (3.48%) in combination with fish oil or squid neutral lipids, in a partially dilapidate formula. The isoenergetic diets were fed ad libitum to four replicate groups (tanks) of 15 shrimps each (5 x 4 x 15), during 28 days. The result of the bioassay with the partially dilapidate formulas was; the best growth rate (191%) and FCR (1.69 +/- 0.041) were obtained with the diet containing 7% of soybean crude lecithin as the unique lipid source. Followed by the diet countering 3.94% deoiled lecithin and 2.42% Menhaden oil (172% and 2.03 +/- 0.054 respectively). As expected, the worst results were obtained without the dietary lecithin 121% and 2.42 +/- 0.129). Crude soybean lecithin alone covered the phospholipid and neutral lipids requirements as well as the combination of deoiled soybean lecithin with fish or squid oil.
Shih, Yi-Jia; Ho, Ping-Ho; Chan, Tin-Yam
Four leucosiid species from Taiwan are presented. Ebalia nudipes Sakai, 1963, with its male first gonopod figured for the first time. Galilia petricola Komai & Tsuchida, 2014, is recorded on the basis of a larger specimen, and distinguishing features with its only congener, G. narusei Ng & Richer de Forges, 2007, reappraised. Nursia rhomboidalis (Miers, 1879), previously known only from Japan, Korea, and mainland China, is also recorded from Taiwan. Myra fugax (Fabricius, 1798) is now formally recorded from Taiwan, and female characters identified to help separate the three known Taiwanese species of Myra.
Galil, Bella S; Ng, Peter K L
Twenty-five species of leucosiid crabs are reported from Madang Province, Papua New Guinea. Of these, seven are new to science: two each are included in Alox Tan & Ng, 1995 and Tanaoa Galil, 2003, and one each in Ryphila Galil, 2009, Seulocia Galil, 2005, and Urnalana Galil, 2005. Fifteen additional species are new records for Papua New Guinea: Alox rugosum (Stimpson, 1858), Ancylodactyla nana (Zarenkov, 1990), Arcania heptacantha De Man, 1907, Heterolithadia fallax (Henderson, 1893), Hiplyra longimana (A. Milne Edwards, 1874), Myra curtimana Galil, 2001, M. digitata Galil 2004, Nursilia dentata Bell, 1855, Oreotlos etor Tan & Richer de Forges, 1993, Parilia major Sakai, 1961, Raylilia coniculifera Galil, 2001, R. uenoi (Takeda, 1995), Toru pilus (Tan, 1996), Urashima pustuloides (Sakai, 1961) and Leucosia rubripalma Galil, 2003. The new species are described and illustrated, and their affinities with allied taxa discussed. Colour photographs are provided for 20 species.
Becker, Carola; Brandis, Dirk; Storch, Volker
Commensal pea crabs inhabiting bivalves have a high reproductive output due to the extension andfecundity of the ovary. We studied the underlying morphology of the female reproductive system in the Pinnotheridae Pinnotheres pisum, Pinnotheres pectunculi and Nepinnotheres pinnotheres using light microscopy and transmission electron microscopy (TEM). Eubrachyura have internal fertilization: the paired vaginas enlarge into storage structures, the spermathecae, which are connected to the ovaries by oviducts. Sperm is stored inside the spermathecae until the oocytes are mature. The oocytes are transported by oviducts into the spermathecae where fertilization takes place. In the investigated pinnotherids, the vagina is of the "concave pattern" (sensu Hartnoll1968): musculature is attached alongside flexible parts of the vagina wall that controls the dimension of its lumen. The genital opening is closed by a muscular mobile operculum. The spermatheca can be divided into two distinct regions by function and morphology. The ventral part includes the connection with vagina and oviduct and is regarded as the zone where fertilization takes place. It is lined with cuticle except where the oviduct enters the spermatheca by the "holocrine transfer tissue." At ovulation, the oocytes have to pass through this multilayered glandular epithelium performing holocrine secretion. The dorsal part of the spermatheca is considered as the main sperm storage area. It is lined by a highly secretory apocrine glandular epithelium. Thus, two different forms of secretion occur in the spermathecae of pinnotherids. The definite role of secretion in sperm storage and fertilization is not yet resolved, but it is notable that structure and function of spermathecal secretion are more complex in pinnotherids, and probably more efficient, than in other brachyuran crabs. Copyright © 2010 Wiley-Liss, Inc.
Rosa, R; Calado, R; Andrade, A M; Narciso, L; Nunes, M L
We studied the amino acid and lipid dynamics during embryogenesis of Homarus gammarus. Major essential amino acids (EAA) in the last stage of embryonic development were arginine, lysine and leucine; major nonessential amino acids (NEAA) were glutamic acid, aspartic acid, valine and glycine. The highest percent of utilization occurred in respect to EAA (27.8%), mainly due to a significant decrease (p<0.05) of methionine (38.3%) and threonine (36.0%). NEAA also decreased significantly (p<0.05, 11.4%), namely serine (38.1%), tyrosine (26.4%) and glutamic acid (25.7%). In contrast, the free amino acid content increased significantly (p<0.05) during embryonic development, especially the free nonessential amino acids (FNEAA). In the last stage, the most abundant FNEAA were glycine, proline, alanine and taurine, and the major free essential amino acids (FEAA) were arginine, lysine and leucine. Lipid content decreased significantly (p<0.05) during embryonic development. A substantial decrease in all neutral lipid classes was observed (>80% of utilization). Major fatty acids were 16:0, 18:0, 18:1n-9, 18:2n-6, 18:3n-3, 20:5n-3 and 22:6n-3. Unsaturated (UFA) and saturated fatty acids (SFA) were used up at similar rates (76.5% and 76.3%, respectively). Within UFA, monounsaturates (MUFA) were consumed more than polyunsaturates (PUFA) (82.9% and 67.5%, respectively).
Parker, A. R.; Mckenzie, D. R.; Ahyong, S. T.
The first demonstration, to our knowledge, of an evolutionary shift in communication mode in animals is presented. Some species of Ovalipes display spectacular iridescence resulting from multilayer reflectors in the cuticle. This reflector is unique in animals because each layer is corrugated and slightly out of phase with adjacent layers. Solid layers are separated from fluid layers in the reflector by side branches acting as support struts. An effect of this reflector is that blue light is reflected over a 'broad' angle around a plane parallel to the sea floor when the host crab is resting. Species of Ovalipes all possess stridulatory structures. The shallow-water species with the best developed stridulatory structures are non-iridescent and use sound as a signal. Deep-water species possess poorly developed stridulatory structures and display iridescence from most regions of the body. In deep water, where incident light is blue, light display is highly directional in contrast to sound produced via stridulation. Sound and light display probably perform the same function of sexual signalling in Ovalipes, although the directional signal is less likely to attract predators. Deep-water species of Ovalipes appear to have evolved towards using light in conspecific signalling. This change from using sound to using light reflects the change in habitat light properties, perhaps the hunting mechanisms of cohabitees, and its progression is an indicator of phylogeny. The changes in sexual signalling mechanisms, following spatial–geographical isolation, may have promoted speciation in Ovalipes.
Background The infraorder Anomura has long captivated the attention of evolutionary biologists due to its impressive morphological diversity and ecological adaptations. To date, 2500 extant species have been described but phylogenetic relationships at high taxonomic levels remain unresolved. Here, we reconstruct the evolutionary history—phylogeny, divergence times, character evolution and diversification—of this speciose clade. For this purpose, we sequenced two mitochondrial (16S and 12S) and three nuclear (H3, 18S and 28S) markers for 19 of the 20 extant families, using traditional Sanger and next-generation 454 sequencing methods. Molecular data were combined with 156 morphological characters in order to estimate the largest anomuran phylogeny to date. The anomuran fossil record allowed us to incorporate 31 fossils for divergence time analyses. Results Our best phylogenetic hypothesis (morphological + molecular data) supports most anomuran superfamilies and families as monophyletic. However, three families and eleven genera are recovered as para- and polyphyletic. Divergence time analysis dates the origin of Anomura to the Late Permian ~259 (224–296) MYA with many of the present day families radiating during the Jurassic and Early Cretaceous. Ancestral state reconstruction suggests that carcinization occurred independently 3 times within the group. The invasion of freshwater and terrestrial environments both occurred between the Late Cretaceous and Tertiary. Diversification analyses found the speciation rate to be low across Anomura, and we identify 2 major changes in the tempo of diversification; the most significant at the base of a clade that includes the squat-lobster family Chirostylidae. Conclusions Our findings are compared against current classifications and previous hypotheses of anomuran relationships. Many families and genera appear to be poly- or paraphyletic suggesting a need for further taxonomic revisions at these levels. A divergence time analysis provides key insights into the origins of major lineages and events and the timing of morphological (body form) and ecological (habitat) transitions. Living anomuran biodiversity is the product of 2 major changes in the tempo of diversification; our initial insights suggest that the acquisition of a crab-like form did not act as a key innovation. PMID:23786343
De Grave, Sammy; Johnson, Magnus L.
The mandibles of caridean shrimps have been widely studied in the taxonomy and functional biology of the group. Within the Palaemonoidea the mandibles reach a high level of structural diversity reflecting the diverse lifestyles within the superfamily. However, the majority of studies have been restricted to light microscopy, with the ultrastructure at finer levels poorly known. This study investigates the mandible of nine species belonging to six of the recognised families of the Palaemonoidea using SEM and analyses the results in a phylogenetic and dietary framework. The results of the study indicate that little phylogenetic information is conveyed by the structure of the mandible, but that its form is influenced by primary food sources of each species. With the exception of Anchistioides antiguensis, all species examined possessed cuticular structures at the distal end of the pars molaris (molar process). Five types of cuticular structures are recognised herein, each with a unique form, but variable in number, placement and arrangement. Each type is presumed to have a different function which is likewise related to diet. PMID:25825676
Gómez Luna, Liliana; Sosa Montano, Antonio; Moreno Castillo, Isabel; Jover Capote, Abdiel
On the basis of fishery intensity and proximity to river mouth, a total of 257 swimming Callinectes crabs were collected from March 2007 to April 2008 in eight localities. Captures were made with hanging nets, to a maximal depth of 1.5 m, establishing a top time of 2 hr. The genus was widely distributed, and it is represented at least by four species: C. sapidus, C. similis, C. rathbunae and C. larvatus, the last two not included in the last list of Cuban crustaceans (Crustacea: Decapoda). The size and shape of the gonopods were very useful as taxonomical criteria, considering the prevalence of males. The most abundant species were C. sapidus (47.08%), and C. similis (30.35%). C rathbunae, which was identified at 75% (6) of the localities, showed a better distribution, followed by C. sapidus, which appears in the 63% (5). Sex rate (R(s)) by species (male:female) was 6.20 for C. rathbunae, 3.58 for C. similis, 1.40 for C. larvatus and 0.40 for C. sapidus. The most abundant species had a lower R value. Morphometrical analysis and weight allowed us to know the average carapace width (CW) and weight (W). C. sapidus had an average CW = 110.57 mm (DS 21.55, n = 121) and W = 84.46 g (SD 43.25, n = 121); C. rathbunae a CW = 115.50 mm (DS 14.94, n = 36) and W = 140.44 g (DS 55.02, n = 36); C. larvatus a CW = 76.04 mm (DS 10.88, n = 22) and W = 31.70 g (DS 14.67, n = 22); and C. similis had the minimal parameter values, with a CW = 59.77 mm (DS 14.09, n = 78) and W = 13.80 g (DS 10.00, n = 78). These are the first records of the coastal crabs in the area. All values are lower than in previous reports. The largest individuals (CW>140 mm: C. rathbunae and C. sapidus) were captured in localities with adequate environmental characteristics. The stomach content suggests nine dietary categories, mainly fishes and macroalgae. The genus Callinectes has a diversified trophic spectrum. These crabs eat the available food, but they have a preference for the most abundant items.
FAMILY PORCELLANIDAE* (M) SECTION BRACHYURA* (M) OTHER DECAPODA* (M) PHYLUM CHAETOGNATHA* (H) PHYLUM CHORDATA SUB-PHYLUM UROCHORDATA CLASS ASCIDIACEA...PHYLUM ARTHROPODA CLASS CRUSTACEA ORDER DECAPODA FAMILY PENAEIDAE Penaeus plebejus Hess Eastern king prawn PHYLUM CHORDATA CLASS ELASMOBRANCHII ORDER
Two deep-water species of caridean shrimps collected during recent dives by the Chinese manned submersible "Jiaolong" represents new records for the South China Sea: Alvinocaris longirostris Kikuchi & Ohta, 1995 (Alvinocarididae) and Acanthephyra faxoni Calman, 1939 (Acanthephyridae). Specimens of these two species were collected from Jiaolong Cold Seep I, off Guangdong Province, China (depth 1138 m). Alvinocaris longirostris is known to be associated with chemosynthetic community, whereas Acanthephyra faxoni is a bathypelagic inhabitant, of which the occurrence in seep site is merely opportunistic. An identification key to species of Alvinocaris is provided.
Götze, Sandra; Saborowski, Reinhard; Martínez-Cruz, Oliviert; Muhlia-Almazán, Adriana; Sánchez-Paz, Arturo
Crustaceans are intensively farmed in aquaculture facilities where they are vulnerable to parasites, bacteria, or viruses, often severely compromising the rearing success. The ubiquitin-proteasome system (UPS) is crucial for the maintenance of cellular integrity. Analogous to higher vertebrates, the UPS of crustaceans may also play an important role in stress resistance and pathogen defense. We studied the general properties of the proteasome system in the hemocytes of the whiteleg shrimp, Penaeus vannamei, and the European brown shrimp Crangon crangon. The 20S proteasome was the predominant proteasome population in the hemocytes of both species. The specific activities of the trypsin-like (Try-like), chymotrypsin-like (Chy-like), and caspase-like (Cas-like) enzymes of the shrimp proteasome differed between species. P. vannamei exhibited a higher ratio of Try-like to Chy-like activities and Cas-like to Chy-like activities than C. crangon. Notably, the Chy-like activity of P. vannamei showed substrate or product inhibition at concentrations of more than 25 mmol L(-1). The K M values ranged from 0.072 mmol L(-1) for the Try-like activity of P. vannamei to 0.309 mmol L(-1) for the Cas-like activity of C. crangon. Inhibition of the proteasome of P. vannamei by proteasome inhibitors was stronger than in C. crangon. The pH profiles were similar in both species. The Try-like, Chy-like, and Cas-like sites showed the highest activities between pH 7.5 and 8.5. The proteasomes of both species were sensitive against repeated freezing and thawing losing ~80-90% of activity. This study forms the basis for future investigations on the shrimp response against infectious diseases, and the role of the UPS therein.
Zalota, A. K.; Kolyuchkina, G. A.; Tiunov, A. V.; Biriukova, S. V.; Spiridonov, V. A.
This work concerns the trophic web positioning of the alien crab Rhithropanopeus harrisii and other common marine invertebrate species and fishes in the benthic ecosystem of the shallows of Taman Bay, Sea of Azov. The base of the trophic web in this system is composed of phytoplankton, macrophytes (algae and marine grasses), and reeds that use atmospheric carbon for photosynthesis. Analysis of the isotopic composition of nitrogen and carbon has shown that although marine grasses are dominating primary producers in the shallows of the bay, primary consumers (such as Cerastoderma glaucum, Porifera gen. sp., Gammarus aequicauda, Deshayesorchestia deshayesii and Idotea balthica) only partially use this organic source; instead, they use a combination of different sources of primary production. It has been shown that the food source of the alien crab is primarily of animal origin. In Taman Bay, R. harrisii is on the same trophic level as other carnivores/scavengers: benthic fishes Syngnathus nigrolineatus, Gobius spp. and native crab Pilumnus hirtellus and shrimp Palaemon adspersus.
de Freitas Rebelo, M; Rodriguez, E M; Santos, E A; Ansaldo, M
Histopathological effects of ammonia on the gills of the estuarine crab Chasmagnathus granulata (Dana, 1851) were evaluated after acute exposure to ammonia concentrations around LC(50) value (17.85 Mm). Disruption of pilaster cells and a subsequent collapse of gill lamellae were the main effects observed. Epithelial necrosis and hyperplasia were also detected. Significant (P<0.05) increases in pCO(2) and lactate, and significant decreases of pO(2) were detected in the haemolymph of ammonia-exposed crabs. These changes suggest that the observed histopathological damage affected gas exchange, possibly leading to death.
Komai, Tomoyuki; Ng, Peter K L
A new species of sesarmid crab, Chiromantes magnus, is described from the Ogasawara (Bonin) Is., Japan. The new species was previously confused with C. dehaani (H. Milne Edwards, 1853). The different carapace shape, proportionally longer ambulatory legs, large adult size and the distinct live coloration distinguish the new species from its two closest congeners, C. dehaani and C. neglectus (De Man, 1887). Available information indicates that C. magnus n. sp. is endemic to the Ogasawara Is.; there is no evidence of the occurrence of the true C. dehaani in the Ogasawara Is.
Ng, Peter K L
A new genus and new species of eumedonine crab, Cebudonus poppeorum, is described from the central Philippines. Superficially similar to Eumedonus H. Milne Edwards, 1834, Gonatonotus White, 1847, Zebrida White, 1847, Zebridonus Chia, Ng & Castro, 1995, and Tiaramedon Chia & Ng, 1998, Cebudonus n. gen. is easily characterised by possessing two long pseudorostral spines, a gently convex and unarmed dorsal carapace surface, elongated chelipeds that have the chela and merus unarmed and not cristate, elongated and slender ambulatory legs in which the merus is not cristate, a relatively narrow anterior male thoracic sternum, and a proportionately broader male abdomen. The general structure and colour pattern (with longitudinal stripes) suggests Cebudonus n. gen. is an obligate symbiont with echinoids.
Huang, Chao; Shih, Hsi-Te; Mao, Si Ying
Abstract A new genus and species of freshwater crab, Yuebeipotamon calciatile gen. n., sp. n., is described from southern China. While the carapace features are superficially similar to species of Sinopotamon Bott, 1967, Longpotamon Shih, Huang & Ng, 2016, and Tenuilapotamon Dai, Song, Li, Chen, Wang & Hu, 1984, the new genus possesses a distinctive combination of carapace, ambulatory leg, male thoracic sternal, male abdominal, and gonopodal characters that distinguish it from these and other genera. Molecular evidence derived from the mitochondrial 16S rDNA supports the establishment of a new genus. PMID:27667941
Ng, Peter K L; Richer De Forges, Bertrand; Jones, Georgina
The nomenclature and taxonomy of the Cape Town Spider Crab, Macropodia falcifera Stimpson, 1858, is treated. The species is rediagnosed and figured, and its ecology discussed. A key is also provided of the Indo-West Pacific species of Macropodia.
Ng, Peter K L; Kumar, Appukuttannair Biju
A new species of Carcinoplax H. Milne Edwards, 1852 (family Goneplacidae) is described from southern India. Carcinoplax fasciata n. sp. is closest to C. specularis Rathbun, 1914, but can be distinguished by its different coloration in life as well as structures of the carapace surface, anterolateral armature, supraorbital margin, chela and male first gonopod.
Ng, Peter K L
A new species of potamid freshwater crab, Malayopotamon weh sp. nov., is described from the island of Pulau Weh off northern Sumatra, Indonesia. The species superficially resembles three Sumatran species: M. batak Ng & Wowor, 1991, M. tobaense (Bott, 1968), and M. turgeo Ng & Tan, 1999, but can easily be distinguished by various carapace as well as gonopod characters.
Ng, Peter K L; Vidthayanon, Chavalit
A new genus and species of potamid cavernicolous crab, Thampramon tonvuthi sp. nov., is described from Thailand. While superficially similar to Tiwaripotamon Bott, 1970, Phaibulamon Ng, 1992, and Nemoron Ng, 1996, the new genus possesses a unique combination of morphological characters including a distinctive carapace form, possession of a relatively long third maxilliped exopod, long ambulatory legs and a unique male first gonopod.
Ng, Peter K L; Grinang, Jongkar
A new species of cave crab, Stygothelphusa antu new species, is described from limestone formations in Temurang, Sarawak, Malaysia. The new species is the most highly adapted to a cavericolous lifestyle among the four known species of Stygothelphusa, having a pale body pigmentation, reduced eyes and elongated pereopods. In contrast, the other three species have normal eyes that almost completely fill the orbits. The new species also differs from its congeners by a number of carapace, pereopod and gonopod characters.
Ng, Peter K L; Lukhaup, Christian
A new genus and new species of free-living hymenosomatid crab, Aletheiana tenella, is described from Central Sulawesi, Indonesia. The two known Sulawesi hymenosomatid species, Cancrocaeca xenomorpha Ng, 1991, and Sulaplax ensifer Naruse, Ng & Guinot, 2008, are both from cave habitats. Aletheiana gen. nov. is most similar to Neorhynchoplax Sakai, 1938 (from freshwater and intertidal habitats in the Indo-West Pacific), and Sulaplax, but can be distinguished by its front possessing only one subventral rostral lobe, the base of the antenna is positioned between the base of the ocular peduncle and antennular fossa, the posterior margin of the epistome has two low, rounded median lobes, the merus of the third maxilliped is elongated, the ambulatory dactylus has a prominent subdistal spine, the cutting edges of the chela are armed with distinct teeth proximally, and the male abdomen is slender and elongate with the telson linguiform.
Saito, Tomomi; Anker, Arthur
Two new species of the spongicolid shrimp genus Microprosthema Stimpson, 1860 are described and illustrated on the basis of material collected recently in Australia and Japan. Type specimens of Microprosthema ningaloo sp. nov. were collected on Ningaloo Reef, Western Australia, whereas type specimens of Microprosthema pallidum sp. nov. were collected on a coral reef off Ishigaki Island, Ryukyu Archipelago, southern Japan. Microprosthema ningaloo sp. nov. and M. pallidum sp. nov. differ from all other species of the genus by a combination of morphological characters, including the gill-exopod formulae, and by their diagnostic colour patterns. This study increases the total number of species described in the genus Microprosthema to 16, nine of them in the Indo-West Pacific. In addition, new records are provided for M. lubricum Saito & Okuno, 2011 (Guam), M. plumicorne (Richters, 1880) (Red Sea, Mariana and Marshall Islands, French Polynesia), M. scabricaudatum (Richters, 1880) (Red Sea, Glorieuses and Tuamotu Islands), and M. validum Stimpson, 1860 (Red Sea, Madagascar, Singapore, French Polynesia), significantly extending their previously known distribution ranges.
Sbragaglia, Valerio; Lamanna, Francesco; M. Mat, Audrey; Rotllant, Guiomar; Joly, Silvia; Ketmaier, Valerio; de la Iglesia, Horacio O.; Aguzzi, Jacopo
The Norway lobster, Nephrops norvegicus, is a burrowing decapod with a rhythmic burrow emergence (24 h) governed by the circadian system. It is an important resource for European fisheries and its behavior deeply affects its availability. The current knowledge of Nephrops circadian biology is phenomenological as it is currently the case for almost all crustaceans. In attempt to elucidate the putative molecular mechanisms underlying circadian gene regulation in Nephrops, we used a transcriptomics approach on cDNA extracted from the eyestalk, a structure playing a crucial role in controlling behavior of decapods. We studied 14 male lobsters under 12–12 light-darkness blue light cycle. We used the Hiseq 2000 Illumina platform to sequence two eyestalk libraries (under light and darkness conditions) obtaining about 90 millions 100-bp paired-end reads. Trinity was used for the de novo reconstruction of transcriptomes; the size at which half of all assembled bases reside in contigs (N50) was equal to 1796 (light) and 2055 (darkness). We found a list of candidate clock genes and focused our attention on canonical ones: timeless, period, clock and bmal1. The cloning of assembled fragments validated Trinity outputs. The putative Nephrops clock genes showed high levels of identity (blastx on NCBI) with known crustacean clock gene homologs such as Eurydice pulchra (period: 47%, timeless: 59%, bmal1: 79%) and Macrobrachium rosenbergii (clock: 100%). We also found a vertebrate-like cryptochrome 2. RT-qPCR showed that only timeless had a robust diel pattern of expression. Our data are in accordance with the current knowledge of the crustacean circadian clock, reinforcing the idea that the molecular clockwork of this group shows some differences with the established model in Drosophila melanogaster. PMID:26524198
Aguzzi, J.; Costa, C.; Ketmaier, V.; Angelini, C.; Antonucci, F.; Menesatti, P.; Company, J. B.
The levels of environmental light experienced by organisms during the behavioral activity phase deeply influence the performance of important ecological tasks. As a result, their shape and coloring may experience a light-driven selection process via the day-night rhythmic behavior. In this study, we tested the phenotypic and genetic variability of the western Mediterranean squat lobster (Munida tenuimana). We sampled at depths with different photic conditions and potentially, different burrow emergence rhythms. We performed day-night hauling at different depths, above and below the twilight zone end (i.e., 700 m, 1200 m, 1350 m, and 1500 m), to portray the occurrence of any burrow emergence rhythmicity. Collected animals were screened for shape and size (by geometric morphometry), spectrum and color variation (by photometric analysis), as well as for sequence variation at the mitochondrial DNA gene encoding for the NADH dehydrogenase subunit I. We found that a weak genetic structuring and shape homogeneity occurred together with significant variations in size, with the smaller individuals living at the twilight zone inferior limit and the larger individuals above and below. The infra-red wavelengths of spectral reflectance varied significantly with depth while the blue-green ones were size-dependent and expressed in smaller animals, which has a very small spectral reflectance. The effects of solar and bioluminescence lighting are discussed as depth-dependent evolutionary forces likely influencing the behavioral rhythms and coloring of M. tenuimana.
Dissanayake, Awantha; Galloway, Tamara S.; Jones, Malcolm B.
This study reports the seasonal variability in aspects of the physiology of the shore crab Carcinus maenas from three estuaries in South-west England, each with varying anthropogenic inputs: Avon Estuary ('relatively low' impact), Yealm Estuary ('intermediate' impact) and Plym Estuary ('relatively high' impact). Crabs collected over 12 months from the Avon had a significantly 'lower' physiological condition in winter and spring compared to summer and autumn; in particular, haemocyte phagocytic capability (a general indicator of immune function) was significantly higher in winter and spring compared to summer and autumn, and total haemolymph antioxidant status (an indicator of oxidative stress) was significantly lower in winter compared to the remainder of the year. Potentially, shore crabs may be more susceptible to the effects of contaminant exposure, such as increased immunotoxicity (thus, reduction of immune function) and/or oxyradicals (or reactive oxygen species) exposure) especially in seasons of increased susceptibility i.e. summer/autumn (lower phagocytic capability) and winter (lowest antioxidant function). As the Avon was taken to represent the 'reference' site, this pattern is considered to reflect the 'normal' seasonal variability in shore crab physiology. Shore crab physiological condition from the 'relatively high' impact estuary (Plym) revealed increased cellular viability and antioxidant status in autumn and winter compared with that of the 'standard' pattern (Avon) However, crabs from the intermediate impact estuary (Yealm) only demonstrated significant physiological differences in summer as shown by a lower cellular viability. All crabs had been exposed to PAHs (confirmed by the presence of PAH metabolites in their urine) which may account for the observed differences in shore crab physiology. In conclusion, to aid understanding of the potential contaminant impacts on biota it is imperative that the 'normal' seasonal variability of physiological condition be established. Biological effects-based monitoring studies should therefore be employed seasonally to potentially highlight 'windows of sensitivity' to contaminant impact.
Liu, Wenliang; Liang, Xiaoli
A new species of the genus Calliaxina Ngoc-Ho, 2003, Calliaxina xishaensissp. n., collected from the South China Sea is described and illustrated. It is distinguishable from Calliaxina thomassini Ngoc-Ho, 2014 by having the rostrum broadly triangular with pointed tip and is distinguishable from Calliaxina novaebritanniae (Borradaile, 1900) and Calliax punica (de Saint Laurent & Manning, 1982) by the posterior margin of telson being convex. It is also the first record of this genus from the China seas. A key to the species of Calliaxina is given.
Christodoulou, Magdalini; Antoniou, Aglaia; Antonios Magoulas; Athanasios Koukouras
Abstract Atyaephyra de Brito Capello, 1867 was described from the Mediterranean region almost 200 years ago. Since then, the genus has been recorded from various freshwater habitats in Europe, North Africa and the Middle East. Despite its long history, the taxonomic status of Atyaephyra species remains confusing and uncertain. Consequently numerous specimens from the known range of Atyaephyra were analysed using morphological characters and mitochondrial COI sequences in an attempt to clarify the taxonomy of this genus. The present study recognises seven Atyaephyra species, more than twice as many as previously recorded (three), four of which are considered as new. The new species are described, additional information to the original descriptions are provided for the remaining three taxa, while neotypes of Atyaephyra desmarestii Millet, 1831 and Atyaephyra stankoi Karaman, 1972 are designated to stabilize their taxonomy. Non-overlapping distinguishing morphological characters are used to discriminate the examined material into five species, e.g., Atyaephyra desmarestii, Atyaephyra stankoi, Atyaephyra orientalis Bouvier, 1913, Atyaephyra thyamisensis sp. n., Atyaephyra strymonensis sp. n. In addition, the genetic analysis supports the existence of multiple phylogenetic clades in the broader Mediterranean area and distinguishes two new cryptic species, namely Atyaephyra tuerkayi sp. n. and Atyaephyra acheronensis sp. n. The geographic distribution of these species is confirmed and their phylogenetic relationships are described. PMID:23166474
Liu, Wenliang; Liang, Xiaoli
Abstract A new species of the genus Calliaxina Ngoc-Ho, 2003, Calliaxina xishaensis sp. n., collected from the South China Sea is described and illustrated. It is distinguishable from Calliaxina thomassini Ngoc-Ho, 2014 by having the rostrum broadly triangular with pointed tip and is distinguishable from Calliaxina novaebritanniae (Borradaile, 1900) and Calliax punica (de Saint Laurent & Manning, 1982) by the posterior margin of telson being convex. It is also the first record of this genus from the China seas. A key to the species of Calliaxina is given. PMID:27917058
Komai, Tomoyuki; Yamada, Yusuke
The palaemonid shrimp genus Palaemonella Dana, 1852 is currently represented by 21 formally described species worldwide, of which 17 species are known from the Indo-West Pacific. In this study, a new species, P. okunoi, is described and illustrated on the basis of two ovigerous female specimens collected from coastal waters in Okinawa Island, Ryukyu Islands, Japan, at depths of 5-30 m. The new species closely resembles P. hachijo Okuno, 1999, but the shorter rostrum, more anteriorly located postrostral teeth on the carapace, the presence of a pair of submedian teeth on the fourth thoracic sternite and the less slender pereopods distinguish P. okunoi n. sp. from P. hachijo. The discovery of the present new species raises the number of Japanese species of Palaemonella to eight. An updated key to the Indo-West Pacific species of the genus is presented.
Pierrot, C; Pequeux, A; Thuet, P
This paper reports the adaptation of a branchial perfusion technique to the gills of the small hyper-hyporegulating crab, Pachygrapsus marmoratus. The physiological quality of the preparation has been established and preliminary measurements of the transepithelial potential difference (PD) and sodium fluxes were reported. A clear-cut distinction has to be made between anterior and posterior gills. With symmetrical bathing conditions (same saline on both sides of the epithelium), a significant transepithelial PD was measured only in posterior gills isolated from crabs acclimated to dilute sea water. This hemolymph-side negative PD is shown to require biological energy and to be sensitive to ouabain. Na+ influx was larger than efflux, indicating the occurrence of a net inward of Na+. The active nature of the Na+ influx was established.
Mendoza, Jose Christopher E
A new species of xanthid crab (Brachyura: Xanthidae) is described from the Bohol Sea in the central Philippines. Xanthias joanneae sp. nov. is most similar in morphology to X. maculatus Sakai, 1961 (type locality: Sagami Bay, Japan), particularly in the presence of distinctive ocelli on the carapace and pereopods. It can be separated from this species by the greater number of ocelli on the dorsal surface of the carapace, wider teeth separated by narrow notches on the carapace anterolateral margin, absence of longitudinal ridges on the external surface of the chelar palm, shorter and stouter ambulatory legs, narrower male anterior thoracic sternum, and stouter G 1.
Nunan, Linda M; Poulos, Bonnie; Redman, Rita; Le Groumellec, Marc; Lightner, Donald V
Molecular detection methods were developed to aid in the diagnosis of a rickettsia-like bacterium (RLB) which caused severe mortalities of farm-raised Penaeus monodon in Madagascar. Using primers derived from the 16S rRNA gene of bacteria, a PCR assay was optimized to amplify this region of the genome of the RLB, using extracted DNA from infected P. monodon tissue as the template. The resulting amplified PCR product was sequenced and 2 novel primers were selected from the variable region of the gene. These primers amplified a 532 bp fragment of DNA originating from the rickettsia-infected samples. The PCR assay was optimized and tested on DNA extracted from specific pathogen-free (SPF) P. vannamei tissue and several other strains of bacteria. The PCR assay with the rickettsia-specific primers was specific for this RLB and did not amplify the other DNA samples tested. The 532 bp PCR-amplified fragment was labeled with digoxigenin (DIG) for in situ hybridization assays. This probe was tested on SPF, RLB and bacteria-infected shrimp specimens preserved in Davidson's fixative. The probe was specific for both natural and experimental rickettsial infections. Hybridization with this probe required a stringent temperature of 65 degrees C, otherwise cross-reactivity was observed with other types of bacteria.
Nunan, Linda M; Pantoja, Carlos R; Gomez-Jimenez, Silvia; Lightner, Donald V
The bacteria that cause necrotizing hepatopancreatitis in Penaeus vannamei adversely affect penaeid shrimp cultured in the western hemisphere. 16S rRNA and gyrase B gene analyses determined the taxonomic position of these bacteria. The name "Candidatus Hepatobacter penaei" is proposed for these pathogenic bacteria, which are members of the Rickettsiales order.
Liu, Wenliang; Liu, Ruiyu
Abstract A new species of the genus Nihonotrypaea Manning & Tamaki, 1998, Nihonotrypaea hainanensis sp. n., collected from the South China Sea, is described and illustrated. It is distinguishable from Nihonotrypaea harmandi (Bouvier, 1901), Nihonotrypaea japonica (Ortmann, 1891), Nihonotrypaea thermophila Lin, Komai & Chan, 2007 and Nihonotrypaea makarovi Martin, 2013 by having the elongated carpus of the male and female major cheliped. The new species is distinguishable from Nihonotrypaea petalura (Stimpson, 1860) by the proximolower margin of the carpus of the male major cheliped bearing several small denticles. PMID:25561829
Grandjean, Frederic; Tan, Mun Hua; Gan, Huan You; Gan, Han Ming; Austin, Christopher M
The Austropotamobius pallipes complete mitogenome has been recovered using Next-Gen sequencing. Our sample of A. pallipes has a mitogenome of 15,679 base pairs (68.44% A + T content) made up of 13 protein-coding genes, 2 ribosomal subunit genes, 22 transfer RNAs, and a 877 bp non-coding AT-rich region. This is the first mitogenome sequenced for a crayfish from the family Astacidae and the 4(th) for northern hemisphere genera.
Ribeiro, Felipe Bezerra; Buckup, Ludwig; Gomes, Kelly Martinez; Araujo, Paula Beatriz
Two new species of Parastacus Huxley, 1879 are described from material collected in the state of Rio Grande do Sul, southern Brazil: Parastacus fluviatilis sp. nov. from highland streams and Parastacus caeruleodactylus sp. nov. from wetlands. Parastacus fluviatilis sp. nov. is distinguished mainly by large chelipeds with dense setae cover on the cutting edge of fingers, telson subtriangular with two lateral blunt spines and strongly concave ventral surface of lateral process of thoracic sternites 6 and 7. Parastacus caeruleodactylus sp. nov. is distinguished mainly by blue cheliped fingers and a large gap between them, reduced abdomen, dorsal and ventral margins of dactylus, propodus and carpus of second pair of pereiopods with tufts of long setae and mid-dorsal carina of exopod of uropods unarmed. According to IUCN Red List criteria both species are considered endangered. Habitat characterization and a method for defining the shape of second abdominal pleura are also provided.
Bruce, A J
A new pontoniine shrimp species, Cuapetes yapiensis, from mangroves at Quamun, on Yap Island, Caroline Islands, is described and illustrated. Cuapetes yapiensis most closely resembles C. darwiniensis Bruce. Six species of Cuapetes are now known from the Caroline Islands.
Bamber, S. D.; Naylor, E.
Pre-moult female Carcinus maenasurine was confirmed as a source of putative sex pheromone. The sexual and temporal specificity of bioactivity in pre-moult female urine was demonstrated when urine samples taken from inter-moult and pre-moult male crabs, and inter-moult females, failed to generate a sexual response from receptive males. Detection sensitivity of male crabs to pre-moult female urine was established at a dilution factor of 1 μl of urine in 10 ml of seawater. Experimental blockage of the site of urine release (the antennal gland opercula) failed to diminish the chemical attractiveness of pre-moult female crabs to test males, implicating at least one further site of putative pheromone release. Observations of female sexual behaviour demonstrated an active role by pre-moult and post-moult female crabs when introduced to male crabs whose locomotor movement had been temporarily restricted.
de Jong, G. D.; Chadwick, J. W.
The role of the crayfish Orconectes virilis in the decomposition of submerged rat carrion and succession of other benthic macroinvertebrates was experimentally investigated in Slaughterhouse Gulch, a small, urban stream in Littleton, Colorado. Crayfish participation in carrion decomposition significantly altered the decomposition rate of the carrion. Nine carcasses were exposed in anchored minnow traps at three degrees of crayfish access: crayfish always present, crayfish having free access, and crayfish excluded. These three treatments required 23 days, 29 days, and 65 days, respectively, for complete decomposition of the rat carrion (<2% original biomass). Sample variability increased with number of crayfish present, especially as decomposition proceeded. Seven other macroinvertebrate taxa were collected from the carcasses, but their presence or absence could not be correlated with crayfish presence. The leech Haemopis marmoratus was generally the first macroinvertebrate to arrive at the carrion, being present in densities of <5 individuals/carcass early in succession and in larger densities (up to 25 individuals/carcass) after extensive decomposition and exposure of the viscera.
Komai, Tomoyuki; Minemizu, Ryo
A third species of the pontoniine shrimp genus Eupontonia Bruce, 1971, E. gracilipes n. sp., is described and illustrated on the basis of a single female specimen collected from shallow water of Ishigaki Island, southern Ryukyu Islands, Japan. The new species is readily distinguished from the two congeneric species, E. noctalbata Bruce, 1971 and E. oahu Bruce, 2010, by a number of morphological characters, including the presence of a distinct postrostral median ridge and of the postrostral median tooth on the carapace. It is considered to be a free-living species. The generic diagnosis of Eupontonia is slightly emended to accommodate the present new species. A key in aid of identification of species of Eupontonia is provided.
Liu, Yuan; Cui, Zhaoxia
The genetics and molecular biology of the commercially important Chinese spiny lobster, Panulirus stimpsoni are little known. Here, we present the complete mitochondrial genome sequence of P. stimpsoni, determined by the long polymerase chain reaction and primer walking sequencing method. The entire genome is 15,677 bp in length, encoding the standard set of 13 protein-coding genes, two ribosomal RNA genes, and 22 transfer RNA genes. The overall A+T content of the genome is 65.6%, lower than most malacostracan species. The gene order is consistent with the pancrustacean ground pattern. Several conserved elements were identified from P. stimpsoni control region, viz. one [TA(A)]n-block, two GA-blocks and three hairpin structures. However, the position of [TA(A)]n-block and number of hairpin structure are different from those in the congeneric P. japonicus and other decapods. Phylogenetic analyses using the concatenated nucleotide and amino acid sequences of 13 protein-coding genes do not support the monophyly of suborder Pleocyemata, which is in contrast to most morphological and molecular results. However, the position of Palinura and Astacidea is unstable, as represented by the basal or sister branches to other Reptantia species. P. stimpsoni, as the second species of Palinura with complete mitochondrial genome available, will provide important information on both genomics and conservation biology of the group.
Rato, Lénia D; Novais, Sara C; Lemos, Marco F L; Alves, Luís M F; Leandro, Sérgio M
The present study evaluated the effects of exposure to different target pCO2 levels: control (C: 370μatm, pH = 8.15) and ocean acidification (OA: 710μatm, pH=7.85) on development and biochemical responses related with oxidative stress and energy metabolism during the crustacean Homarus gammarus (L.) larval development, integrating different levels of biological organization. After hatching in the laboratory, larvae from the same female brood were exposed to the described conditions from hatching until reaching Stage III (last larval stage - 11 days). H. gammarus larvae demonstrated some susceptibility when addressing the predicted pCO2 levels for 2100. Further analysis at the biochemical and physiological level highlighted the occurrence of oxidative stress in the OA scenario (Superoxide Dismutase reduction and higher DNA damage) that was followed by developmental effects, increased inter-moult period from SII to SIII and reduced growth. The extended exposure to these conditions may affect organisms' key life-cycle functions such as physiological resistance, growth, sexual maturation, or reproduction with implications in their future fitness and population dynamics. Copyright © 2017. Published by Elsevier Inc.
Kim, Gyungryul; Yoon, Tae-Ho; Park, Won Gyu; Park, Jung Youn; Kang, Jung-Ha; Park, Hyun; Kim, Hyun Woo
We characterized the total mitochondrial genome of Australian spiny lobster, Panulirus cygnus (George, 1962), which is found along the western coast of Australia. Total mitochondrial genome length of P. cygnus was 15 724 bp, in which 13 proteins, 2 ribosomal RNAs, 22 transfer RNAs, and a putative control region were encoded. Nine and four protein-coding genes are encoded on the H-strand and on the L-strand, respectively. According to the phylogenetic analysis, P. cygnus was most closely related to Panulirus japonicus among the compared six species belonging to Palinuridae. Although overall gene organization was the same, the putative control region (between SrRNA gene and tRNA(Ilel)) is least similar to one another among mitochondrial genomes from the compared six species belonging to Palinuridae.
De Matos-Pita, Susana S; Ramil, Fran
Thirteen hermit crab species of the families Diogenidae, Paguridae and Parapaguridae were captured in deep waters off Mauritania during Maurit surveys. A new species of the genus Paguristes, Paguristes candelae n. sp., is described. Areopaguristes mauritanicus n. comb. is proposed for Paguristes mauritanicus Bouvier, 1906 and Pseudopaguristes marocanus n. comb. for Paguristes marocanus A. Milne-Edwards & Bouvier, 1892; the females of the latter species are reported for the first time. Our data extends the geographical distribution of Pseudopaguristes marocanus southwards and that of Paragiopagurus macroceros northwards. Both species, together with Diogenes pugilator (Roux, 1829), are recorded for the first time in Mauritanian waters. New data about bathymetric ranges are also reported for Pseudopaguristes marocanus n. comb., Areopaguristes mauritanicus n. comb. and Paragiopagurus macroceros.
Cardoso, Irene A; Burukovsky, Rudolf N
The deep sea shrimp genus Nematocarcinus Milne Edwards, 1881 includes 47 species, ten of them have been recorded from the Atlantic Ocean. Herein, material sampled during three scientific projects (REVIZEE Central Fishery project; Campos Basin Deep Sea Environmental Project; Evaluation of Environmental Heterogeneity in the Campos Basin) made in the Southwestern Atlantic, off Brazil, is examined. In addition, material sampled from the South Mid Atlantic Ridge (MAR-ECO Project) was also examined. Four species are recorded for the first time to the southwestern Atlantic Ocean including Mid Atlantic Ridge area: Nematocarcinus faxoni Burukovsky, 2001; N. gracilipes Filhol, 1884; N. rotundus Crosnier & Forest, 1973 and N. tenuipes Spence-Bate, 1888.
Assugeni, Camila de O; Magalhães, Tatiana; Bolaños, Juan A; Tudge, Christopher C; Mantelatto, Fernando L; Zara, Fernando J
Recent studies based on morphological and molecular data provide a new perspective concerning taxonomic aspects of the brachyuran family Mithracidae. These studies proposed a series of nominal changes and indicated that the family is actually represented by a different number and representatives of genera than previously thought. Here, we provide a comparative description of the ultrastructure of spermatozoa and spermatophores of some species of Mithracidae in a phylogenetic context. The ultrastructure of the spermatozoa and spermatophore was observed by scanning and transmission electron microscopy. The most informative morphological characters analysed were thickness of the operculum, shape of the perforatorial chamber and shape and thickness of the inner acrosomal zone. As a framework, we used a topology based on a phylogenetic analysis using mitochondrial data obtained here and from previous studies. Our results indicate that closely related species share a series of morphological characteristics of the spermatozoa. A thick operculum, for example, is a feature observed in species of the genera Amphithrax, Teleophrys, and Omalacantha in contrast to the slender operculum observed in Mithraculus and Mithrax. Amphithrax and Teleophrys have a rhomboid perforatorial chamber, while Mithraculus, Mithrax, and Omalacantha show a wider, deltoid morphology. Furthermore, our results are in agreement with recently proposed taxonomic changes including the separation of the genera Mithrax (previously Damithrax), Amphithrax (previously Mithrax) and Mithraculus, and the synonymy of Mithrax caribbaeus with Mithrax hispidus. Overall, the spermiotaxonomy of these species of Mithracidae represent a novel set of data that corroborates the most recent taxonomic revision of the family and can be used in future taxonomic and phylogenetic studies within this family. © 2017 Wiley Periodicals, Inc.
intergrades between Polycheles t. typhlops and Polycheles typhlops perarmatus is discussed thoroughly. The fact that no polychelid has been photographed...possibility of vertical breeding migrations in some species of Polycheles . The problem of ’hard’ and ’soft’ species of the genus Willemoesia is also
Chu, Ta-Jen; Lee, Ying-Chou
The oriental river prawn (Macrobrachium nipponense) is mainly distributed in East Asia. The phylogeography, population genetic structure and historical demography of this species in the East Asia were examined by using partial sequences of the cytochrome oxidase subunit I (COI) and 16S rRNA in mitochondrial DNA. Ten populations that included 239 individuals were collected from Taiwan (Shihmen Reservoir, SMR, Mingte Reservoir, MTR and Chengching Lake Reservoir, CLR), mainland China (Taihu Lake, TLC, Min River, MRC, Jiulong River, JRC and Shenzhen Reservoir, SRC), Japan (Biwa Lake, BLJ and Kasumigaura Lake, KLJ) and Korea (Han River, HRK). The nucleotide diversity (π) of all individuals was 0.01134, with values ranging from 0.0089 (BLJ, Japan) to 0.01425 (MTR, Taiwan). A total of 83 haplotypes were obtained, and the haplotypes were divided into 2 main lineages: lineage A included the specimens from BLJ, KLJ, CLR, MTR, TLC, MRC and JRC, and lineage B comprised the ones from HRK, SRC, SMR, MTR, TLC, MRC and JRC. Lineage A could be further divided two sub-lineages (A1 and A2). Individuals of lineage A2 were only from TLC. Demographic expansion was observed in each lineage, starting within the second-to-latest interglacial period for lineage A and within the last glacial period for lineage B. All FST values among the ten populations were significantly different, except for the values between MRC and JRC, and SMR and SRC. The phylogeography and genetic structure of M. nipponense in East Asia might be influenced by Pleistocene glacial cycles, lake isolation and human introduction. The possible dispersal routes of M. nipponense in the East Asia were also discussed. PMID:28267807
Lobato, Roberta Oliveira; Nunes, Silvana Manske; Wasielesky, Wilson; Fattorini, Daniele; Regoli, Francesco; Monserrat, José Marìa; Ventura-Lima, Juliane
The effects of cadmium (Cd) and arsenic (As), dosed alone or in combination have been poorly investigated in crustaceans. Besides, it is not known if dietary supplementation of exogenous antioxidants, like lipoic acid (LA), might prevent or even reverse toxic effects of Cd and As. The objective of the present study was to evaluate the role of lipoic acid in modulating biochemical responses after Cd and As exposures in Litopenaeus vannamei. Muscle from shrimp exposed to Cd alone or Cd+As showed a decrease in glutathione (GSH) levels, while the pre-treatment with LA reversed this situation. In this tissue, the pre-treatment with LA also induced an increase in glutathione-S-transferase (GST) activity in all groups. In hepatopancreas it was observed a marked accumulation of Cd and As, a decrease in the reactive oxygen species (ROS) concentration in response to Cd exposure alone (-LA); concomitant in the same group it was observed an increment of metallothionein-like content. As exposure induced an increase in GSH levels but LA reversed this increase. Also, LA showed to increase the GST activity in all groups treated. Besides, in this organ LA showed to augment total antioxidant competence. Obtained results indicate that LA can be used as a chemo-protectant against oxidative insults in shrimp.
Hamidah, H.; Abinawanto, Bowolaksono, A.
The freshwater crayfish is one of the most important fish species as the protein resources. Lake and rivers are the habitat of crayfish in Papua. Morphological characters of crayfish, such as color, total body lengths (L) and body weight (W) were influenced by the habitat. The purpose of the study, therefore, was to compare the total body length and body weight as well as the unique color of crayfish from Uter lake (Atinjo district), Seremuk river (Haha village), Baliem river (Pike village; Hubukiak district, Jayawijaya), and Baliem river (Wesaput village; Wesaput district). Length-weight (body length; LB versus wet weight; WWT) relationships were determined for male and female crayfish (Cherax spp.) The length-weight relationships of total individuals was W = 0,022215.L3,159. This regression differed significantly (R2 = 97.5 %) between locations. Both males and females exhibited positive allometric growth as statistical difference was observed in the mean of the wet weight and body length between males and females. Besides, Canonical function was subjected to determine population distribution based on length-weight data.
Felder, Darryl L
A new species of Lepidophthalmus lacking a ventral median sclerite on the second abdominal somite is described from coastal waters of the southwestern Gulf of Mexico. Lepidophthalmus statoni sp. nov., originally recognized only as a unique population in allozyme studies, is sympatric with the ventrally plated species Lepidophthalmus manningi Felder & Staton, 2000, but more closely resembles Lepidophthalmus louisianensis (Schmitt, 1935) from the northern and northwestern Gulf of Mexico. Apparently restricted to intertidal and shallow subtidal tropical waters, the new species is known to range from western Campeche to middle-upper reaches of Veracruz, Mexico. As many members of the genus, it commonly inhabits euryhaline inlets, estuaries, and protected shorelines, including richly organic muddy to clayey sands and sandy muds adjacent to shoreline vegetation. Coloration is documented and discussed as a tool to facilitate field identifications, as are morphological characters.
Christie, Andrew E; Chi, Megan
The decapod infraorder Astacidea is comprised of clawed lobsters and freshwater crayfish. Due to their economic importance and their use as models for investigating neurochemical signaling, much work has focused on elucidating their neurochemistry, particularly their peptidergic systems. Interestingly, no astacidean has been the subject of large-scale peptidomic analysis via in silico transcriptome mining, this despite growing transcriptomic resources for members of this taxon. Here, the publicly accessible astacidean transcriptome shotgun assembly data were mined for putative peptide-encoding transcripts; these sequences were used to predict the structures of mature neuropeptides. One hundred seventy-six distinct peptides were predicted for Procambarus clarkii, including isoforms of adipokinetic hormone-corazonin-like peptide (ACP), allatostatin A (AST-A), allatostatin B, allatostatin C (AST-C) bursicon α, bursicon β, CCHamide, crustacean hyperglycemic hormone (CHH)/ion transport peptide (ITP), diuretic hormone 31 (DH31), eclosion hormone (EH), FMRFamide-like peptide, GSEFLamide, intocin, leucokinin, neuroparsin, neuropeptide F, pigment dispersing hormone, pyrokinin, RYamide, short neuropeptide F (sNPF), SIFamide, sulfakinin and tachykinin-related peptide (TRP). Forty-six distinct peptides, including isoforms of AST-A, AST-C, bursicon α, CCHamide, CHH/ITP, DH31, EH, intocin, myosuppressin, neuroparsin, red pigment concentrating hormone, sNPF and TRP, were predicted for Pontastacus leptodactylus, with a bursicon β and a neuroparsin predicted for Cherax quadricarinatus. The identification of ACP is the first from a decapod, while the predictions of CCHamide, EH, GSEFLamide, intocin, neuroparsin and RYamide are firsts for the Astacidea. Collectively, these data greatly expand the catalog of known astacidean neuropeptides and provide a foundation for functional studies of peptidergic signaling in members of this decapod infraorder. Copyright © 2015 Elsevier Inc. All rights reserved.
Bouzon, J L; Freire, A S
Eight species of Brachyura and two species of Anomura were registered for the first time on the Santa Catarina coast, in the waters around the Arvoredo Marine Biological Reserve. The animals were collected by scuba divers, between 3 and 22 meters depth, from September 2001 to February 2003. A total of 31 decapod species were collected, and most of the new occurrences had already been registered in the adjacent northern waters.
Komai, Tomoyuki; Reshmi, Rema; Kumar, Appukuttannair Biju
A new species of the hermit crab genus Paguristes Dana, 1851 (Diogenidae), P. luculentus, is described and illustrated on the basis of three male specimens collected from off the Kerala State, southwestern India. It belongs to the species group characterized by the posterior lobes of the telson unarmed on the terminal margins, but the characteristic armature of the chelae and carpi of the chelipeds, consisting of a covering of numerous small corneous-tipped spines, and the presence of numerous small corneous-tipped or corneous spines on the mesial faces of the dactyli of the second pereopods immediately distinguish the new species from other congeneric species. The new species represents the ninth of the genus known from Indian waters.
Doweld, Van Tu; Dang, Van Dong; Cao, Thi Kim Thu; Hoang, Ngoc Khac
A new species of semi-terrestrial crab of the family Potamidae, Rathbunamon chumomrayense sp. nov. is described from Chu Mom Ray National Park, the Central Highlands of Vietnam. The new species can be distinguished from R. lacunifer (Rathbun, 1904), the only other species in the genus, by a suite of characters, including the slightly more rugose anterolateral regions, confluent epigastric and postorbital cristae that are sinuous, less convex anterolateral margins, relatively shorter fingers of the chelipeds, and the terminal segment of the male first gonopod being slightly curved outwards, with narrower dorsal flap.
Marchand, J; Leignel, V; Moreau, B; Chénais, B
Hydrothermal vent conditions are particular and organisms living in these environments may have developed detoxification mechanisms and/or genetic adaptations. In particular, physico-chemical conditions are thought to generate reactive oxygen species, highly toxic for organisms. The enzyme superoxide dismutase constitutes the first line of defense against oxidative damage. To improve our understanding of the environmental impacts exerted on the vent organisms, we have characterized the two manganese superoxide dismutase cDNAs (mitochondrial: mMnSOD and cytoplasmic: cMnSOD) of three members of the Bythograeidae (Bythograea thermydron, Cyanagraea praedator and Segonzacia mesatlantica), the only endemic crab family living in hydrothermal vents. In comparison, the isolation of manganese superoxide dismutase cDNAs was also carried out in several littoral crab families. MnSOD signatures were found in both sequences from each species studied, as well as different residues involved in metal coordination and protein activity. The phylogenetic analysis performed confirms the probable ancient duplication that gave rise to the two MnSODs (cMnSOD and mMnSOD). This study describes two potential distinct mMnSOD isoforms presenting particular peptide signals. Nevertheless, no sequence particularity that could support the hypothesis of a genetic adaptation was found in Bythograeidae's MnSODs compared to the other sequences. The mRNA expression analysis performed by real-time PCR on B. thermydron and S. mesatlantica compared to Cancer pagurus and Necora puber revealed a higher cMnSOD and mMnSOD mRNA expression in hydrothermal crabs compared to littoral crabs.
Becker, Carola; Klaus, Sebastian; Tudge, Christopher C
Pea crabs of the subfamily Pinnotherinae (Pinnotheridae) have a high investment in reproduction and an outstanding reproductive output, probably as an adaptation to the required increase in reproductive rate due to the pinnotherids small size and their parasitic, host-dependant way of life. In the present study, we investigate the male internal reproductive structures and the ultrastructure of spermatozoa of Pinnotheres pisum and Nepinnotheres pinnotheres by histological methods and both scanning- and transmission electron microscopy. In the Brachyura, the male internal reproductive systems generally consist of paired testes and corresponding vasa deferentia where spermatozoa develop and mature. Spermatozoal ultrastructure of the investigated pinnotherids conforms to the thoracotreme type, however, N. pinnotheres has an accessory opercular ring and a periopercular rim, neither of which are present in spermatozoa of P. pisum. Spermatozoa are enclosed within spermatophores in the secretory proximal vas deferens. Two types of secretions were observed in P. pisum and N. pinnotheres: an electron dense substance secreted in the proximal vas deferens involved in spermatophore formation, and large electron-luscent vesicles constituting the seminal plasma in the medial and distal vas deferens. The medial vas deferens is strongly widened compared to other brachyurans to purpose storing spermatophores embedded in seminal plasma. Tubular appendices, which produce and store large amounts of seminal plasma, arise from the distal region of the vas deferens. The appendices extend into the ventral cephalothorax and also in the first pleomere. The latter being an exceptional location for reproductive structures among male brachyurans. Copyright © 2013 Wiley Periodicals, Inc.
Lee, B Y; Low, Martyne E Y
Thomas Bell proposed 37 species- and 5 genus-group names for the Leucosiidae in four publications that appeared in 1855. The version appearing in the Proceedings of the Linnean Society of London is the earliest of these publications and the first available description of these taxa.
Chiesa, Juan José; Aguzzi, Jacopo; García, José Antonio; Sardà, Francesc; de la Iglesia, Horacio O
The temporal distribution of behavioral programs throughout the 24-h day, known as temporal niche of a species, is determined by ecological factors that directly affect the adaptive value of the timing of specific behaviors. Temporal niche switching has been described in several species and is likely adaptive in habitats where the daily timing of those factors changes. Benthic species whose habitats span a wide range of water depths are exposed to considerable depth-dependent environmental changes. Temporally scheduled trawl surveys of the Norway lobster, Nephrops norvegicus, reveal that animals emerge from burrows at night on the shallow shelf (10-50 m deep), at crepuscular hours on the lower shelf (50-200 m), and at daytime on the slope (200-400 m). The mechanisms underlying nocturnality/diurnality switches are chiefly unknown, and Nephrops offers a unique model for their study. The depth-dependent decrease in luminance is a likely candidate determining the temporal distribution of behavior. The authors explored this possibility in the laboratory by exposing Nephrops to light:dark (LD) cycles of 470-nm monochromatic lighting that mimic conditions at the 100-m-deep shelf (10 lux) or the 300-m slope (0.1 lux). Two groups of animals were respectively exposed to each light intensity according to the following protocol: an initial 12:12 LD stage followed by constant darkness (DD), followed in turn by a second 12:12 LD stage. Activity at the burrow opening (door-keeping = DK), as well as full emergence (E), was continuously monitored. Under 10-lux LD cycles, most animals showed nocturnal DK activity-with some being crepuscular or diurnal-and all animals showed nocturnal E activity. In contrast, both behaviors were clearly diurnal in animals under 0.1-lux LD cycles. The phase of the nocturnal and diurnal DK rhythms detected respectively at 10 and 0.1 lux upon release into DD revealed that these rhythms are entrained circadian rhythms. The present data indicate that nocturnality/diurnality switches in Nephrops in its natural habitat, evidenced by captures at different depths, are likely determined by light intensity. This temporal niche switching involves different patterns of photic entrainment, leading to bona fide circadian diurnal or nocturnal phenotypes, as well as exogenous masking of behavioral outputs.
Magalhães, Célio; Wehrtmann, Ingo S; Lara, Luis Rólier; Mantelatto, Fernando L
The taxonomy and geographic distribution of the freshwater crabs of the family Pseudothelphusidae Ortmann, 1893, of Costa Rica, Central America, particularly of the genus Ptychophallus Smalley, 1964, are revised. Historical materials deposited in major collections of several institutions were examined, as well as valuable collections in the Zoological Museum of the University of Costa Rica that include abundant specimens obtained recently (2007-2010) in the southern region of the country. The pseudothelphusids of Costa Rica consists of 15 currently valid species belonging to Achlidon Smalley, 1964 (two species), Allacanthos Smalley, 1964 (two species), Potamocarcinus H. Milne Edwards, 1853 (three species), and Ptychophallus (eight species). Two species seem to be restricted to the Atlantic drainage, while seven are known only from the Pacific drainage; six species occur in both drainages. Ptychophallus comprises 13 valid species; four new synonymies are proposed: P. osaensis Rodríguez, 2001, P. campylus Pretzmann, 1968, P. tumimanus ingae Pretzmann, 1978, and P. barbillaensis Rodríguez & Hedström, 2001, as junior synonyms of P. paraxantusi (Bott, 1968), P. tristani (Rathbum 1896), P. tumimanus (Rathbun, 1898), and P. uncinatus Campos & Lemaitre, 1999, respectively. Two species, P. colombianus (Rathbun, 1896) and P. exilipes (Rathbun, 1898), are considered species inquerendae. Lectotype designations are made for P. montanus and P. colombianus. Three species of Ptychophallus are known exclusively from Costa Rica, five exclusively from Panama, and five species occur in both countries; one species appears to be exclusive of the Atlantic drainage, whereas five are known only from the Pacific drainage and seven occur in both drainages. The gonopod morphology of all species is redescribed and illustrated, and maps of their geographic distribution are furnished. A key to the species of Pseudothelphusidae from Costa Rica and to all species of Ptychophallus is provided.
Keiler, Jonas; Richter, Stefan; Wirkner, Christian S
Porcelain crabs (Porcellanidae) are one of three taxa within anomuran crustaceans (Anomala) which possess a crab-like body form. Curiously, these three lineages evolved this shape independently from true crabs (Brachyura) in the course of the evolutionary process termed carcinization. The entire pleon in porcelain crabs is flexed under the cephalothorax and the carapace is approximately as broad as long. Despite their crab-like habitus, porcelain crabs are phylogenetically nested within squat lobsters (Munidopsidae, Munididae, Galatheidae). With a pleon which is only partly flexed under the cephalothorax and a cephalothorax which is longer than it is broad, squat lobsters represent morphologically intermediate forms between lobster-like and crab-like body shapes. Carcinization has so far mostly been studied with respect to outer morphology; however, it is evident that internal anatomical features are influenced through this change of body shape too. In this paper, the situation in Galatheoidea is elucidated by adding more taxa to existing descriptions of the hemolymph vascular systems and associated structures and organs. Micro-computer tomography and 3D reconstruction provide new insights. Autapomorphic states of various internal anatomical characters are present in nearly all the studied species, also reflecting some degree of anatomical disparity found within Galatheoidea. The ventral vessel system of porcelain crabs differs distinctly from that of squat lobsters. The differences in question are coherent (i.e. structural dependent) with morphological transformations in the integument, such as the shortening of the sternal plastron, which evolved in the course of carcinization. Shifts in the gonads and the pleonal neuromeres are coherent with the loss of the caridoid escape reaction, which in turn is a consequence of carcinization. The arterial transformations, however, are minor compared to other instances of carcinization in anomuran crustaceans since the last common ancestor of squat lobsters and porcelain crabs was already "half carcinized".
Galil, Bella S
Seven species of calappid crabs were identified from material collected during four IRD-MNHN expeditions conducted in 1998 and 1999 in shallow and deep waters off Fiji. Six species are reported for the first time from the islands. One new species, Mursia murimura n. sp., is described and illustrated. The new species differs from the closely related M. diwata Galil & Takeda, 2004, with which it shares a stout, distally auriculated first male pleopod, by possessing much longer lateral carapacial and cheliped spines.
Bernardes, Samuel C; Pepato, Almir R; von Rintelen, Thomas; von Rintelen, Kristina; Page, Timothy J; Freitag, Hendrik; de Bruyn, Mark
The evolutionary history of the old, diverse freshwater shrimp genus Caridina is still poorly understood, despite its vast distribution - from Africa to Polynesia. Here, we used nuclear and mitochondrial DNA to infer the phylogeographic and evolutionary history of C. typus, which is one of only four species distributed across the entire range of the genus. Despite this species' potential for high levels of gene flow, questions have been raised regarding its phylogeographic structure and taxonomic status. We identified three distinct lineages that likely diverged in the Miocene. Molecular dating and ancestral range reconstructions are congruent with C. typus' early dispersal to Africa, possibly mediated by the Miocene Indian Ocean Equatorial Jet, followed by back dispersal to Australasia after the Jet's closure. Furthermore, several different species delimitation methods indicate each lineage represents a distinct (cryptic) species, contradicting current morphospecies delimitation of a single C. typus taxon. The evolutionary history of C. typus lineages is complex, in which ancient oceanic current systems and (currently unrecognised) speciation events preceded secondary sympatry of these cryptic species.
Loughman, Zachary J.; Simon, Thomas P.; Welsh, Stuart
Cambarus (Puncticambarus) smilax is a stream-dwelling crayfish that appears to be endemic to the Greenbrier River basin in the Valley and Ridge province of West Virginia. Within the Greenbrier system it occurs primarily in tributaries to the Greenbrier mainstem, with stable populations in the East and West Fork, and Thorny, Knapp, and Deer creeks. The new species is morphologically most similar to C. (P.) robustus, from which it can be distinguished by a combination of the following characters: adult palm length comprising 73–76% of palm width as opposed to 63–70% in C. (P.)robustus; ventral surface of chela of cheliped with 0–2 subpalmar tubercles compared to 3–6 subpalmar tubercles in C. (P.) robustus; lack of tubercles on the dorsal surface of chela; longer, more tapering, less rectangular rostrum (47–52% rostrum width/length ratio) compared to C. (P.) robustusshorter, less tapering rectangular rostrum (54–63% rostrum width/length ratio); and the central projection of the form-I male gonopod curved ≤90 degrees to the shaft.
Perger, Robert; Wall, Adam
Abstract In this contribution a new species of the land crab genus Gecarcinus Leach, 1814, from the Neotropical Pacific coast of South America is described and illustrated. In addition to its unique body color, Gecarcinus nobilii sp. n. is distinguished from congeners by a distinctly wider carapace front and differences in the shape of the infraorbital margin. The new species is not isolated from Gecarcinus populations from the Pacific coast of Central America by an insurmountable geographic barrier. Considering the closure of the Panamanian Isthmus as a calibration point for morphological divergence between the trans-isthmian mainland populations of Gecarcinus, the virtual lack of morphological differentiation (other than color) between them and the distinctness of G. nobilii sp. n. suggests that G. nobilii sp. n. evolved from a common ancestor before the Isthmus closed. PMID:25152688
Perger, Robert; Wall, Adam
In this contribution a new species of the land crab genus Gecarcinus Leach, 1814, from the Neotropical Pacific coast of South America is described and illustrated. In addition to its unique body color, Gecarcinus nobilii sp. n. is distinguished from congeners by a distinctly wider carapace front and differences in the shape of the infraorbital margin. The new species is not isolated from Gecarcinus populations from the Pacific coast of Central America by an insurmountable geographic barrier. Considering the closure of the Panamanian Isthmus as a calibration point for morphological divergence between the trans-isthmian mainland populations of Gecarcinus, the virtual lack of morphological differentiation (other than color) between them and the distinctness of G. nobilii sp. n. suggests that G. nobilii sp. n. evolved from a common ancestor before the Isthmus closed.
Ford, Alex T
This paper aims to give a historical overview of current understanding about intersexuality in crustaceans, assesses gaps in our knowledge and asks whether it should be an environmental concern. The oldest known cases of intersexuality come from 70 million year old fossil crabs whilst the oldest published case of intersex crustacean stems from a 1730 Royal Society report of a gynandromorph lobster. Many crustacean species are sequential hermaphroditic or simultaneous hermaphrodites. Consequently, there has been confusion as to whether accounts of intersex in the literature are correct. Intersexuality is fairly common throughout the Crustacea and it has been suggested that intersex may arise through different mechanisms. For example, sexual gynandromorphism may arise through disruption in early embryonic development whereas intersexuality may also arise through perturbations of androgenic gland hormone and sexual differentiation in later development. The causes of intersex are multifaceted and can occur through a number of mechanisms including parasitism, environmental sex determination, genetic abnormalities and increasingly pollution is being implicated. Despite many studies on the effects of endocrine disrupters on crustaceans, very few have focussed on wild populations or male related endpoints; rather many laboratory studies have been attempting to assess biomarkers of feminisation. This is surprising as many of the seminal papers on endocrine disruption focussed on effects found in the wild and male specimens. This paper argues that we might have been addressing the right questions (i.e. pollution induced intersex), but in the wrong way (feminisation); and therefore gives recommendations for future directions for research. Biomarker development has been hampered by paucity of genomic and endocrine knowledge of many crustacean model species; however this is rapidly changing with the advent of cheaper affordable genomic techniques and high throughput sequencing.
Sharifian, Sana; Kamrani, Ehsan; Sharifian, Salim
A new species of freshwater crab, Sodhiana iranica n. sp. (Decapoda: Brachyura: Gecarcinucidae), is described from Bastak, Iran. This is fourth species of Sodhiana Yeo & Ng, 2012, described, and is the second one known from Iran. It can be distinguished from congeners by the form of its carapace and the structure of the male first gonopod.
Abstract Background Isopoda are the most diverse Crustacea. In order to encourage the study of isopod crustaceans and their use in biodiversity studies, systematics, ecology, physiology and more, one needs to know who the isopods are and where to find them. New information This is a short “how to” guide focusing on the free-living marine and freshwater isopods: where they live and how to collect and preserve them. The tools and techniques described here are simple, but invaluable in accessing the natural history of these remarkable creatures. PMID:26023284
... 40 Protection of Environment 25 2012-07-01 2012-07-01 false Peanuts, Tree Nuts, Milk, Soybeans... Peanuts, Tree Nuts, Milk, Soybeans, Eggs, Fish, Crustacea, and Wheat; exemption from the requirement of a..., tree nuts, milk, soybeans, eggs (including putrescent eggs), fish, crustacea, and wheat are...
... 40 Protection of Environment 24 2011-07-01 2011-07-01 false Peanuts, Tree Nuts, Milk, Soybeans... Peanuts, Tree Nuts, Milk, Soybeans, Eggs, Fish, Crustacea, and Wheat; exemption from the requirement of a..., tree nuts, milk, soybeans, eggs (including putrescent eggs), fish, crustacea, and wheat are...
... 40 Protection of Environment 24 2014-07-01 2014-07-01 false Peanuts, Tree Nuts, Milk, Soybeans... Peanuts, Tree Nuts, Milk, Soybeans, Eggs, Fish, Crustacea, and Wheat; exemption from the requirement of a..., tree nuts, milk, soybeans, eggs (including putrescent eggs), fish, crustacea, and wheat are...
... 40 Protection of Environment 25 2013-07-01 2013-07-01 false Peanuts, Tree Nuts, Milk, Soybeans... Peanuts, Tree Nuts, Milk, Soybeans, Eggs, Fish, Crustacea, and Wheat; exemption from the requirement of a..., tree nuts, milk, soybeans, eggs (including putrescent eggs), fish, crustacea, and wheat are...
... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Peanuts, Tree Nuts, Milk, Soybeans... Peanuts, Tree Nuts, Milk, Soybeans, Eggs, Fish, Crustacea, and Wheat; exemption from the requirement of a..., tree nuts, milk, soybeans, eggs (including putrescent eggs), fish, crustacea, and wheat are...
Korn, Olga M; Kornienko, Elena S; Golubinskaya, Darya D
First stage larva of a new mud shrimp Nihonotrypaea makarovi Marin, 2013 (Decapoda: Axiidea: Callianassidae) obtained from the ovigerous female is described and illustrated for the first time. The first zoea of N. makarovi is well distinguished from the first larvae of N. japonica and N. petalura, sympatric callianassid species inhabiting Russian waters of the Sea of Japan, only by the greater size and by the presence of two terminal setae on the antennal endopod.
Sinev, Artem Y; Yusoff, Fatimah M
Fauna of Cladocera (Crustacea: Branchiopoda) of Sabah state of Malaysia, Borneo Island, was evaluated for the first time. Samples from 40 locations were studied, and 31 species of Cladocera were revealed, including three species of Sididae, one species of Daphnidae, one species of Moinidae, four species of Macrothricidae, two species of Ilyocryptidae, and 20 species of Chydoridae. One species of Ilyocryptidae, Ilyocryptus yooni Jeong, Kotov and Lee, 2012, is recorded for Malaysia for the first time, and one more, Anthalona sp., is probably new for science. Of 31 species recorded for Sabah, only three are true planktonic species and 28 are substrate-associated species. Absence of large natural lakes, habitats with most rich cladoceran fauna, can be an important factor limiting diversity of Cladocera in Sabah.
La Fauce, Kathy; Owens, Leigh
RNA interference has evolved from being a nuisance biological phenomenon to a valuable research tool to determine gene function and as a therapeutic agent. Since pioneering observations regarding RNA interference were first reported in the 1990s from the nematode worm, plants and Drosophila, the RNAi phenomenon has since been reported in all eukaryotic organisms investigated from protozoans, plants, arthropods, fish and mammals. The design of RNAi therapeutics has progressed rapidly to designing dsRNA that can specifically and effectively silence disease related genes. Such technology has demonstrated the effective use of short interfering as therapeutics. In the absence of a B cell lineage in arthropods, and hence no long term vaccination strategy being available, the introduction of using RNA interference in crustacea may serve as an effective control and preventative measure for viral diseases for application in aquaculture.
Drobne, Damjana; Drobne, Samo
The advantage of using terrestrial isopods in toxicity studies is that a battery of parameters can be tested at different levels of biological complexity. Feeding parameters for example link organism level response to potential ecological consequences but a problem with using feeding parameters in toxicity tests with terrestrial isopods is their high variability. The aim of our study was to set benchmark values for feeding parameters for isopod Porcellioscaber (Isopoda, Crustacea) in laboratory-controlled experiments. In the work presented here, the daily feeding rate of the central 50% of the control population of Porcellioscaber and a correlation between feeding rate and isopod weight were set. Values outside these ranges need additional evaluation to increase the relevance of test outcomes. We suggest using benchmark values for feeding parameters as well as the coefficient of variation (a) to identify animals with altered feeding parameters with respect to controls, and (b) to assess the data quality in each experiment.
Ďuriš, Zdeněk; Lin, Chia-Wei
A new species of shrimp Metapontonia scorpio symbiotic with scleractinian coral Diploastrea heliopora is described from Taiwan. The species belongs to the smallest symbiotic shrimps of the family Palaemonidae. It is remarkable by a unique ability to turn its last two pleonites with tail fan dorsally over the 4th and preceding pleonal segments, thus resembling scorpions. For such movement, the respective opposing dorsal margins of the 4th-6th segments are deeply concave. The new species is characterized by a short dorsally directed rostrum, incomplete orbit, semicircular scaphocerite, and medially concave basal antennular segment. The only species of the genus, M. fungiacola, is compared with the new species based on morphology and DNA. Metapontonia fungiacola is for the first time reported from Taiwan and Papua New Guinea. The morphological and colour variability of the species is discussed. The scleractinian corals Platygyra lamellina (Merulinidae), Lobophyllia hemprichii, cf. Micromusa sp., Symphyllia cf. radians (Lobophylliidae), and Galaxea sp. (Oculinidae), are new host records for the species.
Williner, Verónica; Torres, María Victoria; Carvalho, Débora Azevedo; König, Natalia
Abstract The relative growth of a number of morphological dimensions of the South American freshwater crab Trichodactylus borellianus (Trichodactylidae) were compared and related to sexual dimorphism. Crabs were collected from ponds in the Middle Paraná River in Argentina. A regression model with segmented relationship was used to test for relative growth between these measurements where breakpoints infer the body size at which crabs reach sexual maturity. In both sexes the carapace width and the length, height, and thickness of the right and left chelae were measured, as well as the male pleopod length and the female abdomen width. All of these measurements were found to show positive allometry with the exception of the male pleopod length and the left chelae, which did not show a breakpoint. In females the breakpoint for the abdomen width inferred a morphological sexual maturity at carapace width 6.9 mm. In males the break point for the pleopod length was at carapace width 6.6 mm, with that for the chelae measurements was between carapace widths 6.4 and 6.9 mm. The relative growth pattern in Trichodactylus borellianus was found to be similar to that recorded for other species of the family Trichodactylidae. PMID:25561835
Xu, Peng; Liu, Feng; Ding, Zhongjun; Wang, Chunsheng
During recent dives by the Chinese manned submersible "Jiaolong", some shrimp specimens were sampled from the deep sea of the Northwestern Pacific Ocean. A new species of the caridean family Thoridae, Paralebbeus jiaolongi sp. nov., is described and illustrated in this study. The rostrum armed with only one subterminal ventral tooth can easily distinguish the new species from its congeners.
Tan, Mun Hua; Lee, Yin Peng; Poore, Gary C.B.
Background Whole mitochondrial DNA is being increasingly utilized for comparative genomic and phylogenetic studies at deep and shallow evolutionary levels for a range of taxonomic groups. Although mitogenome sequences are deposited at an increasing rate into public databases, their taxonomic representation is unequal across major taxonomic groups. In the case of decapod crustaceans, several infraorders, including Axiidea (ghost shrimps, sponge shrimps, and mud lobsters) and Caridea (true shrimps) are still under-represented, limiting comprehensive phylogenetic studies that utilize mitogenomic information. Methods Sequence reads from partial genome scans were generated using the Illumina MiSeq platform and mitogenome sequences were assembled from these low coverage reads. In addition to examining phylogenetic relationships within the three infraorders, Axiidea, Gebiidea, and Caridea, we also investigated the diversity and frequency of codon usage bias and mitogenome gene order rearrangements. Results We present new mitogenome sequences for five shrimp species from Australia that includes two ghost shrimps, Callianassa ceramica and Trypaea australiensis, along with three caridean shrimps, Macrobrachium bullatum, Alpheus lobidens, and Caridina cf. nilotica. Strong differences in codon usage were discovered among the three infraorders and significant gene order rearrangements were observed. While the gene order rearrangements are congruent with the inferred phylogenetic relationships and consistent with taxonomic classification, they are unevenly distributed within and among the three infraorders. Discussion Our findings suggest potential for mitogenome rearrangements to be useful phylogenetic markers for decapod crustaceans and at the same time raise important questions concerning the drivers of mitogenome evolution in different decapod crustacean lineages. PMID:28265498
Yang, Jin-Shu; Yang, Wei-Jun
Background Metazoan mitochondrial genomes usually consist of the same 37 genes. Such genes contain useful information for phylogenetic analyses and evolution modelling. Although complete mitochondrial genomes have been determined for over 1,000 animals to date, hydrothermal vent species have, thus far, remained excluded due to the scarcity of collected specimens. Results The mitochondrial genome of the hydrothermal vent galatheid crab Shinkaia crosnieri is 15,182 bp in length, and is composed of 13 protein-coding genes, two ribosomal RNA genes and only 18 transfer RNA genes. The total AT content of the genome, as is typical for decapods, is 72.9%. We identified a non-coding control region of 327 bp according to its location and AT-richness. This is the smallest control region discovered in crustaceans so far. A mechanism of cytoplasmic tRNA import was addressed to compensate for the four missing tRNAs. The S. crosnieri mitogenome exhibits a novel arrangement of mitochondrial genes. We investigated the mitochondrial gene orders and found that at least six rearrangements from the ancestral pancrustacean (crustacean + hexapod) pattern have happened successively. The codon usage, nucleotide composition and bias show no substantial difference with other decapods. Phylogenetic analyses using the concatenated nucleotide and amino acid sequences of the 13 protein-coding genes prove consistent with the previous classification based upon their morphology. Conclusion The present study will supply considerable data of use for both genomic and evolutionary research on hydrothermal vent ecosystems. The mitochondrial genetic characteristics of decapods are sustained in this case of S. crosnieri despite the absence of several tRNAs and a number of dramatic rearrangements. Our results may provide evidence for the immigrating hypothesis about how vent species originate. PMID:18510775
Campos, Martha R
Two new species of freshwater crabs of the pseudothelphusid genus Neostrengeria Pretzmann, 1965, N. fernandezi n. sp., and N. lassoi n. sp., are described. The genus is endemic to the eastern Andes of Colombia. Neostrengeria fernandezi was collected in Las Cacas cave, Pauna, Boyacá Department and N. lassoi in a stream within Los Aviones cave, La Guadalupe, Santander Department, within the cave as well as in a waterfall outside the cave. With the addition of N. fernandezi and N. lassoi the total number of species of the genus Neostrengeria increases to 27. Like all others species of Neostrengeria, the new species are distinguished primarily by the morphology of the first male gonopod, particularly by the form of lateral, accessory and mesial lobes, outline of the apex, and the mesio-caudal projection of the spermatic channel.
Monitoring PAH contamination in the field (South west Iberian Peninsula): biomonitoring using fluorescence spectrophotometry and physiological assessments in the shore crab Carcinus maenas (L.) (Crustacea: Decapoda).
Dissanayake, Awantha; Bamber, Shaw D
Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous pollutants of the marine environment, arising predominantly from petrochemical contamination and pyrogenic sources. A biomarker of PAH exposure was employed in a field study (South West, Spain) in both captured (indigenous) and deployed (caged) shore crabs (Carcinus maenas) in the chronic PAH-exposed Bays of Algeciras and Gibraltar (from associated harbour and boating activity) compared to a relatively 'clean' site (Cadiz). Metabolite fluorescence was attributed to the following key priority PAH groups; naphthalenes (NAPs), pyrenes (PYRs) and benzo[a]pyrenes (BAPs). Temporal variability was assessed using deployed populations over an eight week period. Petrogenic and pyrogenic PAH contamination (as an indicator of the PAH type) was demonstrated using a ratio between FF(BAP + PYR)/FF(NAP). Physiological assessments from deployed crabs demonstrated both physiological and cellular alterations as shown by reduced heart rates (at rest) and increased cellular stress in crabs from the PAH contaminated sites.
Wood, Louisa E.; De Grave, Sammy; Daniels, Savel R.
We compare the genetic structuring and demographic history of two sympatric caridean shrimp species with distinct life history traits, one amphidromous species Palaemon capensis and one marine/estuarine species Palaemon peringueyi, in the historical biogeographical context of South Africa. A total of 103 specimens of P. capensis collected from 12 localities and 217 specimens of P. peringueyi collected from 24 localities were sequenced for the mitochondrial cytochrome oxidase one (CO1) locus. Results from analyses of molecular variance (AMOVA), pairwise ΦST comparisons and haplotype networks demonstrate weak to moderate genetic differentiation in P. capensis and P. peringueyi respectively. P. peringueyi exhibits partial isolation between populations associated with distinct biogeographic regions, likely driven by the region’s oceanography. However, there is minimal evidence for the occurrence of discrete regional evolutionary lineages. This demonstrated lack of genetic differentiation is consistent with a marine, highly dispersive planktonic phase in both the amphidromous P. capensis and the marine/estuarine P. peringueyi. Bayesian skyline plots, mismatch expansions and time since expansion indicate that both species maintained stable populations during the Last Glacial Maximum (LGM), unlike other southern African aquatic species. PMID:28282399
Gan, Zhibin; Li, Xinzheng; Kou, Qi; Chan, Tinyam; Chu, Kahou; Huang, Hui
The four palaemonoid (sub)families Anchistioididae, Gnathophyllidae, Hymenoceridae, and Pontoniinae are similar in morphology, and all live in marine habitats. Their systematic relationships are controversial. In this study, we used sequences from a mitochondrial ribosomal gene (16S rRNA) and three nuclear genes (H3, NaK, and enolase) to explore the phylogenetic relationships of these four taxa. Our tree based on 43 species belonging to 28 genera shows that Gnathophyllidae and Hymenoceridae are nested within Pontoniinae. This result is consistent with evidence from larval morphology. The defining characteristics of Gnathophyllidae and Hymenoceridae, a vestigial or missing mandibular incisor process and a broadened third maxilliped, can also be found in Pontoniinae; conversely, on the basis of published species descriptions, gnathophyllids and hymenocerids meet most of the defining characteristics of Pontoniinae. The peculiar form of the third maxilliped in gnathophyllids and hymenocerids might be the result of adaptive evolution, as these particular features are also present in pontoniines. According to our phylogenetic tree, Anchistioididae are more remote from Pontoniinae, which is consistent with the distinct morphological differences in the pleopods. The pontoniine genera analyzed (together with Gnathophyllidae and Hymenoceridae) are divided into two clades. The members of Clade I exhibit primordial characteristics similar to those of the Palaemoninae, and might be direct descendants of the ancestor of the Pontoniinae; members of Clade II are more specialized.
Hiller, Alexandra; Werding, Bernd
Petrolisthes paulayi sp. n. is described from specimens collected in French Polynesia. The new species belongs to an assemblage of morphologically similar Indo-West Pacific (IWP) species, here designated as the "mesobranchial-spine group". All species in the group bear carapace spines, including one or more mesobranchial spines, and transverse, piliferous striations on the dorsal surface of carapace and chelipeds. Petrolisthes paulayi sp. n. is distinguishable from all species in the group by its forwardly produced, trilobate front, and a characteristic combination of carapace spines. We also report on the range extension and live coloration of Petrolisthes aegyptiacus Werding & Hiller, another species of the mesobranchial-spine group, so far considered a Red Sea endemic. Specimens from the Mascaréne Islands confirm that the geographic range of the species extends to the southern Indian Ocean. While specimens morphologically similar to Petrolisthes aegyptiacus, and collected in the Line and Society Islands, suggest a large range extension to the Central Pacific, it is probable that these individuals represent an undescribed species closely related to Petrolisthes aegyptiacus.
Drava, Giuliana; Capelli, Renzo; Minganti, Vincenzo; De Pellegrini, Rodolfo; Orsi Relini, Lidia; Ivaldi, Michela
Concentrations of total and organic mercury, cadmium, lead, copper, iron, manganese and zinc were determined in the muscular tissue of 135 specimens of Aristeus antennatus (Risso, 1816) collected during a 3-year period in the Ligurian sea (NW Mediterranean). The aim of the present work was to study the relationships between the concentrations of these trace elements and the main biological parameters characterising the organisms, i.e. sex and size with special attention to the sexual maturity of the female specimens. Mercury is the only element showing a significant correlation with the size of the specimens, and for this reason it could give some indications about the age of the shrimps. However, comparison between females collected at four different reproductive phases shows that reproductive individuals are characterised by higher levels of mercury with respect to non-reproductive individuals of the same size.
Barathkumar, S; Das, N P I; Satpathy, K K
A new species of sand crab of the genus Jonas Hombron & Jacquinot, 1846 (family Corystidae) is described from specimens collected from Kalpakkam, southeastern coast of India. Two other species, J. indicus (Chopra, 1935), and J. choprai Serène, 1971, have previously been recorded from this area. A detailed description of the new species is given and compared with the closely related J. formosae Balss, 1922, also from the Indo-West Pacific.
Ng, Peter K L; Rahayu, Dwi Listyo; Shih, Hsi-Te
A new genus and new species of pinnotheroid crab of the family Aphanodactylidae, Ankerius aenigmaticus n. sp., is described from the Red Sea coast of Saudi Arabia. The genus is unusual among aphanodactylids in possessing more gaping third maxillipeds, strongly spiniform chelipeds and ambulatory legs, as well as a relatively longer ambulatory dactylus.
Ye, Haihui; Huang, Huiyang; Song, Ping; Wang, Guizhong
The existence of progesterone receptors (PR) in the Scylla paramamosain (mud crab) was studied using immunological techniques. By Western blotting, PR with an apparent molecular weight of 70 kDa is identified in both the brain and the thoracic ganglion. By immunohistochemistry, PR immunoreactive neurons are detected mainly in the protocerebrum, the subesophageal ganglion and the leg ganglion. PR immunoreactivity is localized mainly in the nuclei of these neurons, while only a few neurons show such activities in their cytoplasm. Our results provide evidence that progesterone modulates the neuroendocrine system mainly via nucleus receptors.
Husana, Daniel Edison M; Kase, Tomoki; Mendoza, Jose Christopher E
A new species of hymenosomatid crab of the genus Elamena H. Milne Edwards, 1837, is described from the island of Samal, in the Davao Gulf, Mindanao, southern Philippines. Elamena samalensis sp. nov. belongs to the Elamena truncata species-group and is most similar to E. simplidenta Ng & Chuang, 1996, in the general form of the carapace and in the presence of only one subdistal tooth on the ambulatory dactyli. It can be distinguished from this species, however, by its more projecting rostrum, relatively longer and more slender ambulatory legs, and by the pointed apex of the female pleotelson.
Do, Van Tu; Le, Van Tho; Phan, Doan Dang
A new genus and new species of semi-terrestrial crab of the family Potamidae, Binhthuanomon vinhtan n. sp., is described from south central Vietnam. The new genus is morphologically closest to Villopotamon Dang & Ho, 2003, and Balssipotamon Dang & Ho, 2008, in the shapes of the carapace and first gonopod but is easily distinguished by distinct carapace characteristics and gonopod 1 structures, and the habitat occupied.
Pedraza, Manuel; Tavares, Marcos; Magalhães, Célio
A new genus and species of freshwater crab, Melothelphusa apiaka n. gen., n. sp., from Mato Grosso, Central Brazil is described and illustrated. Brasiliothelphusa dardanelosensis Magalhães & Türkay, 2010, is assigned to the new genus Melothelphusa. Therefore, the genus Brasiliothelphusa Magalhães & Türkay, 1986, is restricted to its type species B. tapajoense Magalhães & Türkay, 1986. The new taxa can be easily separated from their close relatives by a suite of morphological characters from the first gonopod.
Huang, Chao; Shih, Hsi-Te; Ng, Peter K L
A new genus and species of freshwater crab, Diyutamon cereum n. gen., n. sp., is described from a cave in Guizhou, China. This is the first record of a true stygomorphic crab from China and East Asia, possessing pale body coloration, strongly reduced eyes, and long ambulatory legs. While superficially similar to Chinapotamon Dai & Naiyanetr, 1994, and Tiwaripotamon Bott, 1970, the new genus possesses a diagnostic combination of carapace, ambulatory leg, thoracic sternal, and male abdominal characters that easily distinguishes it from other genera. Molecular data derived from the mitochondrial 16S rDNA supports the establishment of the new genus.
Ohtsuchi, Naoya; Kawamura, Tomohiko; Takeda, Masatsune
A poorly known epialtid crab species, Pugettia pellucens Rathbun, 1932, is redescribed and a closely allied new species P. vulgaris n. sp. is described and illustrated on the basis of material from Sagami Bay, Japan. Pugettia pellucens was originally described as a subspecies of P. quadridens (De Haan, 1839), but it is confirmed that the taxon is distinct from P. quadridens. The superficially similar Pugettia vulgaris n. sp. can be distinguished from P. pellucens by several morphological characters. The new species is also similar to P. elongata Yokoya, 1933, and P. intermedia Sakai, 1938, but can also be separated by various carapace and gonopodal characters.
The identity of the semiterrestrial crab Terrathelphusa kuchingensis (Nobili, 1901) (Crustacea: Decapoda: Brachyura: Gecarcinucidae), with descriptions of four new species from southwestern Sarawak, Borneo, Malaysia.
Grinang, Jongkar; Ng, Peter K L
Four new species of semiterrestrial gecarcinucid crabs are described from limestone and sandstone habitats in southwestern Sarawak, Malaysia: Terrathelphusa aglaia n. sp., T. cerina n. sp., T. kundong n. sp., and T. mas n. sp. The taxonomy of T. kuchingensis (Nobili, 1901) is discussed, its precise identity ascertained from fresh material, and its actual distribution determined. This increases the number of Terrathelphusa species in Borneo to eight.
Ojeda-Escoto, Juan Carlos; Villalobos, José Luis; Álvarez, Fernando
Three new species of freshwater crabs of the genus Pseudothelphusa (De Saussure, 1857) from south-central Mexico are described: Pseudothelphusa acahuizotla n. sp., P. ixtapan n. sp., and P. purhepecha n. sp. The new species are included in Pseudothelphusa due to a male gonopod with torsion and the presence of the characteristic mesial process and caudomarginal projection. Pseudothelphusa acahuizotla n. sp. is morphologically similar to P. belliana Rathbun, 1898, but can be distinguished by the relative size of the distal lobe of the caudomarginal projection and by the presence of a conical tooth on the caudal surface of the mesial process of the male gonopod. Pseudothelphusa ixtapan n. sp. is similar to P. dilatata Rathbun, 1898, and P. morelosis Pretzmann, 1968, and can be distinguished by a mesial process of the male gonopod with only one lateral tooth and an inferior margin with small teeth. Pseudothelphusa puerhepechae n. sp. exhibits a mesial process of the male gonopod with two triangular spines on its lateral margin, a character that with some variations is present in P. nayaritae Álvarez & Villalobos, 1994, P. rechingeri Pretzmann, 1965, P. lophophallus Rodríguez & Smalley, 1969, and P. parabelliana Álvarez 1989; but it can be distinguished by the separation and shape of the two spines of the mesial process and the shape of the lobes of the caudomarginal projection. With the new species described herein there are now 29 species in the genus Pseudothelphusa.
Wong, Juliet M; Pérez-Moreno, Jorge L; Chan, Tin-Yam; Frank, Tamara M; Bracken-Grissom, Heather D
Bioluminescence is essential to the survival of many organisms, particularly in the deep sea where light is limited. Shrimp of the family Oplophoridae exhibit a remarkable mechanism of bioluminescence in the form of a secretion used for predatory defense. Three of the ten genera possess an additional mode of bioluminescence in the form of light-emitting organs called photophores. Phylogenetic analyses can be useful for tracing the evolution of bioluminescence, however, the few studies that have attempted to reconcile the relationships within Oplophoridae have generated trees with low-resolution. We present the most comprehensive phylogeny of Oplophoridae to date, with 90% genera coverage using seven genes (mitochondrial and nuclear) across 30 oplophorid species. We use our resulting topology to trace the evolution of bioluminescence within Oplophoridae. Previous studies have suggested that oplophorid visual systems may be tuned to differentiate the separate modes of bioluminescence. While all oplophorid shrimp possess a visual pigment sensitive to blue-green light, only those bearing photophores have an additional pigment sensitive to near-ultraviolet light. We attempt to characterize opsins, visual pigment proteins essential to light detection, in two photophore-bearing species (Systellaspis debilis and Oplophorus gracilirostris) and make inferences regarding their function and evolutionary significance.
Yazicioglu, Buket; Hamr, Přemek; Kozák, Pavel
The ultrastructure of spermatozoa in three species of cambarid crayfish, Cambarus robustus, Orconectes propinquus, and Orconectes rusticus, were studied and compared with eight previously studied species from different crayfish families using morphological features and biometrical data. The ultrastructure of spermatozoa show a generally conserved pattern including an acrosome and nucleus in the anterior and posterior parts of the cell, respectively, radial arms that wrap around the nucleus, and the whole cell is enclosed by an extracellular capsule. The most outstanding morphological feature in spermatozoa of three studied cambarid crayfish is the crest-like protrusions in the anterior part of the acrosome that can be used as one of the features for distinguishing the members of this family. Results of biometrical data reveal that acrosome size in the representatives of Parastacidae are the smallest, while representatives of Astacidae show the biggest acrosome. The acrosome size in species belonging to Cambaridae occupy an intermediate position between the two other families of freshwater crayfish. In conclusion, a combination of morphological features and biometrical data of spermatozoa can help distinguishing different species of the freshwater crayfish. PMID:27635333
Ayón-Parente, Manuel; Hendrickx, Michel E
A new species of hermit crab, Areopaguristes espetacioni, family Diogenidae, is described and illustrated in detail, including the color pattern in live/fresh specimens. This is the fifth species of Areopaguristes reported from the eastern Pacific. Given the morphological similarity between Areopaguristes espetacioni n. sp. and A. tudgei Lemaitre & Felder, 2012, these can be considered sister species. The presence of a long rostrum, the antennal flagella with short setae, chelipeds and ambulatories legs with dense plumose setae, and telson with calcareous teeth on the posterior margin allow to separate Areopaguristes espetacioni n. sp. from all other species in the genus previously described for the region. A key for Areopaguristes species from the eastern tropical Pacific is provided.
Hernandez-Payan, J C; Hendrickx, M E
The distribution of two species of the deep-water shrimp genus Nematocarcinus A. Milne-Edwards, 1881, occurring off the west coast of Mexico is analyzed based on a large series of recently collected material. Nematocarcinus faxoni Burukovsky, 2000, is by far the most common and abundant species in the area and it is distributed throughout the central and southern Gulf of California and off the entire Baja California Peninsula south to 17º10'15"N. Based on characteristics observed in the new samples and in the type material, N. agassizii Faxon, 1893, is reinstalled as a valid species, and no longer considered a junior of N. gracilipes A. Milne-Edwards, 1881, as proposed by Cardoso & Burukovsky (2014). Along the Pacific coast of Mexico, N. agassizii exhibits a more restricted distribution and it was collected only off the Baja California Peninsula. Previous records of this species in the Gulf of California, where N. faxoni was the only representative of the genus captured during this survey, are considered doubtful.
Abstract A new species, Cherax (Astaconephrops) pulcher sp. n., from Hoa Creek, close to the village Teminabuan in the southern-central part of the Kepala Burung (Vogelkop) Peninsula, West Papua, Indonesia, is described, figured and compared with the morphologically closest species, Cherax boesemani Lukhaup & Pekny, 2008. PMID:26019660
Komai, Tomoyuki; Poore, Gary C B
Rhynchoplax Stimpson, 1858, is resurrected from synonymy with Halicarcinus White, 1846. Rhynchoplax hondai Takeda & Miyake, 1971, a species based on an immature female, is rediagnosed and two new species, R. magnetica n. sp. from northeastern Australia and R. minutula n. sp. from the Ryukyu Islands, Japan, are described. They differ from R. hondai in the shape of the rostrum, form of the subhepatic region and the armature of the pereopodal meri. All differ from the type species R. messor Stimpson, 1858, in having a longer and simple rostrum without supraocular pseudorostral spines and the absence of a postocular spine.
Ďuriš, Zdeněk; Horká, Ivona
Based on recently published molecular phylogenies of Indo-West Pacific palaemonid shrimps and further morphological evidence, the systematic position of several species of the polyphyletic genus Periclimenes is revised. The generic name Ancylocaris Schenkel, 1902 is re-established for the anemone-associated Periclimenes brevicarpalis. Actinimenesgen. n., is proposed for the anemone-associated Periclimenes inornatus, Periclimenes ornatellus and Periclimenes ornatus, all of which have a subspatulate first pereiopod. Cristimenesgen. n., is designated for the echinoderm-associated species, Periclimenes commensalis, Periclimenes cristimanus, and Periclimenes zanzibaricus, all with a unique carpo-propodal articulation of the second pereiopods. Rapimenesgen. n. is established for the hydroid and antipatharian-associated Periclimenes brucei, Periclimenes granulimanus, and Periclimenes laevimanus, for which the long, slender and unequal second pereiopods and prehensile ambulatory propodi are the main synapomorphic characters.
During a survey on decapod crustacean fauna of shallow coral reefs and nearby environments in Okinawa Island, Ryukyu Archipelago, Japan, four specimens of a small but distinctive undescribed species of pagurid hermit crab, which could not be referred to any known genus, were collected. The new taxon, Eutrichopagurus shirakawai n. gen., n. sp., is described and illustrated herein. The new genus is characterized by the possession of 11 pairs of deeply quadriserial phyllobranchiate gills, the third maxilliped with well-developed crista dentata and one or two accessory teeth on the ischium, the presence of unpaired left gonopore in the female, the absence of paired first pleopods in the female, and the telson with prominent tuft of setae on the lateral margin of the posterior lobes; the male is unknown at present. It appears close to Trichopagurus de Saint Laurent, 1968, but the deeply quadriserial gills immediately distinguish Eutrichopagurus from Trichopagurus. The new genus is also compared with other genera characterized by the possession of 11 pairs of quadriserial phyllobranchiate gills and the lack of paired first pleopods in females.
Komai, Tomoyuki; Fujita, Yoshihisa; Maenosono, Tadafumi
Two species referred to the callianassid ghost shrimp genus Rayllianassa Komai & Tachikawa, 2008 are reported herewith. Additional locality records from Japan are provided for R. amboinensis (de Man, 1888), and the synonymy of Callianassa ngochoae Sakai, 1999 with R. amboinensis is discussed. It is shown that R. amboinensis is associated with sponges or alcyonacean soft corals, representing unusual habitats for callianassids. Rayllianassa rudisulcus n. sp. is described on the basis of a single ovigerous female from shallow soft sediment in Ohura Bay, Okinawa Island, Ryukyu Islands. The new species is distinguished from R. amboinensis by the absence of a dorsal oval on the carapace, the antennal peduncle being longer than the antennular peduncle, and the different shape of the third maxilliped. The status of Rayllianassa is also briefly discussed.
Tan, Mun Hua; Gan, Han Ming; Lee, Yin Peng; Poore, Gary C B; Austin, Christopher M
Whole mitochondrial DNA is being increasingly utilized for comparative genomic and phylogenetic studies at deep and shallow evolutionary levels for a range of taxonomic groups. Although mitogenome sequences are deposited at an increasing rate into public databases, their taxonomic representation is unequal across major taxonomic groups. In the case of decapod crustaceans, several infraorders, including Axiidea (ghost shrimps, sponge shrimps, and mud lobsters) and Caridea (true shrimps) are still under-represented, limiting comprehensive phylogenetic studies that utilize mitogenomic information. Sequence reads from partial genome scans were generated using the Illumina MiSeq platform and mitogenome sequences were assembled from these low coverage reads. In addition to examining phylogenetic relationships within the three infraorders, Axiidea, Gebiidea, and Caridea, we also investigated the diversity and frequency of codon usage bias and mitogenome gene order rearrangements. We present new mitogenome sequences for five shrimp species from Australia that includes two ghost shrimps, Callianassa ceramica and Trypaea australiensis, along with three caridean shrimps, Macrobrachium bullatum, Alpheus lobidens, and Caridina cf. nilotica. Strong differences in codon usage were discovered among the three infraorders and significant gene order rearrangements were observed. While the gene order rearrangements are congruent with the inferred phylogenetic relationships and consistent with taxonomic classification, they are unevenly distributed within and among the three infraorders. Our findings suggest potential for mitogenome rearrangements to be useful phylogenetic markers for decapod crustaceans and at the same time raise important questions concerning the drivers of mitogenome evolution in different decapod crustacean lineages.
Pantoja, Carlos R.; Gomez-Jimenez, Silvia; Lightner, Donald V.
The bacteria that cause necrotizing hepatopancreatitis in Penaeus vannamei adversely affect penaeid shrimp cultured in the western hemisphere. 16S rRNA and gyrase B gene analyses determined the taxonomic position of these bacteria. The name “Candidatus Hepatobacter penaei” is proposed for these pathogenic bacteria, which are members of the Rickettsiales order. PMID:23241970
Perdichizzi, Anna; Pirrera, Laura; Micale, Valeria; Muglia, Ugo; Rinelli, Paola
The reproductive features of the giant red shrimp, Aristaeomorpha foliacea, were investigated in the southern Tyrrhenian sea by experimental trawl sampling. The annual length-frequency distribution showed a multimodal trend in females, ranging between 16 and 67 mm carapace length (CL), and a unimodal trend in males (18-45 mm CL). Mature males occurred in different proportions all year round, while females displayed seasonal maturity (June-September), with a peak in July. Six oocyte developmental stages were identified, the most advanced of which (Pv, postvitellogenic) had never been described before in this species. Ovary development followed a group-synchronous pattern, with the yolked oocyte stock clearly separated from the reservoir of unyolked oocytes, suggesting that A. foliacea is a total spawner, with determinate fecundity. Based upon histological findings, a revision of macroscopic maturity staging employed in Mediterranean bottom trawl surveys (MEDITS) is proposed.
Muñoz, J Enrique García; Raso, J Enrique García; Rodríguez, Antonio
The freshwater shrimp genus Atyaephyra de Brito Capello, 1867 is a complex of cryptic species with morphologically overlapping features, which has led to invalid identifications until recently. The genus is distributed around the entire Mediterranean Basin and surrounding areas. In 2009 we used a molecular approach with 16S and Cox1 genes to identify the European and African populations and to show the existence of different species and groups of haplotypes (García Muñoz et al. 2009). Christodoulou et al. (2012) recently identified four species in Greece (Atyaephyra stankoi, A. thyamisensis, A. strymonensis and A. acheronensis) based on morphology and some partial sequences of Cox1. In the present study we analyse several Greek populations of Atyaephyra spp. using morphology and two mitochondrial markers (16S and Cox1). Our molecular data confirm the taxonomic validity of A. stankoi, A. thyamisensis and A. strymonensis but show that A. acheronensis should be considered a synonym of A. desmarestii. The limited distribution of A. desmarestii in only a few rivers in the Ionian region is probably the result of a posterior introduction from neighbouring European areas. After the genetic identification and as a consequence of the high variability observed within species and between rivers, mainly in A. thyamisensis, we re-describe this species and provide morphological data for the other species. We also give information on the chromatophore pattern in larvae, which could be very useful in the future for recognizing species and their distribution. The distribution of Greek Atyaephyra species seems to be related to the very complex paleogeographical history of the Paratethys and Mediterranean Sea in the Balkan Peninsula. Three areas can be recognized in relation to the distribution of these species: a global region, a western region separated from the eastern region by the Pindos Mountains, and a Macedonia-Thracian region.
Ďuriš, Zdeněk; Horká, Ivona
Abstract Based on recently published molecular phylogenies of Indo-West Pacific palaemonid shrimps and further morphological evidence, the systematic position of several species of the polyphyletic genus Periclimenes is revised. The generic name Ancylocaris Schenkel, 1902 is re-established for the anemone-associated Periclimenes brevicarpalis. Actinimenes gen. n., is proposed for the anemone-associated Periclimenes inornatus, Periclimenes ornatellus and Periclimenes ornatus, all of which have a subspatulate first pereiopod. Cristimenes gen. n., is designated for the echinoderm-associated species, Periclimenes commensalis, Periclimenes cristimanus, and Periclimenes zanzibaricus, all with a unique carpo-propodal articulation of the second pereiopods. Rapimenes gen. n. is established for the hydroid and antipatharian-associated Periclimenes brucei, Periclimenes granulimanus, and Periclimenes laevimanus, for which the long, slender and unequal second pereiopods and prehensile ambulatory propodi are the main synapomorphic characters. PMID:28228674
Hiller, Alexandra; Werding, Bernd
Abstract Petrolisthes paulayi sp. n. is described from specimens collected in French Polynesia. The new species belongs to an assemblage of morphologically similar Indo-West Pacific (IWP) species, here designated as the “mesobranchial-spine group”. All species in the group bear carapace spines, including one or more mesobranchial spines, and transverse, piliferous striations on the dorsal surface of carapace and chelipeds. Petrolisthes paulayi sp. n. is distinguishable from all species in the group by its forwardly produced, trilobate front, and a characteristic combination of carapace spines. We also report on the range extension and live coloration of Petrolisthes aegyptiacus Werding & Hiller, another species of the mesobranchial-spine group, so far considered a Red Sea endemic. Specimens from the Mascaréne Islands confirm that the geographic range of the species extends to the southern Indian Ocean. While specimens morphologically similar to Petrolisthes aegyptiacus, and collected in the Line and Society Islands, suggest a large range extension to the Central Pacific, it is probable that these individuals represent an undescribed species closely related to Petrolisthes aegyptiacus. PMID:27667952
Five new species of freshwater crabs of the genera Ghatiana Pati & Sharma, 2014, and Gubernatoriana Bott, 1970 (Crustacea, Decapoda, Brachyura: Gecarcinucidae Rathbun, 1904) from the Western Ghats, India.
Pati, S K; Thackeray, T; Khaire, A
Five new species of gecarcinucid freshwater crabs, Ghatiana atropurpurea n. sp., Ghatiana splendida n. sp., Gubernatoriana alcocki Pati n. sp., Gubernatoriana thackerayi Pati n. sp., and Gubernatoriana waghi Pati n. sp. are described from the Western Ghats in Maharashtra and Goa states of India. Ghatiana atropurpurea n. sp. can be differentiated from other species of Ghatiana Pati & Sharma, 2014 by the shape and colour of its carapace, and the sigmoid-shaped male first pleopod (G1). Ghatiana splendida n. sp. is separated from its congeners mainly by its long anterolateral margin of the carapace and short terminal article of the G1. Besides, the colour pattern (deep pink carapace and chelipeds, orange ambulatory legs) of G. splendida n. sp. is exceptional among its congeners. Gubernatoriana alcocki n. sp. is unique among species of Gubernatoriana Bott, 1970 due to its inwardly curved tip of the terminal article of the G1. The stout and cone-shaped terminal article of the G1 of G. thackerayi n. sp. is characteristic among its congeners. In addition, G. thackerayi n. sp. has a unique colouration amongst congeners (violet-red carapace and ambulatory legs, orange-red chelipeds). Gubernatoriana waghi n. sp. can be distinguished from its congeners by the quadrate-shaped carapace, narrow frontal margin, pointed tips of the cheliped fingers, short terminal article of the G1 and very short or vestigial terminal article of the male second pleopod (G2). The body colour (burnt orange carapace and ivory coloured chelipeds and ambulatory legs) of G. waghi n. sp. is also important to distinguish live crabs of the genus. Key to the species of Ghatiana and Gubernatoriana is provided.
Wang, Yan-Rong; Sha, Zhong-Li
Three species of the genus Automate De Man, 1888 are described herein, including two new species: A. anacanthopusoides sp. nov. and A. spinosa sp. nov.. Automate anacanthopusoides sp. nov. can be easily identified by the presence of a rostrum, the notch on the lower margin of the major chela, the stout minor cheliped and the cutting edge of the pollex not dentate, and by the absence of spines on the ventral margin of the propodus of the third and fourth pereiopod. Automate spinosa sp. nov. can be easily identified by the nearly straight anterior margin of the carapace, and the presence of spines on the ventral margin of the propodus of third and fourth pereiopod. A key of all species of the Automate is provided.
Lukhaup, Christian; Panteleit, Jörn; Schrimpf, Anne
A new species, Cherax snowden sp. n., from the Oinsok River Drainage, Sawiat District in the central part of the Kepala Burung (Vogelkop) Peninsula, West Papua, Indonesia, is described, figured and compared with the closest related species, Cherax holthuisi Lukhaup & Pekny, 2006. This species is collected and exported for ornamental purposes and its commercial name in the pet trade is "orange tip" or "green orange tip". Both species may be easily distinguished morphologically or by using sequence divergence, which is substantial, for considering Cherax snowden sp. n. to be a new species.
Shy, Jhy-Yun; Wowor, Daisy; Ng, Peter K L
The giant freshwater prawn Macrobrachium spinipes (Schenkel, 1902) is recorded from Taiwan for the first time and extends the distribution of the species to north of the Tropic of Cancer. The Taiwanese specimens differ slightly from material from Indonesian Papua in the density of the spination of the adult second pereipods, the relative length of the ridge of the posterior submedian plate of thoracite sternite 4, and the color of the carapace, abdomen and pleural condyles.
Komai, Tomoyuki; Maenosono, Tadafumi; Fujita, Yoshihisa
Two new species of the callianassid ghost shrimp are described and illustrated on the basis of specimens from the Ryukyu Islands, Japan. These are provisionally assigned to the genus Cheramus Spence Bate, 1888, and appear closest to Callianassa acutirostella Sakai, 1988, also provisionally transferred to Cheramus herewith. These three species can be differentiated by characters of the telson, third maxilliped, chelipeds and uropod. The taxonomic status of Cheramus is briefly discussed.
Komai, Tomoyuki; Okuno, Junji; Minemizu, Ryo
The caridean shrimp genus Thor Kingsley, 1878 (Thoridae) is currently represented by 14 species distributed in shallow tropical to subtropical waters in the Indo-Pacific, East Pacific and West Atlantic oceans. In this study, two species of the genus are reported on the basis of material from Okinawa and Kume islands in the Ryukyu Archipelago, southern Japan. Thor leptochelus (Xu & Li, 2015) n. comb., recently described from Xisha Islands, China and originally assigned to Thinora Bruce, 1997, is transferred to Thor. Relationship of the species to three congeneric species (T. cordelli Wicksten, 1996, T. spinipes Bruce, 1983 and T. spinosus Boone, 1935) is discussed. The second is T. marguitae Bruce, 1973, representing the rediscovery since the original description and new record for Japanese waters. The four specimens of T. leptochelus were all free-living, whereas the single specimen of T. marguitae was found to be associated with a solitary fungiid coral, as previously reported.
Osawa, Masayuki; Kawai, Takashi; Sakamaki, Takashi
Seven hermit crab species of the pagurid genus Pagurixus Melin, 1939 are reported on the basis of material recently collected from the northern and central islands of the Ryukyu Islands, southwestern Japan. Four species are new to the hermit crab fauna of the Ryukyu Islands: P. acanthocarpus Komai & Okuno, 2009; P. fasciatus Komai & Myorin, 2005; P. formosus Komai, 2010; and P. tweediei (Forest, 1956). One species is described as new to science: P vicinus sp. nov. is closely similar to P. fasciatus in both morphology and coloration, but distinguished by the armature on the left cheliped and right second pereopod. Paguruxus carininanus Komai & Osawa, 2006 and P. pseliophorus Komai & Osawa, 2006, both previously known from the Ryukyu Islands, are here reported from new localities.
Komai, Tomoyuki; Yamada, Yusuke; Yunokawa, Kyo
A new species of the alpheid shrimp genus Salmoneus Holthuis, 1955, S. antricola n. sp., is described and illustrated on the basis of a single ovigerous specimen from an aphotic marine cave at a depth of 12 m, off Ie Island, Okinawa Islands, the Ryukyu Archipelago. It is morphologically similar to five species presently referred to the S. jarli (Holthuis, 1951) species group: S. erasimorum Dworschak, Anker & Abed-Navandi, 2000, S. komaii Anker, 2011, S. paulayi Anker, 2011, S. poupini Anker, 2011, and S. sketi Fransen, 1991. However, the minor cheliped with an elongate carpus being subequal to the chela, the lack of teeth on the cutting edges of the minor cheliped fingers, and the very slender third to fifth pereopods are obvious characters that distinguish S. antricola n. sp. from all of its presumed close relatives. Among the 50 species of Salmoneus, only S. sketi and the present new species are known from marine caves.
A new shallow-water squat lobster, Galathea ryuguu, is described on the basis of material obtained from a colony of unidentified sea fan of the genus Muricella Verrill, 1868. The new species is most closely allied to G. squamea Baba, 1979, but is distinguished by the ornamentation and armature of the carapace, third maxilliped, and ambulatory legs.
Anker, Arthur; Pachelle, Paulo P G
The bumpy-clawed snapping shrimp, Alpheus malleator Dana, 1852 (Alpheidae), is revised based on the recently collected and older museum material from the eastern Pacific (Panama, Ecuador), Caribbean (Panama, Puerto Rico, Trinidad & Tobago), Brazil (São Paulo), and West Africa (Cape Verde, Senegal, Guinea, Equatorial Guinea, Congo). The eastern Pacific material is assigned to A. wonkimi sp. nov., based on one morphological difference in the colour and thickness of the uropodal spiniform seta, as well as previously published molecular data. The Caribbean, Brazilian and West African material is considered to represent a single, widespread, morphologically variable, amphi-Atlantic taxon, A. malleator. Alpheus pugilator A. Milne-Edwards, 1878 is retained as ajunior synonym of A. malleator, whereas A. tuberculosus Osorio, 1892, A. malleator var. edentatus Zimmer, 1913 and A. belli Coutière, 1898, the latter two based on juvenile specimens, are tentatively placed in the synonymy of A. malleator. Illustrations, including colour photographs, are provided for A. wonkimi sp. nov. and A. malleator and their morphological variability is discussed and illustrated.
Yang, Jin-Shu; Nagasawa, Hiromichi; Fujiwara, Yoshihiro; Tsuchida, Shinji; Yang, Wei-Jun
Metazoan mitochondrial genomes usually consist of the same 37 genes. Such genes contain useful information for phylogenetic analyses and evolution modelling. Although complete mitochondrial genomes have been determined for over 1,000 animals to date, hydrothermal vent species have, thus far, remained excluded due to the scarcity of collected specimens. The mitochondrial genome of the hydrothermal vent galatheid crab Shinkaia crosnieri is 15,182 bp in length, and is composed of 13 protein-coding genes, two ribosomal RNA genes and only 18 transfer RNA genes. The total AT content of the genome, as is typical for decapods, is 72.9%. We identified a non-coding control region of 327 bp according to its location and AT-richness. This is the smallest control region discovered in crustaceans so far. A mechanism of cytoplasmic tRNA import was addressed to compensate for the four missing tRNAs. The S. crosnieri mitogenome exhibits a novel arrangement of mitochondrial genes. We investigated the mitochondrial gene orders and found that at least six rearrangements from the ancestral pancrustacean (crustacean + hexapod) pattern have happened successively. The codon usage, nucleotide composition and bias show no substantial difference with other decapods. Phylogenetic analyses using the concatenated nucleotide and amino acid sequences of the 13 protein-coding genes prove consistent with the previous classification based upon their morphology. The present study will supply considerable data of use for both genomic and evolutionary research on hydrothermal vent ecosystems. The mitochondrial genetic characteristics of decapods are sustained in this case of S. crosnieri despite the absence of several tRNAs and a number of dramatic rearrangements. Our results may provide evidence for the immigrating hypothesis about how vent species originate.
Baba, Keiji; Wicksten, Mary K
A new species of squat lobster, Uroptychus atlanticus, is described on the basis of a female specimen taken at a depth of 713-841 m in the southeastern Gulf of Mexico. The new species is readily distinguished from all known species of the genus from the western Atlantic by the very spinose carapace and pereopods, and a transverse row of spines on each of the abdominal tergites 1 and 2.
Nègre-Sadargues, G; Castillo, R; Segonzac, M
Pigments and trophic behaviour of three species of Alvinocarididae from a Mid-Atlantic hydrothermal site were analysed. Carotenoid pigments are responsible for the more or less marked colouration of these animals. The carotenoid content of whole animals and different tissues were evaluated. Rimicaris exoculata exhibits an increased carotenoid level at the juvenile stage, while Chorocaris chacei and Alvinocaris markensis contain only few traces of pigment. Free and esterified astaxanthin, reported for most pelagic crustaceans, are present in these deep-sea shrimps. The origin of carotenoids of crustaceans living in the aphotic zone is discussed.
Wang, Yan-Rong; Sha, Zhong-Li
One new species of alvinocaridid Alvinocaris kexueae sp. nov. is described from hydrothermal vents on the Manus Basin, Southwest Pacific. This is the fifteenth species in Alvinocaris Williams & Chace, 1982. The new species is easily recognized by the combination of the rostrum distinctively overreaching the distal end of the antennular peduncle, and the armature of its dorsal and ventral margins; the unarmed third abdominal segment, and by the posterior margin of the telson having one triangular tooth medially and 6 pairs unequal spines. It is morphologically most similar to A. brevitelsonis Kikuchi & Hashimoto, 2000 described from Minami-Ensei Knoll, Okinawa Trough, but can easily be distinguished from it by the proportionally longer rostrum, by the dorsal teeth of the rostrum, by the shape of the chela of the first pereiopod, and by the teeth on the fourth abdominal segment. The genetic divergence of COI gene analyzed clearly supports the new taxon.
Campos, Martha R; Magalhães, Célio
A new genus of pseudothelphusid crab, Colombiathelphusa gen. nov., is established to include Colombiathelphusa culmarcuata n. sp., from the Chocó Department, western Colombia. The new genus is characterized by the morphology of the male first gonopod, which has a prominent lateral process, a cephalic surface with two spine-like cephalic processes subdistally, and the outline of the apex strongly recurved, resembling a bow's arch. The new species is described and illustrated. The first location record of Eidocamptophallus chacei (Pretzmann, 1967), is made and its male first gonopod is redescribed and illustrated. Possible affinities of both taxa are discussed.
Muñoz, J Enrique García; Cuesta, Jose A; Raso, J Enrique García
Study of hermit crabs from Alboran Sea has allowed recognition of two different morphological forms under what had been understood as Pagurus forbesii. Based on morphological observations with various species of Pagurus, and molecular studies, a new species is described as P. pseudosculptimanus. An overview of species of Pagurus from the eastern Atlantic and Mediterranean Sea is provided.
A second species of the pagurid genus Enneophyllus McLaughlin, 1997, E. ecarina n. sp., is described and illustrated on the basis of two specimens collected from the upper bathyal depths off Amami-ohshima Island, Ryukyu Islands, southern Japan. The new species is immediately distinguished from the sole known congener, E. spinirostris McLaughlin, 1997, from the Banda Sea, Indonesia, by the non-operculiform right chela and fewer ventral spiniform setae of the ambulatory dactyli. The type species of Enneophillus, E. spinirostris, was represented only by the male holotype, and examination of the female paratype of this new species enables documentation of female characteristics in the generic diagnosis. Like E. spinirostris, the new species inhabits scaphopod shells.
von Rintelen, Kristina; Page, Timothy J; Cai, Yixiong; Roe, Kevin; Stelbrink, Björn; Kuhajda, Bernard R; Iliffe, Thomas M; Hughes, Jane; von Rintelen, Thomas
Atyid freshwater shrimps are globally distributed and form an important part of freshwater ecosystems, particularly in the tropics and subtropics. Despite their widespread distribution and ecological importance, their phylogenetic relationships are largely unresolved. Here we present the first comprehensive molecular phylogeny of the Atyidae investigating the evolutionary relationships among 32 of the 42 genera using mitochondrial and nuclear markers. Our data indicate that the established classification of the Atyidae is in need of substantial taxonomic revision at all taxonomic levels. We suggest a new suprageneric systematization of atyids and discuss problematic issues at the generic level, particularly in the most speciose genus, Caridina. Molecular clock based divergence time estimates for atyids vary widely, but invariably support the assumption that atyids are an ancient freshwater lineage with an origin in the mid-Cretaceous at the very latest. Atyid distribution patterns are the result of instances of both long-distance dispersal and vicariance, depending largely on the reproductive mode of taxa. From an evolutionary perspective, the high frequency of independent origin of both a complete (landlocked) freshwater life cycle and a cave-dwelling mode of life is remarkable and unparalleled among crustaceans.
Shih, Hsi-Te; Huang, Chao; Ng, Peter K L
Freshwater crabs of the genus Sinopotamon Bott, 1967 (family Potamidae) are widely distributed along the Yangtze River (= Chang Jiang) drainage and are endemic to China. Two distinct clades can be distinguished within Sinopotamon s. lato. on the basis of morphological and molecular data. One clade corresponds to Sinopotamon s. str., with the type species Potamon (Potamon) davidi Rathbun, 1904, and 11 other species, all which occur in the Sichuan Basin (including Sichuan Province and Chongqing City) and reach the border areas of adjacent Shaanxi, Hubei, and Guizhou provinces. A new genus, Longpotamon gen. nov., is proposed for the second clade, with Sinopotamon exiguum Dai, 1997, designated as the type species. Sinopotamon s. str. can be distinguished from Longpotamon gen. nov. by the shape of the male telson and by characters of the male first gonopod and the female vulvae. These differences are supported by the mitochondrial 16S rDNA and cytochrome oxidase subunit I (COI) genetic data. Longpotamon gen. nov. is the largest clade, with 73 known species and a wide distribution along the Yangtze River drainage extending north to the Yellow River drainage and south to the eastern side of Wuyishan Range. The two genera overlap in the Sichuan Basin and the adjacent provinces.
Low, Martyn E Y; Ng, Peter K L; Evenhuis, Neal L
The names and dates of the publications of Brachyura of Guérin (Guérin-Méneville from 1836) are reviewed, and previously unidentified or overlooked names are identified. Several identical new names used in multiple publications by Guérin (also under the name Guérin-Méneville), and others that appeared in the same year necessitated the accurate determination of publication dates to establish priority. The authorships of three names should be credited to Guérin (1832): Gecarcinus lateralis (Gecarcinidae), Halimus aries (Majidae), and Libinia spinosa (Epialtidae), the first previously attributed to Fréminville (1835), the last two to H. Milne Edwards (1834). The overlooked genus- and species-group names Cyclocarcinus pinnotheroides Guérin-Méneville, 1838, are determined to be senior subjective synonyms of the genus- and species-group names Hapalonotus reticulatus (De Man, 1879) (Pilumnidae). Applying Article 23.9.1 of the International Code of Zoological Nomenclature, precedence is reversed between the genus-group names and the correct name is Hapalonotus pinnotheroides (Guérin-Méneville, 1838). Current and widespread use of the genus-group name Thalamita Latreille, 1829 (31 March) (Portunidae) is threatened by the overlooked Thalamites Guérin, 1829 (21 March), and the precedence of the names is also reversed to maintain usage of the former. The genus-group name Eurypodius Guérin (Inachidae) is shown to have been established in 1828, not 1825. Included is a complete bibliography of the publications in which Guérin (also under Guérin-Méneville) established new names for Brachyura, with their accurate publication dates.
Perdichizzi, Anna; Pirrera, Laura; Micale, Valeria; Muglia, Ugo; Rinelli, Paola
The reproductive features of the giant red shrimp, Aristaeomorpha foliacea, were investigated in the southern Tyrrhenian sea by experimental trawl sampling. The annual length-frequency distribution showed a multimodal trend in females, ranging between 16 and 67 mm carapace length (CL), and a unimodal trend in males (18–45 mm CL). Mature males occurred in different proportions all year round, while females displayed seasonal maturity (June—September), with a peak in July. Six oocyte developmental stages were identified, the most advanced of which (Pv, postvitellogenic) had never been described before in this species. Ovary development followed a group-synchronous pattern, with the yolked oocyte stock clearly separated from the reservoir of unyolked oocytes, suggesting that A. foliacea is a total spawner, with determinate fecundity. Based upon histological findings, a revision of macroscopic maturity staging employed in Mediterranean bottom trawl surveys (MEDITS) is proposed. PMID:22629127
Bracken-Grissom, Heather D; Felder, Darryl L
Alpheus floridanus Kingsley, 1878 has been previously treated as a single, morphologically diverse species with a broad distribution in the eastern and western Atlantic Ocean and eastern Pacific Ocean. However, variations in morphology and color patterns, in addition to genetic evidence, have prompted futher investigation. Morphological characters, including curvature and length of the scaphocerite, number teeth on the incisor process of the mandible, number of pereopodal spines, proportions of the major chela, as well as color patterns, support recognition of several species in the Alpheus floridanus complex. Alpheus floridanus sensu stricto (s.s.) is redescribed based upon a lectotype selected from the former syntypic pair. The mutilated second specimen of the syntypic pair is identified as A. platycheirus Boone, 1927, which is fully redescribed. Three species are described as new: A. hephaestus sp. nov. from the eastern Pacific, and A. roblesi sp. nov. and A. ulalae sp. nov. from the western Atlantic. Morphological comparisions to the eastern Atlantic A. floridanus africanus Balss, 1916 are discussed, however a formal treatment of this subspecies is not the objective of this study. Our proposed taxonomic revisions of the A. floridanus complex are supported in a companion molecular genetic analysis (following paper, this volume).
Boyle, Robert Tew; McNamara, John Campbell
A model for intracellular transport of pigment granules in the red ovarian chromatophores of the freshwater shrimp Macrobrachium olfersi is proposed on the basis of shifts in the equilibrium of resting forces acting on an elastic pigment matrix. The model describes a pigment-transport mechanism in which mechanochemical protein motors like kinesin and myosin alternately stretch and compress a structurally unified, elastic pigment matrix. Quantifiable properties of the spring-matrix obey Hooke's Law during the rapid phases of pigment aggregation and dispersion. The spring-like response of the pigment mass is estimated from previous kinetic experiments on pigment translocation induced by red pigment concentrating hormone, or by the calcium ionophore A23187. Both translocation effectors trigger an initial phase of rapid pigment aggregation, and their removal or washout after complete aggregation produces a phase of rapid pigment dispersion, followed by slow pigment translocation. The rapid-phase kinetics of pigment transport are in reasonable agreement with Hooke's Law, suggesting that such phases represent the release of kinetic energy, probably produced by the mechanochemical protein motors and stored in the form of matrix deformation during the slow phases of translocation. This semiquantitative model should aid in analyzing intracellular transport systems that incorporate an elastic component.
Han, Yuan-Yuan; Komai, Tomoyuki; Sha, Zhong-Li
A new species of the pagurid hermit crab, Alainopaguroides sinensis sp. nov., is described and illustrated on the basis of a single ovigerous female specimen collected from the South China Sea. It is immediately distinguished from other known congeneric species by the possession of a subdistal spine on the lateral margin of the basal segment of the antennular peduncle, although the most similar congener is A. andamanensis McLauglin, 2002. This is the first record of the genus from the South China Sea. An identification key to the species of the genus Alainopaguroides McLaughlin, 1997 is provided.
Komai, Tomoyuki; Poupin, Joseph
Three species of the pagurid hermit crab genus Pagurixus Melin, 1939, are reported from Europa Island in the Mozambique Strait, western Indian Ocean: P. haigae Komai & Osawa, 2007, P. annulus n. sp., and P. europa n. sp. Pagurixus haigae is recorded from the western Indian Ocean for the first time. Pagurixus annulus n. sp. and P. europa n. sp. are referred to the P. boninensis (Melin, 1939) species group and P. anceps (Forest, 1954) group, respectively. Diagnostic characters of these two new species are discussed.
Komai, Tomoyuki; Osawa, Masayuki
Pylopaguropsis vicina, a new species of the Paguridae, is described and illustrated from southern Japan and Indonesia. This new species is most similar to P. laevispinosa McLaughlin and Haig, but is distinguished by the armature of the chelae and ambulatory dactyli, spination of the telson, and stripe pattern of the pereopods. Reexamination of specimens referred to P. laevispinosa by recent authors has shown these assignments to be incorrect. A brief supplemental description is provided for P. laevispinosa in order to clarify its systematic status. An amended key to species of the genus Pylopaguropsis is presented.
The pagurid hermit crab genus Trichopagurus de Saint Laurent, 1968 is currently represented by three shallow water spe- cies from the tropical Indo-West Pacific region. In this paper, three species of the genus, including one new species, are reported. Trichopagurus tenuidactylus n. sp. is described on the basis of a single ovigerous female from the Bohol Sea, the Philippines, and compared with two close relatives, T. asper Komai & Poupin, 2012 and T. macrochela Komai & Os- awa, 2005. New locality records are provided for T. macrochela (the Philippines) and T. trichophthalinus (Forest, 1954) (Taiwan and Marianas). An identification key to the four species of the genus is presented.
Calyptraeotheres sp. nov. (Crustacea: Decapoda: Pinnotheridae), symbiont of the slipper shell Crepidula striolata Menke, 1851 (Mollusca: Gastropoda: Calyptraeidae) from the Gulf of California, Mexico.
Ayón-Parente, Manuel; Hendrickx, Michel E
Calyptraeotheres camposi sp. nov. is described from the Gulf of California, Mexico. The new species is close to C. granti (Glassell, 1933) and C. pepeluisi Campos & Hernández-Ávila, 2010 from the Mexican Pacific and to C. hernandezi Hernández-Ávila & Campos 2006 from the Western Atlantic. These four species feature a third maxilliped with a 2-segmented endopod palp and the exopod with unsegmented flagellum. Calyptraeotheres camposi sp. nov. differs from C. granti and C. hernandezi by having the eyes visible in dorsal view, the carapace with arcuate anterolateral margins, the dorsal, longitudinal depressions connected with the transversal depression, and the propodus of pereiopod 2 equal or slightly longer than the carpus. From C. pepeluisi it is distinguished by the absence of a transversal depression on the carapace and the longitudinal depressions not connecting, the carpus and propodus of the third maxilliped being sub-trapezoidal and sub-conical, respectively, in lieu of subrectangular, and the inner surface of the fixed finger nude instead of bearing short setae near the cutting edge and ventral margin.
Ng, Peter K L; Shih, Hsi-Te
Specimens of the gecarcinid land crab Discoplax longipes A. Milne-Edwards, 1867, from the western Pacific, can be separated into two distinct groups on the basis of DNA (mitochondrial 16S rDNA and cytochrome oxidase subunit I) and structure of the male first gonopod. On the basis of this data, the material that occurs from the Loyalty Islands to French Polynesia is shown to be D. longipes s. str., whereas specimens from Guam are here referred to a new pseudocryptic species, D. michalis n. sp. The two species are described and figured; and a revised key to the long-legged Discoplax species is provided.
Menaethiops abumusa n. sp. is closely similar to M. bicornis Alcock, 1985, and M. gadaniensis Kazmi & Tirmizi, 1999, regarding the relatively contiguous rostral spines. The new species is easily distinguishable from its two congeners by having distinctly round angles of orbital eaves and distally divergent rostral spines. Whereas in M. bicornis, and M. gadaniensis, the angles of orbital eaves are anteriorly produced and rostral spines are closely attached to each other along their entire length. Other morphological differences include the carapace spination/granulation, basal antennal segments, and morphology of the male's first gonopod. Menaethiops gadaniensis was described from Gadani, Pakistan and was only known from the type locality, but is here recorded for the first time from the Gulf of Oman.
Huang, Chao; Mao, Si Ying
Two new Chinese genera and species of freshwater crabs, Yuexipotamon arcophallus, new genus, new species, and Minutomon shanweiense, new genus, new species, are described from Zhaoqing City and Shanwei City, respectively. The former is superficially closest to Huananpotamon Dai & Ng, 1994, while the latter resembles Sinopotamon Bott, 1967, and Mediapotamon Dai, 1995. The two new genera, however, possess distinctive combinations of carapace, third maxilliped, male thoracic sternal and first gonopodal characters that easily distinguish them from other genera. Notes on the general biology of the two new species are also given.
Naruse, Tohru; Zhu, Chunchao; Zhou, Xianmin
Heterochelamon tessellatum n. sp. and H. castanea n. sp. are described trom the Guangxi Zhuang Autonomous Region, southern China. Heterochelamon tessellatum n. sp. and H. castanea n. sp. are morphologically most similar to H. yangshuoense Türkay & Dai, 1997, and H. guangxiense Türkay & Dai, 1997, respectively. The new species can be differentiated from these allied species by differences in the shape of external orbital tooth, epibranchial tooth, and male first gonopod. The present study brings the number of Heterochelamon species to five. A key to species of the genus Heterochelamon is provided.
Takeda, Masatsune; Tachikawa, Hiroyuki
Four species of palicoid crabs, Neopalicus jukesii (White, 1847) and Rectopalicus ampullatus Castro, 2000 of the family Palicidae, and Crossotonotus spinipes (De Man, 1888) and a new species of Pleurophricus A. Milne-Edwards, 1873 of the family Crossotonotidae, are recorded from the Ogasawara Islands, Japan. Diagnostics for the new species are the protruded bilobed front, six subacute lobate teeth at each lateral margin of the carapace, six rounded lobes at the posterior margin of the carapace, a crested armature of the cheliped carpus, and the strongly depressed ambulatory legs, which readily distinguish it from its two congeners, P. cristatipes A. Milne-Edwards, 1873 known by two males from Australia and the Kai Islands in Indonesia, and P. longirostris (Moosa & Serène, 1981) known by a female from the Sunda Strait, Indonesia.
Komai, Tomoyuki; Tsuchida, Shinji; Clark, Malcolm R
A fifth species of the pagurid genus Cestopagurus Bouvier, 1897, is described and illustrated on the basis of a single male specimen collected at a depth of 499 m from Hinepuia submarine volcano in the Kermadec Arc, New Zealand. The new species, C. hinepuia, appears similar to C. puniceus Komai & Takeda, 2005 known from waters off Japan, but the different armature of chelipeds distinguishes the new species. It is the first representative of the genus recorded from the South Pacific Ocean. A key for identification of species of the genus is presented.
Wang, Teng-Wei; Ahyong, Shane T; Chan, Tin-Yam
Lithodid crabs (Lithodidae Samouelle, 1819), commonly known as king crabs, are frequent targets of commercial fishing worldwide with most of them living in deep water (Sakai 1971; Ahyong et al. 2010). Lithodes Latreille, 1806, is the second largest genus of lithodid crabs, currently including 29 species worldwide (Ahyong 2010). In Taiwanese waters, however, only two species, L. turritus Ortmann, 1892, and L. formosae Ahyong & Chan, 2010, have been reported (Wu et al. 1998; Ahyong & Chan 2010; Ahyong et al. 2010). We report herein the discovery of L. longispina Sakai, 1971, previously known reliably only from Japan (Sakai 1971; Ikeda 1998; Ahyong 2010), from off southwestern Taiwan, including a specimen collected in the vicinity of a cold seep.
Lukhaup, Christian; Panteleit, Jörn; Schrimpf, Anne
Abstract A new species, Cherax snowden sp. n., from the Oinsok River Drainage, Sawiat District in the central part of the Kepala Burung (Vogelkop) Peninsula, West Papua, Indonesia, is described, figured and compared with the closest related species, Cherax holthuisi Lukhaup & Pekny, 2006. This species is collected and exported for ornamental purposes and its commercial name in the pet trade is “orange tip” or “green orange tip”. Both species may be easily distinguished morphologically or by using sequence divergence, which is substantial, for considering Cherax snowden sp. n. to be a new species. PMID:26448698
Baba, Keiji; Wicksten, Mary K
Eight species of squat lobsters of the genus Uroptychus are reported from the western Atlantic based on the collections of the Museum of Comparative Zoology at Harvard, the Smithsonian Institution and Texas A&M University. Uroptychus nitidus (A. Milne-Edwards, 1880) is reviewed and redescribed, with a syntype taken at Blake Station 200 off Martinique designated as the lectotype. Uroptychus alphonsei n. sp. is named for U. nitidus variety C Chace, 1942, U. fenneri n. sp. for U. nitidus variety A Chace, 1942, and U. janiceae n. sp. for U. nitidus variety B Chace, 1942; U. lindae n. sp. is described on the basis of specimens collected by the Alaminos in the Caribbean Sea off northern Columbia; U. rafai n. sp. is described based on a sole specimen taken from the Straits of Florida; U. reedae n. sp. is described from among the syntypes of U. nitidus; and U. uncifer (A. Milne-Edwards, 1880) is redescribed to elaborate on its specific status, with the designation of lectotype from Blake Station 299 off the coast of Barbados. The number of species of Uroptychus from the western Atlantic now stands at 21. A key to these species is provided.
A new species of the snapping shrimp genus Alpheus Fabricius, 1798, Alpheus ikedosoma, is described and illustrated on the basis of material from Boso Peninsula and Ariake Sea, Japan. All examined specimens were extracted with the help of a bait suction pump from burrows of innkeeper worm (Annelida: Echiura), constructed on easily accessible intertidal sand beaches or sand flats. The host worm from Boso Peninsula was identified as Ikedosoma elegans (Ikeda, 1904) (Echiuridae). The new species is tentatively referred to the A. brevirostris (Olivier, 1811) species group, but it is characteristic in having several unusual features for the group, such as the very short rostrum without dorsal ridge, the absence of adrostral grooves on the carapace, the strongly reduced dorsolateral spines on the telson, the unarmed antennal basicerite, the non-elongate, almost glabrous major chela, and the lack of movable spines or spinules on ventromesial margin of each cheliped merus. The new species represents the sixth species of Alpheus associated with echiuran burrows.
Lim, Jong Tae; Hwang, Ui Wook
The whole mitochondrial genome (14,915 nt) of Pollicipes mitella (Crustacea, Maxillopoda, Cirripedia, Thoracica) was sequenced and characterized. It is the shortest of the 31 completely sequenced crustacean mitochondrial genomes, with the exception of a copepod Tigriopus japonicus (14,628 nt). It consists of the usual 13 protein-coding genes, 22 tRNA genes, 2 rRNA genes, and 1 relatively short non-coding region (294 nt). The thoracican cirripeds apart from Megabalanus volcano have the same arrangement of protein-coding genes as Limulus polypemus, but there are frequent tRNA gene translocations (at least 8). Some interesting translocation features that may be specific to the thoracican cirriped lineage are as follows: 1) trnK-trnQ lies between the control region and trnI, 2) trnA-trnE lies between trnN and trnS1, 3) trnP lies between ND4L and trnT, and 4) trnY-trnC lies between trnS2 and ND1. In P. mitella there are two trnL genes (L1 and L2) in the typical crustacean positions (ND1-L1-LrRNA and CO1-L2-CO2). The present result is compared and discussed with the other three cirriped mitochondrial genomes from one pedunculate (Pollicipes polymerus) and two sessiles (Tetraclita japonica and M. volcano) published so far. Mitochondrial protein phylogenies reconstructed by the BI and ML algorithms show that the thoracican Cirripedia is monophyletic (BPP 100/BP 100) and associated with Remipedia (BPP 98/BP 35). In addition, Oligostraca, including Ostracoda, Branchiura, and Pentastomida, is a monophyletic group (BPP 99/BP 68), and is basal to all the other examined arthropods. Remipedia + Cirripedia appears as an independent lineage within Arthropoda, apart from Thoracopoda (Malacostraca, Branchiopda, and Cephalocarida). The Thoracopoda is paraphyletic to Hexapoda. The present result suggests that the monophylies of Crustacea and Maxillopoda should be reconsidered.
Kim, Sanghee; Choi, Han-Gu; Park, Joong-Ki; Min, Gi-Sik
We determined the complete mitochondrial (mt) genome sequence of the red king crab, Paralithodes camtschaticus (Decapoda, Anomura). P. camtschaticus is one of the largest arthropods and the most expensive commercially available gourmet seafood. The genome sequence of P. camtschaticus is 16,720 bp in size and its gene content, gene order, and transcriptional polarity are almost identical to those of the hermit crab Pagurus longicarpus, which is thought to be derived from a common ancestor. However, P. camtschaticus mtDNA showed tRNA translocation in two blocks compared to that of P. longicarpus. Prior to this study, complete mt genomes of only two species of Anomura have been reported. Thus, our genomic data will provide additional information for constructing the decapod phylogeny.
the digestive system of terrestrial isopods. Journal of Zoology 217:599-627, 1989. DSTO-TR-2098 47 H. J. Hansen. Studies on Arthropoda II. On...the comparitive morphology of the appendages in the Arthropoda . In: A Crustacea, Copenhagen:Gyldendalske Boghandel, 1925, p. 1-175. K. Harrison and
Martin, G G; Lin, H M; Luc, C
In 1941, a single type of hemocyte was described in the blood of the brine shrimp Artemia salina using light microscopy. This condition is unusual because most crustaceans examined using morphological, cytochemical, and functional methods have at least two types of hemoctyes. Upon examining A. franciscana, we found a single type of disk-shaped hemocyte, with a centrally located nucleus and about 15 large (6 microm diameter) granules. The granules stain for the presence of acid phosphatase and react with L-DOPA suggesting, respectively, that they are involved in degrading ingested material and possess the phenoloxidase system. Hemocytes require calcium for adhesion, bind together to mend small wounds in the body wall, and are able to phagocytose bacteria. Blood cells of A. franciscana are morphologically and functionally similar to those of the primitive chelicerate, Limulus polyphemus, and both forms have apparently given rise to more advanced taxa with multiple types of hemocytes. The major difference between the two species is the presence of the phenoloxidase system in the Crustacea and its apparent absence in the chelicerates. Copyright 1999 Wiley-Liss, Inc.
Pérez-Losada, Marcos; Høeg, Jens T; Crandall, Keith A
Background The Thecostraca are arguably the most morphologically and biologically variable group within the Crustacea, including both suspension feeders (Cirripedia: Thoracica and Acrothoracica) and parasitic forms (Cirripedia: Rhizocephala, Ascothoracida and Facetotecta). Similarities between the metamorphosis found in the Facetotecta and Rhizocephala suggests a common evolutionary origin, but until now no comprehensive study has looked at the basic evolution of these thecostracan groups. Results To this end, we collected DNA sequences from three nuclear genes [18S rRNA (2,305), 28S rRNA (2,402), Histone H3 (328)] and 41 larval characters in seven facetotectans, five ascothoracidans, three acrothoracicans, 25 rhizocephalans and 39 thoracicans (ingroup) and 12 Malacostraca and 10 Copepoda (outgroup). Maximum parsimony, maximum likelihood and Bayesian analyses showed the Facetotecta, Ascothoracida and Cirripedia each as monophyletic. The better resolved and highly supported DNA maximum likelihood and morphological-DNA Bayesian analysis trees depicted the main phylogenetic relationships within the Thecostraca as (Facetotecta, (Ascothoracida, (Acrothoracica, (Rhizocephala, Thoracica)))). Conclusion Our analyses indicate a convergent evolution of the very similar and highly reduced slug-shaped stages found during metamorphosis of both the Rhizocephala and the Facetotecta. This provides a remarkable case of convergent evolution and implies that the advanced endoparasitic mode of life known from the Rhizocephala and strongly indicated for the Facetotecta had no common origin. Future analyses are needed to determine whether the most recent common ancestor of the Thecostraca was free-living or some primitive form of ectoparasite. PMID:19374762
Camacho, Ana I.; Dorda, Beatriz A.; Rey, Isabel
Abstract This is the first published database of Bathynellacea. It includes all data of bathynellids (Crustacea, Bathynellacea) collected in the last 64 years (1949 to 2013) on the Iberian Peninsula and Balearic Island. The samples come from groundwater (caves, springs, wells and hyporrheic habitat associated rivers) from both sampling campaigns and occasional sampling conducted throughout the Iberian Peninsula and Balearic Islands. The dataset lists occurrence data of bathynellids distribution, sampling sites (with localities, county and geographic coordinates), taxonomic information (from family to species level) and sampling sources (collector and sampling dates) for all records. The descriptions of new species and species identifications have been carried out by an expert taxonomist (AIC) with 25 years experience in the bathynellids studies (see references). Many of the sampling sites are type localities of endemic species from Iberian Peninsula. The dataset includes 409 samples record corresponding to two families, 12 genera and 58 species, 42 of them formally described plus 16 taxa unpublished and 47 samples in study. All species known from the study area are included, which nearly sum up a quarter of species of Bathynellacea known in the world (250 species). PMID:24693212
Adamowicz, Sarah J.; Purvis, Andy; Wills, Matthew A.
The prospect of finding macroevolutionary trends and rules in the history of life is tremendously appealing, but very few pervasive trends have been found. Here, we demonstrate a parallel increase in the morphological complexity of most of the deep lineages within a major clade. We focus on the Crustacea, measuring the morphological differentiation of limbs. First, we show a clear trend of increasing complexity among 66 free-living, ordinal-level taxa from the Phanerozoic fossil record. We next demonstrate that this trend is pervasive, occurring in 10 or 11 of 12 matched-pair comparisons (across five morphological diversity indices) between extinct Paleozoic and related Recent taxa. This clearly differentiates the pattern from the effects of lineage sorting. Furthermore, newly appearing taxa tend to have had more types of limbs and a higher degree of limb differentiation than the contemporaneous average, whereas those going extinct showed higher-than-average limb redundancy. Patterns of contemporary species diversity partially reflect the paleontological trend. These results provide a rare demonstration of a large-scale and probably driven trend occurring across multiple independent lineages and influencing both the form and number of species through deep time and in the present day. PMID:18347335
Adamowicz, Sarah J; Purvis, Andy; Wills, Matthew A
The prospect of finding macroevolutionary trends and rules in the history of life is tremendously appealing, but very few pervasive trends have been found. Here, we demonstrate a parallel increase in the morphological complexity of most of the deep lineages within a major clade. We focus on the Crustacea, measuring the morphological differentiation of limbs. First, we show a clear trend of increasing complexity among 66 free-living, ordinal-level taxa from the Phanerozoic fossil record. We next demonstrate that this trend is pervasive, occurring in 10 or 11 of 12 matched-pair comparisons (across five morphological diversity indices) between extinct Paleozoic and related Recent taxa. This clearly differentiates the pattern from the effects of lineage sorting. Furthermore, newly appearing taxa tend to have had more types of limbs and a higher degree of limb differentiation than the contemporaneous average, whereas those going extinct showed higher-than-average limb redundancy. Patterns of contemporary species diversity partially reflect the paleontological trend. These results provide a rare demonstration of a large-scale and probably driven trend occurring across multiple independent lineages and influencing both the form and number of species through deep time and in the present day.
Ahn, Dong-Ha; Min, Gi-Sik; Park, Joong-Ki; Kim, Sanghee
The violet-spotted reef lobster Enoplometopus debelius Holthuis, 1983 (Decapoda, Astacidea, Enoplometopidae) is found in the tropical reef areas of the Indo-Pacific region, and is a highly prized and very popular species in the aquarium trade industry. The complete mitochondrial genome of E. debelius has 15,641 base pairs consisting of 13 protein-coding genes, 22 transfer RNAs, 2 ribosomal RNAs, and a control region of 746 bp. The base composition of E. debelius is 36.4% A, 35.3% T, 18.1% C, 10.3% G, and the species has an AT content of 71.7%. The E. debelius mitogenome was found to have a gene arrangement and transcriptional polarity identical to that of the Homarus americanus mitogenome, a representative of the arthropod ground pattern. Here, we present the complete mitogenome sequence of E. debelius, which is the first in the superfamily Enoplometopoidea. These data will provide a useful molecular resource for the phylogenetic study of the infraorder Astacidea/order Decapoda.
Machida, Ryuji J; Miya, Masaki U; Yamauchi, Mitsugu M; Nishida, Mutsumi; Nishida, Shuhei
We determined the nearly complete DNA sequence of the mitochondrial genome of Antarctic krill Euphausia superba (Crustacea: Malacostraca), one of the most ecologically and commercially important zooplankters in Antarctic waters. All of the genome sequences were purified by gene amplification using long polymerase chain reaction (PCR), and the products were subsequently used as templates for either direct sequencing using a primer-walking strategy or nested PCR with crustacea-versatile primers. Although we were unable to determine a portion of the genome owing to technical difficulties, the sequenced position, 14,606 bp long, contained all of the 13 protein-coding genes, 19 of the 22 transfer RNA genes, and the large subunit as well as a portion of the small subunit ribosomal RNA genes. Gene rearrangement was observed for 3 transfer RNA genes (tRNACys, tRNATyr, and tRNATrp) and the 2 leucine tRNA genes.
Liu, Qiu-Ning; Chai, Xin-Yue; Jiang, Sen-Hao; Zhou, Chun-Lin; Xuan, Fu-Jun; Tang, Bo-Ping
Here we present the complete mitochondrial (mt) genome of Procambarus clarkii (Decapoda: Cambaridae) and provide its annotation. The complete mt genome was determined to be 15 929 bp and contains 22 tRNA genes, 13 protein-coding genes (PCGs), two rRNA genes, and a D-loop region. The nucleotide composition was biased toward A + T nucleotides (72.91%) and the AT skew of this mt genome was slightly negative. All the 22 tRNA genes displayed a typical clover-leaf structure, with the exception of trnS1 (AGN). About 13 PCGs were initiated by ATN codons, except for cox1 and nad2 genes which were initiated by ACG and GTG, respectively. Six of the 13 PCGs harbor the incomplete termination codon by T or TA. The D-loop region of the mt genome was 1188 bp in length and the A + T content was 81.08%. Phylogenetic analysis showed that the placement of P. clarkii was within the Cambaridae. This mt genome sequence will provide a better understanding for crayfish evolution in the future.
HYŽNÝ, MATÚŠ; VESELSKÁ, MARTINA KOČOVÁ; DVOŘÁK, PAVEL
Because of close morphological affinities, fossil cheliped fragments of the ghost shrimp Ctenocheles (Decapoda, Axiidea, Ctenochelidae) can be easily misidentified as remains of different decapod crustacean taxa. Re-examination of the Cretaceous decapods deposited in the National Museum in Prague revealed that all supposed specimens of the lobster genus Oncopareia found in the Middle Coniacian calcareous claystones of the Březno Formation, including one of the Fritsch’s original specimens of Stenocheles parvulus, actually belong to Ctenocheles. This material together with newly collected specimens from the same locality, allowed for erection of a new species, Ctenocheles fritschi. Its major chela possesses a serrated ischium and ovoid, unarmed merus; therefore, it is considered a close relative of the extant C. collini and C. maorianus. Ctenocheles fritschi sp. nov. represents the first report on the occurrence of the genus from the Bohemian Cretaceous Basin. It is one of the oldest records of Ctenocheles and simultaneously one of the best preserved fossils of the genus reported to date. Confusing taxonomy of S. parvulus is reviewed and shortly discussed. PMID:25983568
Robles, Rafael; Felder, Darryl L
Ghost shrimps (Decapoda: Callianassidae) are common estuarine and marine burrowing organisms of tropical to temperate waters, typically found in intertidal to shallow subtidal habitats. Except for an abbreviated planktonic larval phase, most callianassids live as obligate burrowers and appear to depend on the burrow for shelter, reproduction, and feeding. Recent studies have shown the genus Lepidophthalmus, a group largely restricted to estuaries and river mouths, to be surprisingly speciose, but relationships among these taxa and driving forces for their separation remain poorly understood. We include fifteen described species of Lepidophthalmus in a molecular phylogenetic analysis based upon sequence analyses of the 16S and 12S mitochondrial genes. Our findings clarify the monophyletic membership of the genus and confirm postulated species separations. We reconfirm validity of Lepidophthalmus eiseni, reject two recently proposed new genera for selected members of Lepidophthalmus, and define ecologically and morphologically informative clades among congeners. Limited capability for larval dispersal and regional biogeographic history could well account for high diversity and regional endemism observed within the genus. Biogeographic scenarios, including continental drift, closure of the Panamanian Isthmus, and post-glacial dispersals, are invoked to account for proposed reconstructions of historical relationships.
Ki, Jang-Seu; Dahms, Hans-Uwe; Hwang, Jiang-Shiou; Lee, Jae-Seong
In this study, we analyzed the complete mitochondrial (mt) genome of a hydrothermal vent crab Xenograpsus testudinatus (Decapoda: Brachyura) obtained from the hydrothermal vents off Kueishantao Island, Taiwan, which extend from the deep sea Okinawa Trench. The mitogenome of X. testudinatus was 15,796 bp in length and contained the same 37 genes (e.g. 2 rRNAs, 22 tRNAs, and 13 PCGs) found in other metazoan mitogenomes. Analysis of the structural mt gene order in X. testudinatus revealed that the 13 PCGs, excluding a translocation of ND6-Cyt b cluster, were similarly ordered when compared to the pancrustacean ground pattern; however the tRNAs were severely rearranged. Phylogenetic analysis of decapod mitogenomes showed that the molecular taxonomy of the vent crab was in accordance with its morphological systematics. Together, these findings suggest that the vent crab studied here has little mitochondrial genetic variation when compared with morphologically defined conspecifics from other marine habitats.
Podsiadlowski, Lars; Bartolomaeus, Thomas
We determined the nearly complete mitochondrial genome of Pseudosquilla ciliata (Crustacea, Stomatopoda), including all protein-coding genes and all but one of the transfer RNAs. There were no gene rearrangements relative to the pattern shared by crustaceans and hexapods. Phylogenetic analysis using concatenated amino acid sequences of the mitochondrial protein-coding genes confirmed a basal position of Stomatopoda among Eumalacostraca. Pancrustacean relationships based on mitogenomic data were analyzed and are discussed in relation to crustacean and hexapod monophyly and hexapod affinities to crustacean subtaxa.
Haryanti; Sugama, Ketut; Nishijima, Toshitaka
The bacteria in the genus Vibrio are heterothrophic, which exist in the larval rearing water of Crustacea and often show diverse pathogenicities to marine animals. In order to assess the bacterial diversity associated with Crustacean seed production, 32 strains were isolated from black tiger shrimp (Penaeus monodon) and mangrove crab (Scylla paramamosain) larvae and their rearing-water and characterized using biochemical and molecular approaches. Two or more genotypically different species were identified. The vibriosis of black tiger shrimp was causes by V. harveyi, V. alginolyticus and Vibrio spp. predominantly, while that of crab by V. harveyi and V. alginolyticus only.
Hickerson, M J; Cunningham, C W
The entire mitochondrial gene order of the crustacean Pagurus longicarpus was determined by sequencing all but approximately 300 bp of the mitochondrial genome. We report the first major gene rearrangements found in the clade including Crustacea and Insecta. At least eight mitochondrial gene rearrangements have dramatically altered the gene order of the hermit crab P. longicarpus relative to the putatively ancestral crustacean gene order. These include two rearrangements of protein-coding genes, the first reported for any nonchelicerate arthropod. Codon usage and amino acid sequences do not deviate substantially from those reported for other crustaceans. Investigating the phylogenetic distribution of these eight rearrangements will add additional characters to help resolve decapod phylogeny.
Ardika, Puji Utari; Farajallah, Achmad; Wardiatno, Yusli
Specimens of Hippa adactyla (Crustacea, Anomura, Hippidae) were collected from several coasts of Indonesia (Sumatera, Java, Bali-Lombok and Sulawesi). This finding represents the first record of this species in Indonesia and confirms its presence in the Indian Ocean and in the Wallacea region. Its systematic and morphological characteristics are described, and its distribution in Indonesia is presented. One of the main characteristics of this species is a median lobe in the anterior part of the carapace, which has 3–4 lobes. Likewise, the left antenna has 2–6 articles. PMID:26868713
Ardika, Puji Utari; Farajallah, Achmad; Wardiatno, Yusli
Specimens of Hippa adactyla (Crustacea, Anomura, Hippidae) were collected from several coasts of Indonesia (Sumatera, Java, Bali-Lombok and Sulawesi). This finding represents the first record of this species in Indonesia and confirms its presence in the Indian Ocean and in the Wallacea region. Its systematic and morphological characteristics are described, and its distribution in Indonesia is presented. One of the main characteristics of this species is a median lobe in the anterior part of the carapace, which has 3-4 lobes. Likewise, the left antenna has 2-6 articles.
Dewes, L J; Sandrini, J Z; Monserrat, J M; Yunes, J S
Microcystins are usually the predominant cyanotoxins present in both drinking and recreational waters after cyanobacterial blooms. Their classic toxic effect is hepatotoxicity through inhibition of serine/threonine phosphatases. However, recent studies also reported oxidative stress generation and disruption of ion regulation in aquatic organisms after microcystins exposure. In the present study, aqueous extracts of Microcystis aeruginosa were administered to the estuarine crab Chasmagnathus granulatus (Decapoda, Brachyura) by gavage in variable doses (from 34 to 860 microg kg(-1)) and exposure times (6, 12, and 72 h). A control group was exposed to saline solution. Analyzed variables included oxygen consumption, lipid peroxidation (LPO), enzyme activities (glutathione S-transferases or GST; alanine aminotransferase or ALT; aspartate aminotransferase or AST; and lactate dehydrogenase or LDH), glycogen, and microcystins content. Oxygen consumption increased in organisms exposed for 12h to 860 microg kg(-1) of microcystins and a similar result was observed after 72 h at doses equal to or higher than 34 microg kg(-1). LPO levels increased in doses equal to or higher than 34 microg kg(-1) after 72 h. GST and LDH activities increased after 12 h (at a dose of 860 microg kg(-1)), but ALT and AST activities remained unaltered in all experimental conditions. Glycogen content decreased after 72 h exposure at doses equal to or higher than 172 microg kg(-1). After 12h of exposure to 860 microg kg(-1) of microcystins, the concentration found in the hepatopancreas of C. granulatus was 13.17+/-0.56 microg kg(-1). In crabs exposed to doses higher than 172 microg kg(-1) during 72 h this value raised to 32.14+/-4.12 microg kg(-1). The obtained results indicated that microcystins exposure led the tissue to an oxidative stress condition (high LPO levels), at least in part favored by the augment of oxygen consumption, altering the glycogen metabolism. GST responses were only observed
Kaya, Murat; Tozak, Kabil Özcan; Baran, Talat; Sezen, Göksal; Sargin, Idris
Chitin and its derivatives are commercially important biopolymers due to their applications in medicine, agriculture, water treatment, cosmetics and various biotechnological areas. Since chitin and its derivatives exhibit different chemical and physical properties depending on the source and isolation method, there is a growing demand for new chitin sources other than crab and shrimp worldwide. In this study Gammarus, a Crustacea, was investigated as a novel chitin source. Gammarus, which belongs to the family Gammaridae Crustacea, lives in the bottom of aquatic ecosystems. More than 200 species are known worldwide. One of these species, G. argaeus was investigated for chitin isolation. The alpha chitin isolated from G. argaeus was characterized by using analysis techniques such as infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), X-ray diffraction (XRD) and scanning electron microscopy (SEM). All these analyses confirmed that the isolated chitin from G. argaeus was in the alpha form. Furthermore, we described that dry weight of this species contained 11-12 % chitin. SEM examination of the isolated α-chitin revealed that it was composed of nanofibrils (15-55 nm) and pores (about 150 nm). PMID:26966425
Zhang, Yu-Bo; Gerken, Sarah; Chen, Xiang-Sheng
A replacement name is proposed for genus Dayus Gerken, 2001 (Crustacea: Peracarida: Cumacea), preoccupied by Dayus Mahmood, 1967 (Insecta: Hemiptera: Cicadellidae). The following changes are proposed: Jennidayus new replacement name = Dayus Gerken, 2001 (nec Mahmood 1967); Jennidayus pharocheradus (Gerken, 2001), comb. n. = Dayus pharocheradus Gerken, 2001; Jennidayus acanthus (Gerken, 2001), comb. n. = Dayus acanthus Gerken, 2001; Jennidayus makrokolosus (Gerken, 2001), comb. n. = Dayus makrokolosus Gerken, 2001.
San Vicente, Carlos; Corbari, Laure
A new species of the genus Petalophthalmus (Crustacea: Mysida: Petalophthalmidae) is described, based on one specimen collected from the Bismarck Sea (Papua New Guinea, Western Pacific Ocean). This species can be distinguished from the other species of the genus Petalophthalmus by the globular cornea and the armature of the telson. This new species lives between 800 and 1065 m depth. A discussion on the geographic and bathymetric distribution and an identification key to world species of Petalophthalmus are provided.
Carapelli, Antonio; Liò, Pietro; Nardi, Francesco; van der Wath, Elizabeth; Frati, Francesco
Background The phylogeny of Arthropoda is still a matter of harsh debate among systematists, and significant disagreement exists between morphological and molecular studies. In particular, while the taxon joining hexapods and crustaceans (the Pancrustacea) is now widely accepted among zoologists, the relationships among its basal lineages, and particularly the supposed reciprocal paraphyly of Crustacea and Hexapoda, continues to represent a challenge. Several genes, as well as different molecular markers, have been used to tackle this problem in molecular phylogenetic studies, with the mitochondrial DNA being one of the molecules of choice. In this study, we have assembled the largest data set available so far for Pancrustacea, consisting of 100 complete (or almost complete) sequences of mitochondrial genomes. After removal of unalignable sequence regions and highly rearranged genomes, we used nucleotide and inferred amino acid sequences of the 13 protein coding genes to reconstruct the phylogenetic relationships among major lineages of Pancrustacea. The analysis was performed with Bayesian inference, and for the amino acid sequences a new, Pancrustacea-specific, matrix of amino acid replacement was developed and used in this study. Results Two largely congruent trees were obtained from the analysis of nucleotide and amino acid datasets. In particular, the best tree obtained based on the new matrix of amino acid replacement (MtPan) was preferred over those obtained using previously available matrices (MtArt and MtRev) because of its higher likelihood score. The most remarkable result is the reciprocal paraphyly of Hexapoda and Crustacea, with some lineages of crustaceans (namely the Malacostraca, Cephalocarida and, possibly, the Branchiopoda) being more closely related to the Insecta s.s. (Ectognatha) than two orders of basal hexapods, Collembola and Diplura. Our results confirm that the mitochondrial genome, unlike analyses based on morphological data or nuclear
Gómez, Rocío; Van Damme, Kay; Gosálvez, Jaime; Morán, Eugenio Sánchez; Colbourne, John K
We present the first detailed cytological study of male meiosis in Daphnia (Crustacea: Branchiopoda: Cladocera)-an aquatic microcrustacean with a cyclical parthenogenetic life cycle. Using immunostaining of the testes in Daphnia magna for baseline knowledge, we characterized the different stages of meiotic division and spermiogenesis in relation to the distribution of proteins involved in synapsis, early recombination events and sister chromatid cohesion. We also studied post-translational histone modifications in male spermatocytes, in relation to the dynamic chromatin progression of meiosis. Finally, we applied a DNA fragmentation test to measure sperm quality of D. magna, with respect to levels of inbreeding. As a proxy for fertility, this technique may be used to assess the reproductive health of a sentinel species of aquatic ecosystems. Daphnia proves to be a model species for comparative studies of meiosis that is poised to improve our understanding of the cytological basis of sexual and asexual reproduction.
Song, Ji-Hun; Kim, Sanghee; Shin, Sook; Min, Gi-Sik
In this study, we determined the mitogenome sequence of Neomysis japonica (Crustacea, Malacostraca, Mysida), which is the first complete mitogenome sequence in the order Mysida. The mitogenome of N. japonica is 17,652 bp in length and contains 13 protein-coding genes (PCGs), 22 transfer RNAs (tRNAs), 2 ribosomal RNAs (rRNAs), and a control region (CR). Mitogenome analysis of N. japonica revealed a novel gene order that included inversions in three PCGs and five tRNAs, compared with H. americanus, the ancestral pancrustacean ground pattern. The results will be useful for the detailed study of mitogenome evolution and the phylogenetic relationships among the orders in the class Malacostraca. As seen from the phylogenetic tree, N. japonica belongs to the order Mysida within Malacostraca.
Fan, Yu-Peng; Lu, Bo; Yang, Jin-Shu
The sequence of the mitochondrial genome (mitogenome) of the fairy shrimp Phallocryptus tserensodnomi Alonso & Ventura 2013 (Crustacea: Anostraca: Thamnocephalidae) has been determined. It is 16,493 bp with an AT-content of 65.4%, which encodes information of the typical 37 genes as all other metazoan mitogenomes. Both AT-content and putative control region of the genome show moderate values among all mitogenomes of the Branchiopoda sequenced to date. The mitochondrial gene order shows the same arrangement with the Artemiidae which is different from the pancrustacean ancestral pattern, due to translocation and inversion of two tRNA genes. Our results will provide important materials for not only phylogenetic but also biogeographic studies of the Anostraca.
Liu, Xue-Chen; Li, Hua-Wei; Jermnak, Usuma; Yang, Jin-Shu
In this study, we amplified, sequenced and analyzed the complete mitogenome of the freshwater fairy shrimp Streptocephalus sirindhornae (Crustacea: Anostraca: Streptocephalidae). The full-length of the S. sirindhornae mitogenome is a circular molecule of 16,887 bp in size with an A + T content of 64.5%. It has the largest putative control region (2794 bp) with the lowest A + T content (62.6%) for all determined branchiopod mitogenomes. The genome consisted of 37 genes that are involved in the respiration chain as well as the mitochondrial translation system. The S. sirindhornae mitogenome exhibits an identical gene arrangement as the Artemia pattern, which shows translocation and inversion of two transfer-RNA genes compared to the pancrustacean ancestral pattern. This is by far the first determined mitogenome of a freshwater fairy shrimp. The results of our study will provide significant data for reconstructing the consensus Branchiopoda tree of life.
Drobne, Damjana; Drobne, Samo
Abstract The advantage of using terrestrial isopods in toxicity studies is that a battery of parameters can be tested at different levels of biological complexity. Feeding parameters for example link organism level response to potential ecological consequences but a problem with using feeding parameters in toxicity tests with terrestrial isopods is their high variability. The aim of our study was to set benchmark values for feeding parameters for isopod Porcellio scaber (Isopoda, Crustacea) in laboratory-controlled experiments. In the work presented here, the daily feeding rate of the central 50% of the control population of Porcellio scaber and a correlation between feeding rate and isopod weight were set. Values outside these ranges need additional evaluation to increase the relevance of test outcomes. We suggest using benchmark values for feeding parameters as well as the coefficient of variation (a) to identify animals with altered feeding parameters with respect to controls, and (b) to assess the data quality in each experiment. PMID:25561844
Roterman, C. N.; Copley, J. T.; Linse, K. T.; Tyler, P. A.; Rogers, A. D.
The phylogeny of the superfamily Chirostyloidea (Decapoda: Anomura) has been poorly understood owing to limited taxon sampling and discordance between different genes. We present a nine-gene dataset across 15 chirostyloids, including all known yeti crabs (Kiwaidae), to improve the resolution of phylogenetic affinities within and between the different families, and to date key divergences using fossil calibrations. This study supports the monophyly of Chirostyloidea and, within this, a basal split between Eumunididae and a Kiwaidae–Chirostylidae clade. All three families originated in the Mid-Cretaceous, but extant kiwaids and most chirostylids radiated from the Eocene onwards. Within Kiwaidae, the basal split between the seep-endemic Kiwa puravida and a vent clade comprising Kiwa hirsuta and Kiwa spp. found on the East Scotia and Southwest Indian ridges is compatible with a hypothesized seep-to-vent evolutionary trajectory. A divergence date estimate of 13.4–25.9 Ma between the Pacific and non-Pacific lineages is consistent with Kiwaidae spreading into the Atlantic sector of the Southern Ocean via the newly opened Drake Passage. The recent radiation of Kiwaidae adds to the list of chemosynthetic fauna that appear to have diversified after the Palaeocene/Eocene Thermal Maximum, a period of possibly widespread anoxia/dysoxia in deep-sea basins. PMID:23782878
Phoronis pallida (Phoronida) occurs as a commensal within the burrow of Upogebia pugettensis (Decapoda: Thalassinidea). Upogebia-conditioned seawater (UCSW) induced an exploratory swimming behavior in competent larvae of P. pallida in a dosage-dependent manner. This behavior included a significant increase in swimming speed that was directed downward, along with the repeated probing of the bottom with the sensory portion of the oral hood. The waterborne cue from the shrimp was present in the gut effluent, and the swimming behavior was not the result of the elevated ammonia concentration. Molecular weight separation of the UCSW estimated that the cue was between 10 and 50 kDa. Enzymatic treatments showed that the cue's activity could be eliminated by arginase and significantly reduced by lipase. Competent larvae were also induced to metamorphose when exposed to 20 mM CsCl for 30 min. Larvae did not respond to CsCl when cultured about 4 weeks past the onset of competence. Compared with actinotroch larvae of other phoronid species, P. pallida larvae exhibit greater behavioral specificity and neuronal differences within the hood sense organ. These anatomical and behavioral differences may have been maintained through a coevolutionary process among P. pallida and species of thalassinid shrimps that share Upogebia life-history characteristics.
Roterman, C N; Copley, J T; Linse, K T; Tyler, P A; Rogers, A D
The phylogeny of the superfamily Chirostyloidea (Decapoda: Anomura) has been poorly understood owing to limited taxon sampling and discordance between different genes. We present a nine-gene dataset across 15 chirostyloids, including all known yeti crabs (Kiwaidae), to improve the resolution of phylogenetic affinities within and between the different families, and to date key divergences using fossil calibrations. This study supports the monophyly of Chirostyloidea and, within this, a basal split between Eumunididae and a Kiwaidae-Chirostylidae clade. All three families originated in the Mid-Cretaceous, but extant kiwaids and most chirostylids radiated from the Eocene onwards. Within Kiwaidae, the basal split between the seep-endemic Kiwa puravida and a vent clade comprising Kiwa hirsuta and Kiwa spp. found on the East Scotia and Southwest Indian ridges is compatible with a hypothesized seep-to-vent evolutionary trajectory. A divergence date estimate of 13.4-25.9 Ma between the Pacific and non-Pacific lineages is consistent with Kiwaidae spreading into the Atlantic sector of the Southern Ocean via the newly opened Drake Passage. The recent radiation of Kiwaidae adds to the list of chemosynthetic fauna that appear to have diversified after the Palaeocene/Eocene Thermal Maximum, a period of possibly widespread anoxia/dysoxia in deep-sea basins.
Geiselbrecht, Hannes; Melzer, Roland R
The mandibles of decapod zoea-I larvae are robustly built masticating mouthparts equipped with several processes and spines. Superficial examination of these sturdy, inflexible structures can suggest that they are lacking sensory receptors. However, detailed TEM analysis of their ultrastructure revealed up to 11 sensillar cell clusters on the gnathal edges of the mandibles of the zoea-I in Palaemon elegans Rathke, 1837. Based on ultrastructural criteria we distinguish 7 types of sensilla: mechanoreceptors, chemoreceptors and mechano- and chemoreceptors. One sensory unit located at the base of the 'lacinia mobilis' exhibits the typical features of a crustacean mechanosensitive sensillum with an external seta and corresponding ultrastructure. Another unit shows features indicating bimodal contact chemosensitivity. A third one is similar to known olfactory chemoreceptors. Using the concept of modality-specific structures we analyse the structure and functional morphology of each sensillum, and give a comprehensive overview of the sensory abilities of zoea mandibles. We take a closer look at the ultrastructure of the 'lacinia mobilis', providing further features to trace its evolutionary history in Decapoda, and thus contributing to a better understanding of malacostracan phylogeny.
Wang, Tai-Chuan; Nai, Yu-Shin; Wang, Chih-Yuan; Solter, Leellen F; Hsu, Hui-Chen; Wang, Chung-Hsiung; Lo, Chu-Fang
A new microsporidium was isolated from the endemic, Taiwanese shrimp, Caridina formosae (Decapoda, Atyidae) from northern Taiwan. A conspicuous symptom of infection was presence of opaque white xenomas located in the proximity of the alimentary tract, the surface of the hepatopancreas, and the gills. A fully developed xenoma consisted of a hard, thick capsule filled with sporophorous vesicles containing multiple spores. Microsporidia developed synchronously within the same sporophorous vesicle, although the stage of parasite development differed among the vesicles. Fresh spores were pyriform, mononucleated and measured 6.53 × 4.38 μm. The polar filament was anisofilar with 9-11 coils. Phylogenetic analysis based on the small subunit ribosomal DNA sequence showed that the isolate is most similar to the fish microsporidian clade containing the genera Kabatana, Microgemma, Potaspora, Spraguea, and Teramicra. The highest sequence identity, 80%, was with Spraguea spp. Based on pathogenesis, life cycle and phylogenetic analysis, we erect a new genus and species, Triwangia caridinae for the novel microsporidium.
On a New Species of Parasitic Barnacle (Crustacea: Rhizocephala), Sacculina shiinoi sp. nov., Parasitizing Japanese Mud Shrimps Upogebia spp. (Decapoda: Thalassinidea: Upogebiidae), Including a Description of a Novel Morphological Structure in the Rhizocephala.
Lützen, Jørgen; Itani, Gyo; Jespersen, Åse; Hong, Jae-Sang; Rees, David; Glenner, Henrik
The rhizocephalan Sacculina shiinoi sp. nov. parasitizes three species of Upogebia in Japan. It is described morphologically and compared with another Upogebia parasite, Sacculina upogebiae Shiino, 1943 from Japan and Korea. These two species are the only sacculinids that parasitize mud shrimps. DNA analyses clearly show the two species to be separate and not closely related. The cuticle differs in being provided with close-set, branched, and spiny excrescences in S. shiinoi, while it lacks excrescences, but forms small scales in S. upogebiae. In S. upogebiae, the bulbous sperm-producing part and the narrow receptacle duct are separated by a compartmentalized mid portion, which is missing in S. shiinoi. A ridge, having a thickened, fluffy cuticle with a U-shaped course, passes across the visceral mass between the two receptacle openings in S. shiinoi. Such a structure has never been described in other rhizocephalans, and its function is uncertain.
Calappid and leucosiid crabs (Crustacea: Decapoda: Brachyura) from Kerala, India, with the description of a new species of Mursia Desmarest, 1823, from the Arabian Sea and redescription of M. bicristimana Alcock & Anderson, 1894.
Kumar, Biju A; Kumar, M Sushil; Galil, Bella S
Eleven species of calappid and leucosiid crabs were identified from by-catch landed by trawlers at four fishing ports in Kerala, India that were surveyed in 2007 and supplemented by material obtained in January 2013. Four species are reported for the first time from India, six are new records for Kerala. The status of Mursia bicristimana Alcock & Anderson, 1894, is clarified and the species redescribed. A new species of Mursia is described from the Gulf of Aden, Arabian Sea.
First stage zoeal morphology of four ghost crabs Ocypode ceratophthalmus (Pallas, 1772), O. cordimanus Latreille, 1818, O. sinensis Dai, Song & Yang, 1985 and O. stimpsoni Ortmann, 1897 (Crustacea, Decapoda, Ocypodidae).
Jiang, Guo-Chen; Liu, Hong-Chang; Chan, Tin-Yam; Chan, Benny K K
Light and scanning electron microscopy (SEM) were used to examine the first zoeal stage of four ghost crabs, Ocypode ceratophthalmus (Pallas, 1772), O. cordimanus Latreille, 1818, O. sinensis Dai, Song & Yang, 1985 and O. stimpsoni Ortmann, 1897. Finding diagnostic characters to distinguish between the four species proved difficult because their setal appendage patterns were identical. However the rectangular and pockmarked patterns on the ventral carapace are rather pronounced in O. ceratophthalmus and O. stimpsoni but weak in O. cordimanus and O. sinensis. The spinulation on the furca of the telson is less in O. cordimanus than in the other three species.
De Forges, Bertrand Richer; Ng, Peter K L; Ahyong, Shane T
The inachid spider crab genus, Parapleisticantha Yokoya, 1933 [type species: Parapleisticantha japonica Yokoya, 1933] is removed from the synonymy of Pleistacantha Miers, 1879 [type species: Pleistacantha sanctijohannis Miers, 1879], and recognised as a valid genus. Parapleisticantha differs from Pleistacantha sensu stricto primarily by having a less spiny carapace, stouter and more inflated male chelipeds, and by lacking a slender subdistal process on the male first gonopod. We redescribe Parapleisticantha japonica based on the Japanese type material and describe as new a second species, Parapleisticantha ludivinae n. sp., recently discovered in the Philippines.
A new species of fiddler crab from the Ogasawara (Bonin) Islands, Japan, separated from the widely-distributed sister species Uca (Paraleptuca) crassipes (White, 1847) (Crustacea: Decapoda: Brachyura: Ocypodidae).
Shih, Hsi-Te; Komai, Tomoyuki; Liu, Min-Yun
A new species of fiddler crab (Brachyura: Ocypodidae), Uca boninensis sp. nov., is described from the Ogasawara (Bonin) Islands, Japan. The new species has previously been identified with the widely distributed U. crassipes (White, 1847), from which it differs by having a slightly differently shaped carapace, and relatively stouter male first gonopods (G1). The recognition of the new species is also supported by differences in the mitochondrial cytochrome oxidase I (COI) and control region (CR) genes. U. boninensis sp. nov., appears to be endemic to the Ogasawara Islands, and as the only known population is small, urgent conservation measures are needed for its protection. Our study brings the total number of the Japanese fiddler crab species to 12.
Lira, Simone Maria DE Albuquerque; Santana, Claudeilton Severino DE; Lima, Cynthia Dayanne Mello DE; Montes, Manuel DE Jesus Flores; Schwamborn, Ralf
The current biogeographic and taxonomic knowledge on decapod larvae in tropical oceans is still very incomplete, in spite of their huge ecological and socio-economic importance. The present study reports two new records for decapod larval forms in pelagic environments off oceanic islands in the western tropical Atlantic, and provides detailed diagnoses and images of these larvae. Samples were taken from July 2010 to November 2014 using neuston, bongo and WP-2 nets at three localities: St. Peter and St. Paul's Archipelago (SPSP), Rocas Atoll (RA) and Fernando de Noronha Archipelago (FN). The larval forms Cerataspis monstrosa (Gray, 1828) and Amphionides reynaudii (H. Milne Edwards, 1832) were recorded around these areas, constituting the first record for these oceanic islands. Out of 121 samples analyzed, one specimen of C. monstrosa (Mysis II) was found off FN, and 20 specimens of A. reynaudii in nine distinct stages (Mysis II, IV, VI, VII, VIII, IX, X, XI, XII) were found off SPSP, RA and FN.
A new subtidal species of the genus Petrolisthes Stimpson, 1858 (Crustacea: Decapoda: Porcellanidae) from Okinawa, with an account of species of the genus known from the Ryukyu Islands, southwestern Japan.
Osawa, Masayuki; Uyeno, Daisuke
A new porcellanid crab, Petrolisthes uruma sp. nov., is described based on a single specimen collected from Okinawajima Island in the Ryukyus, southwestern Japan. The unique holotype was collected from a subtidal depth of 10 m, though vast majority of the genus occur in intertidal to shallow subtidal zone. The new species is morphologically closest to P. noluccensis (De Man, 1888), but is distinguished by the weaker striation on the carapace, the proportionally longer carpus of the cheliped, the number of the anterior marginal teeth of the carpus of the cheliped, and the meri of the second and third pereopods each with a much stronger spine at the lateroventral distal angle. A brief note on species of Petrolisthes presently known from the Ryukyu Islands is given.
Komai, Tomoyuki; Higashiji, Takuo
Two species of the squat lobster genus Munida Leach, 1820, M. pollioculus n. sp. and M. zebra Macpherson, 1994, are recorded from deep-waters off Okinawa Islands, the Ryukyu Islands, at depths of 1000 m and 495 m, respectively. The new species closely resembles M. clevai Macpherson, 1999 and M. microps Alcock, 1894, but it differs from the latter two in the absence of a proximal spine on the mesial margin of the cheliped dactylus and the more stout dactylus of the second pereopod. Munida zebra is first recorded from the Northwest Pacific, as well as Japanese waters, with its geographical range extended to the north from the previously known southwestern Pacific localities.
Differentiation of three common deep-water hermit crabs (Crustacea, Decapoda, Anomura, Parapaguridae) from the South African demersal abundance surveys, including the description of a new species of Paragiopagurus Lemaitre, 1996
Landschoff, Jannes; Lemaitre, Rafael
Abstract Deep-water hermit crabs of the family Parapaguridae can be abundant (up to 20 kg or 1000 hermit crab individuals per haul) in the trawl bycatch collected during South African demersal abundance research surveys. Until recently, only two parapagurid species had been recognized in the bycatch; Parapagurus bouvieri Stebbing, 1910, and Sympagurus dimorphus (Studer, 1883). Detailed examination of numerous samples of parapagurid specimens from research surveys revealed the existence of a third, undescribed species previously confounded with S. dimorphus, but in fact belonging to a different genus. This new species, Paragiopagurus atkinsonae sp. n. is the 25th in the genus Paragiopagurus Lemaitre, 1996, and has been found only in a small region on the West Coast shelf of South Africa, at depths of 199–277 m. The species is herein fully described and illustrated, including colour images, µCT scans of selected body parts, and CO1 barcode data. The new species is morphologically most similar to P. ventilatus Lemaitre, 2004, a species associated with hydrothermal vents, but differs in armature of the fourth antennal segment (armed with a spine on the dorsolateral distal angle vs. unarmed in P. ventilatus); setation of the antennal flagella (nearly naked vs. with dense setae in P. ventilatus); plumose setation on the third maxillipeds and basal segments of chelipeds (absent vs. present in P. ventilatus); number of rows of scales on the propodal rasp of pereopod 4 (two or three rows vs. one row in P. ventilatus); and degree of telson asymmetry (weakly asymmetrical vs. strongly asymmetrical in P. ventilatus). Paragiopagurus atkinsonae sp. n. is superficially similar to S. dimorphus, with males of the two species showing the same extreme degree of sexual dimorphism on the right cheliped, general light orange colouration, and frequent use of colonial zoanthid carcinoecia for pleonal protection. To aid in future identifications and to facilitate data gathering during surveys, a comparison of P. atkinsonae sp. n. with S. dimorphus is provided, along with descriptions of colouration and photographs of live specimens of all three parapagurid species. Information on taxonomy of the species is summarized, as well as knowledge of their distribution in the demersal research survey regions of South Africa. PMID:28769685
Three species of the pagurid hermit crab genus Catapaguroides A. Milne-Edwards & Bouvier, 1892, all from Japanese waters, are reported. Catapaguroides fragilis (Melin, 1939) is redescribed on the basis of the holotype and additional material from southern Japan. Diagnostic characters of this poorly known species are fully assessed. Two new species, C. bythos and C. rubromaculatus, are described and illustrated on the basis of material from upper bathyal depths off the Ryukyu Islands. Catapaguroides rubromaculatus n. sp. resembles C. fragilis and C. hirsutus Komai & Rahayu, 2013, but the characteristic shape of the ocular peduncle and the elongate male right sexual tube with an anteriorly directed distal portion readily separate C. rubromaculatus n. sp. from the latter two congeners. Catapaguroides bythos n. sp. appears close to C. mortenseni de Saint Laurent, 1968 and C. pectinipes (Lewinsohn, 1969), but the different armature of the chelipeds distinguishes C. bythos n. sp. from the latter two allies. Catapaguroides is now represented by 30 species.
Salgado-Barragán, José; Ayón-Parente, Manuel; Hendrickx, Michel E
A new species of Leptalpheus is described from Estero Pérula, Jalisco, on the Pacific coast of Mexico. Leptalpheus corderoae sp. nov. is most similar to Leptalpheus azuero Anker, 2011 from Panama and Leptalpheus axianassae Dworschak & Coelho, 1999 from Brazil, differing from both of them by a combination of morphological characters, especially the presence of tubercles on the ventral surface of the major chela palm and pollex. The most common host of L. corderoae sp. nov. at the type locality is the callianassid ghost shrimp Lepidophthalmus bocourti (A. Milne Edwards, 1870). Additional specimens of Leptalpheus mexicanus Ríos & Carvacho, 1983, from Estero de Urías, Sinaloa, are reported and compared to the type material from Río Mulegé, as well as to Leptalpheus bicristatus Anker, 2011 from Panama. Finally, Leptalpheus hendrickxi Anker, 2011 is reported from Mexico for the first time, representing a significant northward range extension of the species. In Estero Pérula, L. hendrickxi lives in burrows of Lepidophthalmus bocourti, sometimes together with L. corderoae sp. nov.
Colavite, Jessica; Santana, William; Tavares, Marcos
Stenocionops furcatus (Olivier, 1791) and S. coelatus (A. Milne-Edwards, 1878) have been treated either as subspecies or as species in their own right, but never as each other's synonyms. Compared to S. coelatus, S. furcatus has been regarded as having smoother dorsal surface carapace, shorter rostral spines, straighter and less divergent rostrum. and smaller interorbital width. These morphological differences between the two species, however, can be attributed to changes over ontogeny and, therefore, cannot be used as distinguishing characters. Adults of S. coelatus and S. furcatus can, however, be safely separated from each other by the presence in S. coelatus of a strong crenation on the anterior margin of the male sterno-abdominal cavity, which is absent in S. furcatus. A lectotype for S. coelatus is designated. The synonymy between S. furcatus, Cancer cornudo Herbst, 1804, and Chorinus armatus Randall, 1839, is confirmed based on the holotypes of the latter two species.
Discrete phenotypes are not underpinned by genome-wide genetic differentiation in the squat lobster Munida gregaria (Crustacea: Decapoda: Munididae): a multi-marker study covering the Patagonian shelf.
Wang, Chen; Agrawal, Shobhit; Laudien, Jürgen; Häussermann, Vreni; Held, Christoph
DNA barcoding has demonstrated that many discrete phenotypes are in fact genetically distinct (pseudo)cryptic species. Genetically identical, isogenic individuals, however, can also express similarly different phenotypes in response to a trigger condition, e.g. in the environment. This alternative explanation to cryptic speciation often remains untested because it requires considerable effort to reject the hypothesis that the observed underlying genetic homogeneity of the different phenotypes may be trivially caused by too slowly evolving molecular markers. The widespread squat lobster Munida gregaria comprises two discrete ecotypes, gregaria s. str. and subrugosa, which were long regarded as different species due to marked differences in morphological, ecological and behavioral traits. We studied the morphometry and genetics of M. gregaria s. l. and tested (1) whether the phenotypic differences remain stable after continental-scale sampling and inclusion of different life stages, (2) and whether each phenotype is underpinned by a specific genotype. A total number of 219 gregaria s. str. and subrugosa individuals from 25 stations encompassing almost entire range in South America were included in morphological and genetic analyses using nine unlinked hypervariable microsatellites and new COI sequences. Results from the PCA and using discriminant functions demonstrated that the morphology of the two forms remains discrete. The mitochondrial data showed a shallow, star-like haplotype network and complete overlap of genetic distances within and among ecotypes. Coalescent-based species delimitation methods, PTP and GMYC, coherently suggested that haplotypes of both ecotypes forms a single species. Although all microsatellite markers possess sufficient genetic variation, AMOVA, PCoA and Bayesian clustering approaches revealed no genetic clusters corresponding to ecotypes or geographic units across the entire South-American distribution. No evidence of isolation-by-distance could be detected for this species in South America. Despite their pronounced bimodal morphologies and different lifestyles, the gregaria s. str. and subrugosa ecotypes form a single, dimorphic species M. gregaria s. l.. Based on adequate geographic coverage and multiple independent polymorphic loci, there is no indication that each phenotype may have a unique genetic basis, leaving phenotypic plasticity or localized genomic islands of speciation as possible explanations.
Differentiation of three common deep-water hermit crabs (Crustacea, Decapoda, Anomura, Parapaguridae) from the South African demersal abundance surveys, including the description of a new species of Paragiopagurus Lemaitre, 1996.
Landschoff, Jannes; Lemaitre, Rafael
Deep-water hermit crabs of the family Parapaguridae can be abundant (up to 20 kg or 1000 hermit crab individuals per haul) in the trawl bycatch collected during South African demersal abundance research surveys. Until recently, only two parapagurid species had been recognized in the bycatch; Parapagurus bouvieri Stebbing, 1910, and Sympagurus dimorphus (Studer, 1883). Detailed examination of numerous samples of parapagurid specimens from research surveys revealed the existence of a third, undescribed species previously confounded with S. dimorphus, but in fact belonging to a different genus. This new species, Paragiopagurus atkinsonaesp. n. is the 25(th) in the genus Paragiopagurus Lemaitre, 1996, and has been found only in a small region on the West Coast shelf of South Africa, at depths of 199-277 m. The species is herein fully described and illustrated, including colour images, µCT scans of selected body parts, and CO1 barcode data. The new species is morphologically most similar to P. ventilatus Lemaitre, 2004, a species associated with hydrothermal vents, but differs in armature of the fourth antennal segment (armed with a spine on the dorsolateral distal angle vs. unarmed in P. ventilatus); setation of the antennal flagella (nearly naked vs. with dense setae in P. ventilatus); plumose setation on the third maxillipeds and basal segments of chelipeds (absent vs. present in P. ventilatus); number of rows of scales on the propodal rasp of pereopod 4 (two or three rows vs. one row in P. ventilatus); and degree of telson asymmetry (weakly asymmetrical vs. strongly asymmetrical in P. ventilatus). Paragiopagurus atkinsonaesp. n. is superficially similar to S. dimorphus, with males of the two species showing the same extreme degree of sexual dimorphism on the right cheliped, general light orange colouration, and frequent use of colonial zoanthid carcinoecia for pleonal protection. To aid in future identifications and to facilitate data gathering during surveys, a comparison of P. atkinsonaesp. n. with S. dimorphus is provided, along with descriptions of colouration and photographs of live specimens of all three parapagurid species. Information on taxonomy of the species is summarized, as well as knowledge of their distribution in the demersal research survey regions of South Africa.
A new species of the pagurid hermit crab genus Lophopagurus McLaughlin, 1981 (Crustacea: Decapoda: Anomura) from French Polynesia, and additional record of L. indonesiensis McLaughlin, 1997 from the Philippines.
Komai, Tomoyuki; Rahayu, Dwi Listyo
Two species of the pagurid hermit crab genus Lophopagurus McLaughlin, 1981 are reported herein. Lophopagurus (Lophopagurus) minimus n. sp., described on the basis of two females from Tuamotu Archipelago, French Polynesia, appears closest to L. (L.) nanus (Henderson, 1888), but is easily distinguished from the latter by the different shape of the ocular peduncles and the less developed armature of the right cheliped. A single female from the Bohol Sea, the Philippines, is identified with L. (Australeremus) indonesiensis McLaughlin, 1997, a species for which possible synonymy with L. (A.) triserratus has been suggested. The newly collected specimen confirms the validity of the species and represents its second record since the original description.
Komai, Tomoyuki; Saito, Yuma; Myorin, Eiji
A new species of hermit crab of the family Paguridae, Pagurus rectidactylus, is described and illustrated on the basis of material from inshore waters in the Seto Inland Sea and the Sea of Japan. It appears closest to P. quinquelineatus Komai, 2003, also known from Japan, but is easily distinguished from the latter by the dactylus of the right cheliped almost unarmed or armed only with a few tiny spines or tubercles, instead of dorsal and dorsomesial rows of conspicuous spines, and the more elongate and slender ambulatory legs with more numerous ventral corneous spines on dactyli and propodi. Housing is also different between the two species: the new species exclusively inhabits carcinoecia formed by a hydrozoan Stylactaria misakiensis (Iwasa, 1934), whereas P. quinquelineatus uses gastropod shells without association with coelenterates. A checklist of East Asian (Japanese Archipelago to Taiwan Island, Far Eastern Russia to northern China) species of Pagurus along with general geographical distributions is presented.
"Symmetrical" hermit crabs of the family Pylochelidae (Crustacea: Decapoda: Anomura) collected by the "BIOPAPUA" and "PAPUA NIUGINI" expeditions in the Papua New Guinea, with descriptions of two new species.
Komai, Tomoyuki; Chan, Tin-Yam
Collections made during the recent expeditions to Papua New Guinea ("BIOPAPUA", 2010; "PAPUA NIUGINI", 2012) yielded a total of 12 species from the "symmetrical" hermit crab family Pylochelidae, including two new to science: Bathycheles incisus (Forest, 1987), B. integer (Forest, 1987), Cheiroplatea laticauda Boas, 1926, C. pumicicola Forest, 1987, C. rotundioculus n. sp., Pylocheles mortensenii Boas, 1926, and Xylocheles macrops (Forest, 1987) (Pylochelinae); Parapylocheles scorpio (Alcock, 1894), Trizocheles manningi Forest, 1987, T. moosai Forest, 1987, T. sakaii Forest, 1987, and T. spinidigitus n. sp. (Trizochelinae). Affinities of the two new species are discussed. Parapylocheles scorpio, Trizocheles manningi and T. sakaii are recorded from the South Pacific for the first time. Revised identification keys to species of Cheiroplatea and Trizocheles are provided.
Correct date and authorship of taxa of Middle American freshwater crabs described by Rodríguez & Smalley (1972) (not 1969) and included in Smalley (1970) (Crustacea: Decapoda: Brachyura: Pseudothelphusidae).
Guinot, Danièle; Hendrickx, Michel E
One subgenus and one genus of Pseudothelphusidae described by Gilberto Rodríguez and Alfred E. Smalley from Mexico have been erroneously referred to for over 40 years as variously described in 1968 and 1969. The review of the original publication indicates that these taxa were published in a journal dated 1969 that became available for distribution only in 1972. Smalley (1970), who believed that the original manuscript had been previously published, referred to some of these new taxa (i.e., Epithelphusa, E. mixtepensis, Tehuana and T. veracruzana) and provided sufficient information to make these names available in 1970, thus becoming the correct authorship for these four taxa. Therefore they must be referred to as "Rodríguez & Smalley in Smalley 1970". A list of all affected taxa with the correct publication date and authorship is given. A list of publications in which the taxa authored by Rodríguez and Smalley were erroneously referred to as published in 1969 is also provided.
Ng, Peter K L; Rahayu, Dwi Listyo
The taxonomy of the Indo-West Pacific aphanodactylid crabs Selwynia sibogae (Tesch, 1918) and S. edmondsoni (Rathbun, 1932) is discussed on the basis of the types, and both species are redescribed and figured. Two new species from Papua New Guinea and French Polynesia respectively, are described and compared with congeners. All are symbionts in polychaete tubes. A key to the genus Selwynia is also provided. The poorly known genus Gandoa Kammerer, 2006, is redescribed on the basis of the rediscovered the type species, Voeltzkowia zanzibarensis Lenz, 1905. The lectotype female of Pinnixa brevipes H. Milne Edwards, 1853, is examined and shown to be a senior subjective synonym of G. zanzibarensis.
Copepods play a critical role in marine ecosystems but have been poorly investigated in phylogenetic studies. Morphological evidence supports the monophyly of copepods, whereas interordinal relationships continue to be debated. In particular, the phylogenetic position of the order Harpacticoida is still ambiguous and inconsistent among studies. Until now, a small number of molecular studies have been done using only a limited number or even partial genes and thus there is so far no consensus at the order-level. This study attempted to resolve phylogenetic relationships among and within four major copepod orders including Harpacticoida and the phylogenetic position of Copepoda among five other crustacean groups (Anostraca, Cladocera, Sessilia, Amphipoda, and Decapoda) using 24 nuclear protein-coding genes. Phylogenomics has confirmed the monophyly of Copepoda and Podoplea. However, this study reveals surprising differences with the majority of the copepod phylogenies and unexpected similarities with postembryonic characters and earlier proposed morphological phylogenies; More precisely, Cyclopoida is more closely related to Siphonostomatoida than to Harpacticoida which is likely the most basally-branching group of Podoplea. Divergence time estimation suggests that the origin of Harpacticoida can be traced back to the Devonian, corresponding well with recently discovered fossil evidence. Copepoda has a close affinity to the clade of Malacostraca and Thecostraca but not to Branchiopoda. This result supports the hypothesis of the newly proposed clades, Communostraca, Multicrustacea, and Allotriocarida but further challenges the validity of Hexanauplia and Vericrustacea. The first phylogenomic study of Copepoda provides new insights into taxonomic relationships and represents a valuable resource that improves our understanding of copepod evolution and their wide range of ecological adaptations.
Hyžný, Matúš; Gross, Martin
A new fossil species of the iphiculid genus Iphiculus Adams & White, 1849, (Crustacea, Brachyura) is described on the basis of three specimens from the Middle Miocene Florian Beds of Styria, Austria. Iphiculus eliasi sp. nov. constitutes the first European record of the genus. This occurrence represents the oldest record of Iphiculus, having implications for the palaeobiogeographic history of the family Iphiculidae. It is suggested that Iphiculus may have originated in the Western Tethys and migrated subsequently into the Indo-West Pacific. Alternatively, its current geographic restriction to the Indo-West Pacific can be a remnant of an ancient broader geographic distribution. PMID:27811673
Hyžný, Matúš; Gross, Martin
A new fossil species of the iphiculid genus Iphiculus Adams & White, 1849, (Crustacea, Brachyura) is described on the basis of three specimens from the Middle Miocene Florian Beds of Styria, Austria. Iphiculus eliasi sp. nov. constitutes the first European record of the genus. This occurrence represents the oldest record of Iphiculus, having implications for the palaeobiogeographic history of the family Iphiculidae. It is suggested that Iphiculus may have originated in the Western Tethys and migrated subsequently into the Indo-West Pacific. Alternatively, its current geographic restriction to the Indo-West Pacific can be a remnant of an ancient broader geographic distribution.
MacIsaac, K. G.; Kenchington, T. J.; Kenchington, E. L. R.; Best, M.
We describe the trawl-vulnerable crustacean micronekton and macrozooplankton of the Gully, a large, shelf-incising submarine canyon off Nova Scotia, Canada, and a Marine Protected Area. Over 68 species of pelagic crustacea were collected with an International Young Gadoid Pelagic Trawl during three annual summer surveys at one fixed station in the canyon. Depths sampled ranged from the surface to the upper bathypelagic zone, concentrated in the upper 1250 m, with a maximum depth of 1500 m. The crustacean fauna was dominated by cold temperate species typical of mid- to higher-latitudes in the North Atlantic. Meganyctiphanes norvegica and Eusergestes arcticus were particularly dominant in terms of both observed biomass and abundance above 750 m depth. At least 17 species were new records for Canadian waters. The species assemblage of the station varied primarily with depth and diel cycle, the only dominant members of the assemblage showing pronounced inter-annual variations in catch being M. norvegica and Themisto gaudichaudii, both relatively shallow living species.
Jeffery, Nicholas W; Elías-Gutiérrez, Manuel; Adamowicz, Sarah J
The region of Churchill, Manitoba, contains a wide variety of habitats representative of both the boreal forest and arctic tundra and has been used as a model site for biodiversity studies for nearly seven decades within Canada. Much previous work has been done in Churchill to study the Daphnia pulex species complex in particular, but no study has completed a wide-scale survey on the crustacean species that inhabit Churchill's aquatic ecosystems using molecular markers. We have employed DNA barcoding to study the diversity of the Branchiopoda (Crustacea) in a wide variety of freshwater habitats and to determine the likely origins of the Churchill fauna following the last glaciation. The standard animal barcode marker (COI) was sequenced for 327 specimens, and a 3% divergence threshold was used to delineate potential species. We found 42 provisional and valid branchiopod species from this survey alone, including several cryptic lineages, in comparison with the 25 previously recorded from previous ecological works. Using published sequence data, we explored the phylogeographic affinities of Churchill's branchiopods, finding that the Churchill fauna apparently originated from all directions from multiple glacial refugia (including southern, Beringian, and high arctic regions). Overall, these microcrustaceans are very diverse in Churchill and contain multiple species complexes. The present study introduces among the first sequences for some understudied genera, for which further work is required to delineate species boundaries and develop a more complete understanding of branchiopod diversity over a larger spatial scale.
Glenner, Henrik; Hebsgaard, Martin Bay
The barnacles (Crustacea, Cirripedia) consist of three well-defined orders: the conventional filter-feeding barnacles (Thoracica), the burrowing barnacles (Acrothoracica), and the parasitic barnacles (Rhizocephala). Thoracica and Acrothoracica feed by catching food particles from the surrounding seawater using their thoracic appendages while members of Rhizocephala are exclusively parasitic. The parasite consists of a sac-shaped, external reproductive organ situated on the abdomen of its crustacean host and a nutrient-absorbing root system embedded into the heamolymph of the host. In order to resolve the phylogenetic relationship of the order Rhizocephala and elucidate the evolution of the different life history strategies found within the Rhizocephala, we have performed the first comprehensive phylogenetic analysis of the group. Our results indicate that Rhizocephala is monophyletic with a filter-feeding barnacle-like ancestor. The host-infective stage, the kentrogon larva, inserted in the lifecycle of the rhizocephalan suborder, Kentrogonida, is shown to be ancestral and most likely a homologue of the juvenile stage of a conventional thoracican barnacle. The mode of host inoculation found in the suborder Akentrogonida, where the last pelagic larval stage directly injects the parasitic material into the heamolymph of the host is derived, and has evolved only once within the Rhizocephala. Lastly, our results show that the ancestral host for extant rhizocephalans appears to be the anomuran crustaceans (Anomura), which includes hermit crabs and squat lobsters.
Oda, Shigeto; Tatarazako, Norihisa; Watanabe, Hajime; Morita, Masatoshi; Iguchi, Taisen
We exposed the water flea Daphnia magna (Cladocera, Crustacea) to either juvenile hormone I (JH I), juvenile hormone II (JH II), or the juvenile hormone-mimicking insecticides kinoprene, hydroprene, epofenonane, or fenoxycarb. By 21-day reproduction tests, we investigated the effects on the number of neonates born per female and the offspring sex ratio. All six chemicals induced D. magna to produce male neonates; the male sex ratio of the offspring increased as the chemical concentration increased. EC50 values for production of male neonates were estimated as 400 (JH I), 410 (JH II), 190 (kinoprene), 2.9 (hydroprene), 64 (epofenonane), and 0.92 (fenoxycarb) microg/l. The number of neonates produced was reduced with all chemicals at the concentrations investigated. At the EC50 for male production, five of the six chemicals reduced the reproductive rate to less than 50%; the exception was epofenonane, which caused only a slight reduction in reproductive rate. These results were similar to those obtained for five juvenoids studied previously, one of which was studied here again. There are now 10 chemical substances--all juvenile hormones or their analogs-that are known to induce D. magna to produce male neonates. This suggests that juvenile hormone is involved in initiating male production followed by sexual reproduction in D. magna, and probably in most cladocerans that exhibit cyclic parthenogenesis.
Introduction Within arthropods, several crustacean groups are unique in their early development due to their stereotyped cell division patterns and cell lineages. However, it is still unclear whether these cell division patterns are homologous between the various crustacean groups and whether they could indicate the ground pattern of Tetraconata (Crustacea and Hexapoda). In this study we describe the early development of the raptorial water flea Bythotrephes longimanus as a representative of the Cladocera within branchiopods. Results In B. longimanus the early cell lineage and the cell division pattern are stereotyped up to the fifth cell division cycle. As a morphological marker a nurse cell remnant (ncr) identifies the cell lineage of the smallest and division delayed blastomere up to the 16-cell stage. This marker might be indicative of the germ line. By combining histology, confocal laser scanning microscopy, and 4D microscopy, we reconstruct the early cell lineage and cell division pattern and follow transient formations of cell morphological structures in their temporal and spatial behavior up to gastrulation. Conclusions Correspondences to the early cleavage pattern of other Cladocera suggest that the described pattern can be assumed to be ancestral for either the entire Cladocera or for the majority of the Cladocera comprising Anomopoda, Ctenopoda and Onychopoda. The comparison to the cell division patterns of other crustacean groups such as Malacostraca, Ostracoda, and Copepoda reveals similarities that allow for a discussion of a common pattern for the crustacean groups and a ground pattern for the Tetraconata. PMID:24507018
Jeffery, Nicholas W.; Elías-Gutiérrez, Manuel; Adamowicz, Sarah J.
The region of Churchill, Manitoba, contains a wide variety of habitats representative of both the boreal forest and arctic tundra and has been used as a model site for biodiversity studies for nearly seven decades within Canada. Much previous work has been done in Churchill to study the Daphnia pulex species complex in particular, but no study has completed a wide-scale survey on the crustacean species that inhabit Churchill's aquatic ecosystems using molecular markers. We have employed DNA barcoding to study the diversity of the Branchiopoda (Crustacea) in a wide variety of freshwater habitats and to determine the likely origins of the Churchill fauna following the last glaciation. The standard animal barcode marker (COI) was sequenced for 327 specimens, and a 3% divergence threshold was used to delineate potential species. We found 42 provisional and valid branchiopod species from this survey alone, including several cryptic lineages, in comparison with the 25 previously recorded from previous ecological works. Using published sequence data, we explored the phylogeographic affinities of Churchill's branchiopods, finding that the Churchill fauna apparently originated from all directions from multiple glacial refugia (including southern, Beringian, and high arctic regions). Overall, these microcrustaceans are very diverse in Churchill and contain multiple species complexes. The present study introduces among the first sequences for some understudied genera, for which further work is required to delineate species boundaries and develop a more complete understanding of branchiopod diversity over a larger spatial scale. PMID:21610864
Briggs, Derek E. G.; Sutton, Mark D.; Siveter, David J.; Siveter, Derek J.
A new three-dimensionally preserved arthropod, Cinerocaris magnifica, from the Wenlock Series (Silurian) of Herefordshire, UK, is described and assigned to the Phyllocarida (Crustacea). The description and reconstruction are based on specimens that have been serially ground, reconstructed by computer and rendered in three dimensions as coloured virtual models. Cinerocaris magnifica displayed the tagmosis characteristic of phyllocarids, with eight thoracic and seven abdominal somites, terminating in a telson with furca. The remarkable preservation of the appendages makes this the earliest completely known malacostracan crustacean. Two pairs of antennae (the first with two flagella) were followed by a mandible and first maxilla, each with a slender palp-like ramus. The second maxilla consisted of a limb stem with endites and an endopod that tapered distally. There was no exopod. The thoracopods comprised a limb stem with six or seven endites, an arrangement previously known only in entomostracans, and an endopod with about five endites. Flap-like outer rami correspond to an exopod and epipods. The pleopods bore two long slender oar-blade-like rami. Cladistic analysis places C. magnifica as a plesion within the Echinocaridina. It provides critical evidence of the limb morphology of an early malacostracan, which will be important in understanding crustacean evolution. PMID:15058388
An, Jianmei; Boyko, Christopher B; Li, Xinzheng
Three species of the parasitic isopod genus Minicopenaeon Bourdon, 1981 (Crustacea: Isopoda: Bopyridae) are reported from China, one new to science and two new records from mainland China. Minicopenaeon crosnieri (Bourdon, 1979) formerly known from Madagascar, the Philippines and Taiwan, is recorded from Zhejiang province. Minicopenaeon intermedium Bourdon, 1981 previously recorded from the Philippines and Japan, is recorded from China for the first time. The new species Minicopenaeon liuruiyui n. sp. is recorded from the East and South China Seas. As with other species of the genus, females of the new species have rudimentary coxal plates on the second pereomeres on the short side. The new species can be distinguished from other species by the presence of a widely open brood pouch, head with bilobate anterior edge and median concave groove, and male head with curved posterior margin of the pleon. A key to species of Minicopenaeon is provided and the subspecies M. intermedium curvatum Bourdon, 1981 is synonymised with M. intermedium Bourdon, 1981. Metapenaeopsis philippii (Bate, 1881) and M. coniger (Wood-Mason, 1891) are newly recorded as host species for bopyrids.
Martínez-Díaz, José Luis; Aguillón-Martínez, Martha Carolina; Luque, Javier; Vega, Francisco J.
New decapod specimens from mid-Paleocene shallow marine deposits of NE Mexico represents an important addition to the diversity, paleobiogeography and evolution of the Crustacea record. In this work, we describe additions to the decapod assemblage from the Paleocene (Selandian) Rancho Nuevo Formation (Difunta Group, Parras Basin, Coahuila). Due to the evident size differences with other decapod assemblages, we compare the new assemblage with those from the Lower Paleocene (Danian) Mexia Clay Member of the Wills Point Formation, Texas, and the Lower Eocene (Ypresian) El Bosque Formation in Chiapas. Species reported from the mid-Paleocene (Selandian) assemblage of the Porters Creek Formation (Alabama), are correlatable to the decapod species from NE Mexico in age, size and systematic composition. The erymid lobster Enoploclytia gardnerae (Rathbun, 1935) is represented by several carapaces and chelae remains. One isolated palm of Callianassidae is included. Numerous carapaces of Linuparus wilcoxensis Rathbun, 1935 are described, representing the most abundant lobster. A new record for the raninid Notopoides sp., and presence of Quasilaeviranina sp. cf. arzignagnensis and Quasilaeviranina ovalis are here reported. New raninids, Claudioranina latacantha sp. nov. and Claudioranina sp. (Cyrtorhininae) are also part of this assemblage. Paraverrucoides alabamensis (Rathbun, 1935), and Tehuacana americana (Rathbun, 1935) are represented by several carapaces exhibiting intraspecific morphological variation. Different sizes among the Early and Middle Paleocene and Early Eocene decapod populations suggests a possible effect of variation in seawater temperatures and/or a Lilliput effect after the K/Pg event.
Law, R J; Kelly, C A; Baker, K L; Langford, K H; Bartlett, T
Concentrations of polycyclic aromatic hydrocarbons have been determined in sediments, mussels and crustacea in the vicinity of a former gasworks site by Shoreham Harbour, UK. Very high concentrations of PAH were found in the substrate, an ash-like material deposited on the former gasworks site, which exhibited a profile consistent with the major source of contamination being coal or coke tar produced during the period of gas production at the site. Elevated PAH concentrations were also found in mussels both from the beach below the former gasworks site, and from sites further to the east in Portslade and Hove. The significance of these concentrations were assessed using an approach which involved the calculation of benzo[a]pyrene equivalent conoentrations (BaPEs), summing concentrations of individual PAH on the basis of their comparative potency as carcinogens. BaPE ranged from values of, or close to, zero for crustacea, to 336 microg kg(-1) wet weight in mussels from Southwick Beach. The contaminated mussels are not exploited commercially but may be taken by casual gatherers, and notices have been posted to warn potential consumers.
Kramer, Michael J.; Bellwood, David R.; Taylor, Richard B.; Bellwood, Orpha
Tropical and temperate marine habitats have long been recognised as fundamentally different system, yet comparative studies are rare, particularly for small organisms such as Crustacea. This study investigates the ecological attributes (abundance, biomass and estimated productivity) of benthic Crustacea in selected microhabitats from a tropical and a temperate location, revealing marked differences in the crustacean assemblages. In general, microhabitats from the tropical location (dead coral, the epilithic algal matrix [algal turfs] and sand) supported high abundances of small individuals (mean length = 0.53 mm vs. 0.96 mm in temperate microhabitats), while temperate microhabitats (the brown seaweed Carpophyllum sp., coralline turf and sand) had substantially greater biomasses of crustaceans and higher estimated productivity rates. In both locations, the most important microhabitats for crustaceans (per unit area) were complex structures: tropical dead coral and temperate Carpophyllum sp. It appears that the differences between microhabitats are largely driven by the size and relative abundance of key crustacean groups. Temperate microhabitats have a higher proportion of relatively large Peracarida (Amphipoda and Isopoda), whereas tropical microhabitats are dominated by small detrital- and microalgal-feeding crustaceans (harpacticoid copepods and ostracods). These differences highlight the vulnerability of tropical and temperate systems to the loss of complex benthic structures and their associated crustacean assemblages.
Frigotto, S F; Marochi, M Z; Masunari, S
A study on the relative growth of the crab Acantholobulus schmitti (Rathbun, 1930) (Decapoda, Brachyura, Panopeidae) was performed with allometric techniques. The species is associated with lanterns used for oyster farming at Guaratuba Bay, southern Brazil. Crabs were obtained from five lanterns from March through December 2009. The following morphological characteristics were measured: the carapace width (CW), the height and length of the major cheliped propodus (LPH and LPL), the width of the female abdomen at the base of the 4th somite (AW) and the length of the male gonopod (GL). A total of 1,004 individuals of A. schmitti were measured, of which 451 were males, 323 non-ovigerous females and 230 ovigerous females. The CW of the males varied from 1.87 to 11.86 mm, that of non-ovigerous females from 1.44 to 8.77 mm and that of ovigerous females from 4.09 to 11.12 mm. The plot of LPH against CW showed a mean inflection point at 3.67 mm CW for the males. This result indicated that male crabs are juvenile below this value and adult above it. For the females, the corresponding inflection point occurred at 3.36 mm CW in the plot of AW against CW. These results, CW x LPH and CW x AW, highlight the importance of chelae enlargement at the onset of maturation in males. Similarly, the widening of the abdomen in females is required to accommodate egg clutches during the reproductive period. Heterochely was recorded in both sexes. Right-handed crabs were more frequent than left-handed ones, with percentages of 75.8% in males and 82.7% in females. The population of A. schmitti from Guaratuba Bay becomes sexually mature at an earlier age than A. schmitti from the coast of São Paulo state. The lanterns used in oyster farming furnish a safe habitat in which these crabs can spend their entire benthic life.
Letessier, Tom B.; De Grave, Sammy; Boersch-Supan, Philipp H.; Kemp, Kirsty M.; Brierley, Andrew S.; Rogers, Alex D.
Maintenance of often-observed elevated levels of pelagic diversity and biomass on seamounts, of relevance to conservation and fishery management, involves complex interactions between physical and biological variables that remain poorly understood. To untangle these biophysical processes we explore factors influencing the distribution of epi- and meso-pelagic (0-1000 m) micronektonic crustaceans (>15 mm; order Lophogastridea, family Gnathophausiidea; and order Decapoda) on and off seamounts along the South West Indian Ridge (SWIR, 27° to 42°S) and on a seamount off the Madagascar Ridge (31.6°S, 42.8°E). Thirty-one species of micronektic crustaceans were caught using mid-water trawls within the study area but there was no apparent latitude-related patterns in species richness or abundance. Species richness predicted by rarefraction curves and numerical abundance was highest in the vicinity (<1 km) of seamounts (species richness: 15 to 21; abundance: 10±2 to 20±1 ind.10-3 m-1) compared with over the abyssal plains and ridge slopes (species richness: 9.2-9.9; abundance: 24±2 to 79±8 ind.10-3 m-1). Multivariate analysis of assemblage composition revealed significant groupings of individual trawl samples with respect to whether the sample was on or off a seamount and hydrographic region, but not with time of sampling relative to diel cycle (day/night or dawn) or depth of sampling (0-500, 500-800, >800 m). The dominant species assemblage comprised the shrimps Systellaspis debilis (37%) and Sergia prehensilis (34%), and was restricted to seamounts on the subtropical SWIR. Our observations suggest that the 'oasis effect' of seamounts conventionally associated with higher trophic levels is also applicable to pelagic micronektic crustaceans at lower trophic levels. We suggest that the enhanced biomass and species richness attributed is due to 'habitat enrichment', whereby seamounts provide favourable habitats for both pelagic and bentho-pelagic mid-water crustaceans.
Piednoël, Mathieu; Bonnivard, Eric
the first time a widespread distribution of these elements among a large phylum, here the order Decapoda. They also suggest some peculiar features of these retrotransposons in hydrothermal organisms where a great diversity of elements is already observed. Finally, this paper constitutes the first essential step which allows for considering further studies based on the dynamics of the DIRS1-like retrotransposons among several genomes. PMID:19400949
Badano, Ernesto I; Labra, Fabio A; Martínez-Pérez, Cecilia G; Vergara, Carlos H
Ecologists have been largely interested in the description and understanding of the power scaling relationships between body size and abundance of organisms. Many studies have focused on estimating the exponents of these functions across taxonomic groups and spatial scales, to draw inferences about the processes underlying this pattern. The exponents of these functions usually approximate -3/4 at geographical scales, but they deviate from this value when smaller spatial extensions are considered. This has led to propose that body size-abundance relationships at small spatial scales may reflect the impact of environmental changes. This study tests this hypothesis by examining body size spectra of benthic shrimps (Decapoda: Caridea) and snails (Gastropoda) in the Tamiahua lagoon, a brackish body water located in the Eastern coast of Mexico. We mea- sured water quality parameters (dissolved oxygen, salinity, pH, water temperature, sediment organic matter and chemical oxygen demand) and sampled benthic macrofauna during three different climatic conditions of the year (cold, dry and rainy season). Given the small size of most individuals in the benthic macrofaunal samples, we used body volume, instead of weight, to estimate their body size. Body size-abundance relationships of both taxonomic groups were described by tabulating data from each season into base-2 logarithmic body size bins. In both taxonomic groups, observed frequencies per body size class in each season were standardized to yield densities (i.e., individuals/m(3)). Nonlinear regression analyses were separately performed for each taxonomic group at each season to assess whether body size spectra followed power scaling functions. Additionally, for each taxonomic group, multiple regression analyses were used to determine whether these relationships varied among seasons. Our results indicated that, while body size-abundance relationships in both taxonomic groups followed power functions, the parameters
Speiser, Daniel I; Lampe, Rebecca I; Lovdahl, Valerie R; Carrillo-Zazueta, Brenna; Rivera, Ajna S; Oakley, Todd H
Sexual dimorphisms have long drawn the attention of evolutionary biologists. However, we still have much to learn about the evolutionary, genetic, and developmental drivers of sexual dimorphisms. Here, we introduce ostracods of the genus Euphilomedes (Myodocopida, Ostracoda, and Crustacea) as a promising new system in which to investigate why and how sexual dimorphisms evolve. First, we ask whether male-skewed selective pressure from pelagic predators may help explain a dramatic sexual dimorphism in which male Euphilomedes have compound eyes, but females do not. Manipulative experiments demonstrate that blindfolding reduces the survival rate of male Euphilomedes when they are exposed to predatory fish. Blindfolding of the female rudimentary eyes (rudiments) does not, however, similarly influence the survival rate of brooding females. Further, numerical estimates of sighting distances, based on reasonable extrapolations from Euphilomedes's eye morphology, suggest that the eyes of male Euphilomedes are useful for detecting objects roughly the size of certain pelagic predators, but not conspecifics. We conclude that eyes do not mediate direct interactions between male and female Euphilomedes, but that differences in predation pressure-perhaps associated with different reproductive behaviors-contribute to maintaining the sexually dimorphic eyes of these ostracods. Second, through transcriptome sequencing, we examined potential gene regulatory networks that could underlie sexual dimorphism in Euphilomedes' eyes. From the transcriptome of juvenile male Euphilomedes' eyes, we identified phototransduction genes and components of eye-related developmental networks that are well characterized in Drosophila and other species. The presence of suites of eye regulatory genes in our Euphilomedes juvenile male transcriptome will allow us, in future studies, to test how ostracods regulate the development of their sexually dimorphic eyes.
Drobne, Damjana; Blazic, Mateja; Van Gestel, Cornelis A M; Leser, Vladka; Zidar, Primoz; Jemec, Anita; Trebse, Polonca
Imidacloprid is a neonicotinoid insecticide with neurotoxic action that, as a possible alternative for commonly used organophosphorus pesticides, has gained registration in about 120 countries for use in over 140 agricultural crops. Only few data are available on its toxicity for soil invertebrates. We therefore assessed the effects of imidacloprid on survival, weight gain, feeding rate, total protein content, glutathione S-transferase activity (GST), and digestive gland epithelial thickness in juveniles and adults of the terrestrial isopod Porcellio scaber. After two weeks of feeding on imidacloprid-dosed food, weight gain (NOEC 5 microg/g dry food) and feeding rate (NOEC 10 microg/g) in juveniles, and feeding rate (NOEC<10 microg/g) and digestive gland epithelial thickness (NOEC<10 microg/g) in adults were most affected. In juveniles induction of GST activity and increase of total protein content per wet animal weight was detected at 5 microg/g dry food, whereas in adults a reduction of GST was observed at 25 microg/g (NOEC 10 microg/g). An estimate of actual intake rates suggests that imidacloprid affects isopods at similar exposure concentrations as insects. The toxicity of imidacloprid was similar to that of the organophosphorus pesticide diazinon, tested earlier using the same methods [Stanek, K., Drobne, D., Trebse, P., 2006. Linkage of biomarkers along levels of biological complexity in juvenile and adult diazinon fed terrestrial isopod (Porcellio scaber, Isopoda, Crustacea). Chemosphere 64, 1745-1752]. At actual environmental concentrations, diazinon poses a higher risk to P. scaber. Due to its increasing use in crop protection and higher persistence in soil, imidacloprid might however, be potentially more dangerous after long-term application. We conclude that toxicity testing with P. scaber provides relevant, repeatable, reproducible and comparable toxicity data that is useful for the risk assessment of pesticides in the terrestrial environment.
Messina, Giuseppina; Cazzolla Gatti, Roberto; Droutsa, Angeliki; Barchitta, Martina; Pezzino, Elisa; Agodi, Antonella; Lombardo, Bianca Maria
Biological diversity analysis is among the most informative approaches to describe communities and regional species compositions. Soil ecosystems include large numbers of invertebrates, among which soil bugs (Crustacea, Isopoda, Oniscidea) play significant ecological roles. The aim of this study was to provide advices to optimize the sampling effort, to efficiently monitor the diversity of this taxon, to analyze its seasonal patterns of species composition, and ultimately to understand better the coexistence of so many species over a relatively small area. Terrestrial isopods were collected at the Natural Reserve "Saline di Trapani e Paceco" (Italy), using pitfall traps monthly monitored over 2 years. We analyzed parameters of α- and β-diversity and calculated a number of indexes and measures to disentangle diversity patterns. We also used various approaches to analyze changes in biodiversity over time, such as distributions of species abundances and accumulation and rarefaction curves. As concerns species richness and total abundance of individuals, spring resulted the best season to monitor Isopoda, to reduce sampling efforts, and to save resources without losing information, while in both years abundances were maximum between summer and autumn. This suggests that evaluations of β-diversity are maximized if samples are first collected during the spring and then between summer and autumn. Sampling during these coupled seasons allows to collect a number of species close to the γ-diversity (24 species) of the area. Finally, our results show that seasonal shifts in community composition (i.e., dynamic fluctuations in species abundances during the four seasons) may minimize competitive interactions, contribute to stabilize total abundances, and allow the coexistence of phylogenetically close species within the ecosystem.
Sonakowska, Lidia; Włodarczyk, Agnieszka; Wilczek, Grażyna; Wilczek, Piotr; Student, Sebastian; Rost-Roszkowska, Magdalena Maria
The endodermal region of the digestive system in the freshwater shrimp Neocaridina heteropoda (Crustacea, Malacostraca) consists of a tube-shaped intestine and large hepatopancreas, which is formed by numerous blind-ended tubules. The precise structure and ultrastructure of these regions were presented in our previous studies, while here we focused on the cell death processes and their effect on the functioning of the midgut. We used transmission electron microscopy, light and confocal microscopes to describe and detect cell death, while a quantitative assessment of cells with depolarized mitochondria helped us to establish whether there is the relationship between cell death and the inactivation of mitochondria. Three types of the cell death were observed in the intestine and hepatopancreas-apoptosis, necrosis and autophagy. No differences were observed in the course of these processes in males and females and or in the intestine and hepatopancreas of the shrimp that were examined. Our studies revealed that apoptosis, necrosis and autophagy only involves the fully developed cells of the midgut epithelium that have contact with the midgut lumen-D-cells in the intestine and B- and F-cells in hepatopancreas, while E-cells (midgut stem cells) did not die. A distinct correlation between the accumulation of E-cells and the activation of apoptosis was detected in the anterior region of the intestine, while necrosis was an accidental process. Degenerating organelles, mainly mitochondria were neutralized and eventually, the activation of cell death was prevented in the entire epithelium due to autophagy. Therefore, we state that autophagy plays a role of the survival factor.
Sonakowska, Lidia; Włodarczyk, Agnieszka; Wilczek, Grażyna; Wilczek, Piotr; Student, Sebastian; Rost-Roszkowska, Magdalena Maria
The endodermal region of the digestive system in the freshwater shrimp Neocaridina heteropoda (Crustacea, Malacostraca) consists of a tube-shaped intestine and large hepatopancreas, which is formed by numerous blind-ended tubules. The precise structure and ultrastructure of these regions were presented in our previous studies, while here we focused on the cell death processes and their effect on the functioning of the midgut. We used transmission electron microscopy, light and confocal microscopes to describe and detect cell death, while a quantitative assessment of cells with depolarized mitochondria helped us to establish whether there is the relationship between cell death and the inactivation of mitochondria. Three types of the cell death were observed in the intestine and hepatopancreas–apoptosis, necrosis and autophagy. No differences were observed in the course of these processes in males and females and or in the intestine and hepatopancreas of the shrimp that were examined. Our studies revealed that apoptosis, necrosis and autophagy only involves the fully developed cells of the midgut epithelium that have contact with the midgut lumen–D-cells in the intestine and B- and F-cells in hepatopancreas, while E-cells (midgut stem cells) did not die. A distinct correlation between the accumulation of E-cells and the activation of apoptosis was detected in the anterior region of the intestine, while necrosis was an accidental process. Degenerating organelles, mainly mitochondria were neutralized and eventually, the activation of cell death was prevented in the entire epithelium due to autophagy. Therefore, we state that autophagy plays a role of the survival factor. PMID:26844766
Stegner, Martin E J; Brenneis, Georg; Richter, Stefan
Cephalocarida are Crustacea with many anatomical features that have been interpreted as plesiomorphic with respect to crustaceans or Tetraconata. While the ventral nerve cord (VNC) has been investigated in many other arthropods to address phylogenetic and evolutionary questions, the few studies that exist on the cephalocarid VNC date back 20 years, and data pertaining to neuroactive substances in particular are too sparse for comparison. We reinvestigated the VNC of adult Hutchinsoniella macracantha in detail, combining immunolabeling (tubulin, serotonin, RFamide, histamine) and nuclear stains with confocal laser microscopy, complemented by 3D-reconstructions based on serial semithin sections. The subesophageal ganglion in Cephalocarida comprises three segmental neuromeres (Md, Mx1, Mx2), while a separate ganglion occurs in all thoracic segments and abdominal segments 1-8. Abdominal segments 9 and 10 and the telson are free of ganglia. The maxillar neuromere and the thoracic ganglia correspond closely in their limb innervation pattern, their pattern of mostly four segmental commissures and in displaying up to six individually identified serotonin-like immunoreactive neurons per body side, which exceeds the number found in most other tetraconates. Only two commissures and two serotonin-like immunoreactive neurons per side are present in abdominal ganglia. The stomatogastric nervous system in H. macracantha corresponds to that in other crustaceans and includes, among other structures, a pair of lateral neurite bundles. These innervate the gut as well as various trunk muscles and are, uniquely, linked to the unpaired median neurite bundle. We propose that most features of the cephalocarid ventral nerve cord (VNC) are plesiomorphic with respect to the tetraconate ground pattern. Further, we suggest that this ground pattern includes more serotonin-like neurons than hitherto assumed, and argue that a sister-group relationship between Cephalocarida and Remipedia, as
Ashton, Gail V; Stevens, Mark I; Hart, Mark C; Green, David H; Burrows, Michael T; Cook, Elizabeth J; Willis, Kate J
Caprella mutica (Crustacea, Amphipoda) has been widely introduced to non-native regions in the last 40 years. Its native habitat is sub-boreal northeast Asia, but in the Northern Hemisphere, it is now found on both coasts of North America, and North Atlantic coastlines of Europe. Direct sequencing of mitochondrial DNA (cytochrome c oxidase subunit I gene) was used to compare genetic variation in native and non-native populations of C. mutica. These data were used to investigate the invasion history of C. mutica and to test potential source populations in Japan. High diversity (31 haplotypes from 49 individuals), but no phylogeographical structure, was identified in four populations in the putative native range. In contrast, non-native populations showed reduced genetic diversity (7 haplotypes from 249 individuals) and informative phylogeographical structure. Grouping of C. mutica populations into native, east Pacific, and Atlantic groups explained the most among-region variation (59%). This indicates independent introduction pathways for C. mutica to the Pacific and Atlantic coasts of North America. Two dominant haplotypes were identified in eastern and western Atlantic coastal populations, indicating several dispersal routes within the Atlantic. The analysis indicated that several introductions from multiple sources were likely to be responsible for the observed global distribution of C. mutica, but the pathways were least well defined among the Atlantic populations. The four sampled populations of C. mutica in Japan could not be identified as the direct source of the non-native populations examined in this study. The high diversity within the Japan populations indicates that the native range needs to be assessed at a far greater scale, both within and among populations, to accurately assess the source of the global spread of C. mutica.
Csonka, Diána; Halasy, Katalin; Hornung, Elisabeth
Abstract The marsupium, a brood pouch in peracarid crustaceans (Crustacea, Malacostraca) has evolved in terrestrial environment for providing nutrition and optimal conditions for embryogenesis. In the present study we give details on the histology and ultrastructure of its constituting elements such as oostegites and cotyledons. Marsupia of two different eco-morphological types of woodlice, namely the non-conglobating species Trachelipus rathkii Brandt, 1833 and the conglobating species Cylisticus convexus De Geer, 1778 were investigated. Light microscopic (LM) studies showed some differences in the main structure of the two species’ brood pouch: in Trachelipus rathkii, a ‘clinger’ type woodlice, the oostegites bend outwards during brood incubation as growing offspring require more space, while in Cylisticus convexus, a ‘roller’ type isopod, the sternites arch into the body cavity to ensure space for developing offspring and still allowing conglobation of the gravid females. The quantitative analysis of the oostegites’ cuticle proved that the outer part is about 2.5 - 3 times thicker compared to the inner part in both species. Electron microscopic (TEM) examinations show only small histological differences in the oostegites and cotyledon structure of the two species. Cellular elements and moderately electron dense fleecy precipitate are found in the hemolymph space between the two cuticles of oostegites. The cells contain PAS positive polysaccharide areas. TEM studies revealed some differences in the cotyledon ultrastructure of the two species. Cotyledons of Trachelipus rathkii consist of cells with cristate mitochondria and granular endoplasmic reticulum with cisterns. Cotyledons of Cylisticus convexus consist of cells with densely cristate mitochondria and ribosomes attached to vesicular membrane structures. In both species cells with electron dense bodies were observed. We conclude that - besides the differences in marsupial shapes - the fine
Ren, Xian-qiu; Sha, Zhong-li
A total of 5 species of the genus Kamaka (Crustacea: Amphipoda) are identified from Hainan Province, South China Sea. In those, one species, Kamaka excavata Ariyama, 2007, is recorded for the first time in Chinese waters. Two new species, Kamaka corophina sp. n. and Kamaka foliacea sp. n., are described. A key to the Chinese species is provided. They were collected from littoral zone, mud flat in seaweed of mangrove side, brackish water and seawater, sifted out with sieve.
Harzsch, S; Walossek, D
In the discussion on arthropod phylogeny, the structural evolution of compound eyes and optic ganglia in Crustacea and Insecta is an important topic. On the one hand, many morphological features as well as developmental aspects of the visual system in Insecta and Crustacea correspond in so much detail that eye design in these two groups is likely to have a common euarthropodan ancestor. On the other hand, however, some authors advocate a convergent evolution of the crustacean and insect visual system founding their arguments on differences in the arrangement of the visual neuropils and the fibre connections between Malacostraca and Entomostraca (the "entomostracan enigma"). Therefore, information about cellular aspects of visual system formation in entomostracan Crustacea is likely to enliven this debate, but is not yet available. To fill this gap, we examined the proliferation of neuronal stem cells in the developing visual system of the tadpole shrimp Triops longicaudatus (LeConte, 1846) (Entomostraca, Branchiopoda, Phyllopoda, Calmanostraca, Notostraca) by in vivo incorporation of the proliferation marker bromodeoxyuridine and subsequent immunohistochemical detection. Our results indicate that in the developing visual system of T. longicaudatus, three band-shaped zones containing neuronal stem cells are present corresponding to the proliferation zones found in Malacostraca. We therefore conclude that the ontogenetic mechanisms of visual-system formation are evolutionarily conserved (homologous) in Branchiopoda, Malacostraca, and Insecta.
Ahn, Dong-Ha; Min, Gi-Sik; Park, Joong-Ki; Kim, Sanghee
The complete mitochondrial genome (mitogenome) of the red-banded lobster, Metanephrops thomsoni (Decapoda, Astacidea, Nephropidae), is 19,835 bp in length and contains 13 protein-coding genes (PCGs), 2 ribosomal RNAs, 24 transfer RNAs (including additional copies of trnW and trnL1), and 2 control regions (CR). The mitogenome of M. thomsoni has 10 long intergenic sequences (71-237 bp) with a high AT content (70.0%). The two CRs show 59.6% similarity and have an identical sequence region with a length of 295 bp. The mitogenome of M. thomsoni shows a novel gene arrangement compared with the pancrustacean ground pattern and is identical to that of M. sibogae, except for the two additional tRNAs (trnW and trnL1). Phylogenetic tree from maximum likelihood analysis using the concatenated sequences of 13 PCGs depicted M. thomsoni as one of the members of the superfamily Nephropoidea within Astacidea.
Geiselbrecht, Hannes; Melzer, Roland R
The external and internal structures of adult Neomysis integer mandibles were studied using light and electron microscopy with special reference to the lacinia mobilis, a highly specialized appendage on the gnathal edge of many crustaceans. The right and left lacinia mobilis are equipped with ciliary primary sensory cells revealing that both laciniae are also mechanosensory organs in addition to their mechanical function during mastication. A detailed character analyses indicated that the right lacinia is probably a highly derived sensory seta, whereas two alternative interpretations are considered for the left lacinia; it could be a sensillar appendage equipped with two mechanosensory units, or it could be a movable appendage of the incisor process containing two sensilla deprived of external appendages. The ecdysis of the lacinia mobilis corresponds very well to type I sensillar ecdysis, suggesting classification as a sensillar appendage. These features support a possible homology of the right lacinia mobilis in Peracarida and Decapoda, tracing them to an origin as a member of the setal row. Whether the left lacinia mobilis is a sensillum or an appendage with sensilla cannot be resolved presently.
Ogoh, Katsunori; Ohmiya, Yoshihiro
The primary structure of the mitochondrial genome of the bioluminescent crustacean, Vargula hilgendorfii, the sea-firefly (Arthropoda, Crustacea, Ostracoda), has sequenced using the transposon Tn5. The genome (15,923 bp) contains the same 37 genes (two ribosomal RNAs, 22 transfer RNAs, and 13 protein-coding genes) found in other Arthropoda. Interestingly, duplicate control regions (fragments of 778 and 855 bp) and triplicate short repeat sequences (fragments of 49 bp) occur. The AT composition of the protein-coding genes is lower than the published complete mitochondrial genomes within the Arthropoda. For gene arrangement, 13 transfer RNA genes and two protein-coding genes have moved and inserted directly or inversely relative to the typical Arthropoda order.
The transition from marine to freshwater habitats is one of the major steps in the evolution of life. In the decapod crustaceans, four groups have colonized fresh water at different geological times since the Triassic, the freshwater shrimps, freshwater crayfish, freshwater crabs and freshwater anomurans. Some families have even colonized terrestrial habitats via the freshwater route or directly via the sea shore. Since none of these taxa has ever reinvaded its environment of origin the Decapoda appear particularly suitable to investigate life-history adaptations to fresh water. Evolutionary comparison of marine, freshwater and terrestrial decapods suggests that the reduction of egg number, abbreviation of larval development, extension of brood care and lecithotrophy of the first posthatching life stages are key adaptations to fresh water. Marine decapods usually have high numbers of small eggs and develop through a prolonged planktonic larval cycle, whereas the production of small numbers of large eggs, direct development and extended brood care until the juvenile stage is the rule in freshwater crayfish, primary freshwater crabs and aeglid anomurans. The amphidromous freshwater shrimp and freshwater crab species and all terrestrial decapods that invaded land via the sea shore have retained ocean-type planktonic development. Abbreviation of larval development and extension of brood care are interpreted as adaptations to the particularly strong variations of hydrodynamic parameters, physico-chemical factors and phytoplankton availability in freshwater habitats. These life-history changes increase fitness of the offspring and are obviously favoured by natural selection, explaining their multiple origins in fresh water. There is no evidence for their early evolution in the marine ancestors of the extant freshwater groups and a preadaptive role for the conquest of fresh water. The costs of the shift from relative r- to K-strategy in freshwater decapods are traded
Schnurr, Sarah; Brandt, Angelika; Brix, Saskia; Fiorentino, Dario; Malyutina, Marina; Svavarsson, Jörundur
The Greenland-Scotland Ridge (GSR) is a major topographic feature, extending from Greenland to Scotland. It constrains the water exchange between the northernmost North Atlantic Ocean and the Greenland, Iceland and Norwegian Seas (GIN Seas) and thus forms a potential barrier for faunal exchange from the Arctic to the North Atlantic (and vice versa). Recently an increase in Atlantic water inflow has been observed, leading to changes in physical parameters (i.e. temperature and salinity), which may have an impact on the resident fauna. In this study, we analyzed the composition and distribution of six selected genera of the isopod family Munnopsidae (Crustacea) occurring north and south of the GSR. We examined 82 epibenthic sledge samples and 26 additional sub-samples taken in the course of the Benthic Invertebrates of Icelandic Waters (BIOICE) and Icelandic Marine Animals: Genetics and Ecology (IceAGE) projects, respectively, covering a total depth range from 103 to 2752 m depth. Overall, 58 of the evaluated stations originated in the area north of the GSR, while the remaining 50 samples were collected south of the ridge. In total, 10517 individuals could be assigned to 15 species, most belonging to the genus EurycopeSars, 1864. Due to the presence of the GSR as well as differences in the environment, we expected significant dissimilarities in faunal composition between the two study areas. However, most species (8) occurred on both sides of the ridge, while four species were restricted to the region north of Iceland, and three to the region south of the ridge. Depth (or factors related to depth) appeared to be the most important factor in driving distributional patterns of the studied species. Temperature was also an important driver, but not to the same extent as depth. On the contrary, salinity and sediment type did not have much influence on munnopsid distribution patterns. Hence, the presence of the ridge does not restrict faunal exchange between the northern
de Faria, Samuel Coelho; Augusto, Alessandra Silva; McNamara, John Campbell
We investigate extra- and intracellular osmoregulatory capability in two species of hololimnetic Caridea and Anomura: Macrobrachium brasiliense, a palaemonid shrimp, and Aegla franca, an aeglid anomuran, both restricted to continental waters. We also appraise the sharing of physiological characteristics by the hololimnetic Decapoda, and their origins and role in the conquest of fresh water. Both species survive salinity exposure well. While overall hyperosmoregulatory capability is weak in A. franca and moderate in M. brasiliense, both species strongly hyporegulate hemolymph [Cl(-)] but not osmolality. Muscle total free amino acids (FAA) increase slowly but markedly in response to the rapid rise in hemolymph osmolality consequent to hyperosmotic challenge: 3.5-fold in A. franca and 1.9-fold in M. brasiliense. Glycine, taurine, arginine, alanine and proline constitute ≈85% of muscle FAA pools in fresh water; taurine, arginine, alanine each contribute ≈22% in A. franca, while glycine predominates (70%) in M. brasiliense. These FAA also show the greatest increases on salinity challenge. Muscle FAA titers correlate strongly (R = 0.82) with hemolymph osmolalities across the main decapod sub/infraorders, revealing that marine species with high hemolymph osmolalities achieve isosmoticity of the intra- and extracellular fluids partly through elevated intracellular FAA concentrations; freshwater species show low hemolymph osmolalities and exhibit reduced intracellular FAA titers, consistent with isosmoticity at a far lower external osmolality. Given the decapod phylogeny adopted here and their multiple, independent invasions of fresh water, particularly by the Caridea and Anomura, our findings suggest that homoplastic strategies underlie osmotic and ionic homeostasis in the extant freshwater Decapoda.
Olesen, Jørgen; Haug, Joachim T; Maas, Andreas; Waloszek, Dieter
The species-poor meiofaunal Cephalocarida have played an important role in discussions of the phylogeny and evolution of Crustacea since their discovery in 1955. One reason may be that the morphology of cephalocarids includes some aspects of putatively ancient appearance, such as the simple roof-shaped head shield, the anterior three head appendages resembling those of a nauplius larva, or the trunk-limb-like second maxilla. Cephalocarida have even been suggested to represent the sister taxon to all other Eucrustacea. Presence of possibly plesiomorphic characters, however, does not necessarily point to a basal position in the system. Growing evidence demonstrates that the modification of the fourth post-antennular cephalic appendage, the 'maxilla', into a "mouth part" may have occurred independently in the different eucrustacean lineages, so a trunk-limb-like maxilla is an ancient feature that does not hold only for cephalocarids. Retention of its plesiomorphic shape and function in the Cephalocarida remains, however, noteworthy. Cephalocarids are still little studied and incompletely known, especially their external morphology. By examining several adults and one young specimen of Lightiella monniotae Cals and Delamare Deboutteville, 1970 from New Caledonia, we aimed to a) document as many details as possible, and b) compare these data with other species of Cephalocarida. We also aimed to reconstruct aspects of the ground pattern of Cephalocarida, which is a pre-requisite for any comparisons in a broader perspective of crustacean phylogeny. Among the new findings or conclusions are: (1) Lightiella is in need of a revision since several assumed differences between the species are questionable or subject to intra-specific variability; (2) the cuticle of the trunk-limb basipod is sub-divided into a number of smaller sclerotized areas as in various exceptionally 3D preserved fossil crustaceans from Cambrian 'Orsten' faunal assemblages; (3) a small transitional portion
Exceptionally well-preserved giant spermatozoa in male and female specimens of an ostracod Cypria ophtalmica (Crustacea: Ostracoda) from Late Glacial lacustrine sediments of Southern Carpathians, Romania.
Iepure, Sanda; Namiotko, Tadeusz; Valdecasas, Antonio G; Magyari, Enikö K
Exceptionally well-preserved giant spermatozoa observed between abundant decalcified carapace valves of ostracods (Crustacea: Ostracoda) were found in Late Glacial to Holocene (14,400 to 10,000 cal years BP) lacustrine sediments in the southern Romanian Carpathians. Analysis by scanning electron microscopy and laser scanning confocal microscopy revealed good preservation of the appendages enabling specific identification as Cypria ophtalmica (Candonidae) and indication of the presence of both female and male specimens based on the sexual dimorphism of the second antenna. This record represents the oldest and richest direct evidence of virtually morphologically unaltered animal spermatozoa preserved in females after mating.
Exceptionally well-preserved giant spermatozoa in male and female specimens of an ostracod Cypria ophtalmica (Crustacea: Ostracoda) from Late Glacial lacustrine sediments of Southern Carpathians, Romania
Iepure, Sanda; Namiotko, Tadeusz; Valdecasas, Antonio G.; Magyari, Enikö K.
Exceptionally well-preserved giant spermatozoa observed between abundant decalcified carapace valves of ostracods (Crustacea: Ostracoda) were found in Late Glacial to Holocene (14,400 to 10,000 cal years bp) lacustrine sediments in the southern Romanian Carpathians. Analysis by scanning electron microscopy and laser scanning confocal microscopy revealed good preservation of the appendages enabling specific identification as Cypria ophtalmica (Candonidae) and indication of the presence of both female and male specimens based on the sexual dimorphism of the second antenna. This record represents the oldest and richest direct evidence of virtually morphologically unaltered animal spermatozoa preserved in females after mating.
Włodarczyk, Agnieszka; Sonakowska, Lidia; Kamińska, Karolina; Marchewka, Angelika; Wilczek, Grażyna; Wilczek, Piotr; Student, Sebastian; Rost-Roszkowska, Magdalena
The midgut in the freshwater shrimp Neocaridina davidi (previously named N. heteropoda) (Crustacea, Malacostraca) is composed of a tube-shaped intestine and a large hepatopancreas that is formed by numerous blind-ended tubules. The precise structure and ultrastructure of these regions were presented in our previous papers, while here we focused on the ultrastructural changes that occurred in the midgut epithelial cells (D-cells in the intestine, B- and F- cells in the hepatopancreas) after long-term starvation and re-feeding. We used transmission electron microscopy, light and confocal microscopes and flow cytometry to describe all of the changes that occurred due to the stressor with special emphasis on mitochondrial alterations. A quantitative assessment of cells with depolarized mitochondria helped us to establish whether there is a relationship between starvation, re-feeding and the inactivation/activation of mitochondria. The results of our studies showed that in the freshwater shrimp N. davidi that were analyzed, long-term starvation activates the degeneration of epithelial cells at the ultrastructural level and causes an increase of cells with depolarized (non-active) mitochondria. The process of re-feeding leads to the gradual regeneration of the cytoplasm of the midgut epithelial cells; however, these changes were observed at the ultrastructural level. Additionally, re-feeding causes the regeneration of mitochondrial ultrastructure. Therefore, we can state that the increase in the number of cells with polarized mitochondria occurs slowly and does not depend on ultrastructural alterations. PMID:28282457
Vicente, Carlos San; Frutos, Inmaculada; Cartes, Joan E
A new species of the genus Petalophthalmus (Crustacea: Mysida: Petalophthalmidae) is described, based on specimens collected from the Galicia Bank (northeastern Atlantic Ocean). This species can be distinguished from the other species of the genus Petalophthalmus by the presence of an ocular papilla on its eyes. P. papilloculatus sp. nov. is morphologically close to the cosmopolitan species P. armiger Willemoes-Suhm, 1875, but can be easily distinguished by the presence of an ocular papilla, the longer antennal scales bearing an apical lobe, the unique chitinous ridge on the molar process, the outwards lengthening of the three cuspidate setae on the outer margin of the uropodal exopod and the armature of the telson. This new species lives on fine and very fine sandy bottoms at the bank flanks, between 1536 and 1809 m depths. Probably related to the special biogeographic characteristics of seamounts, the morphological affinity between the new species and P. armiger supports the hypothesis on a common ancestry and recent divergence between both deep sea mysids. An identification key to world species of Petalophthalmus is provided.
Novak, Sara; Drobne, Damjana; Menard, Anja
Abstract Nanoparticles of titanium dioxide are one of most widely used nanomaterials in different products in everyday use and in industry, but very little is known about their effects on non- target cells and tissues. Terrestrial isopods were exposed to food dosed with nano-TiO2 to give final nominal concentration 1000 and 2000 µg TiO2/g dry weight of food. The effects of ingested nano-TiO2 on the model invertebrate Porcellio scaber (Isopoda, Crustacea) after short-term (3 and 7 days) and prolonged (14 and 28 days) dietary exposure was assessed by conventional toxicity measures such as feeding rate, weight change and mortality. Cell membrane destabilization was also investigated. No severe toxicity effects were observed after 3, 7, 14 or 28 days of dietary exposure to nano-TiO2, but some animals, particularly those exposed to lower concentrations of nanoparticles, had severely destabilized digestive cell membranes. It was concluded that strong destabilization of the cell membrane was sporadic, and neither concentration- nor time-related. Further research is needed to confirm this sporadic toxic effect of nanoparticles. PMID:22536113
Sousa, Francisco Diogo R; Elmoor-Loureiro, Lourdes M A; Panarelli, Eliana A
The main goal of this paper is to describe three new species of the genus Monospilus Sars, 1862 (Crustacea: Cladocera). Monospilus macroerosus sp. nov. differs from other species of the genus in several peculiar morphological traits, the most striking being the presence of a saw-shaped pecten of teeth on the postabdominal claw. This species inhabits semiterrestrial habitats (wet leaf litter on hydromorphic soil from gallery forest), exhibiting adaptations related to movement and food handling in this type of habitat. Monospilus brachyspinus sp. nov. inhabits truly aquatic habitats, where lives being associated with macrophytes and submerged leaves. It may be recognized by the postabdominal claw, which is armed with proximal spinulae modified in a short spine. In Monospilus sp., the proximal spinulae are modified in a long and slender spine. So far, Monospilus sp. occurs in southern South America, while Monospilus macroerosus sp. nov. and Monospilus brachyspinus sp. nov. occur in the Cerrado biome in Brazil, in the central portion of South America. Some conclusions about the conservation status of new species also are made.
Hanamura, Yukio; Siow, Ryon; Chee, Phaik-Ean
A year-round survey of the tropical shallow-water mysid Mesopodopsis orientalis (Tattersall, 1908) (Crustacea, Mysidacea) was conducted in the Merbok mangrove estuary, northwestern Peninsular Malaysia. The mysid formed dense aggregations at the river's edge close to the mangrove forest during the daytime, but very few were captured elsewhere in the estuary system. The sampled population was found in a wide range of salinities from 16 to 32, demonstrating broad euryhalinity, and the number of the catch at the littoral zone ranged from 11.8 to 2273 ind m -2. The overall annual mean was 709.2 ind m -2. Females predominated over males in the entire population, and brooding females were present at every monthly sample, indicating that reproduction is continuous year round. The clutch size positively correlated with female body length. The diameter of eggs (Stage I embryos) was unaffected by the seasonality and independent of the maternal size within an observed size range. The life history pattern of the estuarine population of M. orientalis showed close similarity to that of the coastal counterpart. However, the former was found to produce fewer but larger eggs, and the specimens in this population were larger than those in the coastal population at the embryo, juvenile, and adult stages. This evidence indicates that the life history features of the estuarine population would differ to some degree from those of the coastal counterpart.
Franke, Robert; Hoerstgen-Schwark, Gabriele
Juvenile noble crayfish, Astacusastacus (Crustacea, Astacidea) in the second year of age were kept in the laboratory for a twelve-month period under continuing "summer conditions" (LD 16:8, 19°C). Molting processes in this population could be synchronized by artificial moonlight cycles. Peaks of exuviations occurred at "new moons". Males showed a slightly higher degree of synchronization than females. A phase-shift of the artificial lunar cycle in relation to the natural cycle resulted in a corresponding shift of the molting cycle. This clearly demonstrates that changes in the nocturnal light regime provide the primary external information for the lunar-monthly molting rhythm. There is a first indication that lunar photic stimuli do not act directly but as a zeitgeber which entrains an endogenous molting rhythm to the lunar cycle. Moreover, the results of the long-term experiments suggest that the hibernal resting period of A. astacus in the field (no molts between October and April) may also involve some endogenous programming. Continuing artificial summer conditions can delay but not completely suppress this resting period. The adaptive significance of the phenomena and how the findings may be applied to improve the management of crowded crayfish stocks are discussed.
Astall, C. M.; Taylor, A. C.; Atkinson, R. J. A.
Upogebia stellataand U. deltaura(Crustacea: Thalassinidea) construct burrows in nearshore sediments in U.K. waters. Burrow structure is similar in both species; the basic burrow consisting of a two-opening, U-shaped section with a vertical shaft descending from the mid-point of the U. This structure may be variously elaborated. Burrow cross-section is circular, dilations allow turning by somersaulting and surface openings are often constricted. Conditions within the burrows are usually hypoxic and hypercapnic. Burrow water PO 2in the parts normally occupied by the mud-shrimp was between 80-110 Torr, but was much lower (10-45 Torr) in the deepest, poorly-irrigated parts. Both species irrigate their burrows by episodes of pleopod beating of variable duration (mean=8·5±3·5 min and 2·8±0·5 min for U. deltauraand U. stellata, respectively), which draws oxygenated water into the burrow and also particulate food for suspension feeding. When exposed to hypoxia, U. deltauraand U. stellatawere able to maintain their rates of oxygen consumption approximately constant over a wide range of PO 2( Pc=30-50 Torr). Under these conditions, there was a pronounced increase in scaphognathite beat rate but heart rate remained relatively constant. Below the Pc, however, both rates declined.
Shen, Xin; Tsoi, Kwok-Ho; Cheang, Chi-Chiu
Balanus balanus Linnaeus, 1758, the model organism in the order Sessilia (Crustacea: Maxillopoda) is a cold water acorn barnacle in the family Balanidae distributing over the entire northern hemisphere. We present complete mitochondrial genome of this barnacle and analyze mitochondrial genomic characters of the family Balanidae. The length of mitochondrial genome is 15,955 bp, which is larger than those of the other barnacles in the same family. An inversion of a six-gene block (trnPro- nad4L- nad4- trnHis- nad5- trnPhe) is found between B. balanus and two Megabalanus (M. ajax and M. volcano). Three types of mitochondrial gene arrangements revealed in Balanidae have indicated the non-conserved gene orders even at intrafamilial level. Compared to pancrustacean ground pattern, large-scale gene rearrangements are found in B. balanus. Translocations of at least six tRNAs (trnAla, trnGlu/trnSer(AGY), trnPro/trnThr, trnLys, trnGln and trnCys) are identified and translocation and inversion occurred simultaneously in one tRNAs (trnTyr).
Yamaguchi, Tatsuhiko; Suzuki, Hisashi; Soe, Aung-Naing; Htike, Thaung; Nomura, Ritsuo; Takai, Masanaru
The ostracode genus Bicornucythere (Ostracoda, Crustacea) is abundant in modern-day eutrophic marine bays, and is widely distributed in estuaries and inner bays throughout East Asia, including in China, Korea, Japan, and the Russian Far East. The evolutionary history of Bicornucythere is poorly understood. Here, we report on a new species of Bicornucythere (Bicornucythere concentrica sp. nov.) from the upper Eocene Yaw Formation in the Central Myanmar Basin. The oldest previously known Bicornucythere taxon, Bicornucythere secedens, was reported from lower Miocene strata in India, although a molecular phylogeny suggests that the genus first appeared in the Late Cretaceous. Bicornucythere concentrica sp. nov. is at least 10.9 million years older than the earliest known B. secedens. The new species occurs with Ammonia subgranulosa, a benthic foraminifer, an association that is representative of brackish water conditions in modern Asian bays. Our findings indicate that extant genera have inhabited Asian bays since the late Eocene. The paleobiogeography of Bicornucythere indicates that the taxon was dispersed onto Indian coasts during the collision between the Indian and Eurasian plates.
Verslycke, Tim; De Wasch, Katia; De Brabander, Hubert F; Janssen, Colin R
Testosterone metabolism by Neomysis integer (Crustacea; Mysidacea) was assessed to obtain initial data on its metabolic capacity. N. integer were exposed to both testosterone and [(14)C]testosterone. Identification of testosterone metabolites and endogenous steroids was performed using thin-layer chromatography and liquid chromatography with multiple mass spectrometry. Endogenous production of testosterone in mysids was detected for the first time. N. integer were exposed to testosterone and metabolized administered testosterone extensively. At least 11 polar testosterone metabolites (R(f,metabolite) < R(f,testosterone)), androstenedione, dihydrotestosterone, and testosterone were produced in vivo by N. integer. A sex-specific testosterone metabolism was also observed, although this observation requires further confirmation. The anabolic steroid beta-boldenone was also identified for the first time in invertebrates. The metabolic pathway leading to the formation of beta-boldenone remains unknown, since the steroidal precursor androstadienedione could not be detected. These results reveal interesting similarities in enzyme systems in invertebrate and vertebrate species. Alterations in steroid hormone metabolism may be used as a new biomarker for the effects of endocrine disruptors in invertebrates.
Three new species of the Eriopisa group (Crustacea: Amphipoda: Eriopisidae) are described from coastal areas in Japan. Paraflagitopisa gen. nov. is established with P. excavata sp. nov. as its type species. This new genus is characterized by (1) entire lateral cephalic lobe, (2) unfused flagellum of antenna 2, (3) 3-articulated mandibular palp, (4) carpus of gnathopod 1 longer than propodus, (5) transverse palm of gnathopod 1, and (6) slender outer ramus of uropod 3 with long second article, and can be distinguished from the closely related genus, Flagitopisa, by the article 2 of mandibular palp longer than article 3, the undilated bases of pereopods 3-4, and the slender inner ramus of uropod 3. Psammogammarus lobatus sp. nov. is characterized by (1) male gnathopod 2 with excavated palm, (2) posterodistally projected bases of pereopods 5-7, (3) quadrate posteroventral corner of pleonal epimeron 3, (4) short inner ramus of uropod 3, and (5) article 2 of uropod 3 outer ramus longer than article 1. Victoriopisa wadai sp. nov. has the following characters: (1) eyes absent, (2) peduncle of antenna 1 not heavily setose, (3) accessory flagellum with 1-2 articles, (4) flagellum of antenna 2 composed of 2 long and 3 short articles, (5) gnathopod 2 in both sexes with excavated palm, (6) merus of pereopod 7 moderately expanded, and (7) ventral margin of pleonite 2 slightly setose. Key to species of the Eriopisa group in Japan is provided.
Lefébure, T; Douady, C J; Gouy, M; Gibert, J
With today's technology for production of molecular sequences, DNA taxonomy and barcoding arose as a new tool for evolutionary biology and ecology. However, their validities still need to be empirically evaluated. Of most importance is the strength of the correlation between morphological taxonomy and molecular divergence and the possibility to define some molecular thresholds. Here, we report measurements of this correlation for two mitochondrial genes (COI and 16S rRNA) within the sub-phylum Crustacea. Perl scripts were developed to ensure objectivity, reproducibility, and exhaustiveness of our tests. Our analysis reveals a general correlation between molecular divergence and taxonomy. This correlation is particularly high for shallow taxonomic levels allowing us to propose a COI universal crustacean threshold to help species delimitation. At higher taxonomic levels this correlation decreases, particularly when comparing different families. Those results plead for DNA use in taxonomy and suggest an operational method to help crustacean species delimitation that is linked to the phylogenetic species definition. This pragmatic tool is expected to fine tune the present classification, and not, as some would have believed, to tear it apart.
Guy, Martha; Singh, Lucina; Mineau, Pierre
The purpose of this study was to investigate how well single-species laboratory data predict real-world pesticide toxicity effects on Crustacea. Data from field pesticide exposures from experimental mesocosm and small pond studies were converted into toxicity units (TUs) by dividing measured pesticide concentrations by the L(E)C50 for Daphnia or acute 5% hazard concentration for Crustacea (HC5-C). The proportion of crustacean taxa significantly affected by the pesticide treatment, called the count ratio of effect, was used in logistic regression models. Of 200 possible logistic model combinations of the TUs, fate, physicochemical variables, and structural variables versus the count ratio of effect for the mesocosm data, the best model was found to incorporate log(TU HC5-C). This model was used to convert pesticide water quality guidelines from around the world into estimates of the proportion of crustacean taxa predicted to be impacted by exposure to a pesticide at the water quality guideline concentration. This analysis suggests 64% of long-term water quality guidelines and 88% of short-term pesticide water quality guidelines are not protective of the aquatic life they are designed to protect. We conclude that empirically derived data from mesocosm studies should be incorporated into water quality guideline derivation for pesticides where available. Also, interspecific differences in susceptibility should be accounted for more accurately to ensure water quality guidelines are adequately protective against the adverse effects of pesticide exposure.
Kreissl, S; Uber, A; Harzsch, S
In the hot debate on arthropod relationships, Crustaceans and the morphology of their appendages play a pivotal role. To gain new insights into how arthropod appendages evolved, developmental biologists recently have begun to examine the expression and function of Drosophila appendage genes in Crustaceans. However, cellular aspects of Crustacean limb development such as myogenesis are poorly understood in Crustaceans so that the interpretative context in which to analyse gene functions is still fragmentary. The goal of the present project was to analyse muscle development in Crustacean appendages, and to that end, monoclonal antibodies against arthropod muscle proteins were generated. One of these antibodies recognises certain isoforms of myosin heavy chain and strongly binds to muscle precursor cells in malacostracan Crustacea. We used this antibody to study myogenesis in two isopods, Porcellio scaber and Idotea balthica (Crustacea, Malacostraca, Peracarida), by immunohistochemistry. In these animals, muscles in the limbs originate from single muscle precursor cells, which subsequently grow to form multinucleated muscle precursors. The pattern of primordial muscles in the thoracic limbs was mapped, and results compared to muscle development in other Crustaceans and in insects.
Kreissl, S.; Uber, A.
In the hot debate on arthropod relationships, Crustaceans and the morphology of their appendages play a pivotal role. To gain new insights into how arthropod appendages evolved, developmental biologists recently have begun to examine the expression and function of Drosophila appendage genes in Crustaceans. However, cellular aspects of Crustacean limb development such as myogenesis are poorly understood in Crustaceans so that the interpretative context in which to analyse gene functions is still fragmentary. The goal of the present project was to analyse muscle development in Crustacean appendages, and to that end, monoclonal antibodies against arthropod muscle proteins were generated. One of these antibodies recognises certain isoforms of myosin heavy chain and strongly binds to muscle precursor cells in malacostracan Crustacea. We used this antibody to study myogenesis in two isopods, Porcellio scaber and Idotea balthica (Crustacea, Malacostraca, Peracarida), by immunohistochemistry. In these animals, muscles in the limbs originate from single muscle precursor cells, which subsequently grow to form multinucleated muscle precursors. The pattern of primordial muscles in the thoracic limbs was mapped, and results compared to muscle development in other Crustaceans and in insects. Electronic supplementary material The online version of this article (doi:10.1007/s00427-008-0216-1) contains supplementary material, which is available to authorized users. PMID:18443823
In this study, a molecular phylogenetic hypothesis for 16 species of serolid isopods (Crustacea, Isopoda, Serolidae) from Antarctic waters, the deep sea, South America, and Australia is presented. The genes used are a 500-bp fragment of the mitochondrial LSU rRNA gene and a 700-bp fragment located in the variable region V4 of the nuclear SSU rRNA gene. The species composition and monophyly of morphologically defined genera of which several members were available are confirmed by the molecular data (Ceratoserolis, Spinoserolis, and Cuspidoserolis). The molecular data also support the redefinition of Frontoserolis s.l. and Serolella and the erection of the new genera Septemserolis and Paraserolis, as proposed by W]agele. The relationship among several genera is resolved differently in the molecular hypothesis than in the two existing morphological hypotheses, however. The molecular phylogeny may have important consequences for understanding the biogeography of the Serolidae, indicating that all Antarctic species in this study form a monophyletic group which has probably derived from species with closest extant relatives in South America. All 3 species included in this study living today in deep waters (>2000 m) of the Southern Ocean are most closely related to species living on the Antarctic shelf, so that parallel colonization of the deep sea by way of polar submergence can be reconstructed. In this study, a V4 expansion segment is reported which exceeds the longest crustacean sequences known until now by more than 270 bp. Although the V4 expansion segment has proven useful for phylogenetic purposes in this study, there is circumstantial evidence that its mechanism of evolution may depend not only on inheritance of single-site substitutions, making its routine use in phylogenetic studies potentially dangerous. Copyright 2000 Academic Press.
Alexandre, Daniel; Ozório, Renata A; Derner, Roberto B; Fracalossi, Débora M; Oliveira, Gabriel B; Samuels, Richard I; Terra, Walter R; Silva, Carlos P
The effect of dietary protein concentration on the spatial distribution of digestive proteinases in the shrimp Litopenaeus vannamei indicates the existence of endo-ectoperitrophic enzyme circulation in this species. Samples recovered from the midgut gland tissues, stomach contents, three different portions of the midgut and feces were used for quantitative and qualitative analyses of the composition and distribution of the digestive proteinases. Animals were divided into three different groups: (1) animals (controls) fed with a commercial 35% protein diet, (2) animals fed with a commercial diet supplemented with ovalbumin to a final protein concentration of 60%; (3) animals fed with an 80% protein diet. Quantitative determinations using different substrates and zymograms showed that increasing protein concentration in the diet alters the distribution of proteinases along the digestive tract. Composition of proteinases in the midgut gland, stomach contents, midgut sections and feces were similar, but not identical. Chymotrypsin and trypsin paralogues were identified in all enzyme sources in a concentration gradient along the midgut in the control shrimp, the expected distribution supporting the existence of a recycling mechanism. The occurrence of a peritrophic membrane in other Decapoda suggests that endo-ectoperitrophic circulation of digestive enzymes and nutrients may also occur in other crustaceans and also extends beyond the Insecta.
Shih, Hsi-Te; Lee, Jung-Hsiang; Ho, Ping-Ho; Liu, Hung-Chang; Wang, Chia-Hsiang; Suzuki, Hiroshi; Teng, Shao-Jyun
The fiddler crabs, genus Uca Leach, 1814 (Decapoda, Ocypodidae) of Taiwan, including the offshore islands of Penghu (Pescadores), Kinmen (Quemoy), Matsu (Matzu), and Dongsha (Pratas), are revised, with the recognition of five subgenera and 15 species, viz. Uca (Austruca) Bott, 1973: U. lactea (De Haan, 1835), U. perplexa (H. Milne Edwards, 1837), U. triangularis (A. Milne-Edwards, 1873); U. (Gelasimus) Latreille, 1817: U. borealis Crane, 1975, U. jocelynae Shih, Naruse & Ng, 2010, U. tetragonon (Herbst, 1790), U. vocans (Linnaeus, 1758); U. (Paraleptuca) Bott, 1973: U. crassipes (White, 1847), U. splendida (Stimpson, 1858); U. (Tubuca) Bott, 1973: U. acuta (Stimpson 1858), U. arcuata (De Haan, 1835), U. coarctata (H. Milne Edwards, 1852), U. dussumieri (H. Milne Edwards, 1852), U. paradussumieri (Bott, 1973); and U. (Xeruca) Shih, 2015: U. formosensis Rathbun, 1921. Among them, U. acuta, U. paradussumieri, and U. vocans are confirmed to be distributed in Taiwan. Uca formosensis is endemic to Taiwan. The Uca species of the main islands of Japan are also listed. Four species (U. arcuata, U. lactea, U. crassipes and U. borealis) are known, but the recent additional records of U. perplexa and U. vocans need further confirmation. Except U. acuta, U. borealis, U. formosensis, U. lactea, and U. paradussumieri, other 10 Taiwanese species can be found from the Ryukyus too. Only one endemic species, U. boninensis, is reported from the Ogasawara (Bonin) Islands. A key to the 18 species of Uca found in East Asia is also provided in this study.
Effects of extracts from the cyanobacterium Microcystis aeruginosa on ion regulation and gill Na+,K+-ATPase and K+-dependent phosphatase activities of the estuarine crab Chasmagnathus granulata (Decapoda, Grapsidae).
Vinagre, T M; Alciati, J C; Yunes, J S; Richards, J; Bianchini, A; Monserrat, J M
Recent discoveries indicate that microcystins affect enzymes, such as Na(+),K(+)-ATPase, involved in ion regulation of aquatic animals, through K(+)-dependent phosphatase inhibition. In vitro studies showed the inhibitory effect of Microcystis aeruginosa extracts on Na(+),K(+)-ATPase and K(+)-dependent phosphatase activities in gills of Chasmagnathus granulata (Decapoda, Grapsidae). Extracts of M. aeruginosa were prepared from lyophilized or cultures cells of the cyanobacterium. For lyophilized cells, IC(50) values were estimated as 0.46 microg/L (95% confidence interval [CI]=0.40-0.52 microg/L) and 1.31 microg/L (95% CI=1.14-1.51 microg/L) for Na(+),K(+)-ATPase and K(+)-dependent phosphatase, respectively. However, extracts prepared from cultured cells presented a much lower inhibitory potency against both enzymes. Gas chromatography revealed long-chain fatty acids in the lyophilized cell extracts, indicating that they are in part responsible for the enzyme inhibition. In vivo studies showed that the toxin inhibited Na(+),K(+)-ATPase activity in anterior gills, whereas an increased augmented activity of glutathione-S-transferase was observed in both kind of gills, indicating that the crab has increased its ability to conjugate the toxin. No significant differences in hemolymph sodium or chloride concentration were detected. This result is in agreement with the lack of effects of microcystin on Na(+),K(+)-ATPase activity of posterior (osmoregulating) gills.
Krieger, Jakob; Sandeman, Renate E; Sandeman, David C; Hansson, Bill S; Harzsch, Steffen
Several lineages within the Crustacea conquered land independently during evolution, thereby requiring physiological adaptations for a semi-terrestrial or even a fully terrestrial lifestyle. Birgus latro Linnaeus, 1767, the giant robber crab or coconut crab (Anomura, Coenobitidae), is the largest land-living arthropod and inhabits Indo-Pacific islands such as Christmas Island. B. latro has served as a model in numerous studies of physiological aspects related to the conquest of land by crustaceans. From an olfactory point of view, a transition from sea to land means that molecules need to be detected in gas phase instead of in water solution. Previous studies have provided physiological evidence that terrestrial hermit crabs (Coenobitidae) such as B. latro have a sensitive and well differentiated sense of smell. Here we analyze the brain, in particular the olfactory processing areas of B. latro, by morphological analysis followed by 3 D reconstruction and immunocytochemical studies of synaptic proteins and a neuropeptide. The primary and secondary olfactory centers dominate the brain of B. latro and together account for ca. 40% of the neuropil volume in its brain. The paired olfactory neuropils are tripartite and composed of more than 1,000 columnar olfactory glomeruli, which are radially arranged around the periphery of the olfactory neuropils. The glomeruli are innervated ca. 90,000 local interneurons and ca. 160,000 projection neurons per side. The secondary olfactory centers, the paired hemiellipsoid neuropils, are targeted by the axons of these olfactory projection neurons. The projection neuron axonal branches make contact to ca. 250.000 interneurons (per side) associated with the hemiellipsoid neuropils. The hemiellipsoid body neuropil is organized into parallel neuropil lamellae, a design that is quite unusual for decapod crustaceans. The architecture of the optic neuropils and areas associated with antenna two suggest that B. latro has visual and
Background Several lineages within the Crustacea conquered land independently during evolution, thereby requiring physiological adaptations for a semi-terrestrial or even a fully terrestrial lifestyle. Birgus latro Linnaeus, 1767, the giant robber crab or coconut crab (Anomura, Coenobitidae), is the largest land-living arthropod and inhabits Indo-Pacific islands such as Christmas Island. B. latro has served as a model in numerous studies of physiological aspects related to the conquest of land by crustaceans. From an olfactory point of view, a transition from sea to land means that molecules need to be detected in gas phase instead of in water solution. Previous studies have provided physiological evidence that terrestrial hermit crabs (Coenobitidae) such as B. latro have a sensitive and well differentiated sense of smell. Here we analyze the brain, in particular the olfactory processing areas of B. latro, by morphological analysis followed by 3 D reconstruction and immunocytochemical studies of synaptic proteins and a neuropeptide. Results The primary and secondary olfactory centers dominate the brain of B. latro and together account for ca. 40% of the neuropil volume in its brain. The paired olfactory neuropils are tripartite and composed of more than 1,000 columnar olfactory glomeruli, which are radially arranged around the periphery of the olfactory neuropils. The glomeruli are innervated ca. 90,000 local interneurons and ca. 160,000 projection neurons per side. The secondary olfactory centers, the paired hemiellipsoid neuropils, are targeted by the axons of these olfactory projection neurons. The projection neuron axonal branches make contact to ca. 250.000 interneurons (per side) associated with the hemiellipsoid neuropils. The hemiellipsoid body neuropil is organized into parallel neuropil lamellae, a design that is quite unusual for decapod crustaceans. The architecture of the optic neuropils and areas associated with antenna two suggest that B. latro has
A revision of the genus Paracallisoma Chevreux, 1903 (Crustacea: Amphipoda: Scopelocheiridae: Paracallisominae) with a redescription of the type species of the genus Paracallisoma and the description of two new genera and two new species from the Atlantic Ocean.
Horton, Tammy; Thurston, Michael H
The genus Paracallisoma (Crustacea: Amphipoda) is revised and the type species, Paracallisoma alberti is redescribed based on holotype material supplemented with new material from the region of the type locality. This revision results in the establishment of two new genera, Pseudocallisoma gen. nov. and Haptocallisoma gen. nov., and the description of a new species of Haptocallisoma and a new species of Paracallisoma from the North Atlantic Ocean. An account of all known species within the three genera is given and updated keys to the genera and species are provided.
Tanaka, Hayato; Yasuhara, Moriaki
Deep-sea hydrothermal vent fields are among the most extreme habitats on Earth. Major research interests in these ecosystems have focused on the anomalous macrofauna, which are nourished by chemoautotrophic bacterial endosymbionts. In contrast, the meiofauna is largely overlooked in this chemosynthetic environment. The present study describes a new species, Thomontocypris shimanagai sp. nov. (Crustacea: Ostracoda), which was collected from the surface of colonies of neoverrucid barnacles and paralvinellid worms on the chimneys at the Myojin-sho submarine caldera. This is the first discovery of an ostracode from deep-sea hydrothermal vent environments in the western Pacific region. In addition to the species description, we discuss three aspects: 1) adaptation, 2) endemism, and 3) dispersal strategy of the hydrothermal vent ostracodes. Regarding these aspects, we conclude the following: 1) the new species may feed on sloughed-off tissues, mucus secretions, or fecal pellets of sessile organisms, rather than depend on chemoautotrophic bacteria as symbionts for energy; 2) as has been pointed out by other studies, Thomontocypris does not likely represent a vent-specific genus; however, this new species is considered to be endemic at the species level, as it has not been found outside of the type locality; and 3) this new species may have migrated from adjacent deep-sea chemosynthesis-based habitats, such as hydrothermal vents, with wood falls potentially having acted as stepping stones.
Sousa, Francisco Diogo R.; Elmoor-Loureiro, Lourdes Maria Abdu; Santos, Sandro
Abstract Magnospina gen. n. was created to relocate species of the dentifera-group from Alona sensu lato (Crustacea: Cladocera) and include Magnospina dentifera comb. n. and Magnospina siamensis comb. n. The synapomorphies of the Magnospina gen. n. are (1) basal spines longer than 2/3 of the postabdominal claw, (2) presence of 1–4 large denticles, broad at their bases, protruding downwards, without setules between them. Morphological traits such as habitus, rostrum and postabdomen shape, armature of IDL setae, number of setae on the exopod of limb III are also important in the distinction between Magnospina gen. n. and other genera from the Coronatella-branch. The morphology of Magnospina dentifera comb. n. male confirms the closer relationship with the clade composed by the elgans-group from Alona sensu lato, Ovalona and Leberis, but the external morphology, morphology of the postabdominal claw, basal spine and setae 2–3 of IDL support their separation from any of the group cited. It is concluded that the Coronatella-lineage of Aloninae is composed of the genera Coronatella, Anthalona, Karualona, Bergamina, Extremalona, Ovalona, Celsinotum, Leberis and Magnospina gen. n. The elegans-group from Alona sensu lato also belongs to Coronatella-lineage, but still need formal allocation. PMID:27199609
Jondeung, Amnuay; Karinthanyakit, Wirangrong; Kaewkhumsan, Jitlada
The black mud crab, Scylla serrata (Forskål 1775), is the most economically important edible crab in South-East Asia. In the present study, the complete mitochondrial genome of black mud crab, S. serrata, was determined with the sequential polymerase chain reaction and primer walking sequencing. The complete mitochondrial genome was 15,721 bp in length with an A+T content of 69.2 % and contained 37 mitochondrial genes (13 protein coding genes (PCGs), 2 ribosomal RNA genes and 22 transfer RNA genes) and a control region (CR). The analysis of the CR sequence shows that it contains a multitude of repetitive fragments which can fold into hairpin-like or secondary structures and conserved elements as in other arthropods. The gene order of S. serrata mainly retains as the pancrustacean ground pattern, except for a single translocation of trnH. The gene arrangement of S. serrata appears to be a typical feature of portunid crabs. Phylogenetic analyses with concatenated amino acid sequences of 12 PCGs establishes that S. serrata in a well-supported monophyletic Portunidae and is consistent with previous morphological classification. Moreover, the phylogenomic results strongly support monophyletic Pancrustacea (Hexapoda plus "Crustaceans"). Within Pancrustacea, this study identifies Malacostraca + Entomostraca and Branchiopoda as the sister group to Hexapoda, which confirms that "Crustacea" is not monophyletic. Cirripedia + Remipedia appear to be a basal lineage of Pancrustacea. The present study also provides considerable data for the application of both population and phylogenetic studies of other crab species.
Ito, Atsushi; Aoki, Masakazu N; Yahata, Kensuke; Wada, Hiroshi
The Caprellidea (Crustacea) have undergone an interesting morphological evolution from their ancestral gammarid-like form. Although most caprellid families have markedly reduced third and fourth pereopods (the walking thoracic limbs) and pleons (the posterior body parts), one family, Caprogammaridae, has developed pleon with swimming appendages (pleopods), whereas another family, Phtisicidae, possesses well-developed functional third and fourth pereopods. The unique character status of these families implies that there has been reacquisition or multiple losses of both pereopods and the pleon within the Caprellidea lineages. Although the Caprellidea are fascinating animals for the study of morphological evolution, the phylogenetic relationships among the Caprellidea are poorly understood. One obstacle to studying the evolution of the Caprellidea is the difficulty of collecting samples of caprogammarid species. In this study, we obtained live samples of a Caprogammaridae species and confirmed that its pleon and pleopods could perform similar locomotive functions and swimming movements as observed in gammarids. From the phylogenetic analyses on 18S ribosomal RNA gene sequences, we identified three distinct clades of Caprellidea. The ancestral state reconstruction based on the obtained phylogeny suggested that once lost, the third and fourth pereopods were regained in the Phtisicidae, while the pleon was regained in the Caprogammaridae, while we could not exclude the possibility of independent losses. In either case, the caprellid lineage underwent a quite complicated morphological evolution, and possibly the Caprellidea may be an exception to Dollo's law.
Novak, Sara; Drobne, Damjana; Vaccari, Lisa; Kiskinova, Maya; Ferraris, Paolo; Birarda, Giovanni; Remškar, Maja; Hočevar, Matej
Tungsten nanofibers are recognized as biologically potent. We study deviations in molecular composition between normal and digestive gland tissue of WOx nanofibers (nano-WOx) fed invertebrate Porcellio scaber (Iosopda, Crustacea) and revealed mechanisms of nano-WOx effect in vivo. Fourier Transform Infrared (FTIR) imaging performed on digestive gland epithelium was supplemented by toxicity and cytotoxicity analyses as well as scanning electron microscopy (SEM) of the surface of the epithelium. The difference in the spectra of the Nano-WOx treated and control cells showed up in the central region of the cells and were related to lipid peroxidation, and structural changes of nucleic acids. The conventional toxicity parameters failed to show toxic effects of nano-WOx, whereas the cytotoxicity biomarkers and SEM investigation of digestive gland epithelium indicated sporadic effects of nanofibers. Since toxicological and cytological measurements did not highlight severe effects, the biochemical alterations evidenced by FTIR imaging have been explained as the result of cell protection (acclimation) mechanisms to unfavorable conditions and indication of a nonhomeostatic state, which can lead to toxic effects.
Sousa, Francisco Diogo R; Elmoor-Loureiro, Lourdes Maria Abdu; Santos, Sandro
Magnospina gen. n. was created to relocate species of the dentifera-group from Alona sensu lato (Crustacea: Cladocera) and include Magnospina dentifera comb. n. and Magnospina siamensis comb. n. The synapomorphies of the Magnospina gen. n. are (1) basal spines longer than 2/3 of the postabdominal claw, (2) presence of 1-4 large denticles, broad at their bases, protruding downwards, without setules between them. Morphological traits such as habitus, rostrum and postabdomen shape, armature of IDL setae, number of setae on the exopod of limb III are also important in the distinction between Magnospina gen. n. and other genera from the Coronatella-branch. The morphology of Magnospina dentifera comb. n. male confirms the closer relationship with the clade composed by the elgans-group from Alona sensu lato, Ovalona and Leberis, but the external morphology, morphology of the postabdominal claw, basal spine and setae 2-3 of IDL support their separation from any of the group cited. It is concluded that the Coronatella-lineage of Aloninae is composed of the genera Coronatella, Anthalona, Karualona, Bergamina, Extremalona, Ovalona, Celsinotum, Leberis and Magnospina gen. n. The elegans-group from Alona sensu lato also belongs to Coronatella-lineage, but still need formal allocation.
Five species of the family Cyproideidae (Crustacea: Amphipoda) are described from shallow sea in Japan. Cyproidea liodactyla Hirayama, 1978 was collected from Kanagawa and Shizuoka Prefectures and Ariake Sea. Morphological character of the antenna 1 in these specimens is different from the original description. Examining the paratypes of C. liodactyla, the shape of the antenna 1 in the holotype is revealed to be abnormal. Cyproidea okinawensis sp. nov. was collected from Okinawa Island. Its morphological characters resemble C. liodactyla and C. robusta Ren, 2006; however, this new species is different from the former in the smaller eyes, the narrower coxa 5 and the coloration, and from the latter in the ovoid telson. Metacyproidea gen. nov. is established with M. makie sp. nov. from Hachijo Island in Tokyo Prefecture as its type species. This new genus resembles Cyproidea, especially in the peduncular article 2 of antenna 1 with a distinct distal tooth and the posterodorsal end of urosomites with a strong projection. However, Metacyproidea can be distinguished from Cyproidea by the coalesced urosomites 2-3 and the antenna 1 with a 10-16-articulated flagellum. Moolapheonoides acutifalcatus Kobayashi & Ishimaru, 2005 and Terepeltopes dolichorhunia Hirayama, 1983 were also collected from Wakayama and Fukui Prefectures and Kanagawa, Shizuoka and Yamaguchi Prefectures, respectively. A key to species of the family Cyproideidae in Japan is provided.
Tatarazako, Norihisa; Oda, Shigeto
The water flea Daphnia magna (Crustacea, Cladocera) is a cyclical parthenogen, which can reproduce both by parthenogenesis and by sexual reproduction. With its ease of handling in the laboratory, several testing methods using D. magna exist for regulatory toxicity testing. Recently, several studies revealed that one of the major hormone groups in insects and crustaceans, juvenile hormones, are involved in the shift of reproductive mode from parthenogenesis to sexual reproduction (production of male neonates). Using offspring sex ratio as a new endpoint has made it possible to identify chemicals with juvenile hormone-like effects on crustaceans. The testing method using D. magna, in which offspring sex ratio is incorporated as a new endpoint, is now being proposed to the OECD as an enhanced version of the existing OECD Test Guideline 211: Daphnia magna reproduction test. No other clear-cut endpoint for identifying juvenile-hormone disrupting effects has ever been found in crustaceans than the induction of male neonates production in cladocerans. In this regard, it is expected that testing methods using D. magna are suitable for screening and risk assessment of chemicals with juvenile-hormone disrupting effects.
Lera, S; Macchia, S; Dentone, L; Pellegrini, D
The aim of this work was to monitor the sensitivity of two populations of Corophium orientale (Crustacea: Amphipoda) living at the outfall of two rivers (Magra and Serchio), comparing their responses towards two different toxicant solutions. Sensitivity was monthly checked performing the 96h-LC50 static water only test with Cd(NO3)2 and SDS. If no significant differences were found between the two populations, they could have been employed without distinction to perform sediment toxicity bioassays. As regard to Cd, an increasing in LC50 values from summer to winter was evident in each population (Serchio River: August 2003 = 1,36 mg/l, February 2004 = 7,23 mg/l; Magra River: August = 1,21 mg/l, April = 5,01 mg/l). This pattern was correlated to the droop of temperatures in winter period. The responses of the two populations towards the cadmium were compared using the ANOVA. The analysis showed any significant differences between the populations (p = 0.12). The pattern of sensitivity towards SDS for the population living on Magra River was similar to the same pattern found for Cd; as regard to the population living on Serchio River, data were not enough to describe the annual pattern. Anyway, statistical analysis was performed and no significant differences were found between the two populations (p = 0.34).
Understanding Insulin Endocrinology in Decapod Crustacea: Molecular Modelling Characterization of an Insulin-Binding Protein and Insulin-Like Peptides in the Eastern Spiny Lobster, Sagmariasus verreauxi
Mancera, Ricardo L.; Smith, Greg
The insulin signalling system is one of the most conserved endocrine systems of Animalia from mollusc to man. In decapod Crustacea, such as the Eastern spiny lobster, Sagmariasus verreauxi (Sv) and the red-claw crayfish, Cherax quadricarinatus (Cq), insulin endocrinology governs male sexual differentiation through the action of a male-specific, insulin-like androgenic gland peptide (IAG). To understand the bioactivity of IAG it is necessary to consider its bio-regulators such as the insulin-like growth factor binding protein (IGFBP). This work has employed various molecular modelling approaches to represent S. verreauxi IGFBP and IAG, along with additional Sv-ILP ligands, in order to characterise their binding interactions. Firstly, we present Sv- and Cq-ILP2: neuroendocrine factors that share closest homology with Drosophila ILP8 (Dilp8). We then describe the binding interaction of the N-terminal domain of Sv-IGFBP and each ILP through a synergy of computational analyses. In-depth interaction mapping and computational alanine scanning of IGFBP_N’ highlight the conserved involvement of the hotspot residues Q67, G70, D71, S72, G91, G92, T93 and D94. The significance of the negatively charged residues D71 and D94 was then further exemplified by structural electrostatics. The functional importance of the negative surface charge of IGFBP is exemplified in the complementary electropositive charge on the reciprocal binding interface of all three ILP ligands. When examined, this electrostatic complementarity is the inverse of vertebrate homologues; such physicochemical divergences elucidate towards ligand-binding specificity between Phyla. PMID:28832524
Carlini, David B; Satish, Suma; Fong, Daniel W
Gammarus minus, a freshwater amphipod living in the cave and surface streams in the eastern USA, is a premier candidate for studying the evolution of troglomorphic traits such as pigmentation loss, elongated appendages, and reduced eyes. In G. minus, multiple pairs of genetically related, physically proximate cave and surface populations exist which exhibit a high degree of intraspecific morphological divergence. The morphology, ecology, and genetic structure of these sister populations are well characterized, yet the genetic basis of their morphological divergence remains unknown. We used degenerate PCR primers designed to amplify opsin genes within the subphylum Crustacea and discovered two distinct opsin paralogs (average inter-paralog protein divergence ≈ 20%) in the genome of three independently derived pairs of G. minus cave and surface populations. Both opsin paralogs were found to be related to other crustacean middle wavelength sensitive opsins. Low levels of nucleotide sequence variation (< 1% within populations) were detected in both opsin genes, regardless of habitat, and dN/dS ratios did not indicate a relaxation of functional constraint in the cave populations with reduced or absent eyes. Maximum likelihood analyses using codon-based models also did not detect a relaxation of functional constraint in the cave lineages. We quantified expression level of both opsin genes and found that the expression of both paralogs was significantly reduced in all three cave populations relative to their sister surface populations. The concordantly lowered expression level of both opsin genes in cave populations of G. minus compared to sister surface populations, combined with evidence for persistent purifying selection in the cave populations, is consistent with an unspecified pleiotropic function of opsin proteins. Our results indicate that phototransduction proteins such as opsins may have retained their function in cave-adapted organisms because they may play a
Shen, Xin; Tsang, Ling Ming; Chu, Ka Hou; Achituv, Yair; Chan, Benny Kwok Kan
The complete mitochondrial genome of the intertidal barnacle Tetraclita serrata Darwin, 1854 (Crustacea: Maxillopoda: Sessilia) is presented. The genome is a circular molecule of 15,200 bp, which encodes 13 PCGs, 2 ribosomal RNA genes, and 22 transfer RNA genes. All non-coding regions are 591 bp in length, with the longest one speculated as the control region (389 bp), which is located between srRNA and trnK. The overall A+T content of the mitochondrial genome of T. serrata is 65.4%, which is lowest among all the eight mitochondrial genomes reported from sessile barnacles. There are variations of initiation and stop codons in the reported sessile barnacle mitochondrial genomes. Large-scale gene rearrangements are found in these genomes as compared to the pancrustacean ground pattern. ML and Bayesian analyses of all 15 complete mitochondrial genomes available from Maxillopoda lead to identical phylogenies. The phylogenetic tree based on mitochondrial PCGs shows that Argulus americanus (Branchiura) cluster with Armillifer armillatus (Pentastomida), distinct from all ten species from Cirripedia. Within the order Sessilia, Amphibalanus amphitrite (Balanidae) clusters with Striatobalanus amaryllis (Archaeobalanidae), and Nobia grandis (Pyrgomatidae). However, the two Megabalanus (Balanidae) are separated from the above grouping, resulting in non-monophyly of the family Balanidae. Moreover, the two Megabalanus have large-scale rearrangements as compared to the gene order shared by former three species. Therefore, both phylogenetic analysis using PCG sequences and gene order comparison suggest that Balanidae is not a monophyletic group. Given the limited taxa and moderate support values of the internal branches, the non-monophyly of the family Balanidae requires further verification.
Background Gammarus minus, a freshwater amphipod living in the cave and surface streams in the eastern USA, is a premier candidate for studying the evolution of troglomorphic traits such as pigmentation loss, elongated appendages, and reduced eyes. In G. minus, multiple pairs of genetically related, physically proximate cave and surface populations exist which exhibit a high degree of intraspecific morphological divergence. The morphology, ecology, and genetic structure of these sister populations are well characterized, yet the genetic basis of their morphological divergence remains unknown. Results We used degenerate PCR primers designed to amplify opsin genes within the subphylum Crustacea and discovered two distinct opsin paralogs (average inter-paralog protein divergence ≈ 20%) in the genome of three independently derived pairs of G. minus cave and surface populations. Both opsin paralogs were found to be related to other crustacean middle wavelength sensitive opsins. Low levels of nucleotide sequence variation (< 1% within populations) were detected in both opsin genes, regardless of habitat, and dN/dS ratios did not indicate a relaxation of functional constraint in the cave populations with reduced or absent eyes. Maximum likelihood analyses using codon-based models also did not detect a relaxation of functional constraint in the cave lineages. We quantified expression level of both opsin genes and found that the expression of both paralogs was significantly reduced in all three cave populations relative to their sister surface populations. Conclusions The concordantly lowered expression level of both opsin genes in cave populations of G. minus compared to sister surface populations, combined with evidence for persistent purifying selection in the cave populations, is consistent with an unspecified pleiotropic function of opsin proteins. Our results indicate that phototransduction proteins such as opsins may have retained their function in cave
Silva, Erika dos Santos; de Abreu, Cínthia Bruno; Orlando, Tereza Cristina; Wisniewski, Célio; dos Santos-Wisniewski, Maria José
Knowledge of reproductive rates and life cycle of the Cladocera species is essential for population dynamic studies, secondary production and food webs, as well as the management and preservation of aquatic ecosystems. The present study aimed to understand the life cycle and growth of Alona iheringula Kotov & Sinev, 2004 (Crustacea, Anomopoda, Chydoridae), a Neotropical species, as well as its DNA barcoding, providing new information on the Aloninae taxonomy. The specimens were collected in the dammed portion of the Cabo Verde River (21°26′05″ S and 46°10′57″ W), in the Furnas Reservoir, Minas Gerais State, Brazil. Forty neonates were observed individually two or three times a day under controlled temperature (25±1°C), photoperiod (12 h light/12 h dark) and feeding (Pseudokirchneriella subcapitata at a concentration of 105 cells.mL−1 and a mixed suspension of yeast and fish feed in equal proportion). Individual body growth was measured daily under optical microscope using a micrometric grid and 40× magnification. The species had a mean size of 413(±29) µm, a maximum size of 510 µm and reached maturity at 3.24(±0.69) days of age. Mean fecundity was 2 eggs per female per brood and the mean number of eggs produced per female during the entire life cycle was 47.6(±6.3) eggs per female. The embryonic development time was 1.79(±0.23) days and the maximum longevity was 54 days. The species had eight instars throughout its life cycle and four instars between neonate and primipara stage. The present study using molecular data (a 461 bp smaller COI fragment) demonstrated a deep divergence in the Aloninae subfamily. PMID:24878503
Sigvardt, Zandra M S; Rogers, D Christopher; Olesen, Jørgen
Male clam shrimps (Crustacea: Branchiopoda: Laevicaudata, Spinicaudata, and Cyclestherida) have their first one or two trunk limb pairs modified as "claspers," which are used to hold the female during mating and mate guarding. Clasper morphology has traditionally been important for clam shrimp taxonomy and classification, but little is known about how the males actually use the claspers during amplexus (clasping). Homologies of the various clasper parts ("movable finger," "large palp," "palm," "gripping area," and "small palp") have long been discussed between the three clam shrimp taxa, and studies have shown that only some structures are homologous while others are convergent ("partial homology"). We studied the clasper functionality in four spinicaudatan species using video recordings and scanning electron microscopy, and compared our results with other clam shrimp groups. General mating behavior and carapace morphology was also studied. Generally, spinicaudatan and laevicaudatan claspers function similarly despite some parts being nonhomologous. We mapped clasper morphology and functionality aspects on a branchiopod phylogeny. We suggest that the claspers of the three groups were adapted from an original, simpler clasper, each for a "stronger" grip on the female's carapace margin: 1) Spinicaudata have two clasper pairs bearing an elongated apical club/gripping area with one setal type; 2); Cyclestherida have one clasper pair with clusters of molariform setae on the gripping area and at the movable finger apex; and 3) Laevicaudata have one clasper pair, but have incorporated an additional limb portion into the clasper palm and bear a diverse set of setae. J. Morphol. 278:523-546, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.
Frase, Thomas; Richter, Stefan
Using immunohistochemical labeling against acetylated a-tubulin and serotonin in combination with confocal laser scanning microscopy and 3D-reconstruction, we investigated the temporary freshwater pond inhabitant Branchinella sp. (Crustacea: Branchiopoda: Anostraca) for the first time to provide detailed data on the development of the anostracan nervous system. Protocerebral sense organs such as the nauplius eye and frontal filament organs are present as early as the hatching stage L0. In the postnaupliar region, two terminal pioneer neurons grow from posterior to anterior to connect the mandibular neuromeres. The first protocerebral neuropil to emerge is not part of the central complex but represents the median neuropil, and begins to develop from L0+ onwards. In stage L3, the first evidence of developing compound eyes is visible. This is followed by the formation of the visual neuropils and the neuropils of the central complex in the protocerebrum. From the deutocerebral lobes, the projecting neuron tract proceeds to both sides of the lateral protocerebrum, forming a chiasma just behind the central body. In the postnaupliar region, the peripheral nervous system, commissures and connectives develop along an anterior-posterior gradient after the fasciculation of the terminal pioneer neurons with the mandibular neuromere. The peripheral nervous system in the thoracic segments consists of two longitudinal neurite bundles on each side which connect the intersegmental nerves, together with the ventral nervous system forming an orthogon-like network. Here, we discuss, among other things, the evidence of a fourth nauplius eye nerve and decussating projecting neuron tract found in Branchinella sp., and provide arguments to support our view that the crustacean frontal filament (organ) and onychophoran primary antenna are homologous. J. Morphol. 277:1423-1446, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.
Popova, Ekaterina Y; Kotov, Alexey A
Daphnia O.F. Müller (Crustacea: Cladocera: Daphniidae) is an important model in biology. It was concluded earlier that subgenus Daphnia s.str. occurs mainly in the northern hemisphere, subgenus Daphnia (Ctenodaphnia) in the southern hemisphere, which could suggest that: (1) the subgeneric differentiation is correlated with the Laurasia-Gondwanaland subdivision and (2) D. (Ctenodaphnia) is a taxon of Gondwanian origin. Some authors even discussed mechanisms of maintaince of the "ancient subgeneric north-south split", regarding such a pattern as paradoxical. But both molecular clock calculations and fossils of both subgenera from the Jurassic/Cretaceous boundary of Mongolia compromise such ideas and suggest an earlier, Pangaean, differentiation of the subgenera. We discuss the distribution of Daphnia worldwide based on recent literature. Our analysis covers literature data on all described and on undescribed taxa revealed by genetical methods. Distributional data were associated with five main zones: southern cold (I), southern temperate (II), tropical (III), northern temperate (IV), and northern cold (V) zone. We found no "subgeneric north-south split": the distribution of Daphnia s.str. is dissymmetric between the hemispheres (antipolar), while that of Ctenodaphnia is sub-symmetric (bipolar). We suggest that both patterns are not of Mesozoic, but of Cenozoic origin. Mesozoic differentiation of the subgenera does not contradict a recent origin of the extant species, as found in e.g. Notostraca. A superficially attractive hypothesis about a Gondwanian origin of a taxon (Daphnia (Ctenodaphnia)) therefore did not pass the test of the fossil records. In addition, we agree with the opinion that an antipolar is only a variant of a bipolar pattern, as a result of an extinction in the southern hemisphere, and that these patterns are mid-late Cenozoic instead of Mesozoic.
Symbiosis is one of the most successful modes of life displayed by aquatic organisms, as measured by the number of times it evolved and how many symbiotic species are presently in existence. Among the Crustacea copepods utilize an extraordinary range of hosts, occurring on virtually every phylum of marine macroinvertebrates and, jointly with the monogeneans, are the most speciose group of metazoan ectoparasites of marine fishes (Rhode 2005). Several species have a major impact on global finfish and shellfish aquaculture, causing significant effects on farm production, economic viability and sustainability (Shinn et al. 2015). Parasitism by copepods on other metazoans has evolved independently numerous times in the evolutionary history of animal life on Earth and has led to an exceptional diversity in morphologies, physiologies, life-strategies and habitat preferences of its members. Reflecting the diversity of hosts, copepods show an amazing variety of adaptations which secure infection of and survival on the hosts. Since the first descriptions of parasitic copepods occurring on fish by Linnaeus (1758) and the first report of a copepod utilizing an invertebrate host by Say (1818) (Clausidium caudatum (Say, 1818)) the number of described symbiotic copepods has seen a steady increase over a 200-yr period, culminating in a total of 5,306 valid species recognized today. About 38% of all described copepod species utilize either vertebrate (2,450 spp.) or invertebrate hosts (2,856 spp.), however, many host groups have not been thoroughly examined, and for this reason even approximate estimates of true species numbers are futile. Plotting the proposal of new species by decade (Fig. 1) shows a sharp rise since 1950 with 67% of the species having been described in the preceding 65 years. This period of exceptionally rapid progress can be attributed to a number of highly prolific investigators such as Arthur Humes, Il-Hoi Kim, Ju-shey Ho and Jan Stock who, single-handedly or
Skinner, D.M.; Graham, D.E.; Holland, C.A.; Mykles, D.L.; Soumoff, C.; Yamaoka, L.H.
The single, overriding event that occurs during all proecdysial periods in crustaceans is the synthesis of a new exoskeleton that encompasses an enlarged animal when the old shell is cast off. Regeneration of missing appendages and larval or puberty metamorphoses also occur during proecdysis. Proecdysial periods have been divided into substages defined by the occurrence of specific events. Although a number of factors must be postulated to account for individual proecdysial events, only the molting hormone, 20-hydroxyecdysone, has been identified and isolated. Much evidence indicates that the X-organ sinus glands complex, a neurosecretory tissue located in the eyestalks, is the source of a molt inhibiting hormone (MIH) responsible for maintaining animals in anecdysis. An exuviation factor has been proposed to support the extrication of the animal from the old exoskeleton. There is evidence for a limb growth inhibitory factor (LGIF) that affects the rate of growth of regenerating limbs. We are proposing an anecdysial limb autotomy factor (LAF/sub an/) that propels into precocious molts anecdysial limb autotomy factor (LAF/sub pro/) that interrupts the proecdysial period of animals that lose one or more normal or partially regenerated pereopods before a critical time in proecdysis.
Guerra-García, J. M.; Ganesh, T.; Jaikumar, M.; Raman, A. V.
The caprellid fauna of India is investigated. A total of 538 samples (including algae, seagrasses, sponges, hydroids, ascidians, bryozoans, encrusted dead corals, coral rubble, fine and coarse sediments) were collected from 39 stations along the coast of India, covering a wide diversity of habitats from intertidal to 12 m water depth. A new species ( Jigurru longimanus n.sp.) is described, and figures of the 11 valid species reported so far from India are given together with a key for their identification. No caprellids were found in sediments from the northeast (16-20ºN) coast of India while they were abundant in the southeast and west coast. Decreases in salinity due to river discharges associated with lower values of oxygen, higher water temperatures and lower nutrient inputs along the east coast could explain these differences in caprellid composition between the two coastlines. Significantly, lower abundance of caprellids in India, as in other tropical ecosystems, is probably related to the lack of species belonging to the genus Caprella, which reach very high abundances in temperate waters.
Monstrilloid copepods are protelean parasites of different groups of marine benthic invertebrates. Only their first naupliar, preadult, and adult phases are planktonic. Monstrilloids are currently represented by more than 115 nominal species contained in four genera. Its taxonomic knowledge has been hampered by nomenclatural and descriptive problems derived from their peculiar ontogeny and poor definitions of taxa. One of the most important difficulties is that of matching males to females. The only reliable methods to link the sexes of a species are the confirmation of particular apomorphies shared by both sexes, finding both sexes in the same host or as a pre-copulatory male-female pair in the plankton, or by the use of molecular markers. A general overview of the morphology of the group and its life cycle is provided herein. Recently, upgraded descriptive standards have been established and the relevance of redescribing taxa based on type and museum specimens has been demonstrated. The rate of species description per decade has had several peaks between 1840 and 2010: (1971–1980, 1991–2000, 2001–2010), each related to the activity of a few researchers. An analysis of the world distribution of published records of the Monstrilloida revealed that the Northeast Atlantic is the best studied region (45% of all records), followed by the Northwestern Atlantic (17%); the least surveyed areas include regions of the southern hemisphere (less than 3%). The Northeast Atlantic region harbors the highest number of known species (32 nominal species), followed by the Caribbean Sea/Gulf of Mexico (24), the Mediterranean/Black Sea (19), Indonesia-Malaysia-Philippines region (17), Japanese waters (17), and the Brazil-Argentina area (16). Other than these generalized patterns, little can be concluded concerning the biogeography of the group. Many species records are doubtful or improbable, and purportedly cosmopolitan nominal species are being revealed as species complexes yet to be studied. PMID:21853055
LeBlanc, Gerald A.; Wang, Ying H.; Holmes, Charisse N.; Kwon, Gwijun; Medlock, Elizabeth K.
Background Environmental signals to maternal organisms can result in developmental alterations in progeny. One such example is environmental sex determination in Branchiopod crustaceans. We previously demonstrated that the hormone methyl farnesoate could orchestrate environmental sex determination in the early embryo to the male phenotype. Presently, we identify a transcription factor that is activated by methyl farnesoate and explore the extent and significance of this transgenerational signaling pathway. Methodology/Principal Findings Several candidate transcription factors were cloned from the water flea Daphnia pulex and evaluated for activation by methyl farnesoate. One of the factors evaluated, the complex of two bHLH-PAS proteins, dappuMet and SRC, activated a reporter gene in response to methyl farnesoate. Several juvenoid compounds were definitively evaluated for their ability to activate this receptor complex (methyl farnesoate receptor, MfR) in vitro and stimulate male sex determination in vivo. Potency to activate the MfR correlated to potency to stimulate male sex determination of offspring (pyriproxyfen>methyl farnesoate>methoprene, kinoprene). Daphnids were exposed to concentrations of pyriproxyfen and physiologic responses determined over multiple generations. Survivial, growth, and sex of maternal organisms were not affected by pyriproxyfen exposure. Sex ratio among offspring (generation 2) were increasingly skewed in favor of males with increasing pyriproxyfen concentration; while, the number of offspring per brood was progressively reduced. Female generation 2 daphnids were reared to reproductive maturity in the absence of pyriproxyfen. Sex ratios of offspring (generation 3) were not affected in this pyriproxyfen lineage, however, the number of offspring per brood, again, was significantly reduced. Conclusions Results reveal likely components to a hormone/receptor signaling pathway in a crustacean that orchestrates transgenerational modifications to important population metrics (sex ratios, fecundity of females). A model is provided that describes how these signaling processes can facilitate population sustainability under normal conditions or threaten sustainability when perturbed by environmental chemicals. PMID:23613913
Monstrilloid copepods are protelean parasites of different groups of marine benthic invertebrates. Only their first naupliar, preadult, and adult phases are planktonic. Monstrilloids are currently represented by more than 115 nominal species contained in four genera. Its taxonomic knowledge has been hampered by nomenclatural and descriptive problems derived from their peculiar ontogeny and poor definitions of taxa. One of the most important difficulties is that of matching males to females. The only reliable methods to link the sexes of a species are the confirmation of particular apomorphies shared by both sexes, finding both sexes in the same host or as a pre-copulatory male-female pair in the plankton, or by the use of molecular markers. A general overview of the morphology of the group and its life cycle is provided herein. Recently, upgraded descriptive standards have been established and the relevance of redescribing taxa based on type and museum specimens has been demonstrated. The rate of species description per decade has had several peaks between 1840 and 2010: (1971-1980, 1991-2000, 2001-2010), each related to the activity of a few researchers. An analysis of the world distribution of published records of the Monstrilloida revealed that the Northeast Atlantic is the best studied region (45% of all records), followed by the Northwestern Atlantic (17%); the least surveyed areas include regions of the southern hemisphere (less than 3%). The Northeast Atlantic region harbors the highest number of known species (32 nominal species), followed by the Caribbean Sea/Gulf of Mexico (24), the Mediterranean/Black Sea (19), Indonesia-Malaysia-Philippines region (17), Japanese waters (17), and the Brazil-Argentina area (16). Other than these generalized patterns, little can be concluded concerning the biogeography of the group. Many species records are doubtful or improbable, and purportedly cosmopolitan nominal species are being revealed as species complexes yet to be studied.
Simeó, Carles G; Kurtz, Kathryn; Chiva, Manel; Ribes, Enric; Rotllant, Guiomar
This study describes spermatogenesis in a majid crab (Maja brachydactyla) using electron microscopy and reports the origin of the different organelles present in the spermatozoa. Spermatogenesis in M. brachydactyla follows the general pattern observed in other brachyuran species but with several peculiarities. Annulate lamellae have been reported in brachyuran spermatogenesis during the diplotene stage of first spermatocytes, the early and mid-spermatids. Unlike previous observations, a Golgi complex has been found in mid-spermatids and is involved in the development of the acrosome. The Golgi complex produces two types of vesicles: light vesicles and electron-dense vesicles. The light vesicles merge into the cytoplasm, giving rise to the proacrosomal vesicle. The electron-dense vesicles are implicated in the formation of an electron-dense granule, which later merges with the proacrosomal vesicle. In the late spermatid, the endoplasmic reticulum and the Golgi complex degenerate and form the structures-organelles complex found in the spermatozoa. At the end of spermatogenesis, the materials in the proacrosomal vesicle aggregate in a two-step process, forming the characteristic concentric three-layered structure of the spermatozoon acrosome. The newly formed spermatozoa from testis show the typical brachyuran morphology. (c) 2009 Wiley-Liss, Inc.
Two new species of dicyemid mesozoan are described from Sepia longipes, Sasaki, 1913, collected from Tosa Bay in Japan. Dicyema oxycephalum n. sp. is a medium-sized species that is about 1,800 microm in length. It lives in folds of the renal appendages. The vermiform stages are characterized as having 28-34 peripheral cells, a conical calotte, and an axial cell that extends to the base of the propolar cells. Infusoriform embryos consist of 39 cells; 2 nuclei are present in each urn cell and the refringent bodies are solid. Pseudicyema cappacephalum n. sp. is also a medium-size species; it is about 1,000 microm in length. It too lives in folds of the renal appendages. The vermiform stages are characterized as having 32-34 peripheral cells, a cap-shaped calotte, and an axial cell that extends to the base of propolar cells. Infusoriform embryos consist of 39 cells; 2 nuclei are present in each urn cell and the refringent bodies are solid. This is the first description of dicyemids from S. longipes.
Morehouse, Reid L; Tobler, Michael
We furnish an updated crayfish species list for the state of Oklahoma (United States of America), including an updated and illustrated dichotomous key. In addition, we include species accounts that summarize general characteristics, life coloration, similar species, distribution and habitat, life history, and syntopic species. Current and potential distributions were analyzed using ecological niche models to provide a critical resource for the identification of areas with conservation priorities and potential susceptibility to invasive species. Currently, Oklahoma harbors 30 species of crayfish, two of which were recently discovered. Eastern Oklahoma has the highest species diversity, as this area represents the western distribution extent for several species. The work herein provides baseline data for future work on crayfish biology and conservation in Oklahoma and surrounding states.
Diez, Yander L; Lira, Carlos
Marine crustaceans are a well-known invertebrates group in Cuban waters, but some taxa are not well catalogued and the literature about them is scattered. In this work, we present the checklist of porcelain crabs of Cuban Archipelago, including the literature registers and unpublished author's data. A key to the identification of 8 genera and 23 species of the Cuban porcelain crabs is provided. Information about the local distribution of species is presented. In addition, we analyzed the porcelain crab faunal affinities between the ecoregions of the Cuban platform, Greater Antilles islands and the Tropical Northwestern Atlantic (TNA) province. For the first time, we record the presence of the monotypic genus Parapetrolisthes Haig in Cuba. On the Cuban platform, the highest similarities are between the Southcentral and Northwestern ecoregions (50%) and between Northcentral and Northeastern (40%). In the Greater Antilles, Cuba and Puerto Rico are the most similar (54%), but in general, the porcelain crab composition shows a high variation (e. g. 19% between Hispaniola and Puerto Rico). In the Tropical Northwestern Atlantic, five homogeneous groups of porcelain crab species are distinguished. Cuban fauna is most similar to that of Floridian, Western Caribbean and Southern Gulf of Mexico ecoregions. The decrease in species richness is evident from south to north in the TNA Province.
Ahyong, Shane T
Cymonomid crabs collected from the Mozambique Channel off Madagascar by the 2011 MAINBAZA Expedition are reported. Two species of Cymonomus A. Milne Edwards, 1880, are represented, of which one is new to science and the other, C. valdiviae Lankester, 1903, is rediscovered, being previously known only from the holotype. Three species of Cymonomidae are now known from the western Indian Ocean, including C. trifurcus Stebbing, 1920, from South Africa.
In Insecta and malacostracan Crustacea, neurons in the ventral ganglia are generated by the unequal division of neuronal stem cells, the neuroblasts (Nbs), which are arranged in a stereotyped, grid-like pattern. In malacostracans, however, Nbs originate from ectoteloblasts by an invariant lineage, whereas Nbs in insects differentiate without a defined lineage by cell-to-cell interactions within the neuroectoderm. As the ventral ganglia in entomostracan crustaceans were thought to be generated by a general inward proliferation of ectodermal cells, the question arose as to whether neuroblasts in Euarthropoda represent a homologous type of stem cell. In the current project, neurogenesis in metanauplii of the entomostracan crustaceans Triops cancriformis Fabricius, 1780 (Branchiopoda, Phyllopoda) and Artemia salina Linné, 1758 (Branchiopoda, Anostraca) was examined by in vivo incorporation of the mitosis marker bromodeoxyuridine (BrdU) and compared to stem cell proliferation in embryos of the malacostracan Palaemonetes argentinus Nobili, 1901 (Eucarida, Decapoda). The developmental expression of synaptic proteins (synapsins) was studied immunohistochemically. Results indicate that in the ventral neurogenic zone of Branchiopoda, neuronal stem cells with cellular characteristics of malacostracan neuroblasts are present. However, a pattern similar to the lineage-dependent, grid-like arrangement of the malacostracan neuroblasts was not found. Therefore, the homology of entomostracan and malacostracan neuronal stem cells remains uncertain. It is now well established that during arthropod development, identical and most likely homologous structures can emerge, although the initiating steps or the mode of generation of these structures are different. Recent evidence suggests that adult Entomostraca and Malacostraca share corresponding sets of neurons so that the present report provides an example that those homologous neurons may be generated via divergent developmental
Hebel, D. K.; Jones, M. B.; Depledge, M. H.
Typically, the sublethal effects of exposure to environmental contaminants are assessed by measuring the responses of one, or few, biochemical or physiological systems within organisms. An individual's survival potential, however, is determined by the integrated phenotypic response of all its systems working in concert. This concept is illustrated here by reviewing the repertoire of responses at several levels of organization (from the molecular to the behavioural) available to the common shore crab, Carcinus maenas(L.) (Crustacea: Decapoda), during exposure to water-borne copper. Behavioural responses may include avoidance reactions, changes in feeding and mating behaviour, as well as altered locomotory activity. Physiological responses are manifest as alterations in iono- and osmoregulation, circulation and respiration. Cellular responses are reflected in ultrastructural changes, lysosomal alterations, induction of metallothionein and stress proteins, and alterations in the activity of enzymes. Particular attention is focused on the integrated response of the gill since it represents the primary target for water-borne contaminants. It is concluded that to gain a holistic view of the impact of chemical exposure on organisms, the simultaneous measurement of numerous biological variables in a multi-system approach is required. This permits the determination of intra- and inter-specific variability in the repertoire of responses of organisms to chemicals (and other stressors), enabling potential impacts on populations and communities to be better assessed.
Moore, P. G.; Howarth, J.
Field studies using fish-baited creels have confirmed that Carcinus maenas, Necora puber and Pagurus bernhardus (Crustacea: Decapoda), Buccinum undatum (Gastropoda) and Asterias rubens (Echinodermata) are prominent scavenging species in shallow waters in the Clyde Sea area. Capture rates of these species by creels baited with dead fish plus variously damaged C. maenas were examined in the field. The addition of substantially fractured C. maenas significantly reduced the capture of conspecifics, but significantly enhanced the capture of the taxonomically unrelated species A. rubens. The remaining crustacean taxa (of the above) were unaffected by this treatment. The magnitude of th response was related strongly to the extent to which C. maenas were damaged. The effects of hunger on these responses were tested in a laboratory experiment in which the responses of starved and fed batches of C. maenas were investigated. Starved crabs remained attracted to fish bait, despite the proximity of dead conspecifics. Conversely, crabs of the fed batch were significantly more reluctant to enter creels containing damaged conspecifics. The localized presence of odours emanating from dead conspecifics did not cause crabs to remain inactive in shelter. We conclude that taxonomic relatedness to bait, degree of carcass damage and hunger of the scavenger all interact in determining foraging decision-making even by so-called generalist scavengers.
Ward, Deborah A; Sefton, Elaine M; Prescott, Mark C; Webster, Simon G; Wainwright, Geoff; Rees, Huw H; Fisher, Michael J
Proteome maps of hepatopancreas (midgut gland) and ovarian tissues of the crustacean, Cancer pagurus (Decapoda; edible crab) have been produced by 2D-PAGE and identification of proteins, following trypsin proteolysis, by electrospray MS/MS and database searching. Owing to the lack of sequence information on proteins and fully sequenced genomes amongst the decapod crustaceans and given the evolutionary distance to the nearest full genome database (Daphnia), it was necessary to adopt a non-conventional identification approach. Thus, a strategy was developed for effective identification of decapod proteins by sequence similarity, homology-based cross-species database searching, using various algorithms and a combination of NCBI Crustacea and Arthropoda databases, together with the Arthropoda PartiGene database (Blaxter, University of Edinburgh). In both hepatopancreas and ovary tissues, the largest group of proteins identified were a variety of enzymes, followed by a smaller number of storage/transport proteins [including vitellogenin (yolk protein), several subunits of hemocyanin, cryptocyanin, ferritin and calreticulin], with fewer structural proteins (actin, tubulin) and heat-shock proteins, in addition to a number of proteins of miscellaneous functions. Such protein identifications allow the development of tools, such as antibodies and RNA/DNA probes, to investigate the functions of the proteins in specific tissues during development. Copyright © 2010 Elsevier B.V. All rights reserved.
Shih, Hsi-Te; Ng, Peter K L; Christy, John H
Among the fiddler crabs from the Americas, Uca panamensis (Stimpson, 1859) (Crustacea: Decapoda: Ocypodidae) is unusual in its behavior and ecology, living in stony habitats rather than sandy or muddy substrates. This species also has several unusual morphological characters of the carapace and major and minor chelae, and had been placed in either the subgenera Minuca Bott, 1954, or Leptuca Bott, 1973. The armature at the inner corner of the orbital floor, as well as the morphology of the urocardiac ossicles of the gastric mill of U. panamensis, are, however, plesiomorphic characters, and are closer to the condition in species belonging the subgenera Uca and Afruca. Phylogenetic relationships, based on mitochondrial 16S rDNA and cytochrome oxidase subunit I, and nuclear 28S rDNA, supported by its unusual morphological features indicate that this species belongs to its own subgenus. A new subgenus Uca (Petruca) subgen. nov. is herein established for U. panamensis. In addition, the status of Uca thayeri Rathbun, 1900, U. umbratila Crane, 1941, U. virens Salmon & Atsaides, 1968, and U. longisignalis Salmon & Atsaides, 1968, are revised and discussed based on a reappraisal of their phylogenetic relationships.
The structure and distribution of satellite cells of cardiac muscles were examined in twenty-one species of animals chosen from each tribe within the order Decapoda (Arthropoda, Crustacea). The satellite cells were found in all animals observed. Most of them are morphologically identical with those described in different striated muscles of other species, but some cells have unusual features. The decapod satellite cell occasionally lies right over the region corresponding to the intercalated disc between the apposed cardiac muscle cells. The cell sends cytoplasmic processes into the adjacent muscle cells, enabling the plasma membrane to make close contact with the cleft opening of the intercalated disc, and with the myofibril at the level of the Z-line. Another characteristic feature is the presence of "paired" cells. Such cells are clearly separated from each other over most of the contact area by the respective plasma membranes, which are smooth in appearance and devoid of specialized regions. The significance of the presence of satellite cells in decapod cardiac muscle and its possible role are discussed and compared with those described for other species.
Development of a non-denaturing 2D gel electrophoresis protocol for screening in vivo uranium-protein targets in Procambarus clarkii with laser ablation ICP MS followed by protein identification by HPLC-Orbitrap MS.
Xu, Ming; Frelon, Sandrine; Simon, Olivier; Lobinski, Ryszard; Mounicou, Sandra
Limited knowledge about in vivo non-covalent uranium (U)-protein complexes is largely due to the lack of appropriate analytical methodology. Here, a method for screening and identifying the molecular targets of U was developed. The approach was based on non-denaturing 1D and 2D gel electrophoresis (ND-PAGE and ND-2D-PAGE (using ND-IEF as first dimension previously described)) in conjunction with laser ablation inductively coupled plasma mass spectrometry (LA-ICP MS) for the detection of U-containing proteins. The proteins were then identified by µbore HPLC-Orbitrap MS/MS. The method was applied to the analysis of cytosol of hepatopancreas (HP) of a model U-bioaccumulating organism (Procambarus clarkii). The imaging of uranium in 2D gels revealed the presence of 11 U-containing protein spots. Six protein candidates (i.e. ferritin, glyceraldehyde-3-phosphate dehydrogenase, triosephosphate isomerase, cytosolic manganese superoxide dismutase (Mn-SOD), glutathione S transferase D1 and H3 histone family protein) were then identified by matching with the data base of crustacea Decapoda species (e.g. crayfish). Among them, ferritin was the most important one. This strategy is expected to provide an insight into U toxicology and metabolism.
Yuan, Jianbo; Gao, Yi; Zhang, Xiaojun; Wei, Jiankai; Liu, Chengzhang; Li, Fuhua; Xiang, Jianhai
Crustacea, particularly Decapoda, contains many economically important species, such as shrimps and crabs. Crustaceans exhibit enormous (nearly 500-fold) variability in genome size. However, limited genome resources are available for investigating these species. Exopalaemon carinicauda Holthuis, an economical caridean shrimp, is a potential ideal experimental animal for research on crustaceans. In this study, we performed low-coverage sequencing and de novo assembly of the E. carinicauda genome. The assembly covers more than 95% of coding regions. E. carinicauda possesses a large complex genome (5.73 Gb), with size twice higher than those of many decapod shrimps. As such, comparative genomic analyses were implied to investigate factors affecting genome size evolution of decapods. However, clues associated with genome duplication were not identified, and few horizontally transferred sequences were detected. Ultimately, the burst of transposable elements, especially retrotransposons, was determined as the major factor influencing genome expansion. A total of 2 Gb repeats were identified, and RTE-BovB, Jockey, Gypsy, and DIRS were the four major retrotransposons that significantly expanded. Both recent (Jockey and Gypsy) and ancestral (DIRS) originated retrotransposons responsible for the genome evolution. The E. carinicauda genome also exhibited potential for the genomic and experimental research of shrimps. PMID:28678163
Raupach, Michael J.; Radulovici, Adriana E.
Abstract Species identification represents a pivotal component for large-scale biodiversity studies and conservation planning but represents a challenge for many taxa when using morphological traits only. Consequently, alternative identification methods based on molecular markers have been proposed. In this context, DNA barcoding has become a popular and accepted method for the identification of unknown animals across all life stages by comparison to a reference library. In this review we examine the progress of barcoding studies for the Crustacea using the Web of Science data base from 2003 to 2014. All references were classified in terms of taxonomy covered, subject area (identification/library, genetic variability, species descriptions, phylogenetics, methods, pseudogenes/numts), habitat, geographical area, authors, journals, citations, and the use of the Barcode of Life Data Systems (BOLD). Our analysis revealed a total number of 164 barcoding studies for crustaceans with a preference for malacostracan crustaceans, in particular Decapoda, and for building reference libraries in order to identify organisms. So far, BOLD did not establish itself as a popular informatics platform among carcinologists although it offers many advantages for standardized data storage, analyses and publication. PMID:26798245
Martin, Peer; Kohlmann, Klaus; Scholtz, Gerhard
Genetically identical animals are very much in demand as laboratory objects because they allow conclusions about environmental and epigenetic effects on development, structures, and behavior. Furthermore, questions about the relative fitness of various genotypes can be addressed. However, genetically identical animals are relatively rare, in particular, organisms that combine a high reproduction rate and a complex organization. Based on its exclusively parthenogenetic reproduction mode, it has been suggested that the Marmorkrebs (Crustacea, Decapoda, Astacida), a recently discovered crayfish, is an excellent candidate for research addressing the aforementioned questions. However, until now, a study using molecular markers that clearly proves the genetic uniformity of the offspring has been lacking. Here, with this first molecular study, we show that this crayfish indeed produces genetically uniform clones. We tested this with 19 related individuals of various generations of a Marmorkrebs population by means of six different microsatellite markers. We found that all examined specimens were identical in their allelic composition. Furthermore, half of the analyzed loci were heterozygous. These results and the absence of meioses in previous histological studies of the ovaries lead us to conclude the Marmorkrebs propagates apomictically. Thus, a genetically uniform organism with complex morphology, development, and behavior is now available for various laboratory studies.
Williamson, D. I.
It is postulated that some groups of animals have hybrid life-histories, with the larva originating in a different evolutionary line from that which produced the adult. Later the two developmental phases came together to form parts of the same life-history, and only after this synthesis did the larva and adult evolve as products of the same genome. This theory is put forward to try to explain apparent contradictions between the affinities of some larvae and those of their corresponding adults. Examples of groups showing such incongruity are (1) the Dromioidea (Crustacea, Decapoda), (2) the Echinodermata, in its relationships with other phyla and at all taxonomic levels within the phylum, and (3) the Annelida, Echiura, Sipuncula and Mollusca, all of which contain species with trocophore larvae. The theory also seeks to explain forms of metamorphosis in which most larval structures are discarded. It is suggested that these anomalies have all resulted from occasional transfers of the genetic material to dictate a larval form from one species to a distantly related or unrelated one. Heterosperm fertilisation is considered as a possible mechanism, leading to the expression of paternal genes specifying the larval form followed by the expression of maternal genes specifying later development. The theory that different phases in the life-history of a species or group might have different evolutionary geneaologies has profound implications for phylogeny and classification at all taxonomic levels.
Sohn, I.G.; Kornicker, L.S.
An ostracod species of Cypretta is an effective predator in laboratory experiments on 1- to 3-day-old Biomphalaria glabrata, a vector snail of the blood fluke that causes the tropical and subtropical disease schistosomiasis.
Brandt, O.M.; Fujimura, R.W.; Finlayson, B.J. )
The mysid Neomysis mercedis was examined as a test organism for use in acute toxicity tests at intermediate salinities characteristic of estuarine waters. Several sensitive invertebrate species are available for marine assessments (mysids) and freshwater tests (cladocerans), but few are available for estuarine toxicity tests. Observations in the laboratory indicate that Neomysis mercedis can be reared successfully at a temperature of 17[degrees]C, a salinity of 2%, and a population density less than 5/L. Brine shrimp nauplii Artemia salina, algae, and commercial foods were used to sustain mysid cultures. Neomysis mercedis is vivaparous and can complete its life cycle in 3-4 months. Neomysis mercedis is as sensitive as or more sensitive to toxicants than the marine mysid Mysidopsis bahia and the freshwater cladocerans Daphnia magna, Ceriodaphnia dubia, and Simocephalus serrulatus. The mean 96-h LC50 values (concentrations lethal to half the test animals) for N. mercedis, in increasing order, were 0.20 [mu]g/L for thiobencarb, and for malathion, 14 [mu]g/L for carbofuran, 150 [mu]g/L for copper sulfate, 280 [mu]g/L for thiobencarb, and 1,600 [mu]g/L for molinate. Neonates (5 d postrelease) were generally more sensitive than older juveniles. Coefficients of variation (100[center dot]SD/mean) of LC50 values varied from 21 to 35%. 37 refs., 2 figs., 7 tabs.
Trentini, M; Scanabissi, F S
Each ovarian follicle of Triops cancriformis is four-celled; these cells (one oocyte and three nurse cells) are interconnected by cytoplasmic bridges. In the course of differentiation, the nurse cells are clearly recognizable; they increase in size more than the oocyte and their nuclei contain many nucleoli. For the first time in Arthropoda, yolk globules are reported to be present in nurse cell cytoplasm; these globules arise from the smooth endoplasmic reticulum. The functional significance of the intercellular bridges and the trophic role of the nurse cells are discussed.
Reid, Janet W.; Hudson, Patrick L.; Bowen, Charles A.
A recent find of the groundwater-inhabiting copepod crustacean Diacyclops harryi extended the known range of this species far northwestward, to include northern Ohio and the drainage basin of the Laurentian Great Lakes. The species was previously collected in drainages of the Atlantic Slope from New York to North Carolina. Ostracodes tentatively identified as ?Nannocandona n. sp., and amphipods belonging to the subterranean species Bactrurus mucronatus were also found at the Ohio locality.
Fennerosquilla is a monotypic genus that belongs to the family Squillidae, which has the highest generic diversity within Stomatopoda. This genus has been recorded in the north Atlantic Ocean, the Gulf of Mexico and Caribbean Sea, between 105 and 458 m depth. The present specimen was collected during the project "Avaliação da Biota Bentônica e Planctônica na porção offshore das Bacias Potiguar e Ceará", in 2011, from the continental slope region of Brazil. In this expedition Fennerosquilla heptacantha was found at 178-193 m depth, and represents the first record of the species in the south Atlantic Ocean (Rio Grande do Norte State, northeastern Brazil), expanding the southern limit distribution. The specimen is the largest recorded, measuring 149 mm total length. The pigmentation zone on median region of telson and all diagnostic characters are still preserved and agree with the original description. Fennerosquilla heptacantha has a disjunct deep water distribution (more than 100 m) in the tropical western Atlantic, mostly along the continental slope.
Hansen, Bjørn Henrik; Altin, Dag; Booth, Andy; Vang, Siv-Hege; Frenzel, Max; Sørheim, Kristin Rist; Brakstad, Odd Gunnar; Størseth, Trond R
Alkanolamines are surface-active chemicals used in a wide range of industrial, agricultural and pharmaceutical applications and products. Of particular interest is the use of alkanolamines such as diethanolamine (DEA) in the removal of CO(2) from natural gas and for CO(2) capture following fossil fuel combustion. Despite this widespread use, relatively little is known about the ecotoxicological impacts of these compounds. In an attempt to assess the potential effects of alkanolamines in the marine environment, a key species in the North Atlantic, the planktonic copepod Calanus finmarchicus, was studied for molecular effects following sublethal exposure to DEA. DEA-induced alterations in transcriptome and metabolome profiling were assessed using a suppression subtractive hybridization (SSH) gene library method and high resolution magic angle spinning nuclear magnetic resonance (HR-MAS NMR), respectively. Effects were observed on transcription of genes reportedly involved in lipid metabolism, antioxidant systems, metal binding, and amino acid and protein catabolism. These effects were accompanied by altered expression of fatty acid derivates, amino acids (threonine, methionine, glutamine, arginine, alanine and leucine) and cholines (choline, phosphocholine and glycerophosphocholine). Together, SSH and HR-MAS NMR offer complementary screening tools for the assessment of molecular responses of C. finmarchicus to DEA and can be used in the study of other chemicals and organisms. Concentration-response and time-response relationships between DEA exposure and single gene transcription were investigated using quantitative PCR. Specific relationships were found between DEA exposure and the transcription of genes involved in protein catabolism (ubiquitin-specific protease-7), metal ion homeostasis (ferritin) and defence against oxidative stress (gamma-glutamylcysteine synthase, glutathione synthase and Cu/Zn-superoxide dismutase). At the lowest alkanolamine concentration used in these experiments, which corresponded to 0.5% of the LC(50) concentration, no transcriptional effects were observed, giving information regarding the lower molecular effect level. Finally, similar transcription patterns were observed for a number of different genes following exposure to DEA, which indicates analogous mechanisms of toxicity and response. (c) 2010 Elsevier B.V. All rights reserved.
Rogers, D Christopher; Lorenz, Helen Racz
Branchinecta uruguayensis, a new species of fairy shrimp, is described from a single seasonally astatic aquatic habitat in coastal Uruguay. This is the first record of an anostracan from the nation of Uruguay. Male B. uruguayensis n. sp. are separated from other Branchinecta species by the form of the second antennae. Branchinecta uruguayensis n. sp. share the distal antennomere lobiform projection with B. papillata Rogers, De los Rios, & Zúñiga, 2008 and B. achalensis César, 1985. Branchinecta uruguayensis n. sp. females are readily separated from all other Branchinecta by the presence of posteriolateral thoracic spines and lateral crenulations on the first abdomen segment margins. A key is provided to the Branchinectidae of South America.
The order Mysida (2 families, 178 genera, 1132 species) contains species across a broad range of habitats, such as subterranean, fresh, brackish, coastal, and surface to deep-sea habitats. The Stygiomysida (2 families, 2 genera, 16 species), however, are found primarily in subterranean waters, but always in waters with a marine influence. The Mysida and Stygiomysida body is divided into three main regions: cephalon, thorax, and abdomen. They are shrimp-like in appearance, containing morphological features earlier referred to as defining a "caridoid facies". The shrimp-like morphology was to some extent diagnostic for the historic Decapod taxon Schizopoda, containing the Nebalia, Mysida, Lophogastrida, and Euphausiacea. In 1904 the concept of Schizopoda was abandoned, and the Mysidacea (Mysida and Lophogastrida) along with Cumacea, Amphipoda, Isopoda, and Tanaidacea were placed in a new taxon, the Peracarida. Later discoveries of groundwater mysids led to the establishment of Stygiomysida, but placement to either Lophogastrida or Mysida remained unclear. The presence of oostegites and absence of podobranchiae, coupled with non-statocyst bearing uropods have been used to classify the Stygiomysida as a primitive Mysida family, comparable to Petalophthalmidae. On the other hand, equally suggestive characters, but for a Lophogastrida affiliation, was suggested for the archaic foregut characters and again, non-statocyst bearing uropods. With the inclusion of DNA sequence data of ribosomal genes, sister group relationships between Stygiomysida, Lophogastrida, and Mictacea within the Peracarida are observed, which supports a classification of the Stygiomysida as a separate order removed from the Mysida. PMID:25927358
Neiber, Marco T.; Hartke, Tamara R.; Stemme, Torben; Bergmann, Alexandra; Rust, Jes; Iliffe, Thomas M.; Koenemann, Stefan
Remipedia is one of the most recently discovered classes of crustaceans, first described in 1981 from anchialine caves in the Bahamas Archipelago. The class is divided into the order Enantiopoda, represented by two fossil species, and Nectiopoda, which contains all known extant remipedes. Since their discovery, the number of nectiopodan species has increased to 24, half of which were described during the last decade. Nectiopoda exhibit a disjunct global distribution pattern, with the highest abundance and diversity in the Caribbean region, and isolated species in the Canary Islands and in Western Australia. Our review of Remipedia provides an overview of their ecological characteristics, including a detailed list of all anchialine marine caves, from which species have been recorded. We discuss alternative hypotheses of the phylogenetic position of Remipedia within Arthropoda, and present first results of an ongoing molecular-phylogenetic analysis that do not support the monophyly of several nectiopodan taxa. We believe that a taxonomic revision of Remipedia is absolutely essential, and that a comprehensive revision should include a reappraisal of the fossil record. PMID:21625553
Schön, Isa; Pinto, Ricardo L.; Halse, Stuart; Smith, Alison J.; Martens, Koen; Birky, C. William
Background Fully asexually reproducing taxa lack outcrossing. Hence, the classic Biological Species Concept cannot be applied. Methodology/Principal Findings We used DNA sequences from the mitochondrial COI gene and the nuclear ITS2 region to check species boundaries according to the evolutionary genetic (EG) species concept in five morphospecies in the putative ancient asexual ostracod genera, Penthesilenula and Darwinula, from different continents. We applied two methods for detecting cryptic species, namely the K/θ method and the General Mixed Yule Coalescent model (GMYC). We could confirm the existence of species in all five darwinulid morphospecies and additional cryptic diversity in three morphospecies, namely in Penthesilenula brasiliensis, Darwinula stevensoni and in P. aotearoa. The number of cryptic species within one morphospecies varied between seven (P. brasiliensis), five to six (D. stevensoni) and two (P. aotearoa), respectively, depending on the method used. Cryptic species mainly followed continental distributions. We also found evidence for coexistence at the local scale for Brazilian cryptic species of P. brasiliensis and P. aotearoa. Our ITS2 data confirmed that species exist in darwinulids but detected far less EG species, namely two to three cryptic species in P. brasiliensis and no cryptic species at all in the other darwinulid morphospecies. Conclusions/Significance Our results clearly demonstrate that both species and cryptic diversity can be recognized in putative ancient asexual ostracods using the EG species concept, and that COI data are more suitable than ITS2 for this purpose. The discovery of up to eight cryptic species within a single morphospecies will significantly increase estimates of biodiversity in this asexual ostracod group. Which factors, other than long-term geographic isolation, are important for speciation processes in these ancient asexuals remains to be investigated. PMID:22802945
Wongkamhaeng, Koraon; Dumrongrojwattana, Pongrat; Pattaratumrong, Manasawan Saengsakda
The beach-hopper and land-hopper genus Floresorchestia Bousfield, 1984 is most widespread in terrestrial and marine littoral habitats and has been recorded from the South African coasts through to tropical Indo-Pacific and Caribbean Sea. In Thailand, there is only Floresorchestia samroiyodensis Azman, Wongkamhaeng & Dumrongrojwattana, 2014 reported from the swamp of Prachuab Kiri Khan, southern Thailand. In this work, two new species of Floresorchestia from Phutsa Reservoir in Nakhon Ratchasima and the man-made swamp in Burapha University are described. The new species are characterised by the mandible left lacinia mobilis 4-dentate; the posterior margin of merus, carpus and propodus covered in palmate setae; the uropod 3 peduncle with two robust setae and the telson longer than broad. The characters of the specimens are described and illustrated in this paper. All specimens are deposited in the Princess Maha Chakri Sirindhorn Natural History Museum, Prince of Songkla University, Thailand.
Introduction Diaptomid copepods are prevalent throughout continental waters of the Neotropics, yet little is known about their biogeography. In this study we investigate the main biogeographical patterns among the neotropical freshwater diaptomid copepods using Parsimony Analysis of Endemicity (PAE) based on species records within ecoregions. In addition, we assess potential environmental correlates and limits for species richness. Results PAE was efficient in identifying general areas of endemism. Moreover, only ecoregion area showed a significant correlation with diaptomid species richness, although climatic factors were shown to provide possible upper limits to the species richness in a given ecoregion. Conclusion The main patterns of endemism in neotropical freshwater diaptomid copepods are highly congruent with other freshwater taxa, suggesting a strong historical signal in determining the distribution of the family in the Neotropics. PMID:25057279
Rogers, D Christopher; Soufi, Mahmoud
Chirocephalus soulukliensis, an insular new species of fairy shrimp, is described from the Soulukli Wetland in Golestan National Park in northeastern Iran. The new species shares several characters with the loosely organized "Pristicephalus" group. It is readily separated from all congeners by the short, monolamellar form of the antennal appendage, which is un-armed, the distally expanded form of the apophyses, and the sinuate form of the second antennal distal antennomere.
Myers, A A
Seven species of senticaudate amphipods belonging to the families Maeridae and Melitidae are recorded from Palau, Federated States of Micronesia, and are figured. Three species are new to science and are fully described and figured.
McMahon, B R
Work in the last decade has shown that crustacean open circulatory systems are highly efficient and controlled in a complex manner. Control occurs at several levels. Myocardial contraction is initiated in the cardiac ganglion but constantly modulated by the central nervous system, both directly via the cardioregulatory nerves and indirectly via the neurohormonal system. Heart rate and stroke volume can be controlled independently and measurements of both are needed to assess cardiac output accurately. Haemolymph outflow from many arthropod hearts is via a complex multiarterial distribution system, and the regional distribution of cardiac output is tightly controlled via cardioarterial valves at the base of each artery. These valves contain innervated muscle, and differential contraction serves to regulate the efflux of oxygenated haemolymph into a particular system. The major influence on both the evolution and control of arthropod open blood vascular systems is efficiency of oxygen uptake and delivery. This influence is illustrated by reference to a variety of crustacean and other arthropod types.
Linse, Katrin; Jackson, Jennifer A.; Fitzcharles, Elaine; Sands, Chester J.; Buckeridge, John S.
The phylogenetic relationships of seven Antarctic barnacle species, one verrucomorph and six scalpelliforms from the Scotia, Weddell and Ross seas were investigated using DNA sequences from two nuclear genes (18 S and 28 S) and one mitochondrial gene (COI), with a combined total length of 3,151 base pairs. Analyses of these new sequences, together with those of previously published ibliform, lepadiform, scalpelliform, balanomorph and verrucomorph species, confirm that the Scalpelliformes are not monophyletic. Bayesian and maximum likelihood analyses consistently recovered a monophyletic group which comprised Ornatoscalpellum stroemii (Sars) and the Southern Ocean scalpellomorphs; Arcoscalpellum sp. from the Weddell Sea, Arcoscalpellum africanum from Elephant Island, A. bouveti from Bouvet Island, the circum-Antarctic Litoscalpellum discoveryi, Litoscalpellum sp. from Shag Rocks and Scalpellum sp. from the Falkland Trough. We also used multiple fossil constraints in a relaxed clock Bayesian framework to estimate divergence times for the 18 S+28 S phylogeny. Our results indicate a mid Cretaceous divergence for the Weddell Sea Arcoscalpellum sp, followed by a late Cretaceous divergence from the North Atlantic O. stroemii. Subsequent to this, the Antarctic scalpellomorphs began to radiate at the Cretaceous-Tertiary boundary. Monophyly within the scalpellid genera Arcoscalpellum, Litoscalpellum and Scalpellum was strongly rejected by all loci. Our results show incongruence between taxonomy and molecular systematics and highlight the need for more species to be sequenced as well as taxonomic revisions to resolve uncertainties in the phylogenetic relationships of the stalked barnacles.
Wongkamhaeng, Koraon; Dumrongrojwattana, Pongrat; Pattaratumrong, Manasawan Saengsakda
Abstract The beach-hopper and land-hopper genus Floresorchestia Bousfield, 1984 is most widespread in terrestrial and marine littoral habitats and has been recorded from the South African coasts through to tropical Indo-Pacific and Caribbean Sea. In Thailand, there is only Floresorchestia samroiyodensis Azman, Wongkamhaeng & Dumrongrojwattana, 2014 reported from the swamp of Prachuab Kiri Khan, southern Thailand. In this work, two new species of Floresorchestia from Phutsa Reservoir in Nakhon Ratchasima and the man-made swamp in Burapha University are described. The new species are characterised by the mandible left lacinia mobilis 4-dentate; the posterior margin of merus, carpus and propodus covered in palmate setae; the uropod 3 peduncle with two robust setae and the telson longer than broad. The characters of the specimens are described and illustrated in this paper. All specimens are deposited in the Princess Maha Chakri Sirindhorn Natural History Museum, Prince of Songkla University, Thailand. PMID:27917056
Rogers, D Christopher
Nine anostracan biogeographical regions are defined for North America: Appalachia/Ozark, Southwest Arid, Great Plains, Coastal Plain, Neotropical, California, Cold Deserts, Beringia/Canadian Shield, and Transmontane. These regions are quantitatively defined using species distributions compared through Jaccard's Coefficient of Community Similarity, and qualitatively defined using climate data, following the ecoregions protocol of the US Environmental Protection Agency for North America and the Universidad Nacional Autónoma de México for Mexico. Community assemblages are quantified using Fager's Index of Recurring Species Groups. The average Fager's Index for each bioregion, as well as the percentage of taxa co-occurring, generally decreases with the length of time the region has been available for colonisation. The strong Fager's Index/colonisation time availability relationship suggests that the Monopolization Hypothesis of De Meester et al. may function at larger landscape scales.
Cornils, Astrid; Blanco-Bercial, Leocadio
The Paracalanidae are ecologically-important marine planktonic copepods that occur in the epipelagic zone in temperate and tropical waters. They are often the dominant taxon - in terms of biomass and abundance - in continental shelf regions. As primary consumers, they form a vital link in the pelagic food web between primary producers and higher trophic levels. Despite the ecological importance of the taxon, evolutionary and systematic relationships within the family remain largely unknown. A multigene phylogeny including 24 species, including representatives for all seven genera, was determined based on two nuclear genes, small-subunit (18S) ribosomal RNA and Histone 3 (H3) and one mitochondrial gene, cytochrome c oxidase subunit I (COI). The molecular phylogeny was well supported by Maximum likelihood and Bayesian inference analysis; all genera were found to be monophyletic, except for Paracalanus, which was separated into two distinct clades: the Paracalanus aculeatus group and Paracalanus parvus group. The molecular phylogeny also confirmed previous findings that Mecynocera and Calocalanus are genera of the family Paracalanidae. For comparison, a morphological phylogeny was created for 35 paracalanid species based on 54 morphological characters derived from published descriptions. The morphological phylogeny did not resolve all genera as monophyletic and bootstrap support was not strong. Molecular and morphological phylogenies were not congruent in the positioning of Bestiolina and the Paracalanus species groups, possibly due to the lack of sufficient phylogenetically-informative morphological characters. Copyright © 2013 Elsevier Inc. All rights reserved.
Suárez-Morales, Eduardo; Mckinnon, A David
Monstrilloid copepods collected during the past two decades from zooplankton surveys in reef and coastal areas of Australia were analyzed. A first contribution included the taxonomic analysis of three genera of the Monstrilloida, Monstrillopsis Sars, 1921, Maemonstrilla Grygier & Ohtsuka, 2008, and the newly described Australomonstrillopsis Suárez-Morales & McKinnon, 2014. In this document a taxonomic analysis of the species belonging to the genus Cymbasoma Thompson, 1888 is provided. A total of 28 species were found, most of them being undescribed. Seventeen species were described based on females only and eight on male specimens while three species were described from both sexes. Males of Australian species of Cymbasoma are distinguished by details of the genital complex, body size and proportions, ornamentation and processes of the cephalic region, number of caudal setae, and the characteristic structure or ornamentation of the genital lappets. Two main groups of males were distinguished on the basis of the number of caudal setae (3 or 4). As for the females, 20 of the 25 new species of Cymbasoma have fifth legs with an unarmed inner lobe and three setae on the outer lobe; one of these species (C. jinigudira sp. nov.) belongs to the C. longispinosum species-group (sensu Üstün et al. 2014). Another group, consisting of five species, has only two setae on the outer (exopodal) lobe. There were no Australian species of Cymbasoma with a single lobe. A species group, named after C. agoense, is proposed to include species sharing a globose body and a female fifth leg with a large endopodal lobe and an outer (exopodal) lobe with two setae. The females of the new species of Cymbasoma from Australia can be distinguished from their known congeners by unique combinations of characters including the type of body ornamentation, body size and shape, antennule armature and proportions, the presence of distinctive features of the legs 1-4, the presence/absence of processes on the genital compound somite, and the presence/absence of a constriction of the anal somite. We report the occurrence of two previously described species, C. agoense Sekiguchi, 1982 from Japan and C. bali Desai & Krishnaswamy, 1962 from India in Australian waters. Considering the addition of the 25 new species here described, the number of nominal species of the genus is now 66. A key to the Australian species of Cymbasoma (males and females) and a map showing their occurrence in Australia are also provided.
Neiber, Marco T; Hartke, Tamara R; Stemme, Torben; Bergmann, Alexandra; Rust, Jes; Iliffe, Thomas M; Koenemann, Stefan
Remipedia is one of the most recently discovered classes of crustaceans, first described in 1981 from anchialine caves in the Bahamas Archipelago. The class is divided into the order Enantiopoda, represented by two fossil species, and Nectiopoda, which contains all known extant remipedes. Since their discovery, the number of nectiopodan species has increased to 24, half of which were described during the last decade. Nectiopoda exhibit a disjunct global distribution pattern, with the highest abundance and diversity in the Caribbean region, and isolated species in the Canary Islands and in Western Australia. Our review of Remipedia provides an overview of their ecological characteristics, including a detailed list of all anchialine marine caves, from which species have been recorded. We discuss alternative hypotheses of the phylogenetic position of Remipedia within Arthropoda, and present first results of an ongoing molecular-phylogenetic analysis that do not support the monophyly of several nectiopodan taxa. We believe that a taxonomic revision of Remipedia is absolutely essential, and that a comprehensive revision should include a reappraisal of the fossil record.
Lowry, J K; Springthorpe, R T
Floresorchestia floresiana (Weber, 1892) from Flores, F. anomala (Chevreux, 1901) from the Seychelles, F. malayensis (Tattersall, 1922) from Singapore and F. thienemanni (Schellenberg, 1931) from Java are redescribed based on original type material or newly collected material from near the type locality. Nine new species are described, in the widespread Indo-West Pacific and Caribbean talitrid genus Floresorchestia: F. andrevo sp. nov. and F. itampolo sp. nov. from Madagascar; F. kalili sp. nov. from the Bismarck Archipelago, Papua New Guinea; F. laurenae sp. nov. from Timor-Leste; F. oluanpi sp. nov. from southern Taiwan; F. papeari sp. nov. from Tahiti; F. serejoae sp. nov. from far north Queensland, Australia; F. seringat sp. nov. from Singapore; and F. yap sp. nov. from Micronesia; plus Floresorchestia sp. 1 from Hainan Island, South China Sea, Floresorchestia sp. 2 from Kilakarai and other sites in south-eastern India and Floresorchestia sp. 3 from Phuket Island, Thailand. Floresorchestia contains 28 species. In this paper all are catalogued and diagnosed.
Lowry, J K; Bopiah, Arundathi
One new genus and four species of talitrid amphipods are described from Tonga: Platorchestia ano sp. nov.; Talorchestia spinipalma (Dana, 1852); Tongorchestia pangaimotu gen. nov., sp. nov.; T. towneri sp. nov.
Rainbow, P. S.; Moore, P. G.; Watson, D.
Data are presented on the copper and zinc concentrations of four talitrid amphipod species (standard dry weight 10 mg), i.e. Orchestia gammarellus (Pallas), O. mediterranea Costa, Talitrus saltator Montagu and Talorchestia deshayesii (Audouin), from 31 sites in S.W. Scotland, N. Wales and S.W. England. More limited data are also presented for cadmium in O. gammarellus (three sites) and T. deshayesii (one site). In S.W. Scotland, copper concentrations were raised significantly in O. gammarellus from Whithorn and Auchencairn (Solway) and Loch Long and Holy Loch (Clyde). In S.W. England, copper concentrations were highest at Restronguet Creek, Torpoint and Gannel (Cornwall). Samples of O. gammarellus from Islay (inner Hebrides) taken adjacent to the effluent outfalls of local whisky distilleries fell into two groups based on copper concentrations (presumably derived from copper stills), the higher copper levels deriving from the more productive distilleries. High copper levels were found in T. saltator and Tal. deshayesii from Dulas Bay (Wales). Zinc levels in O. gammarellus were high in Holy Loch and Auchencairn (Scotland), Gannel and Torpoint (England) but extremely elevated (as was Zn in O. mediterranea) at Restronguet Creek. Zinc was also high in T. saltator from Dulas Bay (Wales), but not in Tal. deshayesii. Cadmium levels in O. gammarellus from Kilve (Bristol Channel) were much raised. These differences (a) conform with expectations of elevated bioavailability of these metals from well researched areas (S.W. England & N. Wales), and (b) identify hitherto unappreciated areas of enrichment in S.W. Scotland. Orchestia gammarellus is put forward as a suitable biomonitor for copper and zinc in British coastal waters.
Khodami, Sahar; McArthur, J Vaun; Blanco-Bercial, Leocadio; Martinez Arbizu, Pedro
For the first time, the phylogenetic relationships between representatives of all 10 copepod orders have been investigated using 28S and 18S rRNA, Histone H3 protein and COI mtDNA. The monophyly of Copepoda (including Platycopioida Fosshagen, 1985) is demonstrated for the first time using molecular data. Maxillopoda is rejected, as it is a polyphyletic group. The monophyly of the major subgroups of Copepoda, including Progymnoplea Lang, 1948 (=Platycopioida); Neocopepoda Huys and Boxshall, 1991; Gymnoplea Giesbrecht, 1892 (=Calanoida Sars, 1903); and Podoplea Giesbrecht, 1892, are supported in this study. Seven copepod orders are monophyletic, including Platycopioida, Calanoida, Misophrioida Gurney, 1933; Monstrilloida Sars, 1901; Siphonostomatoida Burmeister, 1834; Gelyelloida Huys, 1988; and Mormonilloida Boxshall, 1979. Misophrioida (=Propodoplea Lang, 1948) is the most basal Podoplean order. The order Cyclopoida Burmeister, 1835, is paraphyletic and now encompasses Poecilostomatoida Thorell, 1859, as a sister to the family Schminkepinellidae Martinez Arbizu, 2006. Within Harpacticoida Sars, 1903, both sections, Polyarthra Lang, 1948, and Oligoarthra Lang, 1948, are monophyletic, but not sister groups. The order Canuelloida is proposed while maintaining the order Harpacticoida s. str. (Oligoarthra). Cyclopoida, Harpacticoida and Cyclopinidae are redefined, while Canuelloida ordo. nov., Smirnovipinidae fam. nov. and Cyclopicinidae fam. nov are proposed as new taxa.
This report is part of a series that summarizes the species and localities of Costa Rican marine taxa. A review of the literature on copepods, both pelagic and benthic for the Pacific and Caribbean coast of Costa Rica, includes eighty species. Sixty seven pelagic species have been found, distributed between sixteen calanoid, one cyclopoid, three harparticoid and four poecilostomatoid families. Moreover, thirteen benthonic species distributed into six families, all harparticoids, are reported. Among the pelagic families, Pontellidae has six species, while Paracalanidae and Eucalanidae had five each. Other families, like Calanidae, Pseudodiaptomidae and Acartiidae had four species and most families only one. Forty five species are reported only for the Pacific coast, thirteen for the Caribbean coast, only nine species occurred in both coasts; being a direct consequence of the more intensive research effort in the Pacific. Pelagic copepod biodiversity reflects different oceanographic conditions in both coasts. Typical estuarine species were found in the lower region of the Gulf of Nicoya, while a mixture of estuarine and oceanic species were found in Golfo Dulce. Diversity in the Caribbean, specially at the Cahuita coral reef is lower in comparison with the copepod diversity found in other regions in the Caribbean sea. This may be due to the high sediment resuspension rate characteristic of the Cahuita coral reef, which could affect the reproduction of many holozooplankters, specially copepods. Although sixty seven pelagic copepod species appears to be in low numbers, in terms of specific biodiversity it is as high when compared to numbers found in other tropical areas. Thirteen species are reported in the literature, all harparticoids. Five species, three sub-species and one genera were new to science. Balacopsylla is reported for the first time from a neotropical regions, while the genus Karllangia, represented by two coexisting species in the Caribbean coast, belong to a few circumtropical-subtropical genera. The most diverse family was Tetragonicipitidae. This is the first effort to summarize the available information about the biodiversity of marine copepods for Costa Rica's coasts.
Trilles, Jean-Paul; Rameshkumar, Ganapathy; Ravichandran, Samuthirapandian
Eleven Nerocila species are recorded from 22 marine fishes belonging to 15 families. Three, Nerocila arres, Nerocila depressa, and Nerocila loveni, are new for the Indian fauna. N. arres and Nerocila sigani, previously synonymized, are redescribed and their individuality is restored. Nerocila exocoeti, until now inadequately identified, is described and distinctly characterized. A neotype is designated. New hosts were identified for N. depressa, N. loveni, Nerocila phaiopleura, Nerocila serra, and Nerocila sundaica. Host-parasite relationships were considered. The parasitologic indexes were calculated. The site of attachment of the parasites on their hosts was also observed. A checklist of the nominal Nerocila species until now reported from Indian marine fishes was compiled.
Castellanos, Iván; Gasca, Rebeca
The composition, abundance and distribution of euphausiids from the southern part of the Mexican Caribbean Sea (August 1986) were sampled during the ARCOMM I cruise on board the R/V "Justo Sierra" of UNAM. Sampling was done using a Bongo-net (0.5 mm mesh size) performing oblique hauls from 200 m to the surface at 28 stations. Of the total euphausiid numbers, the most abundant species was Stylocheiron carinatum (49%), followed by Euphausia americana (9.8%) and E. tenera with (7.8%). The highest total density and that of the three most abundant species occurred during the night sampling, and probably was related to vertical migration patterns. The Bray-Curtis index revealed three station assemblages, related to the day-night variations of the euphausiid community. Species were distributed mainly in the oceanic area, and were absent in the neritic zones. The local fauna shows a strong affinity for the euphausiid community of the Gulf of Mexico and other areas of the Caribbean Sea. Four species are considered to be new records for the western Caribbean Sea.
4a-d; Broch 1931:116. Specific features: Parietes longitudinally ribbed, white or pinkish with summits tinged greenish blue (Plate le, f). Articular...1921). Later authors describe the presence of the spines ( Broch 1931; Rosell, 1972). A. zuiho Hiro (1936:632), figs. 8, 9), collected near Darwin...at MRL. 11 6. BIBLIOGRAPHY Bishop, M.W.H. (1951), Distribution of barnacles by ships. Nature, Lond. 167, 531. Broch , H. (1931), Indomalayan Cirripedia
Sidabalok, Conni M; Bruce, Niel L
Three species of Cirolanidae described by Nierstrasz in 1931 are redescribed from the type material: Cirolana indica Nierstrasz, 1931, with new material from Singapore and Lombok Island, Indonesia; C. vanhoeffeni Nierstrasz, 1931; and C. stebbingi Nierstrasz, 1931, which is here transferred to the genus Politolana Bruce, 1981 based on the elongate body, long peduncle of pleopod 1, narrow and slender frontal lamina, flat and robust carpus of pereopod 7, long and acute robust setae on merus-propodus pereopod 1, secondary unguis on dactylus, and antenna peduncle articles 1-2 shorter than the subequal articles 3-5.
Bamber, Roger N; Seaby, Richard M H
Experiments have been undertaken exposing larval common shrimp (Crangon crangon) and lobster (Homarus gammarus) and adult copepods (Acartia tonsa) to the key stresses of entrainment within power-station cooling-water systems. The apparatus has enabled the testing of mechanical, thermal, chlorine and realistic pressure effects both alone and in combination, the range of stressors spanning the standard conditions found within a temperate coastal direct-cooled power station. Mechanical stresses affected only lobster larvae, pressure changes affected only the Acartia adults. Residual chlorine caused significant mortality of Acartia and shrimp larvae, but had no effect on lobster larvae even at 1 ppm. The temperature increment significantly affected all three species, with a synergistic effect on chlorine sensitivity in the shrimp larvae, but only temperatures higher than would be experienced in a normally-operating power station affected the copepods. The majority of individuals of each species would survive passage through a power-station system under normal conditions. It is notable that, within the species tested, generalizations from the responses of one species to those of another are not valid.
Cook, Charles E
Background Animal mitochondrial genomes are physically separate from the much larger nuclear genomes and have proven useful both for phylogenetic studies and for understanding genome evolution. Within the phylum Arthropoda the subphylum Crustacea includes over 50,000 named species with immense variation in body plans and habitats, yet only 23 complete mitochondrial genomes are available from this subphylum. Results I describe here the complete mitochondrial genome of the crustacean Squilla mantis (Crustacea: Malacostraca: Stomatopoda). This 15994-nucleotide genome, the first described from a hoplocarid, contains the standard complement of 13 protein-coding genes, 22 transfer RNA genes, two ribosomal RNA genes, and a non-coding AT-rich region that is found in most other metazoans. The gene order is identical to that considered ancestral for hexapods and crustaceans. The 70% AT base composition is within the range described for other arthropods. A single unusual feature of the genome is a 230 nucleotide non-coding region between a serine transfer RNA and the nad1 gene, which has no apparent function. I also compare gene order, nucleotide composition, and codon usage of the S. mantis genome and eight other malacostracan crustaceans. A translocation of the histidine transfer RNA gene is shared by three taxa in the order Decapoda, infraorder Brachyura; Callinectes sapidus, Portunus trituberculatus and Pseudocarcinus gigas. This translocation may be diagnostic for the Brachyura. For all nine taxa nucleotide composition is biased towards AT-richness, as expected for arthropods, and is within the range reported for other arthropods. Codon usage is biased, and much of this bias is probably due to the skew in nucleotide composition towards AT-richness. Conclusion The mitochondrial genome of Squilla mantis contains one unusual feature, a 230 base pair non-coding region has so far not been described in any other malacostracan. Comparisons with other Malacostraca show that all
Anger, K.; Dawirs, R. R.
The influence of starvation on larval development of the spider crab Hyas araneus (L.) was studied in laboratory experiments. No larval stage suffering from continual lack of food had sufficient energy reserves to reach the next instar. Maximal survival times were observed at four different constant temperatures (2°, 6°, 12° and 18 °C). In general, starvation resistance decreased as temperatures increased: from 72 to 12days in the zoea-1, from 48 to 18 days in the zoea-2, and from 48 to 15 days in the megalopa stage. The length of maximal survival is of the same order of magnitude as the duration of each instar at a given temperature. “Sublethal limits” of early starvation periods were investigated at 12 °C: Zoea larvae must feed right from the beginning of their stage (at high food concentration) and for more than one fifth, approximately, of that stage to have at least some chance of surviving to the next instar, independent of further prey availability. The minimum time in which enough reserves are accumulated for successfully completing the instar without food is called “point-of-reserve-saturation” (PRS). If only this minimum period of essential initial feeding precedes starvation, development in both zoeal stages is delayed and mortality is greater, when compared to the fed control. Starvation periods beginning right after hatching of the first zoea cause a prolongation of this instar and, surprisingly, a slight shortening of the second stage. The delay in the zoea-1 increases proportionally to the length of the initial fasting period. If more than approximately 70 % of the maximum possible survival time has elapsed without food supply, the larvae become unable to recover and to moult to the second stage even when re-fed (“point-of-no-return”, PNR). The conclusion, based on own observations and on literature data, is that initial feeding is of paramount importance in the early development of planktotrophic decapod larvae. Taking into account hormonal and other developmental processes during the first moult cycle, a general hypothesis is proposed to explain the key role of first food uptake as well as the response pattern of the zoea-1 stage to differential starvation periods.
Pinto, Marcelo R; Lucena, Malson N; Faleiros, Rogério Oliveira; Almeida, Eduardo Alves; McNamara, John C; Leone, Francisco A
We evaluate the effects of total ammonia nitrogen-N (TAN) exposure for 72h on (Na(+),K(+))- and V(H(+))-ATPase activities and on their subunit expressions in gills of the diadromous freshwater shrimp Macrobrachium amazonicum. Specific (Na(+),K(+))- and V(H(+))-ATPase activities increased roughly 1.5- to 2-fold, respectively, after exposure to 2.0mmolL(-1) TAN. Quantitative RT-PCR analyses revealed a 2.5-fold increase in V(H(+))-ATPase B subunit mRNA expression while (Na(+),K(+))-ATPase α-subunit expression was unchanged. Immunohistochemical analyses of the gill lamellae located the (Na(+),K(+))-ATPase throughout the intralamellar septal cells, independently of TAN concentration, while the V(H(+))-ATPase was located in both the apical pillar cell flanges and pillar cell bodies. Systemic stress parameters like total hemocyte count decreased by 30% after exposure to 2.0mmolL(-1) TAN, accompanied by increased activities of the oxidative stress enzymes superoxide dismutase, glutathione reductase and glucose-6-phosphate dehydrogenase in the gills. The stress responses of M. amazonicum to elevated TAN include increases in gill (Na(+),K(+))- and V(H(+))-ATPase activities that are accompanied by changes in oxidative stress enzyme activities, immune system effects and an increase in gill V(H(+))-ATPase gene expression. These findings likely underpin physiological effects in a crustacean like M. amazonicum that exploits multiple ecosystems during its life cycle, as well as under culture conditions that may significantly impact shrimp production by the aquaculture industry. Copyright © 2015 Elsevier B.V. All rights reserved.
Klompmaker, Adiël A.
Ghost shrimps of Callianassidae and Ctenochelidae are soft-bodied, usually heterochelous decapods representing major bioturbators of muddy and sandy (sub)marine substrates. Ghost shrimps have a robust fossil record spanning from the Early Cretaceous (~ 133 Ma) to the Holocene and their remains are present in most assemblages of Cenozoic decapod crustaceans. Their taxonomic interpretation is in flux, mainly because the generic assignment is hindered by their insufficient preservation and disagreement in the biological classification. Furthermore, numerous taxa are incorrectly classified within the catch-all taxon Callianassa. To show the historical patterns in describing fossil ghost shrimps and to evaluate taphonomic aspects influencing the attribution of ghost shrimp remains to higher level taxa, a database of all fossil species treated at some time as belonging to the group has been compiled: 250 / 274 species are considered valid ghost shrimp taxa herein. More than half of these taxa (160 species, 58.4%) are known only from distal cheliped elements, i.e., dactylus and / or propodus, due to the more calcified cuticle locally. Rarely, ghost shrimps are preserved in situ in burrows or in direct association with them, and several previously unpublished occurrences are reported herein. For generic assignment, fossil material should be compared to living species because many of them have modern relatives. Heterochely, intraspecific variation, ontogenetic changes and sexual dimorphism are all factors that have to be taken into account when working with fossil ghost shrimps. Distal elements are usually more variable than proximal ones. Preliminary results suggest that the ghost shrimp clade emerged not before the Hauterivian (~ 133 Ma). The divergence of Ctenochelidae and Paracalliacinae is estimated to occur within the interval of Hauterivian to Albian (133–100 Ma). Callichirinae and Eucalliacinae likely diverged later during the Late Cretaceous (100–66 Ma), whereas Callianassinae did not appear before the Eocene (56 Ma). PMID:27499814
De Grave, Sammy; Chan, Tin-Yam; Chu, Ka Hou; Yang, Chien-Hui; Landeira, José M
We present evidence that the single representative of the crustacean order Amphionidacea is a decapod shrimp and not a distinct order. After reviewing available morphological evidence, it is concluded that Amphionides is a larval form, but with an as yet unknown parentage. Although the most likely adult form is in the family Pandalidae, the limited molecular data available cannot fully resolve its affinity. We therefore propose to treat Amphionides reynaudii as incertae sedis within Caridea, rather than a separate family. In view of the large scale, tropical and subtropical distribution of the taxon, the possibility is discussed that Amphionides is more likely to be a composite taxon at generic level, rather than larvae of a single shrimp species.
Kevrekidis, Kosmas; Thessalou-Legaki, Maria
The reproductive biology including insemination frequency, ovarian maturation, gonadosomatic index (GSI), size at first maturity, and fecundity of Melicertus kerathurus were investigated using monthly samples from Thermaikos Gulf. Insemination was recorded by the presence of a spermatophore in the thelycum, and ovarian development was based on macroscopic ovarian staging (ST1-ST5). Inseminated females were found throughout the year with high percentages recorded from April to July. Although all ovarian stages were represented in mated females, insemination increased with size and ovarian maturation. High percentages of vitellogenic or mature ovarian stages were observed from May to July, while immature and developing ovaries were predominant mainly in winter. Spawned ovaries occurred from May to October. Carapace length at first maturity based on the presence of a spermatophore (CL50sp) was estimated at 39.20 mm, while that based on the presence of vitellogenic and mature ovaries (CL50ov) at 40.70 mm. The seasonal peak in the proportion of mature females (ST4) varied with size. Inseminated females at ST4 and GSI peaked in June-July. GSI varied in relation to insemination status and ovarian stage. In large females (>50 mm CL), the decline in mature ovaries and GSI increment with size indicates a relative reduction in the reproductive output. The number of oocytes ranged from 62,742 to 602,947 (mean ± SD: 268,000 ± 113,000). As the prawns are targeted during the spawning season, mainly by the artisanal fishery, and female size at first maturity is selected by artisanal net size, managerial measures toward artisanal fishery should be implemented.
Liu, Qiu-Ning; Chai, Xin-Yue; Jiang, Sen-Hao; Zhou, Chun-Lin; Xuan, Fu-Jun; Zhang, Dai-Zhen; Tang, Bo-Ping
The complete mitochondrial genome (mitogenome) of Litopenaeus vannamei was determined to be 15 989 bp in size, it contains 22 tRNA genes, 13 protein-coding genes (PCGs), two rRNA genes and a D-loop region. The nucleotide composition was biased toward A + T nucleotides (67.8%) and the AT skew of this mitogenome was slightly negative (-0.025). All tRNA genes displayed a typical clover-leaf structure, except for trnS1 (AGN). Thirteen PCGs were initiated by ATN codons, except for cox1 gene which was initiated by ACG. Four of the 13 PCGs had the incomplete termination codon by T. The rrnL was 1371 bp and the rrnS was 853 bp, and the AT content of the combined rRNA genes was 70.9%. The D-loop region of the mitogenome was 985 bp in length and the A + T content was 82.7%, and no tandem repeat was found in this region. Phylogenetic analysis showed that the placement of L. vannamei was within the Penaeidae.
Aloise, Débora de Almeida; Maia-Lima, Francisco de Assis; de Oliveira, Ruth Medeiros; Cabral, Thiago de Melo; Molina, Wagner Franco
Ploidy manipulation has been rarely used in the genetic improvement of cultured marine shrimps. Although polyploid induction has been proven to be successful in Penaeids, including the species Litopenaeus vannamei, the methodology still requires some improvements. In the present work, different thermal shock treatments on ploidy manipulation were tested and a protocol for detecting polyploid individuals was also established. Fertilized eggs were treated by cold (10°C) and heat (38°C) thermal shocks for 8, 12, 15, 18, 20, and 22 min to induce polyploidy. Nuclear measurements within distinct treatments revealed a significant deviation in relation to the mean diameter of nuclei in the control individuals. Triploid and tetraploid metaphases were observed within treated individuals, confirming the increase of interphasic nuclear diameter. The cold thermal shock was more efficient than the hot ones, besides leading to a higher and more homogeneous hatchery rate. A mean number of three nucleoli per nucleus were observed in diploid individuals, while treated samples usually presented up to five nucleoli per nucleus. The standardization of protocols to obtain and detect polyploid products allows further utilization of such methods on a commercial scale in order to evaluate the performance of polyploid individuals in the genetic improvement of L. vannamei.
Anker, Arthur; Caripe, Jonathan Vera
A new species of the infaunal alpheid shrimp genus Leptalpheus Williams, 1965 is described based on material from three localities on the Caribbean coast of Panama and Isla Chimana Grande, Venezuela. Leptalpheus pereirai sp. nov. belongs to a group of species characterised by the presence of well-developed adhesive disks on the major chela and appears to dwell in burrows of the large callianassid ghost shrimp, Glypturus acanthochirus Stimpson 1866.
Osawa, Yumiko; Aoki, Masakazu N; Thiel, Martin; Bauer, Raymond T
The hypothesis of protandrous (male to female) sex change was tested for the first time in a rhynchocinetid shrimp, Rhynchocinetes uritai, with an analysis of life-history traits. Samples were taken monthly for 2 years in Oura Bay, Japan, using a combination of bait and refuge traps. Breeding was seasonal but extended from spring through autumn, with female-phase individuals (FPs) producing broods successively, with their ovaries maturing for a new spawn during incubation of a previous brood. Females incubated numerous (∼500-4000) embryos that suffered insignificant mortality before hatching. Recruitment of juveniles after planktonic larval development began in summer and peaked during the autumn, with negligible recruitment during winter and spring. Cohort analysis confirmed the hypothesis of protandric sex change in this species, with juveniles maturing into the male phase (MP) during their first reproductive season at an age of 6-10 mon, depending on the time of recruitment. Sex change occurred during the following winter when transitional individuals matured into FPs during their second reproductive season at an age of ≥18 mon. Two cohorts were followed from recruitment until the end of the study, indicating a life span of 21-25 mon. Aside from its sexual system, this sex-changing species showed no obvious differences in reproductive and other life-history traits from those of gonochoric species from similar latitudes and habitats. © 2015 Marine Biological Laboratory.
Pedale, Adriana B; Fujimoto, Rodrigo Y; Santos, Rudã F B; Abrunhosa, Fernando A
The sodium metabisulphite salt is usually used in shrimp culture to prevent black spot. Unfortunately the toxicological effect of this xenobiotic in decapod crabs is unknown. Thus, the present study aims to investigate the sodium metabisulphite LC(50) - 96 h in the mangrove species Ucides cordatus. Crabs were collected in the tidal creek margins in Bragança estuarine and were submitted to preliminary test (screening) and posterior definitive test. Crabs were exposed in five different concentrations and a control group in five replicates, two crabs per recipient (5 L) during 96 hours. A negative correlation was observed to sodium metabisulphite concentration in relation to dissolved oxygen and pH. At the end of the experiment were obtained the following mortality index in relation to sodium metabisulphite concentrations: 100% in 86.0 mg.L(-1), 74% in 62.0 mg.L(-1), 52% in 52.0 mg.L(-1), 44% in 38.0 mg.L(-1). The value of LC(50) - 96 h for U. cordatus was determinate at 42.58 mg.L(-1)/Na(2)S(2)O(5). The results strongly indicate that sodium metabisulphite is toxic for U. cordatus, and this crab could be used for biomonitoring the environmental impact.
Giraldes, Bruno Welter; Al-Maslamani, Ibrahim; Smyth, David
The Indo-West Pacific genus Coleusia Galil 2006, was recently described and now comprises seven species. We describe a new species from the western Arabian Gulf, Coleusia janani n. sp. The new species is closely related to the congener C. biannulata (Tyndale-Biscoe & George, 1962), and can be distinguished from other species at these genus congeners mainly by the straight upward apical shape of the male first pleopod (G1). An updated identification key to the species of Coleusia, as well as an overview of the geographical distribution of the species included in the genus are also presented.
Alkaladi, Ali; Zeil, Jochen
We describe the structural organization of the ommatidium in the compound eye of the fiddler crab, Uca vomeris, at both the light- and the electron-microscopy levels. We pay particular attention to the organization of the optical system, the retinular cells, the rhabdom, and of pigment cells. Although the fiddler crab compound eye is of the apposition type, typical for Brachyuran crabs, we identify a number of novel, functionally relevant aspects of ommatidial organization that have not previously been described. The flat corneal facet lenses provide the main focusing power and therefore must contain a gradient of refractive index. Each ommatidium has the typical set of eight retinular cells, with a distal retinular cell R8 lying close to the proximal tip of the crystalline cone. R8 is shaped into four lobes, which are separated by proximal extensions of the four crystalline cone cells and of distal extensions of retinular cells R1-R7. The microvilli in the R8 rhabdom are not aligned in a uniform direction, while the microvilli of the main rhabdom show the typical crustacean pattern of alternating bands of horizontally (R3, R4, R7) and vertically aligned microvilli (R1, R2, R5, R6). We describe in detail the distribution and structural properties of screening pigment granules in the two types of pigment cells and in the retinular cells in the equatorial eye. We discuss the functional significance of this fine-structural organization of the fiddler crab compound eye in relation to visual processing and visual ecology. Copyright © 2013 Wiley Periodicals, Inc.
Hui, Min; Liu, Yuan; Cui, Zhaoxia
The taxonomy and phylogeny of brachyuran crabs, and particularly of the Podotremata, have been the subjects of controversy due to their morphological diversity and complexity. The first complete mitochondrial genome (mitogenome) sequence of primitive crab Homologenus malayensis has been determined. The mitogenome is 15,793 bp in length, with A + T content 71.7%. The gene content and order are consistent with those in typical brachyuran crabs. A putative control region of 883 bp is identified due to its position (between srRNA and tRNA(Ile)) and AT richness (75.5%). Notably, the control region in H. malayensis contains nine identical specific repeat units of 42 bp and 11 identical repeat units of 2 bp with a total length of 400 bp, which is different from other crabs. These results are expected to provide useful information on both genomics and the future phylogenetic study of primitive crabs.
Hyžný, M.; van Bakel, B.W.M.; Guinot, D.
On the basis of several carapaces, a new species of xanthid crab, Etisus evamuellerae, is described from the Middle Miocene of the Vienna (Austria) and Great Hungarian basins. It differs from the coeval xanthids, Xantho moldavicus and Pilodius vulgaris, in having a distinctly protruding front and comparatively longer carapace. Contrary to those two species, the new one makes up for just a small percentage in the decapod crustacean assemblages studied. PMID:25983383
Meyer, Kirstin S; Cumberlidge, Neil; Koppin, Jennifer C
A new genus and species of freshwater crab is described from Madagascar. The new species is morphologically closest to the three species of the genus Foza Reed & Cumberlidge, 2006, but can easily be distinguished by having a completely smooth carapace with an unarmed anterolateral margin and a mandible with a distinctly shortened anterior lobe. This unusual suite of characters is sufficient to warrant the recognition of a new monotypic genus to accommodate this species.
Vidal-Gadea, A G; Belanger, J H
Decapod crustaceans have been the focus of neuroethological studies for decades. With few exceptions, however, their musculature remains scarcely described. We study the neuroethology of legged locomotion in the portly spider crab, Libinia emarginata (Brachyura, Majoidea), which preferentially walks forward. Majoid crabs are thought to be among the first to have adopted the crab form (carcinification) from lobster-like ancestors, making them interesting subjects for comparative and phylogenetic studies. The radial arrangement of the legs around the thorax, coupled with its unidirectional walking modality makes L. emarginata a good candidate for the presence of anterior and posterior limb specializations. Here we describe the complete muscular anatomy of all the pereopods of L. emarginata and compare our findings with other decapods described in the literature. The number of proximal muscle bundles differs between the anterior and posterior pereopods of L. emarginata. We describe an intersegmental bundle of the flexor muscle similar to the one present in distantly related, forward walking macruran species. The behavioral repertoire, amenability to experimental investigations, and phylogenetic position make spider crabs useful species for the study of the neural control of legged locomotion. To our knowledge, this is the first instance of a complete description and comparison of the musculature in all the locomotor appendages of one species.
Castejón, Diego; Ribes, Enric; Durfort, Mercè; Rotllant, Guiomar; Guerao, Guillermo
The morphology of the foregut of the Say's mud crab Dyspanopeus sayi was described in adults and larvae. The ossicle system was illustrated based on a staining method with Alizarin-Red. The gastric teeth and cardio-pyloric valve were dissected and examined using optical and scanning electron microscopy. In the adults, the morphology of ossicles and gastric teeth of D. sayi is very similar to the related species Rhithropanopeus harrisii. The foregut of first zoea (ZI) presented a functional cardio-pyloric valve while the filter press was lacking. The filter press was observed in the pyloric chamber from ZII. The most significant changes in morphology take place after metamorphosis from ZIV to megalopa, including the occurrence of the gastric mill. The organization and morphology of many megalopal foregut ossicles are recognizable in the adult phase, although the morphology of the gastric teeth differs from the morphology of adults. A correlation of gastric mill structures with food preferences and their contribution to the phylogeny are briefly discussed. Copyright © 2014 Elsevier Ltd. All rights reserved.
Cobos, Vanesa; Díaz, Vanessa; Raso, Jose Enrique García; Manjón-Cabeza, M. E.
The present work completes a series of studies on the biology of the shrimp Hippolyte inermis Leach 1815, where we suggested the species to be gonochoristic. The morphology of the male reproductive system (testes, vasa deferentia, gonopores) and the different stages of male germ cell development are described for the first time in the genus Hippolyte, using TEM, SEM, and histological methods. All males from 1.70 to 3.42 mm in carapace length had active testes and well-developed vasa deferentia. No case of sex reversal could be found.
Alvarez, Fernando; Iliffe, Thomas M; Villalobos, José Luis
A new species of mud shrimp of the genus Naushonia Kingsley, 1897 is described from two anchialine caves on the island of Great Abaco in the Bahamas. Naushonia tinkeri n. sp. is the fifteenth species in the genus and the second to be described from the Bahamas. The new species is morphologically similar to N. augudrea (Juarrero & García, 1997) from Holguín Province, eastern Cuba, with which it shares a carapace with cervical and cardiac grooves; however, it can be distinguished by having a pigmented cornea, the first pereiopod with a proportionately longer propodus and dactylus without a toothed external margin, and the telson longer relative to the uropod length. The new species inhabits anchialine caves and is the largest one reported until now.
Loughman, Zachary J.; Simon, Thomas P.
Abstract The crayfish fauna of West Virginia consists of 23 species and several undescribed taxa. Most survey efforts documenting this fauna have been conducted in lotic waterways throughout the Appalachian plateau, Allegheny Mountains, and Ridge and Valley physiographic provinces. Bottomland forests, swamps, and marshes associated with large river floodplain such as the Ohio River floodplain historically have been under-surveyed in the state. These habitats harbor the richest primary burrowing crayfish fauna in West Virginia, and are worthy of survey efforts. In an effort to fill this void, the crayfish fauna of West Virginia’s Ohio River floodplain was surveyed from 2004 through 2009. From this survey, nine species from four genera were documented inhabiting the floodplain. Zoogeography, biology, and conservation status is provided for all nine crayfishes. The dominant genus along the floodplain is Cambarus, which includes Cambarus (Cambarus) carinirostris, Cambarus (Cambarus) bartonii cavatus, Cambarus (Procambarus) robustus and Cambarus (Tubericambarus) thomai. Cambarus (Tubericambarus) thomai is the most prevalent burrowing species occurring along the floodplain. The genus Orconectes consists of two native species, Orconectes (Cambarus) obscurus and Orconectes (Cambarus) sanbornii; and two invasive taxa, Orconectes (Gremicambarus) virilis and Orconectes (Procambarus) rusticus. Orconectes (Cambarus) obscurus has experienced a range extension to the south and occupies streams formerly occupied by Orconectes (Cambarus) sanbornii. Both invasive taxa were allied with anthropogenic habitats and disturbance gradients. The genera Fallicambarus and Procambarus are represented by a single species. Both Fallicambarus (Cambarus) fodiens and Procambarus (Orconectes) acutus are limited to the historic preglacial Marietta River Valley. PMID:21594135
Storch, V.; Anger, K.
Zoea-1 larvae of Hyas araneus were kept under different nutritional conditions. Their midgut glands were investigated with a transmission electron microscope. The glandular epithelium consists of the cell types known from adult decapods. It is mainly the R-cell type that undergoes ultrastructural alterations which reflect nutritional conditions. R-cells of fed larvae are characterized by large lipid inclusions; after a certain period of food deprivation (point-of-no-return) the original ultrastructure cannot be reestablished. Refeeding results in large glycogen deposits in these cells.
Boyko, Christopher B; Mendoza, Jose C E; Castro, Peter
A review is made of those brachyurans that are symbiotic or otherwise associated with scleractinian corals on Easter Island, southeastern Pacific Ocean. A total of seven species is reported, including three species from two families not previously known from the island. Earlier records of Trapezia are analyzed and, although as many as six species have been previously reported, we conclude that only three species are known to occur on the island with certainty.
Vázquez-Bader, Ana Rosa; Gracia, Adolfo
Distribution and abundance of species of Crangonidae and Glyphocrangonidae in the Mexican deep-waters of the Gulf of Mexico were analyzed through six research cruises onboard of the R/V Justo Sierra of the Universidad Nacional Autónoma de México using an otter trawl in a depth range of 300-1200 m. We collected two and five species of the Crangonidae and Glyphocrangonidae families, respectively. We provide information about its depth and geographic distribution, abundance, frequency of occurrence and size structure. Glyphocrangon, composed of five species (G. aculeata, G. alispina, G. haematonotus, G. longleyi and G. spinicauda), was the most common and abundant component during the benthic trawls with a total of 1125 individuals. The family Crangonidae recorded only one genus and two species (Parapontocaris caribbaea and P vicina) with 21 individuals. A taxonomic key for these crangonid and glyphocrangonid shrimps of the Gulf of Mexico is also provided.
Ocaña, Frank A; Vega, Antonio; Córdova, Elier A
Studies on the ecology of Ocypode quadrata have been mostly carried out in the Northern and Southern part of its distribution range. In despite that this species is common in Cuban beaches, there are no quantitative studies regarding its abundance and spatial distribution. The aim of this study was to report some aspects about the spatial variation of O. quadrata density in sandy beaches, with different levels of human influence, in the North coast of Eastern Cuba. For this, on May 2010, eight beaches with different levels of human influence were surveyed. On each beach, the number of crabs burrows were counted in 45 quadrats of 4m2 located in three different strata (P1, P2 and P3). According to burrow opening diameter, crabs were separated into young and adults forms. To determine the existence of statistical differences in the density of crab burrows among beaches and strata, a two-way ANOVA was developed with a Scheffé-procedure post hoc test. A total of 355 burrows were counted in 360 sample units. The composition by size classes was 237 burrows for young and 118 for adults. From the total of burrows, 74% were located in P1, 20% in P2 and 6% in P3. The higher concentration of burrows was found at Jiguaní beach (0.52 +/- 0.08 burrows/m2) while the lesser concentration was found at Estero Ciego beach (0.06 +/- 0.01 burrows/m2). Most of the beaches did not present significant differences in the burrows density (Scheffé, p>0.05), according to ANOVA results, in despite their different human influence level. Density of individuals was significantly higher in the upper intertidal (P1) areas (Scheffé, p<0.05) with predominance of young crabs. Total density diminished in P2 and P3 strata where a predominance of adult individuals was observed. The interaction term of beach and strata evidenced that the pattern of variation among strata was not the same for all beaches. The general pattern of adults and young specimen spatial distribution in the beaches was very similar to those reported in the literature. In the present study, the first conducted in Cuban beaches, we did not find evidence of direct relationship between the level of human impact and the density of ghost crab burrows.
Costa, Pedro R; Rodrigues, Susana M; Botelho, Maria J; Sampayo, Maria Antónia de M
The swimming crab Polybius henslowii may play an important role in the movement of the amnesic shellfish toxin, domoic acid (DA), through the marine food chain. High DA concentrations have been determined in crab samples harvested along the Portuguese coast during the summer of 2002, reaching a level of 323.1 microg DA/g crab tissue. Toxin distribution in the different crab organs showed levels as high as 571.6 microg DA/g in the visceral tissues. Levels of toxin 4-12 times lower were detected in the remaining tissues. This crab might be a prominent vector of the toxin to higher trophic levels, including fishes, sea birds and even humans. In Portugal P. henslowii is commercialised during the summer in some local markets. DA concentrations were found close to the legal limit of 20 microg/g in samples purchased at Figueira da Foz market. The crabs are boiled prior to reaching the consumers. The cooking process was evaluated. Determination of toxin losses during the cooking process showed a toxin reduction higher than 50%. DA was determined by HPLC-UV and confirmed by spectra acquired with diode-array detector.
Richman, Nadia I; Böhm, Monika; Adams, Susan B; Alvarez, Fernando; Bergey, Elizabeth A; Bunn, John J S; Burnham, Quinton; Cordeiro, Jay; Coughran, Jason; Crandall, Keith A; Dawkins, Kathryn L; DiStefano, Robert J; Doran, Niall E; Edsman, Lennart; Eversole, Arnold G; Füreder, Leopold; Furse, James M; Gherardi, Francesca; Hamr, Premek; Holdich, David M; Horwitz, Pierre; Johnston, Kerrylyn; Jones, Clive M; Jones, Julia P G; Jones, Robert L; Jones, Thomas G; Kawai, Tadashi; Lawler, Susan; López-Mejía, Marilu; Miller, Rebecca M; Pedraza-Lara, Carlos; Reynolds, Julian D; Richardson, Alastair M M; Schultz, Mark B; Schuster, Guenter A; Sibley, Peter J; Souty-Grosset, Catherine; Taylor, Christopher A; Thoma, Roger F; Walls, Jerry; Walsh, Todd S; Collen, Ben
Rates of biodiversity loss are higher in freshwater ecosystems than in most terrestrial or marine ecosystems, making freshwater conservation a priority. However, prioritization methods are impeded by insufficient knowledge on the distribution and conservation status of freshwater taxa, particularly invertebrates. We evaluated the extinction risk of the world's 590 freshwater crayfish species using the IUCN Categories and Criteria and found 32% of all species are threatened with extinction. The level of extinction risk differed between families, with proportionally more threatened species in the Parastacidae and Astacidae than in the Cambaridae. Four described species were Extinct and 21% were assessed as Data Deficient. There was geographical variation in the dominant threats affecting the main centres of crayfish diversity. The majority of threatened US and Mexican species face threats associated with urban development, pollution, damming and water management. Conversely, the majority of Australian threatened species are affected by climate change, harvesting, agriculture and invasive species. Only a small proportion of crayfish are found within the boundaries of protected areas, suggesting that alternative means of long-term protection will be required. Our study highlights many of the significant challenges yet to come for freshwater biodiversity unless conservation planning shifts from a reactive to proactive approach.
Paramo, Jorge; Pérez, Daniel; Wolff, Matthias
The shallow water pink shrimp (Farfantepenaeus notialis) is among the socioeconomically most important resources of the Caribbean. The lack of biological and fishery information is of great concern for the fisheries management authorities. The presented study therefore aimed at the investigation of the reproductive cycle, the size composition and the size at first maturity of this species as a basis for the ordination and management of this resource. The study was conducted from June 2012 to May 2013 off the coast of the Caribbean Sea of Colombia. A total of 5 356 individuals were collected, identified, classified and preserved for their subsequent analysis in the laboratory. Size, weight, sex and gonad stage were recorded for each specimen. Significant differences were found in sex ratio in all months sampled with a clear predominance of females. Mature females were found year-around, but two reproductive peaks were identified during the periods October-December and April-June. The mean catch total length size (MCS) for females and males was 148.00mm and 122.54mm, respectively. The mean size at maturity (LT50%) was 129.34mm for females and 97.77mm for males. MCS was always above LT50% for both sexes. Considering the large reduction in fishing effort in the Colombian Caribbean Sea over the last years, we could expect that the shrimp population is in a rebuilding process or perhaps it may be already restored.
Vázquez-Bader, Ana Rosa; Gracia, Adolfo
Abstract We examined the diversity, abundance, distribution, and average size of squat lobsters collected during eight cruises conducted on the continental shelf and slope of the Gulf of Mexico (Mexican/USA border to the Caribbean Sea). Six species belonging to two genera of Chirostyloidea, and 25 species of four genera of Galatheoidea are reported. A total of 1513 specimens were obtained of which 95 were Chirostylidae, two Galatheidae, 285 Munidopsidae, and 1131 Munididae. Of the species collected, 13.8% were only known from Caribbean Sea. Three species of Chirostylidae—Gastroptychus salvadori, Uroptychus capillatus, and Uroptychus spiniger—as well two of Munidopsidae, Munidopsis bradleyi and Munidopsis riveroi, are recorded for the first time in the Gulf of Mexico. The upper bathymetric range of one species and the lower one for eight species are extended. Biological and ecological traits of squat lobsters in the southern Gulf of Mexico are also provided. PMID:27667921
Gan, Zhibin; Li, Xinzheng
The monotypic genus Phycocaris Kemp, 1916, which was established based on material from the Indian Ocean and previously only known from the type localities, Australia and Japan, is now newly recorded from the South China Sea. A detailed description of Phycocaris simulans Kemp, 1916 based on the specimen collected from Hainan Island is presented. Specific features and the differences between the Indian Ocean and the present material are described.
Olguín, Nicole; Ocampo, Emiliano H; Farias, Nahuel
The lithodid crab Paralomis spinosissima is previously known only in Sub-Antarctic waters from South Georgia Island to the Drake Passage. Here we recorded a juvenile male obtained off shores of Mar del Plata (~37°S), Argentina. This new occurrence extends the distribution range of the species over 1300 km northwards in the Atlantic Ocean.
Vereshchaka, Alexander L.; Kulagin, Dmitry N.; Lunina, Anastasia A.
The paper addresses the phylogeny and classification of the hydrothermal vent shrimp family Alvinocarididae. Two morphological cladistic analyses were carried out, which use all 31 recognized species of Alvinocarididae as terminal taxa. As outgroups, two species were included, both representing major caridean clades: Acanthephyra purpurea (Acanthephyridae) and Alpheus echiurophilus (Alpheidae). For additional support of the clades we utilised available data on mitochondrial Cytochrome c Oxidase I gene (CO1) and 16S ribosomal markers. Both morphological and molecular methods resulted in similar tree topologies and nearly identical clades. We consider these clades as evolutionary units and thus erect two new subfamilies: Rimicaridinae (Alvinocaridinides, Manuscaris, Opaepele, Shinkaicaris, Rimicaris), Alvinocaridinae (Alvinocaris), whilst recognising Mirocaridinae (with genera Mirocaris and Nautilocaris) at subfamily level. One genus, Keldyshicaris could not be assigned to any subfamily and is thus left as incertae sedis. The monophyly of Alvinocardinae was supported by morphological data, but not supported by molecular data (two analyses); the monophyly of all subfamilies was supported both by morphological and molecular data. Chorocaris is herein synonymized with Rimicaris, whilst Opaepele vavilovi is herein transferred to a new genus Keldyshicaris. Morphological trends within Alvinocarididae are discussed and short biogeographical remarks are given. We provide emended diagnoses for all subfamilies and genera along with keys to all recognized species. PMID:26161742
Pedraza-Lara, Carlos; Doadrio, Ignacio; Breinholt, Jesse W.; Crandall, Keith A.
The Dwarf crayfish or Cambarellinae, is a morphologically singular subfamily of decapod crustaceans that contains only one genus, Cambarellus. Its intriguing distribution, along the river basins of the Gulf Coast of United States (Gulf Group) and into Central México (Mexican Group), has until now lacked of satisfactory explanation. This study provides a comprehensive sampling of most of the extant species of Cambarellus and sheds light on its evolutionary history, systematics and biogeography. We tested the impact of Gulf Group versus Mexican Group geography on rates of cladogenesis using a maximum likelihood framework, testing different models of birth/extinction of lineages. We propose a comprehensive phylogenetic hypothesis for the subfamily based on mitochondrial and nuclear loci (3,833 bp) using Bayesian and Maximum Likelihood methods. The phylogenetic structure found two phylogenetic groups associated to the two main geographic components (Gulf Group and Mexican Group) and is partially consistent with the historical structure of river basins. The previous hypothesis, which divided the genus into three subgenera based on genitalia morphology was only partially supported (P = 0.047), resulting in a paraphyletic subgenus Pandicambarus. We found at least two cases in which phylogenetic structure failed to recover monophyly of recognized species while detecting several cases of cryptic diversity, corresponding to lineages not assigned to any described species. Cladogenetic patterns in the entire subfamily are better explained by an allopatric model of speciation. Diversification analyses showed similar cladogenesis patterns between both groups and did not significantly differ from the constant rate models. While cladogenesis in the Gulf Group is coincident in time with changes in the sea levels, in the Mexican Group, cladogenesis is congruent with the formation of the Trans-Mexican Volcanic Belt. Our results show how similar allopatric divergence in freshwater organisms can be promoted through diverse vicariant factors. PMID:23155379
Richman, Nadia I.; Böhm, Monika; Adams, Susan B.; Alvarez, Fernando; Bergey, Elizabeth A.; Bunn, John J. S.; Burnham, Quinton; Cordeiro, Jay; Coughran, Jason; Crandall, Keith A.; Dawkins, Kathryn L.; DiStefano, Robert J.; Doran, Niall E.; Edsman, Lennart; Eversole, Arnold G.; Füreder, Leopold; Furse, James M.; Gherardi, Francesca; Hamr, Premek; Holdich, David M.; Horwitz, Pierre; Johnston, Kerrylyn; Jones, Clive M.; Jones, Julia P. G.; Jones, Robert L.; Jones, Thomas G.; Kawai, Tadashi; Lawler, Susan; López-Mejía, Marilu; Miller, Rebecca M.; Pedraza-Lara, Carlos; Reynolds, Julian D.; Richardson, Alastair M. M.; Schultz, Mark B.; Schuster, Guenter A.; Sibley, Peter J.; Souty-Grosset, Catherine; Taylor, Christopher A.; Thoma, Roger F.; Walls, Jerry; Walsh, Todd S.; Collen, Ben
Rates of biodiversity loss are higher in freshwater ecosystems than in most terrestrial or marine ecosystems, making freshwater conservation a priority. However, prioritization methods are impeded by insufficient knowledge on the distribution and conservation status of freshwater taxa, particularly invertebrates. We evaluated the extinction risk of the world's 590 freshwater crayfish species using the IUCN Categories and Criteria and found 32% of all species are threatened with extinction. The level of extinction risk differed between families, with proportionally more threatened species in the Parastacidae and Astacidae than in the Cambaridae. Four described species were Extinct and 21% were assessed as Data Deficient. There was geographical variation in the dominant threats affecting the main centres of crayfish diversity. The majority of threatened US and Mexican species face threats associated with urban development, pollution, damming and water management. Conversely, the majority of Australian threatened species are affected by climate change, harvesting, agriculture and invasive species. Only a small proportion of crayfish are found within the boundaries of protected areas, suggesting that alternative means of long-term protection will be required. Our study highlights many of the significant challenges yet to come for freshwater biodiversity unless conservation planning shifts from a reactive to proactive approach. PMID:25561679
Sepahvand, Vahid; Momtazi, Farzaneh; Tudge, Christopher
A new species of callianassid ghost shrimp is described from the Persian Gulf, Iran. Cheramus iranicus sp. nov. is the first member of Cheramus described from Iranian subtidal waters and can be differentiated by a large cheliped with a ventroproximal spine on the merus and 7 spines on the ventral margin of the ischium, the endopod of the uropod has 4 movable spines on the distal margin and the posterior margin of the telson is strongly bilobed with a prominent medial tooth and two pairs of lateral movable spines. It is compared to other described Cheramus-like species showing a high degree of morphological similarity.
Mokhtari, Mohammad; Savari, Ahmad; Rezai, Hamid; Kochanian, Preeta; Bitaab, Amir
Fiddler crabs are known as the most conspicuous bioturbating animals in mangrove forest, which by their burrowing activities promote nutrient cycling in ecosystems. Mangroves, crabs and bacteria are connected in the form of positive feedback loop, whereby an increase in the activity of any participant will tend to increase the activity of all others as well. Population structure, growth, mortality, recruitment, biomass and production of fiddler crabs as dominant species of deposit-feeder crabs have been investigated from May 2005 to March 2006 in the Sirik mangrove estuary in the eastern part of Strait of Hormuz. Ten 1 m 2 squares of the substrate were randomly sampled during low tide. There was a significant change in organic content in the sampling area during study period. The sex ratio was significantly deviated from 1:1 ratio in large sizes, where males were dominated year around. Fiddler crabs showed seasonal growth pattern during a year, which the maximum growth was observed during autumn and early summer and ceased during winter by low temperature. Growth parameters were estimated by Appeldoorn's method and fitted with seasonalized von Bertalanffy growth models. The Kimura likelihood ratio test revealed significant differences in the overall growth curves between males and females, originated from the differences in k and L between sexes. Males were found to exhibit higher growth rate and larger size than females, this could be attributed to the higher investment of energy for reproduction in females. Reproduction was restricted to spring and early summer, while recruitment occurs at the end of summer. Total annual production of males and females was 37.90 and 10.05 g dry weight/10 m 2 respectively and major production took place during early summer. Because of impact of temperature on the activity of fiddler crabs in subtropical regions, density of crabs has significant positive correlation with temperature ( P < 0.01), while growth rate shows significant negative correlation with organic matter of sediment ( P < 0.05). In conclusion these crabs showed lower mortality and production rate with the seasonal growth and recruitment in comparison with tropical species.
Simith, Darlan J B; Diele, Karen; Abrunhosa, Fernando A
Megalopae of many decapod crab species accelerate their development time to metamorphosis (TTM) when exposed to natural physical and/or chemical cues characteristic of the parental habitat. In the present study, the influence of natural settlement cues on the moulting rates and development TTM in megalopae of the fiddler crab Uca vocator was investigated. The effects of mud from different habitats (including well-preserved and degraded-polluted mangrove habitats) and conspecific adult 'odours' (seawater conditioned with crabs) on the induction of metamorphosis were compared with filtered pure seawater (control). 95 to 100% of the megalopae successfully metamorphosed to first juvenile crab stage in all treatments, including the control. However, the development TTM differed significantly among treatments. Settlement cues significantly shortened development, while moulting was delayed in their absence. The fact that megalopae responded to metamorphosis-stimulating cues originating from both adult and non-adult benthic habitats demonstrates that settlement in this species may occur in a wider range of habitats within the mangrove ecosystem, including impacted areas.
Rodríguez, E M; López Greco, L S; Fingerman, M
The effect of cadmium chloride (1 mg/L) on oocyte growth of the fiddler crab, Uca pugilator, was studied during the slow vitellogenesis phase of ovarian maturation of this carb. In vivo experiments were done with both intact and eyestalkless crabs. The intact cadmium-exposed crabs exhibited a significantly lower oocyte diameter than the controls at the end of the 2-week exposure period, but no significant differences were detected among the eyestalkless crabs, suggesting that the effect of cadmium could be on the sinus gland in the eyestalks, increasing secretion of the gonad-inhibiting hormone (GIH). To test this hypothesis, in vitro experiments were done, incubating pieces of ovary with and without eyestalk tissue, in the presence of thoracic ganglion, needed for oocyte growing due to the secretion of the gonad-stimulating hormone (GSH). Only when eyestalk tissue was present in the incubation media was oocyte growth inhibited by cadmium compared to the controls. These results strongly suggest that cadmium acts at least in part to increase the secretion of GIH from the sinus gland. GIH could then in turn act by (a) inhibiting secretion of GSH by the thoracic ganglion, (b) directly inhibit the oocytes, or (c) both (a) and (b).
Vázquez-Bader, Ana Rosa; Gracia, Adolfo
We examined the diversity, abundance, distribution, and average size of squat lobsters collected during eight cruises conducted on the continental shelf and slope of the Gulf of Mexico (Mexican/USA border to the Caribbean Sea). Six species belonging to two genera of Chirostyloidea, and 25 species of four genera of Galatheoidea are reported. A total of 1513 specimens were obtained of which 95 were Chirostylidae, two Galatheidae, 285 Munidopsidae, and 1131 Munididae. Of the species collected, 13.8% were only known from Caribbean Sea. Three species of Chirostylidae-Gastroptychus salvadori, Uroptychus capillatus, and Uroptychus spiniger-as well two of Munidopsidae, Munidopsis bradleyi and Munidopsis riveroi, are recorded for the first time in the Gulf of Mexico. The upper bathymetric range of one species and the lower one for eight species are extended. Biological and ecological traits of squat lobsters in the southern Gulf of Mexico are also provided.
Yang, Chien-Hui; Liu, Yuan; Cui, Zhaoxia; Chan, Tin-Yam
Complete sequence of the mitochondrial genome (mitogenome) for the rare lobster genus Palinurellus (species P. wieneckii) is reported for the first time. The genus Palinurellus is peculiar looking and was previously considered to belong to a distinct family Synaxidae. However, recent molecular phylogenetic analyses based on partial sequences of various genes showed that Synaxidae is an invalid family and Palinurellus should be placed inside Palinuridae. The complete mitogenome of P. wieneckii is compared to the genetic structures with six other Achelata species with mitogenome sequence reported. The gene order of P. wieneckii is identical to the other Achelata lobsters, but with lower A + T content (63.6% versus 64.5-67.5%). Sequence nucleotide dissimilarity of P. wieneckii is considerably higher (37.7-40.3%) than amongst the five Palinuridae s.s. species (17.1-32.9%), and approximate to the range between Palinuridae s.s. and Scyllaridae (39.1-40.4%).
Carter, Chris G; Westbury, Heath; Crear, Bradley; Simon, Cedric; Thomas, Craig
The Southern rock lobster, Jasusedwardsii, is a temperate species of spiny lobster with established well managed fisheries in Australia and New Zealand. It has also been under consideration as a species with aquaculture potential. Agonistic behaviour has important consequences under aquaculture conditions that encompass direct effects, such as damage or death of protagonists, and indirect effects on growth that relate to resource access, principally food and refuge. This study aimed to identify and characterize behaviours and to make a preliminary investigation of their occurrence under tank culture. Juvenile Jasusedwardsii were examined in a flow-through seawater system using a remote video camera system. Twenty-nine behaviours were divided into three sub-groups: aggressive (11), avoidance (6) and others (12). Aggressive behaviours included attacks, pushing, lifting, clasping and carrying an opponent. Avoidance behaviours included moving away in a backwards-, forwards- or side-stepping motion as well as with more vigorous tail flips. These behaviours were components of twelve behavioural groups that described contact, attack and displacement between individuals. Activity was crepuscular with two clear peaks, one in the morning and the other in the evening. The occurrence of behavioural groups was not different between the morning and evening. The frequency of aggressive behaviours was not affected by changes made to stocking density or access to food. The implications of agonistic behaviours are discussed further in relation to developing aquaculture.
Colpo, Karine Delevati; Ribeiro, Liara Colpo; Wesz, Bruna; Ribeiro, Ludmilla Oliveira
In order to determine the feeding preference of Aegla platensis in streams and the importance of microorganisms in its detritivore diet, we carried out two experiments designed to evaluate the food preferences of A. platensis (1) among leaves with different levels of microbial colonization and (2) among insect larvae (Chironomidae, Simuliidae, Hydropsychidae) and microbially conditioned leaves. A. platensis preferred animal over plant food items; when only leaves were offered, this aeglid preferred the leaves with higher levels of microorganism conditioning.
Breinholt, Jesse W.; Porter, Megan L.; Crandall, Keith A.
Background The genus Cambarus is one of three most species rich crayfish genera in the Northern Hemisphere. The genus has its center of diversity in the Southern Appalachians of the United States and has been divided into 12 subgenera. Using Cambarus we test the correspondence of subgeneric designations based on morphology used in traditional crayfish taxonomy to the underlying evolutionary history for these crayfish. We further test for significant correlation and explanatory power of geographic distance, taxonomic model, and a habitat model to estimated phylogenetic distance with multiple variable regression. Methodology/Principal Findings We use three mitochondrial and one nuclear gene regions to estimate the phylogenetic relationships for species within the genus Cambarus and test evolutionary hypotheses of relationships and associated morphological and biogeographical hypotheses. Our resulting phylogeny indicates that the genus Cambarus is polyphyletic, however we fail to reject the monophyly of Cambarus with a topology test. The majority of the Cambarus subgenera are rejected as monophyletic, suggesting the morphological characters used to define those taxa are subject to convergent evolution. While we found incongruence between taxonomy and estimated phylogenetic relationships, a multiple model regression analysis indicates that taxonomy had more explanatory power of genetic relationships than either habitat or geographic distance. Conclusions We find convergent evolution has impacted the morphological features used to delimit Cambarus subgenera. Studies of the crayfish genus Orconectes have shown gonopod morphology used to delimit subgenera is also affected by convergent evolution. This suggests that morphological diagnoses based on traditional crayfish taxonomy might be confounded by convergent evolution across the cambarids and has little utility in diagnosing relationships or defining natural groups. We further suggest that convergent morphological evolution appears to be a common occurrence in invertebrates suggesting the need for careful phylogenetically based interpretations of morphological evolution in invertebrate systematics. PMID:23049950
Page, Timothy J.; Humphreys, William F.; Hughes, Jane M.
Background We investigated the large and small scale evolutionary relationships of the endemic Western Australian subterranean shrimp genus Stygiocaris (Atyidae) using nuclear and mitochondrial genes. Stygiocaris is part of the unique cave biota of the coastal, anchialine, limestones of the Cape Range and Barrow Island, most of whose nearest evolutionary relations are found in coastal caves of the distant North Atlantic. The dominance of atyids in tropical waters and their food resources suggest they are pivotal in understanding these groundwater ecosystems. Methodology/Principle Findings Our nuclear and mitochondrial analyses all recovered the Mexican cave genus Typhlatya as the sister taxon of Stygiocaris, rather than any of the numerous surface and cave atyids from Australia or the Indo-Pacific region. The two described Stygiocaris species were recovered as monophyletic, and a third, cryptic, species was discovered at a single site, which has very different physiochemical properties from the sites hosting the two described species. Conclusions/Significance Our findings suggest that Stygiocaris and Typhlatya may descend from a common ancestor that lived in the coastal marine habitat of the ancient Tethys Sea, and were subsequently separated by plate tectonic movements. This vicariant process is commonly thought to explain the many disjunct anchialine faunas, but has rarely been demonstrated using phylogenetic techniques. The Cape Range's geological dynamism, which is probably responsible for the speciation of the various Stygiocaris species, has also led to geographic population structure within species. In particular, Stygiocaris lancifera is split into northern and southern groups, which correspond to population splits within other sympatric subterranean taxa. PMID:18286175
De Grave, Sammy; Chan, Tin-Yam; Chu, Ka Hou; Yang, Chien-Hui; Landeira, José M.
We present evidence that the single representative of the crustacean order Amphionidacea is a decapod shrimp and not a distinct order. After reviewing available morphological evidence, it is concluded that Amphionides is a larval form, but with an as yet unknown parentage. Although the most likely adult form is in the family Pandalidae, the limited molecular data available cannot fully resolve its affinity. We therefore propose to treat Amphionides reynaudii as incertae sedis within Caridea, rather than a separate family. In view of the large scale, tropical and subtropical distribution of the taxon, the possibility is discussed that Amphionides is more likely to be a composite taxon at generic level, rather than larvae of a single shrimp species. PMID:26642937
Tropea, Carolina; Hermida, Gladys N; López Greco, Laura S
This work investigates the effects of androgenic gland (AG) ablation on the structure of the reproductive system, development of secondary sexual characters and somatic growth in Cherax quadricarinatus males. The AG ablation, which was performed at an early developmental stage (initial weight: 1.85±0.03 g), had no effect on the somatic growth parameters (specific growth rate and growth increment), but it prevented the re-formation of male gonopores and appendices masculinae. However, the red patch differentiation and chelae size were similar to those in control males. All the ablated animals developed a male reproductive system. Testis structure was macroscopically and histologically normal. The distal portion of the vas deferens (DVD) was enlarged in some animals, with histological alterations of the epithelium and the structure of the spermatophore. Results suggest that the higher growth in males than in females may be due to an indirect effect of the AG on energy investment in reproduction rather than to a direct effect of an androgen. This is the first report of a potential action of the AG on the secretory activity of the distal VD and the structural organization of the spermatophore. Although the AG may play a role in the development of male copulatory organs, its association with the red patch development deserves further research. The results obtained in the present study support and complement those from intersexes of the same species.
Castillo, Jesylén; Eslava, Nora; González, Leo Walter
Callinectes danae is a common species captured with crab traps in nearby areas of coastal lagoons in Margarita Island. Although its considerable economic importance as a fishery resource, few studies have been done on population dynamics and its fishery potential in local coastal environments to support decision making in fishery administration. We present growth pattern details of Callinectes danae to better estimate its population size and exploitation feasibility. For this, we analyzed a total of 3 623 specimens that were monthly captured in crab pots by artisanal fishermen in Las Marites lagoon, from October 2007 to September 2008. The length-weight ratio was determined, and growth parameters estimated from both length and weight curves of the von Bertalanffy model. The general sex ratio showed no significant difference between males and females (chi2 = 0.04, p > 0.05). However, values of slopes b between males and females were significantly different (t(s) = 2.75, p < 0.05), as well as intercepts a (t(s) = 2.44, p < 0.05). Thus, the length-weight ratio was determined separately: W = 7.48e(-5)*L(2.98) for males and W = 1.21e(-4)*L(2.87) for females, indicating a negative allometric growth in both sexes. Growth parameters were established as: L(infinity) =134.80mm, W(infinity) = 166.04g and k = 0.86/yr for males; L(infinity) = 122.35mm, W(infinity) = 118.45g and k = 0.63/yr for females. Lifespan was estimated at 3.05 years for males and 4.24 years for females. We concluded that Callinectes danae is a species with short lifespan and moderately rapid growth. The coefficient of variation values (CV), of the phi-prime growth performance index (Ø'), showed a different growth pattern compared to those obtained in other regions. We propose that a management strategy will be the periodical review of the minimum capture size for fishing area, after the great variability found in growth parameters.
Souza, Allan T.; Ilarri, Martina I.; Campos, Joana; Marques, João C.; Martins, Irene
The present study compared the carapace structure of Carcinus maenas in two nearby sites (2 km apart) within Minho estuary, submitted to different physicochemical and ecological conditions (water temperature, pH, crabs' density and sex ratio). The carapace structure of the carapace and chelae of the crabs presented significant differences between sampling sites ( t-test; p < 0.01). The SIMPER analysis revealed that the Weight/CW and Thickness/CW ratios explained all the dissimilarities found among sites. Overall, the male carapace was proportionally thicker at station 2 ( t-test; p < 0.01), while the female carapace was proportionally thicker at station 1 ( t-test; p < 0.001). A thicker carapace can be advantageous when competing for food or a sexual partner. We hypothetized that, since at station 2, the density of individuals was twice higher than at station 1, it is likely that agonistic encounters are more frequent, thus favouring a thicker carapace.
Sampaio, Hebert A; Martinelli-Lemos, Jussara M
The present work investigated the occupation and the correlation of the shrimp abundance in relation to environmental variables in different habitats (mangroves, salt marshes and rocky outcrops) in an Amazon estuary. The collections were made in August and November 2009, at low syzygy tide on Areuá Beach, situated in the Extractive Reserve of Mãe Grande de Curuçá, Pará, Brazil totaling 20 pools. In each environment, we recorded the physical-chemical factors (pH, salinity, and temperature) and measured the area (m2) and volume (m3) of every pool through bathymetry. The average pH, salinity, temperature, area and volume of tide pools were 8.75 (± 0.8 standard deviation), 35.45 (± 3), 29.49 °C (± 2.32), 27.41 m2 (± 41.18), and 5.19 m3 (± 8.01), respectively. We caught a total of 4,871 shrimps, distributed in three families and four species: Farfantepenaeus subtilis (98.36%) (marine) followed by Alpheus pontederiae (0.76%) (estuarine), Macrobrachium surinamicum (0.45%) and Macrobrachium amazonicum (0.43%) predominantly freshwater. The species F. subtilis and A. pontederiae occurred in the three habitats, whereas M. surinamicum occurred in salt marsh and rocky outcrop and M. amazonicum only in marisma. Temperature and pH were the most important environmental descriptors that significantly affected the density and biomass of shrimps.
Harlioğlu, Muzaffer M
Twin stage 1 juveniles from the signal crayfish, Pacifastacus leniusculus, were observed in this study. No such observations have been found in the literature. The twins consist of two stage 1 juveniles that are fused at the head. Each juvenile has a separate abdomen and thorax and has the appropriate number of appendages and a telson, all characteristic of a normal stage 1 juvenile.
Shull, Heather C; Pérez-Losada, Marcos; Blair, David; Sewell, Kim; Sinclair, Elizabeth A; Lawler, Susan; Ponniah, Mark; Crandall, Keith A
Euastacus crayfish are endemic to freshwater ecosystems of the eastern coast of Australia. While recent evolutionary studies have focused on a few of these species, here we provide a comprehensive phylogenetic estimate of relationships among the species within the genus. We sequenced three mitochondrial gene regions (COI, 16S, and 12S) and one nuclear region (28S) from 40 species of the genus Euastacus, as well as one undescribed species. Using these data, we estimated the phylogenetic relationships within the genus using maximum-likelihood, parsimony, and Bayesian Markov Chain Monte Carlo analyses. Using Bayes factors to test different model hypotheses, we found that the best phylogeny supports monophyletic groupings of all but two recognized species and suggests a widespread ancestor that diverged by vicariance. We also show that Euastacus and Astacopsis are most likely monophyletic sister genera. We use the resulting phylogeny as a framework to test biogeographic hypotheses relating to the diversification of the genus.
Oliva, Damián; Medan, Violeta; Tomsic, Daniel
Behavioral responses to looming stimuli have been studied in many vertebrate and invertebrate species, but neurons sensitive to looming have been investigated in very few animals. In this paper we introduce a new experimental model using the crab Chasmagnathus granulatus, which allows investigation of the processes of looming detection and escape decision at both the behavioral and neuronal levels. By analyzing the escape response of the crab in a walking simulator device we show that: (i) a robust and reliable escape response can be elicited by computer-generated looming stimuli in all tested animals; (ii) parameters such as distance, speed, timing and directionality of the escape run, are easy to record and quantify precisely in the walking device; (iii) although the magnitude of escape varies between animals and stimulus presentations, the timing of the response is remarkably consistent and does not habituate at 3 min stimulus intervals. We then study the response of neurons from the brain of the crab by means of intracellular recordings in the intact animal and show that: (iv) two subclasses of previously identified movement detector neurons from the lobula (third optic neuropil) exhibit robust and reliable responses to the same looming stimuli that trigger the behavioral response; (v) the neurons respond to the object approach by increasing their rate of firing in a way that closely matches the dynamics of the image expansion. Finally, we compare the neuronal with the behavioral response showing that: (vi) differences in the neuronal responses to looming, receding or laterally moving stimuli closely reflect the behavioral differences to such stimuli; (vii) during looming, the crab starts to run soon after the looming-sensitive neurons begin to increase their firing rate. The increase in the running speed during stimulus approach faithfully follows the increment in the firing rate, until the moment of maximum stimulus expansion. Thereafter, the neurons abruptly stop firing and the animal immediately decelerates its run. The results are discussed in connection with studies of responses to looming stimuli in the locust.
Melo, N F A C; Neumann-Leitão, S; Gusmão, L M O; Martins-Neto, F E; Palheta, G D A
Lucifer faxoni (BORRADAILE, 1915) and L. typus (EDWARDS, 1837) are species first identified in the neritic and oceanic waters off the Amazon. Samplings were made aboard the vessel "Antares" at 22 stations in July and August, 2001 with a bongo net (500-µm mesh size). Hydrological data were taken simultaneously for comparative purposes. L. faxoni was present at thirteen of the fourteen neritic stations analysed, as well as at five of the eight oceanic stations. L. typus was present at three of the fourteen neritic stations and in one of the eight oceanic stations. The highest density of L. faxoni in the neritic province was 7,000 ind.m(-3) (St. 82) and 159 ind.m(-3) (St. 75) in the oceanic area. For L. typus, the highest density observed was 41 ind.m(-3) (St. 64) in the neritic province. In the oceanic province, the highest single density value was recorded at station 75 (5 ind.m(-3)). Overall, L. faxoni typically presented the highest densities.
Carvalho-Saucedo, Liliana; Ramírez-Santiago, Cecilia; Pérez, Carlos
This paper describes the characteristics of male and female germ cells during gonadal development and the gonadal maturity scale of the blue crab, Callinectes sapidus. A total of 20 specimens were collected monthly from June to November 2012, in two areas off the coast of the Gulf of Mexico: the San Andrés Lagoon and Alvarado Lagoon. The gonads were removed and processed following the standard technique of hematoxylin and eosin staining. An important event in oogenesis (pre-vitellogenesis) was the appearance of a perinuclear vesicle in the cytoplasm and the accumulation of yolk granules. Later, vitellogenesis began and there was an accumulation of nutritive droplets and fragmentation of the perinuclear vesicle. During spermatogenesis, the accumulation of two fluids was observed that were involved in the formation of the spermatophore and the delay of spermiogenesis. Based on the histological features of gonad maturity, five stages were described (inactive, early gametogenesis, development, maturity, and resorption), in females and males. This proposal can be useful for the study of reproductive seasonality of this species.
Loo, Lars-Ove; Pihl Baden, Susanne; Ulmestrand, Mats
Suspension feeding in adults of the Norway lobster Nephrops norvegicus (40-74 g) and the European lobster Homarus gammarus (280-350 g) was tested in experiments offering planktonic food items of different sizes from 200 to 600 μm and measuring the clearing capacity. Both lobster species were found to effectively clear water of food particles comprising nauplii of the brine shrimp Artemia salina of about 600 μm in size. These were reduced to 50% of the initial concentration within 5 h and to 90% within 12 h. When N. norvegicus was offered food particles averaging 200 μm, a significant reduction in average size occurred, indicating that the minimum retention size is around 200 μm. Fluorescently dyed Artemia salina were recovered in the stomach and intestine of lobsters proving that the filtered particles are passed to the digestive tract. Results from other experiments, using the blood pigment (haemocyanin) concentration as an index of nutritional state, indicated that the lobsters can get some nutritional advantage from suspension feeding. Suspension feeding in larger decapods has not been described previously, so the significance of this finding is discussed with respect to changes in behavioural and ecological role.
Márquez, Edna J; Hurtado-Alarcón, Julio C; Isaza, Juan P; Alzate, Juan F; Campos, Néstor H
The Caribbean king crab Damithrax spinosissimus (former Mithrax spinosissimus) is a large brachyuran in the tropical and subtropical western Atlantic. This is the first report of the complete mitochondrial genome of D. spinosissimus, which was pyrosequenced by FLX 454 technology. The mtDNA encodes for 13 proteins, 22 tRNAs and 2 ribosomal RNAs. In addition, the coding sequences and gene synteny were similar to other previously reported mitogenomes of brachyuran.
Lu, Jian-ping; Zhang, Xiao-hui; Yu, Xiao-yun
The structural change of the oviduct of freshwater shrimp (Macrobrachium nipponense) during spawning was examined by electron microscopy. The oviduct wall structural characteristics seem to be influenced significantly by the spawning process. Before the parturition and ovulation, two types of epithelial cells (types I and II) are found in the epithelium. The free surfaces of type I and type II cells have very dense long microvilli. Under the type I and type II cells, are a relatively thick layer of secreting material and a layer of mostly dead cells. After ovulation, two other types of epithelial cells (types III and IV) are found in the oviduct wall epithelium. The free surface of type III cells only has short microvilli scattered on the surface. The thick layer with secreting material and the dead cell layer disappeared at this stage. In some type III cells, the leaking out of cytoplasm from broken cell membrane led to the death of these type III cells. The transformation of all four types of epithelial cells was in the order: IV→I→II→III. PMID:16365928
Abrunhosa, Fernando A; Arruda, Danielle C B; Simith, Darlan J B; Palmeira, Carlos A M
The present study investigated whether the callianassid Callichirus major shows a lecithotrophic behaviour during larval development. Two experiments were carried out. In the first experiment, larvae were subjected to an initial period of feeding, while in the second they were subjected to an initial period of starvation. In Experiment 1, 80% of C. major larvae succeeded moulting to juvenile stage in treatment with larvae fed every day. In the treatments with larvae fed for 1, 2 and 3 days there was total mortality before they reached the megalopal stage. In Experiment 2, zoea larvae showed more resistance when subjected to an initial period of starvation in which larvae starved for 1, 2 and 3 days and had survival rates of 100, 60 and 80%, respectively. But, a delay in the development duration of the zoeal stages was observed. Total mortality was observed for larvae reared in the treatment with entire starvation. The results suggest that zoeal stages of C. major are not lecithotrophic.
DeVries, M. C.; Epifanio, C. E.; Dittel, A. I.
Gravid female portunid crabs, Callinectes arcuatus, were held in a recirculating seawater system and the development of the eggs was observed. Based on morphological criteria, nine developmental stages were noted. The relationship between a given stage and the subsequent time to hatching was determined. Based on this, an index was devised that predicted hatching date from microscopic observation of an egg mass. This index was used to predict the date of hatching of eggs from 439 crabs collected in the Gulf of Nicoya, Central America, and the frequency of hatching was analysed in relation to the lunar and tidal cycles. Significantly more eggs hatched during periods of spring than neap tides. The adaptive significance of this rhythmicity is unclear at present.
Fransen, Charles H J M; Reijnen, Bastian T
During fieldwork in 2009 at Ternate, Indonesia, a pair of a pontoniine shrimp species belonging to the genus Conchodytes was collected from a bivalve mollusk of the genus Spondylus. This constitutes the first record of a species of the genus Conchodytes associated with a spondylid host. The specimens can be distinguished from other known Conchodytes species based on both morphology and colour pattern. Its COI barcode however, strongly resembles those obtained from three specimens of C. meleagrinae and is nested in the C. meleagrinae clade of the reconstructed phylogeny. Based on morphology and colouration only the specimens associated with the Spondylus bivalve would have been described as a species new to science. The modest conflicting molecular data have lead the authors to fully describe and figure the Spondylus associated specimens and compare them with the Pinctada associated specimens. Based on the present information it is decided not to give the Spondylus associated specimens the status as a distinct species but regard them as host-related (colour)morph of Conchodytes meleagrinae.
Loughman, Zachary J.; Simon, Thomas P.; Welsh, Stuart A.
West Virginia's crayfishes have received moderate attention since publication of Jezerinac et al.'s (1995) monograph of the state fauna. Survey efforts were initiated over the summers of 2006 and 2007 to gather voucher material for the Indiana Biological Survey's Crustacean Collection. These collections have provided new information regarding the distribution, natural history, life history, taxonomy, and conservation status of Cambarus (Cambarus) carinirostris, C. (C.) bartonii cavatus, C. (C.) sciotensis, C. (Hiaticambarus) chasmodactylus, C. (H.) elkensis, C. (H.) longulus, C. (Jugicambarus) dubius, C. (Puncticambarus) robustus, Orconectes (Procericambarus) cristavarius, and O. (P.) rusticus. Orconectes (Faxonius) limosus has apparently been extirpated from West Virginia and should be removed from the state's list of extant crayfishes.
Loughman, Zachary J.; Simon, Thomas P.; Welsh, Stuart A.
West Virginia's crayfishes have received moderate attention since publication of Jezerinac et al.'s (1995) monograph of the state fauna. Survey efforts were initiated over the summers of 2006 and 2007 to gather voucher material for the Indiana Biological Survey's Crustacean Collection. These collections have provided new information regarding the distribution, natural history, life history, taxonomy, and conservation status of Cambarus (Cambarus) carinirostris, C. (C.) bartonii cavatus, C. (C.) sciotensis, C. (Hiaticambarus) chasmodactylus, C. (H.) elkensis, C. (H.) longulus, C. (Jugicambarus) dubius, C. (Puncticambarus) robustus, Orconectes (Procericambarus) cristavarius, and O. (P.) rusticus. Orconectes (Faxonius) limosus has apparently been extirpated from West Virginia and should be removed from the state's list of extant crayfishes.
Loughman, Zachary J.; Welsh, Stuart; Fetzner, James W.; Thoma, Roger F.
A list is provided of all crayfishes (family Cambaridae) in the southern United States, which includes common names, global conservation status, an alternative review of the conservation status based on the IUCN red list criteria, and state distribution. This list includes 357 native crayfishes, of which 12 (3.4%) are critically endangered, 37 (10.4%) are endangered, 126 (35.3%) are vulnerable, 181 (50.7%) are lower risk, and 1 (0.3%) is not evaluated. The leading factors causing imperilment are restricted ranges caused by anthropogenic impacts from changes in land use, contaminants, invasion by non-indigenous species, and habitat fragmentation. In order to conserve and manage diversity of native crayfish, consistency is needed in determining conservation status and more complete distribution and life history information are needed for about 60% of species.
Bláha, Martin; Patoka, Jiří; Kozák, Pavel; Kouba, Antonín
The phylogenetic relationships among imported ornamental crayfish belonging to the genus Cherax were inferred from a combined dataset of 3 mitochondrial genes (COI, 16S and 12S) and by comparison with available GenBank sequences of 14 Cherax species. Furthermore, the concordance of previously described species obtained from a wholesaler (Cherax boesemani, C. holthuisi and C. peknyi) with available GenBank sequences was verified based on COI with special respect to comparison with sequences assigned as Cherax species. Recently described species C. gherardiae, C. pulcher and C. subterigneus belong to the northern group of Cherax species. Comparison and analysis with other GenBank COI sequences show previously unreported diversity of New Guinean species, suggesting 5 putative new species. Surprisingly, species assigned to the subgenus Astaconephrops do not form a monophyletic clade; this subgenus should be reappraised relative to the purported typical morphological characteristic of the uncalcified patch on male chelae. Increasing importation of crayfish underscores the importance of accurate species identification. Use of basic molecular methods is a necessary requisite for documenting occurrence, abundance and population trends of target species. Consequently, it helps to support eventual conservation decision-making by stakeholders.
Patoka, Jiří; Bláha, Martin; Kouba, Antonín
Cherax (Astaconephrops) gherardii n. sp. is a moderate burrowing crayfish endemic to the Ajamaru Lakes of West Papua, Indonesia. This species is one of the crayfish species from this region that are exploited for ornamental purposes. Its commonly used commercial name in the pet trade is "Rainbow Crayfish" or "Blue Moon Crayfish", and its native name is "udang kuku biru". The new species is genetically and morphologically similar to Cherax boesemani, however, both species may be easily distinguished morphologically or by using sequence divergence, which is substantial for considering C. gherardii n. sp. to be a valid species.
Yanin, B. T.; Baraboshkin, E. Yu.
Burrows of Thalassinoides, which are attributed to the group of dwelling structures, occur in all the marine and coastal facies. The Lower Cretaceous sections of southwestern and central Crimea yielded the representative collection of Thalassinoides burrows belonging to the ichnospecies Th. suevicus (Rieth, 1932), which served as an object for this investigation. The burrows are confined to coarse-grained terrigenous, carbonate, and mixed sediments and contain assemblages of ichnofossils indicating coastal and shallow-water marine Skolithos and Cruziana ichnofacies. In the Mesozoic-Cenozoic, the producers of the Thalassinoides burrows were decapods, confirmed by finds of crayfish Hoploparia in them.
Anker, Arthur; Firdaus, Muhammad; Pratama, Idham Sumarto
An unusual new species of the alpheid shrimp genus Salmoneus Holthuis, 1955 is described from Sekotong Bay, southwestern Lombok, Indonesia. The holotype and single known specimen of Salmoneus yoyo sp. nov. was collected with a suction pump from a burrow of unknown host, on a seagrass flat partly exposed at low tide. The new species presents three characters on the chelipeds that are unique within Salmoneus: a conspicuous, mesially curved, hook-like process on the distomesial margin of the merus, a row of blunt teeth on the ventromesial margin of the merus, and a series of blunt teeth on the ventromesial margin of the propodus. Salmoneus yoyo sp. nov. also has a characteristic colour pattern consisting of bright red chromatophores occupying most of the carapace surface, except for the frontal and post-frontal areas.
Nadia I. Richman; Monika Böhm; Susan B. Adams; Fernando Alvarez; Elizabeth A. Bergey; John J. S. Bunn; Quinton Burnham; Jay Cordeiro; Jason Coughran; Keith A. Crandall; Kathryn L. Dawkins; Robert J. DiStefano; Niall E. Doran; Lennart Edsman; Arnold G. Eversole; Leopold Füreder; James M. Furse; Francesca Gherardi; Premek Hamr; David M. Holdich; Pierre Horwitz; Kerrylyn Johnston; Clive M. Jones; Julia P. G. Jones; Robert L. Jones; Thomas G. Jones; Tadashi Kawai; Susan Lawler; Marilu López-Mejía; Rebecca M. Miller; Carlos Pedraza-Lara; Julian D. Reynolds; Alastair M. M. Richardson; Mark B. Schultz; Guenter A. Schuster; Peter J. Sibley; Catherine Souty-Grosset; Christopher A. Taylor; Roger F. Thoma; Jerry Walls; Todd S. Walsh; Ben Cohen
Rates of biodiversity loss are higher in freshwater ecosystems than in most terrestrial or marine ecosystems, making freshwater conservation a priority. However, prioritization methods are impeded by insufficient knowledge on the distribution and conservation status of freshwater taxa, particularly invertebrates. We evaluated the extinction risk of the worldâs 590...
Calado, Ricardo; Vitorino, António; Dinis, Maria Teresa
This study evaluates possible parasitic castration induced by a bopyrid isopod of the genus Parabopyrella, which parasitizes the branchial chamber of the simultaneously hermaphroditic shrimp Lysmata amboinensis. Parasitized shrimp (PS) carried embryos and produced significantly fewer larvae (mean +/- SD: 363 +/- 102; p = 0.002) than formerly parasitized shrimp (FPS) (1297 +/- 143) and unparasitized shrimp (US) paired with other US (1409 +/- 102), with PS (1362 +/- 234) or with FPS (1384 +/- 157). Starvation trials revealed no significant differences in the quality of larvae produced by PS, FPS and US paired with other US, PS and FPS. Host embryo production is only quantitatively, not qualitatively, affected, probably due to nutritional drain and/or endocrine disruption caused by the parasite. The host male sexual system remains fully functional and 'reproductive death' does not occur. The feminization of pleopods that prevents parasitized males of gonochoric species from successfully copulating seems to have no effect on L. seticaudata: pleopods are always feminized during their transition from male to simultaneous hermaphrodite phase, with adults being able to successfully fertilize broods. Parabopyrella sp. significantly affects the female sexual system of its host, but does not cause castration, as recorded for L. seticaudata parasitized by the bopyrid isopod Eophryxus lysmatae (an abdominal parasite).
Naupliar and Metanaupliar Development of Thysanoessa raschii (Malacostraca, Euphausiacea) from Godthåbsfjord, Greenland, with a Reinstatement of the Ancestral Status of the Free-Living Nauplius in Malacostracan Evolution
Akther, Hasna; Agersted, Mette Dalgaard; Olesen, Jørgen
The presence of a characteristic crustacean larval type, the nauplius, in many crustacean taxa has often been considered one of the few uniting characters of the Crustacea. Within Malacostraca, the largest crustacean group, nauplii are only present in two taxa, Euphauciacea (krill) and Decapoda Dendrobranchiata. The presence of nauplii in these two taxa has traditionally been considered a retained primitive characteristic, but free-living nauplii have also been suggested to have reappeared a couple of times from direct developing ancestors during malacostracan evolution. Based on a re-study of Thysanoessa raschii (Euphausiacea) using preserved material collected in Greenland, we readdress this important controversy in crustacean evolution, and, in the process, redescribe the naupliar and metanaupliar development of T. raschii. In contrast to most previous studies of euphausiid development, we recognize three (not two) naupliar (= ortho-naupliar) stages (N1-N3) followed by a metanauplius (MN). While there are many morphological changes between nauplius 1 and 2 (e.g., appearance of long caudal setae), the changes between nauplius 2 and 3 are few but distinct. They involve the size of some caudal spines (largest in N3) and the setation of the antennal endopod (an extra seta in N3). A wider comparison between free-living nauplii of both Malacostraca and non-Malacostraca revealed similarities between nauplii in many taxa both at the general level (e.g., the gradual development and number of appendages) and at the more detailed level (e.g., unclear segmentation of naupliar appendages, caudal setation, presence of frontal filaments). We recognize these similarities as homologies and therefore suggest that free-living nauplii were part of the ancestral malacostracan type of development. The derived morphology (e.g., lack of feeding structures, no fully formed gut, high content of yolk) of both euphausiid and dendrobranchiate nauplii is evidently related to their non
Macpherson, Enrique; Richer de Forges, Bertrand; Schnabel, Kareen; Samadi, Sarah; Boisselier, Marie-Catherine; Garcia-Rubies, Antoni
We analyzed the distribution patterns of the galatheid squat lobsters (Crustacea, Decapoda, Galatheidae) of the Pacific Ocean. We used the presence/absence data of 402 species along the continental slope and continental rise (200-2000 m) obtained from 54 cruises carried out in areas around the Philippines, Indonesia, Solomon, Vanuatu, New Caledonia, Fiji, Tonga, Wallis and Futuna and French Polynesia. The total number of stations was ca. 3200. We also used published data from other expeditions carried out in the Pacific waters, and from an exhaustive search of ca. 600 papers on the taxonomy and biogeography of Pacific species. We studied the existence of biogeographic provinces using multivariate analyses, and present data on latitudinal and longitudinal patterns of species richness, rate of endemism and the relationship between body sizes with the size of the geographic ranges. Latitudinal species richness along the Western and Eastern Pacific exhibited an increase from higher latitudes towards the Equator. Longitudinal species richness decreased considerably from the Western to the Central Pacific. Size frequency distribution for body size was strongly shifted toward small sizes and endemic species were significantly smaller than non-endemics. This study concludes that a clear separation exists between the moderately poor galatheid fauna of the Eastern Pacific and the rich Western and Central Pacific faunas. Our results also show that the highest numbers of squat lobsters are found in the Coral Sea (Solomon-Vanuatu-New Caledonia islands) and Indo-Malay-Philippines archipelago (IMPA). The distribution of endemism along the Pacific Ocean indicates that there are several major centres of diversity, e.g. Coral Sea, IMPA, New Zealand and French Polynesia. The high proportion of endemism in these areas suggests that they have evolved independently.
Wu, Jiang-Li; Kang, Xian-Jiang; Guo, Ming-Shen; Mu, Shu-Mei; Zhang, Zhao-Hui
During spermatogenesis in most animals, the basic proteins associated with DNA are continuously changing and somatic-typed histones are partly replaced by sperm-specific histones, which are then successively replaced by transition proteins and protamines. With the replacement of sperm nuclear basic proteins, nuclei progressively undergo chromatin condensation. The Chinese Mitten Crab (Eriocheir sinensis) is also known as the hairy crab or river crab (phylum Arthropoda, subphylum Crustacea, order Decapoda, and family Grapsidae). The spermatozoa of this species are aflagellate, and each has a spherical acrosome surrounded by a cup-shaped nucleus, peculiar to brachyurans. An interesting characteristic of the E. sinensis sperm nucleus is its lack of electron-dense chromatin. However, its formation is not clear. In this study, sequences encoding histones H3 and H4 were cloned by polymerase chain reaction amplification. Western blotting indicated that H3 and H4 existed in the sperm nuclei. Immunofluorescence and ultrastructural immunocytochemistry demonstrated that histones H3 and H4 were both present in the nuclei of spermatogonia, spermatocytes, spermatids and mature spermatozoa. The nuclear labeling density of histone H4 decreased in sperm nuclei, while histone H3 labeling was not changed significantly. Quantitative real-time PCR showed that the mRNA expression levels of histones H3 and H4 were higher at mitotic and meiotic stages than in later spermiogenesis. Our study demonstrates that the mature sperm nuclei of E. sinensis contain histones H3 and H4. This is the first report that the mature sperm nucleus of E. sinensis contains histones H3 and H4. This finding extends the study of sperm histones of E. sinensis and provides some basic data for exploring how decapod crustaceans form uncondensed sperm chromatin.
Raupach, Michael J.; Barco, Andrea; Steinke, Dirk; Beermann, Jan; Laakmann, Silke; Mohrbeck, Inga; Neumann, Hermann; Kihara, Terue C.; Pointner, Karin; Radulovici, Adriana; Segelken-Voigt, Alexandra; Wesse, Christina; Knebelsberger, Thomas
During the last years DNA barcoding has become a popular method of choice for molecular specimen identification. Here we present a comprehensive DNA barcode library of various crustacean taxa found in the North Sea, one of the most extensively studied marine regions of the world. Our data set includes 1,332 barcodes covering 205 species, including taxa of the Amphipoda, Copepoda, Decapoda, Isopoda, Thecostraca, and others. This dataset represents the most extensive DNA barcode library of the Crustacea in terms of species number to date. By using the Barcode of Life Data Systems (BOLD), unique BINs were identified for 198 (96.6%) of the analyzed species. Six species were characterized by two BINs (2.9%), and three BINs were found for the amphipod species Gammarus salinus Spooner, 1947 (0.4%). Intraspecific distances with values higher than 2.2% were revealed for 13 species (6.3%). Exceptionally high distances of up to 14.87% between two distinct but monophyletic clusters were found for the parasitic copepod Caligus elongatus Nordmann, 1832, supporting the results of previous studies that indicated the existence of an overlooked sea louse species. In contrast to these high distances, haplotype-sharing was observed for two decapod spider crab species, Macropodia parva Van Noort & Adema, 1985 and Macropodia rostrata (Linnaeus, 1761), underlining the need for a taxonomic revision of both species. Summarizing the results, our study confirms the application of DNA barcodes as highly effective identification system for the analyzed marine crustaceans of the North Sea and represents an important milestone for modern biodiversity assessment studies using barcode sequences. PMID:26417993
Naupliar and Metanaupliar Development of Thysanoessa raschii (Malacostraca, Euphausiacea) from Godthåbsfjord, Greenland, with a Reinstatement of the Ancestral Status of the Free-Living Nauplius in Malacostracan Evolution.
Akther, Hasna; Agersted, Mette Dalgaard; Olesen, Jørgen
The presence of a characteristic crustacean larval type, the nauplius, in many crustacean taxa has often been considered one of the few uniting characters of the Crustacea. Within Malacostraca, the largest crustacean group, nauplii are only present in two taxa, Euphauciacea (krill) and Decapoda Dendrobranchiata. The presence of nauplii in these two taxa has traditionally been considered a retained primitive characteristic, but free-living nauplii have also been suggested to have reappeared a couple of times from direct developing ancestors during malacostracan evolution. Based on a re-study of Thysanoessa raschii (Euphausiacea) using preserved material collected in Greenland, we readdress this important controversy in crustacean evolution, and, in the process, redescribe the naupliar and metanaupliar development of T. raschii. In contrast to most previous studies of euphausiid development, we recognize three (not two) naupliar (= ortho-naupliar) stages (N1-N3) followed by a metanauplius (MN). While there are many morphological changes between nauplius 1 and 2 (e.g., appearance of long caudal setae), the changes between nauplius 2 and 3 are few but distinct. They involve the size of some caudal spines (largest in N3) and the setation of the antennal endopod (an extra seta in N3). A wider comparison between free-living nauplii of both Malacostraca and non-Malacostraca revealed similarities between nauplii in many taxa both at the general level (e.g., the gradual development and number of appendages) and at the more detailed level (e.g., unclear segmentation of naupliar appendages, caudal setation, presence of frontal filaments). We recognize these similarities as homologies and therefore suggest that free-living nauplii were part of the ancestral malacostracan type of development. The derived morphology (e.g., lack of feeding structures, no fully formed gut, high content of yolk) of both euphausiid and dendrobranchiate nauplii is evidently related to their non
Background Malacostracan evolutionary history has seen multiple transformations of ontogenetic mode. For example direct development in connection with extensive brood care and development involving planktotrophic nauplius larvae, as well as intermediate forms are found throughout this taxon. This makes the Malacostraca a promising group for study of evolutionary morphological diversification and the role of heterochrony therein. One candidate heterochronic phenomenon is represented by the concept of the ‘egg-nauplius’, in which the nauplius larva, considered plesiomorphic to all Crustacea, is recapitulated as an embryonic stage. Results Here we present a comparative investigation of embryonic muscle differentiation in four representatives of Malacostraca: Gonodactylaceus falcatus (Stomatopoda), Neocaridina heteropoda (Decapoda), Neomysis integer (Mysida) and Parhyale hawaiensis (Amphipoda). We describe the patterns of muscle precursors in different embryonic stages to reconstruct the sequence of muscle development, until hatching of the larva or juvenile. Comparison of the developmental sequences between species reveals extensive heterochronic and heteromorphic variation. Clear anticipation of muscle differentiation in the nauplius segments, but also early formation of longitudinal trunk musculature independently of the teloblastic proliferation zone, are found to be characteristic to stomatopods and decapods, all of which share an egg-nauplius stage. Conclusions Our study provides a strong indication that the concept of nauplius recapitulation in Malacostraca is incomplete, because sequences of muscle tissue differentiation deviate from the chronological patterns observed in the ectoderm, on which the egg-nauplius is based. However, comparison of myogenic sequences between taxa supports the hypothesis of a zoea-like larva that was present in the last common ancestor of Eumalacostraca (Malacostraca without Leptostraca). We argue that much of the developmental
Hernández-Avila, Iván; Tagliafico, Alejandro; Rago, Nestor
Bivalve aggregations constitute a microhabitat for a wide variety of organisms in intertidal, subtidal and deep-water marine benthic habitats. Increase in density of bivalve beds could offer more crevices and substratum for the associated fauna, affecting community composition. Beds of the Atlantic Pearl Oyster (Pinctada imbricata) and the Turkey Wing (Arca zebra) of contrasting population densities were evaluated to determine the composition and structure of the associated macrofauna of three taxa (Crustacea Decapoda, Mollusca and Echinodermata). We evaluated plots of three levels of bed density in both species, the associated fauna were identified and counted. Other species were collected by qualitative samples. Univariate and multivariate descriptors were tested comparing the associated fauna between the beds of two species at three levels of density. In these beds a total of 104 species belonging to 58 families were recorded. Mithraculus forceps (Majidae), Crucibulum auricula (Calyptraeidae) and Ophiotrix angulata (Ophiothrichidae) were the most common species found in these assemblages. The medium and high-density bivalve beds exhibited greater species number, abundance, Shannon diversity, evenness, taxonomic diversity, and taxonomic distinctness of associated fauna, than low-density bivalve beds. Moreover, multivariate analysis detected different assemblages of associated fauna between beds with different densities. Additionally, similarities were found in the communities of macrofauna in both beds of P imbricata and Area zebra. Our results suggest that bivalve aggregations at Cubagua Island provide additional habitat for macrofauna living in other shallow habitats such as Thalassia beds, corals and rocky environments. Bed density, associated with topographic complexity, represents an important factor for the composition and complexity of the associated fauna.