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This study examines the phylogeny of all twenty-eight recent species of Group A of the genus Loxoconcha Sars, 1866. Based on the total number of pores on the carapace, three species subgroups of this genus are shown by Differentiation of Distributional pattern of Pore-system (DDP) analysis. All species have the same number and distribution pattern of pores in and before A-4 instar. The difference in the total number of pores on the carapace is found from instar A-3 to adult, and thus three patterns are recognised. In instar A-3 these numbers are 42, 43 and 44 for subgroups A1, A2 and A3 respectively. In addition, the present study shows an identical number of anterior false radial pores among the subgroups at all instars. However, the number of posterior false radial pores is different in three subgroups from instar A-3. In this instar, these numbers of subgroups A1, A2 and A3 are equivalent to 3, 4 and 5. By combining this study with previous studies, the geographical distribution of the three subgroups is shown. Species of subgroup A1 are distributed worldwide, except for the distribution areas of subgroups A2 and A3. Species in subgroups A2 and A3 are restricted to the Atlantic coasts of Europe, North Africa and the Mediterranean. [ABSTRACT FROM AUTHOR]

The relationships of crustaceans and hexapods (Pancrustacea) have been much discussed and partially elucidated following the emergence of phylogenomic data sets. However, major uncertainties still remain regarding the position of iconic taxa such as Branchiopoda, Copepoda, Remipedia, and Cephalocarida, and the sister group relationship of hexapods. We assembled the most taxon-rich phylogenomic pancrustacean data set to date and analyzed it using a variety of methodological approaches. We prioritized low levels of missing data and found that some clades were consistently recovered independently of the analytical approach used. These include, for example, Oligostraca and Altocrustacea. Substantial support was also found for Allotriocarida, with Remipedia as the sister of Hexapoda (i.e. Labiocarida), and Branchiopoda as the sister of Labiocarida, a clade that we name Athalassocarida (="nonmarine shrimps"). Within Allotriocarida, Cephalocarida was found as the sister of Athalassocarida. Finally, moderate support was found for Hexanauplia (Copepoda as sister to Thecostraca) in alliance with Malacostraca. Mapping key crustacean tagmosis patterns and developmental characters across the revised phylogeny suggests that the ancestral pancrustacean was relatively short-bodied, with extreme body elongation and anamorphic development emerging later in pancrustacean evolution. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • The first molecular phylogeny of the caridean Pandaloidea is reconstructed. • Genetic data from eight markers are generated for most Pandaloidea genera. • Thalassocarididae should be considered a junior synonym of Pandalidae. • Synapomorphies are recovered for the major clades. Abstract One of the systematically controversial superfamilies in Caridea is the predominately deep-sea or cold water Pandaloidea, largely because this species-rich group of nearly 200 species in 25 genera exhibits a very high diversity of body forms and ecology. Although the relationships amongst the taxa within Pandaloidea have been repeatedly discussed based on morphology, no comprehensive molecular phylogeny exists. In this study, we present the first molecular phylogeny of the group, based on a combined dataset of two mitochondrial (12S and 16S rRNA) and six nuclear (ATP synthase β-subunit, enolase, glyceraldehyde-3-phosphate dehydrogenase, histone 3, phosphoenolpyruvate carboxykinase and sodium–potassium ATPase α-subunit) markers, based on 62 species (about 1/3 of known biodiversity) in 22 genera (88% of genera) of two pandaloid families (Pandalidae, Thalassocarididae) and outgroups from seven other caridean families. With generally high support, the relationships within the clade are fully resolved. Pandalidae is shown to be paraphyletic with Thalassocarididae deeply nested within as a monophyletic group, and the latter is herein considered to be a synonym of Pandalidae. Five major clades are recovered, with the shallow water genera Anachlorocurtis , Chlorocurtis , Chlorotocella and Miropandalus forming a sister clade to the remaining genera. At the genus level, the phylogeny indicates Plesionika , Heterocarpus and Pandalus to be not monophyletic. The validity of Pandalopsis , Stylopandalus and Calipandalus is challenged and these genera are considered herein to be junior synonyms of Pandalus (Pandalopsis) and Plesionika (Stylopandalus and Calipandalus). Although not fully resolved, some evidence potentially considers Nothocaris to be a valid genus. Ancestral State Reconstruction successfully recovered 15 synapomorphies for the major clades, with 11 of them reported to be of systematic significance for the first time. [ABSTRACT FROM AUTHOR]

During the ongoing partial taxonomic revision of the genus Echinolaophonte on the basis of populations previously collected from various shores of the Turkish coasts, a new species of Echinolaophonte was discovered and named Echinolaophonte mordoganensis sp. nov. The new species is morphologically most closely related to E. minuta and E. veniliae. The new species can easily be distinguished from its congeners by the combination of the following features: i) the shape of the rostrum, ii) having 2 ornamented setae instead of 1 on the syncoxa of the maxilliped, and iii) pattern difference in the P1-P4 setal formula in both male and female. The phylogenetic position of the new species in the genus has also been briefly discussed. [ABSTRACT FROM AUTHOR]

In this study, the complete mitochondrial DNA (mtDNA) sequence of the crab Parasesarma affine is determined, characterized and compared with other decapod crustaceans. The P. affine mitochondrial genome (mitogenome) is 15,638 bp in size, and contains 13 protein-coding genes (PCGs), 2 ribosomal RNA (rRNA) genes, 22 transfer RNA (tRNA) genes and a control region (CR). Then, 23 of the 37 genes are encoded by the heavy (+) strand while 14 are encoded by the light (−) strand. All PCGs are initiated by ATN codons and 4 of the 13 PCGs harbored the incomplete termination codon by T or TA. The CR with a high A + T% (82.33%) spans 678 bp. The nucleotide composition of the P. affine mitogenome is also biased toward A + T nucleotides (74.83%). The gene order of P. affine has a difference that trnI - trnQ turns into trnQ - trnI when compared with ancestor of Brachyura, which can also been seen in other Sesarmidae species. Phylogenetic tree based on nucleotide sequences of mitochondrial 13 PCGs from 49 decapod crustaceans and one outgroup using Bayesian inference (BI) and Maximum Likelihood (ML), which determined that P. affine belongs to Sesarmidae and Parasesarma is monophyletic. [ABSTRACT FROM AUTHOR]

Caridina pseudodenticulata is a land-locked freshwater shrimp, which is endemic to North and West Taiwan. It is listed as Vulnerable under criteria A1ce in the IUCN Red List. Our study used mitochondrial DNA fragment sequences of the cytochrome oxidase subunit I (COI) gene to examine its genetic structure. In total, 204 sequences were analyzed from 22 populations, and all 39 haplotypes were identified. Our study (1) found that the genetic diversity within population of this species was similar to that of other land-locked freshwater prawn in Taiwan; (2) displayed that during glaciation, the Taiwan Strait was largely above water, an event which created opportunities for colonization Taiwan and dispersal widely; (3) showed that although the phylogenetic analysis showed the lack of a population genetic structure, the AMOVA and haplotypes distribution pattern revealed geographically divided; (4) indicated that C. pseudodenticulata could across to neighbor rivers through the mouths of rivers, which confluent with each other during floods. [ABSTRACT FROM AUTHOR]

The family Cyamidae, known as whale lice, is analysed herein by cladistic methods based on morphological characters. The analysis was performed using the program TNT and was based on a data matrix of 71 characters × 31 terminal taxa, including all seven known genera. Results showed Cyamidae to be a monophyletic clade. Balaenocyamus gen. nov. is erected to include Cyamus balaenopterae, which has eight synapomorphies. The other six genera were monophyletic. In addition, two new subfamilies are proposed: Isocyaminae subfam. nov. to include Isocyamus, Orcinocyamus, Platycyamus, Neocyamus, Scutocyamus and Syncyamus, and Cyaminae subfam. nov. to include Balaenocyamus gen. nov. and Cyamus. A key to all eight genera of Cyamidae, including diagnoses of the family, subfamilies and genera, is provided. [ABSTRACT FROM AUTHOR]

Abstract: Multiple species show significant trait shifts in response to urbanization. Yet, the impact of anthropogenic warming linked to the urban heat island effect is remarkably understudied. In addition, the relative contributions of phenotypic plasticity and genetic change underlying trait shifts in response to urbanization are poorly known. A common garden study with the water flea Daphnia magna revealed that both genetic differentiation in response to urbanization and phenotypic plasticity in response to higher rearing temperature (24°C) induced significant parallel multivariate shifts in life‐history strategy along the slow–fast pace‐of‐life axis. Urban animals and animals reared at higher temperatures are characterized by fast maturation, early release of progeny, a smaller size at maturity, increased fecundity and higher performance (given by maximal population growth rate “r”) compared to genotypes isolated from rural ponds and animals reared at lower temperatures, respectively. Evolution in response to urbanization accounted for 30% of the total observed shift in life history and caused a significant change in mean trait values, while plasticity responses to experimental warming were unaltered between urban and rural populations. The total trait change achieved through both plasticity and evolution ranged from 8% to 56% depending on the trait. Our results provide clear evidence for evolution underlying an increase in pace of life of populations in response to urbanization. Given the pivotal role of Daphnia in aquatic ecosystems, this shift potentially feeds back to population structure, top‐down control of algae and food web dynamics in urban freshwater ecosystems. In addition, we argue that adaptation to urban heat islands might render these populations preadapted in a context of future climate change. plain language summary is available for this article. [ABSTRACT FROM AUTHOR]

Several species of palaemonid shrimps are known to act as fish-cleaning symbionts, with cleaning interactions ranging from dedicated (obligate) to facultative. We confirmed five evolutionarily independent origins of fish cleaning symbioses within the family Palaemonidae based on a phylogenetic analysis and the ancestral state reconstruction of 68 species, including 13 fish-cleaners from the genera Ancylomenes , Brachycarpus , Palaemon , Periclimenes , and Urocaridella . We focus in particular on two distantly related lineages of fish cleaning shrimps with allopatric distributions, the Indo-West Pacific Ancylomenes and the western Atlantic monophyletic Ancylomenes / Periclimenes group, which exhibit striking similarities in morphology, colouration and complex behaviour. Specifically, representatives of both lineages are similar in: (1) the general body shape and colour pattern; (2) the utilization of sea anemones as conspicuous cleaning stations; and (3) the use of sideways body swaying to visually promote their bright colour spots in order to attract fish clients. Such morphological, ecological and ethological convergences are apparently due to adaptations to fish cleaning linked to the establishment of similar modes of communication with fish clients in these species. [ABSTRACT FROM AUTHOR]

According to the Climatic Variability Hypothesis [CVH], thermal plasticity should be wider in organisms from temperate environments, but is unlikely to occur in tropical latitudes where temperature fluctuations are narrow. In copepods, food availability has been suggested as the main driver of phenotypic variability in adult size if the range of temperature change is less than 14°C. Leptodiaptomus garciai is a calanoid copepod inhabiting Lake Alchichica, a monomictic, tropical lake in Mexico that experiences regular, narrow temperature fluctuations but wide changes in phytoplankton availability. We investigated whether the seasonal fluctuations of temperature and food produce phenotypic variation in the life-history traits of this tropical species. We sampled L. garciai throughout a year and measured female size, egg size and number, and hatching success, along with temperature and phytoplankton biomass. The amplitude of the plastic responses was estimated with the Phenotypic Plasticity Index. This index was also computed for a published dataset of 84 copepod populations to look if there is a relationship between the amplitude of the phenotypic plasticity of adult size and seasonal change in temperature. The temperature annual range in Lake Alchichica was 3.2°C, whereas phytoplankton abundance varied 17-fold. A strong pattern of thermal plasticity in egg size and adult female size followed the inverse relationship with temperature commonly observed in temperate environments, although its adaptive value was not demonstrated. Egg number, relative reproductive effort and number of nauplii per female were clearly plastic to food availability, allowing organisms to increase their fitness. When comparing copepod species from different latitudes, we found that the magnitude of thermal plasticity of adult size is not related to the range of temperature variation; furthermore, thermal plasticity exists even in environments of limited temperature variation, where the response is more intense compared to temperate populations. [ABSTRACT FROM AUTHOR]

Abstract: Aim: The mid‐Miocene closure of the Tethys (Terminal Tethyan Event, TTE) induced by the collision of the African–Arabian plate with the Eurasian plate is considered to be a major driver of tropical marine biodiversity. We used intertidal talitrids of Talorchestia sensu lato to test the hypothesis that the TTE can best explain the current disjunct distribution of this genus along Mediterranean‐East Atlantic and Indo‐West Pacific coastlines. Location: Mediterranean‐East Atlantic and Indo‐West Pacific. Methods: We sequenced four nuclear and two mitochondrial loci for 87 samples across the Mediterranean‐East Atlantic to Indo‐Pacific areas. We examined phylogenetic relationships, estimated divergence times and reconstructed ancestral geographical distributions of Talorchestia sensu lato within a wide geographical context. Results: The phylogenetic analyses revealed that Talorchestia sensu lato is monophyletic. Divergence time estimation and ancestral range reconstruction show that the genus originated from the Tethys during the Miocene and split into Mediterranean‐East Atlantic and Indo‐West Pacific lineages c. 15 Ma. The Mediterranean‐East Atlantic lineage further diverged into west and east Mediterranean clades, and the Indo‐West Pacific lineage contains Indian Ocean and west Pacific clades. Main conclusions: The evolutionary history of Talorchestia sensu lato corresponds well with the geological history of Tethyan closure, suggesting that the Tethyan closure drove the vicariant diversification of Talorchestia sensu lato into Mediterranean‐East Atlantic and Indo‐West Pacific lineages. This indicates that the intertidal environment may be the last to be separated by the TTE, and the diversification pattern of intertidal crustaceans can best reflect the vicariance effect of Tethyan closure. Deep divergences within clades were related to geological isolation in the Mediterranean‐East Atlantic region and across the Indo‐Pacific boundary. [ABSTRACT FROM AUTHOR]

In this study, the authors first obtained the mitochondrial genome of Somanniathelphusa boyangensis. The results showed that the mitochondrial genome is 17,032bp in length, included 13 protein-coding genes, 2 rRNAs genes, 22 tRNAs genes and 1 putative control region, and it has the characteristics of the metazoan mitochondrial genome A+T bias. All tRNA genes display the typical clover-leaf secondary structure except tRNASer(AGN), which has lost the dihydroxyuridine arm. The GenBank database contains the mitochondrial genomes of representatives of approximately 22 families of Brachyura, comprising 56 species, including 4 species of freshwater crab. The authors established the phylogenetic relationships using the maximum likelihood and Bayesian inference methods. The phylogenetic relationship indicated that the molecular taxonomy of S. boyangensis is consistent with current morphological classification, and Parathelphusidae and Potamidae are derived within the freshwater clade or as part of it. In addition, the authors used the COX1 sequence of Somanniathelphusa in GenBank and the COX1 sequence of S. boyangensis to estimated the divergence time of this genus. The result displayed that the divergence time of Somanniathelphusa qiongshanensis is consistent with the separation of Hainan Island from mainland China in the Beibu Gulf, and the divergence time for Somanniathelphusa taiwanensis and Somanniathelphusa amoyensis is consistent with the separation of Taiwan Province from Mainland China at Fujian Province. These data indicate that geologic events influenced speciation of the genus Somanniathelphusa. [ABSTRACT FROM AUTHOR]

Global trait-based analyses can shed light on the factors predisposing species to high extinction risk, and can help bridge knowledge gaps in speciose and poorly known taxa. In this paper, I conduct the first global comparative study of crayfish extinction risk. I collated data on intrinsic (biology and ecology) and extrinsic (environment and threats) factors for 450 crayfish species assessed on the IUCN Red List. Phylogenetic multiple regression models were used to identify correlates of risk in all species; in centres of diversity (American cambarids and Australian parastacids); and among threat types (agriculture, water management, pollution). I assessed the relative ability of threat maps quantifying specific threats (e.g. river fragmentation, mercury deposition) or a generic threat (human population density) to predict crayfish extinction risk. I also quantified the effects of range size on extinction risk with variation partitioning and multiplicative bivariate regressions. Crayfish with small range size, small body size, habitat dependency on caves, and with ranges in areas of low precipitation, high altitude and high human population density were at higher risk of extinction. Correlates of risk varied between American cambarids and Australian parastacids, suggesting that centres of diversity shape patterns of extinction risk in crayfish. The explanatory power of models ranged between 31 and 65%, with low explanatory power for models based on threat types. Few specific threat measures were significantly related to extinction risk, suggesting that large-scale threat mapping may not be informative for freshwater invertebrates. In the absence of population data for most freshwater invertebrates, trait-based models are powerful and cost-effective tools for understanding and mitigating drivers of extinction risk. [ABSTRACT FROM AUTHOR]

Quantitative sampling during the POS397 GroMet expedition in 2010 allowed analysis of the community structure of Zosimeidae on the Great Meteor Seamount (GMS) plateau. Twelve species ofZosimeBoeck, 1873 were identified; 11 were recorded in the middle, nine in the northern, and 10 in the southern region. Similarity and diversity analyses showed no differences in community structure between these regions. The community seemed unaffected by geographical features; similarities between regions could reflect the uniform sediment structure and the complex water current system.Zosimecan be characterised as monophyletic, due to the apomorphic one-segmented endopod of the mandible, armed with at most four setae. Two new species are described.Zosime carstenisp. nov. (incrassatagroup) is defined by blunt spinules on the outer spines of exopods 1–3 of pereiopods 2–4 and the spinose nature of the innermost distal element of endopod 3 of pereiopods 1–4.Zosime eliasisp. nov. (typicagroup) is defined by a flexible outer seta on the maxillipedal endopod. As both species bear an eight-segmented antennule (most plesiomorphic condition known so far), the recently erectedanneaegroup is included into thetypicagroup. An updated key ofZosimeat the species level is given. www.zoobank.org/urn:lsid:zoobank.org:pub:0BA28922-C575-4AAD-AD64-FDDBA22C34CC [ABSTRACT FROM PUBLISHER]

Structural, molecular and life cycle data are presented for two microsporidian species of the genus Berwaldia : B. singularis Larsson, 1981 (type species of the genus) and B. schaefernai Vávra and Larsson, 1994, parasites of Daphnia pulex Leydig, 1860 and Daphnia galeata Sars, 1863, respectively. Analysis of the SSU rDNA gene confirmed the species status of both species and showed that the GenBank sequence data submitted previously in GenBank for the genus Berwaldia , are from microsporidia that are not Berwaldia . Correct SSU rDNA gene sequences for B. schaefernai and B. singularis are now deposited in GenBank. The life cycle of these two species appears incomplete as the spores collected from their respective infected hosts will not infect the same host when fed per os. B. schaefernai appears as a frequent parasite of Daphnia longispina/galeata complex daphnids, influencing the behaviour of the infected host. In addition, two new species, of Berwaldia , one infecting fat body tissues of Daphnia longispina / galeata complex, and the other, infecting hypodermis and fat cells of Simocephalus vetulus (O. F. Müller, 1776) are described. [ABSTRACT FROM AUTHOR]

To date, the genusAtopobathynellaSchminke, 1973, contains 12 Gondwanan species, including two species from India. Three new species of this genus, viz.A. indicasp. nov.,A. nelloreensissp. nov., andA. inopinatasp. nov., from southeastern India are described herein. The various characters and their states inAtopobathynella, in relation to other parabathynellid species known so far, are discussed; especially its closeness with the genusKimberleybathynellais highlighted. A morphological phylogenetic analysis of the genusAtopobathynella,along with its closely related genusKimberleybathynellais also done, and the inter-relationships among the 15 species ofAtopobathynellaand six species ofKimberleybathynellaare deduced, using the software PAUP 4.0b10. This analysis, based on 39 unordered characters, has yielded 23 most parsimonious trees, with a length of 138 steps, a consistency index (CI) of 0.3768, a homoplasy index (HI) of 0.6232, a retention index (RI) of 0.6211, and a rescaled consistency index (RC) of 0.2341. The cladogram thus obtained suggests the grouping of ((A.wattsi,A. glenayleensis), (A. readi, ((((A. gascoyneensis,A. hospitalis),A. hinzeae), (((A. compagana,A. chelifera),A. valdiviana), (((A. operculata,A. paraoperculata),A. nelloreensis), (A. indica,A. inopinata)))), (A. schminkei, (((((K. gigantea,K. kimberleyensis),K. argylensis),K. pleochaeta),K. mandorana),K. hexapoda)))), outgroup). It also shows that the five Indian species are nestled between the AustralianAtopobathynellaandKimberleybathynellaspecies. The Indian species appear to be much derived as compared to their Australian counterparts. A brief note on the origin of Bathynellacea is also added at the end. www.zoobank.org/urn:lsid:zoobank.org:pub:18BD9A75-5D38-470F-B8C2-D56F645831C4 [ABSTRACT FROM AUTHOR]

The mitochondrial genome (mt genome) provides important information for understanding molecular evolution and phylogeny. The further understand the molecular evolution and phylogeny of Helice tientsinensis , the complete mt genome was determined. It is 16,212 bp long and includes 13 protein-coding genes (PCGs), 22 tRNA genes, two rRNA genes and a control region. The genome composition of H. tientsinensis was highly A + T biased 69.0% and showed negative AT skew (− 0.017) and GC skew (− 0.289). One PCG, all rRNAs and 12 of the tRNAs appeared to be rearranged with respect to the pancrustacean ground pattern gene order. Tandem duplication, followed by random deletion, is widely considered to explain translocation of mitochondrial genes. Consecutive recombinations events could explain inversions of genes. The phylogenetic analyses showed that H. tientsinensis has close relationships with Eriocheir japonica sinensis , E. j. hepuensis and E. j. japonica ; this indicated that H. tientsinensis belongs in the Grapsoidea, part of the Varunidae family. This study provides evidence for a better understanding of gene rearrangements, as well as the evolutionary status of H. tientsinensis and related species. [ABSTRACT FROM AUTHOR]

The genus Acanthonyx Latreille, 1828 (Majoidea, Epialtidae) contains 17 or 18 known species, depending on competing taxonomic views, that are widely distributed across the world. Morphologically, most species look superficially alike, and therefore, similar taxonomic concepts have been described under different names. Consequently, there is today a considerable list of synonyms, which further complicates the taxonomy of the genus Acanthonyx. In this study, we conducted a phylogeographical and phylogenetic analysis of populations of the genus Acanthonyx in the NE Atlantic, Mediterranean and Macaronesia using the mitochondrial cytochrome oxidase subunit I ( COI) and the nuclear 28S rRNA loci. Our phylogenetic and phylogeographical results revealed that Acanthonyx lunulatus sensu lato is a complex of three distinct lineages: one corresponding to the previously described Acanthonyx brevifrons, another to A. lunulatus sensu stricto and a third to a yet undescribed group. Whereas our results confirms that A. brevifrons deserves the status of a species, as it can be easily distinguishable from A. lunulatus by a few morphological traits, we could not find any such traits suitable for the discrimination between A. lunulatus sensu stricto and the third lineage. Furthermore, the degree of COI divergence between this lineage and A. lunulatus is below average levels for Decapoda species. Yet, no shared haplotypes have been detected between them. The differences found in the nuclear gene (indels), together with the sympatric occurrence of the two forms, prompt for a more detailed analysis of this group. Overall, the results show that significant genetic differentiation between specimens with similar morphology occurs in the Epialtidae, thus reinforcing the importance of combining morphological and genetic tools to fully resolve the taxonomy of these decapods. [ABSTRACT FROM AUTHOR]

Squat lobsters have a worldwide distribution and are highly visible crustaceans living in a broad range of habitats. In this study, partial sequences of two mitochondrial DNA genes (16S rRNA and COI) and a nuclear gene (H3) were obtained for all but one of the known species of the shallow-water genera Sadayoshia (Munididae) and Lauriea, Macrothea and Triodonthea (Galatheidae). Lauriea siagiani appeared to be phylogenetically closer to Triodonthea and Macrothea than to other Lauriea species, suggesting the need for taxonomic re-evaluation of these taxa. All species of Sadayoshia formed a monophyletic group that would have diverged during the Paleogene (around 50 Mya). Our results support the hypothesis that the late Paleogene-Neogene transition was a period of rapid diversification for shallow-water species of both Galatheidae and Munididae in the Indo-Pacific region. This is probably related to high tectonic activity among the Eurasian, Philippine Sea, Indo-Australian and Pacific plates and corresponding changes in distribution of habitats and ocean currents during the late Paleogene. Finally, the tropical south-west Pacific province is identified as a major diversification centre for shallow-water squat lobsters, from where species dispersed to other Pacific and Indian Ocean regions. [ABSTRACT FROM AUTHOR]

The molecular systematics of the subterranean amphipod genus Haploginglymus is addressed through the phylogenetic analysis of three DNA gene fragments (nuclear ribosomal 28S and protein-coding Histone 3, plus mitochondrial Cytochrome c Oxidase subunit I). We take advantage of the description of a new species from southern Spain (Haploginglymus geos sp. nov.) to assess the singularity of this genus endemic to the Iberian Peninsula and the inclusion of the morphologically aberrant H. morenoi within Haploginglymus. Our results corroborate the monophyly of the family Niphargidae but shows Niphargus to be paraphyletic as it currently stands, with Haploginglymus appearing nested within it. A strongly supported sister-group relationship between niphargids and the (thalassoid) pseudoniphargids is recovered as well, but we propose the Niphargidae should continue to be considered as a primary limnic group for biogeographic purposes despite its presumed marine derivation. Our findings are in agreement with previous studies that suggest the family Niphargidae originated in the late Cretaceous in the NE Atlantic, from where it eventually expanded across continental Europe. [ABSTRACT FROM AUTHOR]

With 104 endemic species family Candonidae is one of the most diverse crustacean groups in Lake Baikal, yet their phylogenetic relationships and position in the family have not been addressed so far. Here, we study the phylogenetic position of Baikal candonids within the family and their evolutionary history using molecular markers for the first time since their original description. We choose 10 Baikal and 28 species from around the world, and three ribosomal RNA-s (18S, 28S, and 16S), and analyze individual and concatenated datasets using Bayesian Inference in MrBayes and BEAST. For molecular divergence time estimates, four fossil records are used to calibrate the root and three internal nodes. The 28S dataset is tested under the strict molecular clock, while for other data we use relaxed clocks. Resulting trees show incongruence between molecular and fossil divergence time estimates, with the former suggesting older ages. Strict molecular clock analysis results in narrower node age confidence intervals and younger time estimates than other analysis. All trees support at least two candonid lineages in Baikal, with two independent colonization events, and 28S suggests a major radiation between 12 and 5 Mya. This divergence time estimate mostly agrees with another, unrelated, ostracod group in the lake and other lake animals as well. Baikal candonid clades show a close phylogenetic relationship with Palearctic lineages, but their deep divergence is indicative of separate genera. Results also suggest a monophyly of tribes that today live exclusively in subterranean waters, and we offer several hypotheses of their evolutionary history. [ABSTRACT FROM AUTHOR]

The thick-clawed crayfish Astacus pachypus (Rathke, 1837) is the least known species within the Astacidae, mostly due to limited access to samples and declining populations in recent decades. In the present study, for the first time, we report the phylogenetic position of this vulnerable native European freshwater crayfish within the genus Astacus , based on mitochondrial (COI and 16S rRNA) and nuclear (ITS2) molecular markers. Genetic results suggest its closest relationship is to A. leptodactylus (Eschscholtz, 1823), as previously suggested by morphology and common area of occurrence. [ABSTRACT FROM AUTHOR]

Aim The Carpathian Mountains are an important European biodiversity hotspot and are characterized by a dynamic geological history. Their freshwater amphipod fauna is ubiquitous and diverse, consisting of micro-endemic lineages that apparently reflect historical geological events. In this study, we propose that the complementary distribution of two widespread morphotypes belonging to the Gammarus balcanicus species complex reflects two chronologically distinct uplift episodes of the Carpathian Archipelago during the Miocene. Location Southeastern Europe. Methods We sequenced two mitochondrial ( COI and 16S) and three nuclear (28S, 18S and EF1α) markers from 68 localities ( n = 171) across the Carpathian Arc. Distance and phylogenetic-based methods were used to quantify cryptic diversity from the mitochondrial markers. We examined phylogenetic relationships, estimated divergence times and reconstructed ancestral geographical distributions of the Carpathian lineages within a wider geographical and phylogenetic context. Results Our results revealed that one morphotype, Gammarus cf. balcanicus, is a highly diverse and polyphyletic entity (consisting of at least 20 cryptic lineages), mostly inhabiting the areas corresponding to old Carpathian palaeo-islands. We estimated that this morphotype originated and diversified on this archipelago throughout the Miocene. In contrast, a distinct morph, previously described as G. balcanicus dacicus (elevated here to species rank as G. dacicus [new status]), is monophyletic and comprises only two lineages that likely originated and diversified on younger landmasses at the onset of the Late Miocene. Furthermore, it appears that the Pleistocene glaciations did not have a significant effect on the observed distribution and diversity patterns. Each cryptic lineage detected by mitochondrial markers was also supported by at least one nuclear marker. Main conclusions The different timings of landmass uplifts of the Carpathian palaeo-archipelago seem to have played a central role in the evolution and diversification of local lineages of the G. balcanicus species complex. This indicates that the genetic legacy of long-gone archipelagos can persist for millions of years in contemporaneous continental biotas. [ABSTRACT FROM AUTHOR]

Hermit crabs of the family Coenobitidae comprise the land hermit crabs, with 16 Coenobita species, and the coconut crab Birgus latro. They are terrestrial but spend their marine life as planktonic larvae. Some coenobitid crabs are widely distributed in the Indo-West Pacific region, and some species occupy narrower ranges. To improve our knowledge of coenobitid crab speciation and geographical distribution patterns, we examined the phylogenetic relationship between Coenobita purpureus, which has a narrow distribution in the Northwestern Pacific, and its more widely distributed coenobitids including B. latro, Coenobita brevimanus, Coenobita cavipes, Coenobita perlatus, Coenobita rugosus and Coenobita violascens based on the mtDNA cytochrome c oxidase subunit I (COI) and 16S rDNA genes. We also assessed the phylogeography of Co. purpureus populations based on the COI gene. Our phylogenetic and phylogeographical analyses revealed that (i) Co. purpureus clustered with Co. rugosus and (ii) the Co. purpureus population in the Ogasawara Islands was genetically distinct from those in other regions, which showed genetic panmixia. It has been hypothesized that Co. purpureus evolved in the isolated landmasses of the Ryukyu region during the Pliocene, and that its population expanded and colonized the Ogasawara Islands in the late Pleistocene. Further phylogeographical studies on Coenobita species with relatively narrow distributions coupled with characterization of their phylogenetic relationships with widely distributed congeners will advance our knowledge of the speciation and geographical distribution history of coenobitid crabs. [ABSTRACT FROM AUTHOR]

The mitochondrial genomes of three North American stygobiont amphipodsStygobromus tenuis potomacus,S. foliatusandS. indentatuscollected from Caroline County, VA, were sequenced using a shotgun sequencing approach on an Illumina NextSeq500 (Illumina Inc., San Diego, CA). All three mitogenomes displayed 13 protein-coding genes, 22 tRNAs and two rRNAs typical of metazoans. WhileS. tenuisandS. indentatusdisplayed identical gene orders similar to the pancrustacean ground pattern,S. foliatusdisplayed a transposition of thetrnL2-cox2genes to afteratp8-atp6. In addition, a shortatp8gene, longerrrnLgene and large inverted repeat within the Control Region distinguishedS. foliatusfromS. tenuis potomacusandS. indentatus. Overall, it appears that gene order varies considerably among amphipods, and the addition of theseStygobromusmitogenomes to the existing sequenced amphipod mitogenomes will prove useful for characterizing evolutionary relationships among various amphipod taxa, as well as investigations of the evolutionary dynamics of the mitogenome in general. [ABSTRACT FROM PUBLISHER]

ABSTRACT We report experimental evidence of egg polyphenism in clonal lineages of Heterocypris incongruens from an ephemeral pond on a Mediterranean Island (Lampedusa, Italy). In controlled laboratory conditions, clonal females produced three different kinds of eggs: (i) resting and desiccation-resistant eggs, (ii) nonresting eggs that hatched gradually within 2 month hydroperiod, and (iii) nonresting delayed development eggs that hatched synchronously. Clonal females showed a diversified bet-hedging strategy to spread risk of reproduction in ponds with unpredictable hydroperiod. They adjusted proportion of different egg phenotypes in response to experimental temperature and photoperiod that are proxies for different hydroperiod unpredictability. The proportion of resting eggs is not affected by maternal age at deposition, but mother's age has a key role in defining the development time and the hatching phenology of nonresting eggs. Genetically identical eggs kept at the same controlled laboratory conditions showed a U-shaped distribution of development time. Development time variance decreased with mother's age at deposition. The resulting wedge-shaped relationship between development time and mother's age at deposition may be interpreted by considering mother's age as a proxy for the probability of drought onset. The older the mother, the shorter the latency to drought and the shorter is the time for nonresting eggs to hatch. Considering only the delayed development of eggs that hatch synchronously, development time is inversely related to the mother's age at deposition: this relationship generates the observed hatching peak. [ABSTRACT FROM AUTHOR]

We have created barcode library for commonArgulusspp. infectingCarassius auratus, which could also be used to identify premature forms ofArgulusspp. even by non-professionals. InfectedC. auratuswas examined and purchased from ornamental fish-trading centers and the adult life stage ofArgulusspp. was identified and DNA barcoded. The eggs ofArgulusspp. were collected using bottle implants. The collected eggs are barcoded and precisely identified by matching with the adult sequences. Four species of adultArgulusspp. were identified, namelyArgulus japonicus, Argulus indicus, Argulus siamensis, andArgulus foliaceus. Precise identification of egg samples was done by two different analyses, namely (i) BLAST analysis and (ii) phylogenetic clustering of adults and eggs. All egg samples including the control were precisely identified by BLAST analysis and the results are consistent with phylogenetic clustering of adult and egg’s DNA barcodes. In order to establish the DNA barcode technology for the identification of allArgulusspp and its premature forms, the development of full-fledged barcode library that includes all species of this genus is very important for the benefit of ornamental fish industries. [ABSTRACT FROM AUTHOR]

In this study, the evolutionary history of the white-clawed crayfish (WCC) was evaluated using large-scale datasets comprising >1350 specimens from the entire distribution range. Using species delimitation methods on mitochondrial DNA (mtDNA) sequences, we propose four primary species hypotheses for WCC. Sequences for several nuclear regions were screened but none showed significant variation within WCC. This result favours a single secondary species hypothesis and indicates the existence of a mito-nuclear discordance in WCC. Therefore, mtDNA groups were considered only as genetic units that carry information about ancient divergences within WCC and not as taxonomic units. The reconstruction of ancestral ranges and divergence time estimates were used to link the current genetic structure with paleogeographic processes. These results showed that the emergence of mtDNA groups in WCC could be related to the Messinian Salinity Crisis, the climate cooling during the Pliocene and Pleistocene, and (paleo)shifting of the Adriatic Sea coastline in the Padanovenezian Plain. The most recent common ancestor of the mtDNA groups most likely originated from Dalmatia (eastern Adriatic coast) as indicated by the reconstruction of ancestral ranges. This ecoregion, along with the Gulf of Venice Drainages, harbours a high genetic diversity and should be emphasised as an area of the highest conservation priority. [ABSTRACT FROM AUTHOR]

The infraorder Stenopodidea is a relatively small group of marine decapod crustaceans including the well known cleaner shrimps, but their higher taxonomy has been rather controversial. This study provides the most comprehensive molecular phylogenetic analyses of Stenopodidea using sequence data from two mitochondrial (16S and 12S rRNA) and two nuclear (histone H3 and sodium-potassium ATPase α-subunit (NaK)) genes. We included all 12 nominal genera from the three stenopodidean families in order to test the proposed evolutionary hypothesis and taxonomic scheme of the group. The inferred phylogeny did not support the familial ranking of Macromaxillocarididae and rejected the reciprocal monophyly of Spongicolidae and Stenopididae. The genera Stenopus, Richardina, Spongiocaris, Odontozona, Spongicola and Spongicoloides are showed to be poly- or paraphyletic, with monophyly of only the latter three genera strongly rejected in the analysis. The present results only strongly support the monophyly of Microprosthema and suggest that Paraspongiola should be synonymised with Spongicola. The three remaining genera, Engystenopus, Juxtastenopus and Globospongicola, may need to be expanded to include species from other genera if their statuses are maintained. All findings suggest that the morphological characters currently adopted to define genera are mostly invalid and substantial taxonomic revisions are required. As the intergeneric relationships were largely unresolved in the present attempt, the hypothesis of evolution of deep-sea sponge-associated taxa from shallow-water free-living species could not be verified here. The present molecular phylogeny, nevertheless, provides some support that stenopoididean shrimps colonised the deep sea in multiple circumstances. [ABSTRACT FROM AUTHOR]

Porcellanidae Haworth, 1825 is a family of marine anomuran crabs distributed throughout tropical and temperate regions of all the oceans, typically littoral and sublittoral waters, with a considerable diversity of lifestyles, habitats and colouration. Pachycheles Stimpson, 1858 and Neopisosoma Haig, 1960 share, among other morphological characteristics, the fragmentation of the lateral carapace walls. The morphology of this body region was key to supporting the establishment of Neopisosoma, which increased uncertainty about the taxonomic status of these genera due to the high intraspecific variation of this character. Our study reconstructs the phylogenetic relationship between Pachycheles and Neopisosoma based on mitochondrial and nuclear DNA sequences to evaluate whether these are valid taxa. While Pachycheles seems to be monophyletic, the position of Neopisosoma mexicanum (Streets, 1871) indicates that the group is polyphyletic, and deserves further investigation. Pachycheles is revealed to be older than Neopisosoma, and likely originated in the Indo-Pacific, later spreading to the American continent during the early Tertiary. Neopisosoma may have arisen much later in the Caribbean Province before the closure of the Isthmus of Panama, explaining its distribution, which is restricted mainly to Central America. The inclusion of a considerable number of species from both genera represents a significant advance in the study of this controversial group. The phylogenetic reconstruction of Pachycheles unveiled clades corroborated by morphology, but also revealed unclear relationships, which may indicate the potential existence of cryptic species. [ABSTRACT FROM AUTHOR]

Luciferidae is a family of peculiar and widely distributed shrimps with an unclear systematic position and uncertain internal phylogeny. We undertook a phylogenetic analysis of Luciferidae based on 169 morphological characters (147 binary, 22 multistate). Several characters were based on scanning electron microscopy studies of the reproductive organs (e.g. petasma). All seven recognized species of Luciferidae were included as well as 17 additional species representing all other genera of Sergestoidea. Characters were polarized using three outgroups of the superfamily Penaeoidea, occurring in three different types of oceanic habitat. The phylogenetic analysis revealed monophyly of Luciferidae and the presence of two terminal robust clades within the family, which we treat as separate genera, Lucifer and Belzebub gen. nov. Morphological trends within Luciferidae are discussed, and diagnoses and keys to genera and all species are given. [ABSTRACT FROM AUTHOR]

Sinopotamon Bott, 1967 is the most speciose and widely distributed freshwater crab genus in East Asia. Our extensive sampling includes about 76% of the known Sinopotamon taxa, and nearly covers its entire distribution area. Based on mitochondrial cytochrome oxidase I (COI) and 16S rRNA, as well as nuclear 28S rRNA and histone H3, we reconstructed the Sinopotamon phylogeny using maximum likelihood and Bayesian approaches. The divergence time was estimated and multiple methods were used to conduct diversification analyses. The ancestral geographic distribution and character state were reconstructed. Three main clades (Clades I, II and III) that roughly correspond to their main geographic distribution ranges were recovered. Our results challenge the current view of the four major species groups based on the morphological differences in the male first gonopod (G1). The most recent common ancestor of Sinopotamon most likely originated from the Sichuan Basin and surrounding mountains (SBSM) and subsequently dispersed throughout central and eastern China. The exceptionally rapid, recent diversification was detected in Clade II. The high incidence of species-level non-monophyly found in Clade II can be explained by recent rapid radiation. Climatic changes, morphological innovations, range expansion and geographical heterogeneity may all contribute to the diversification in Sinopotamon . This study contributes to our knowledge on diversification of freshwater benthic macro-invertebrates in the East Asian inland ecosystem. [ABSTRACT FROM AUTHOR]

The barnacles of the superorder Acrothoracica are small, burrowing, epibiotic, and dioecious (large female with dwarf male) crustaceans largely found in the carbonate sediments and skeletons of marine invertebrates. The acrothoracicans represent the Cirripedia with the most plesiomorphic characters and have prominently featured in phylogenetic speculations concerning these crustaceans. Traditionally, Acrothoracica was divided into two main orders, Pygophora and Apygophora. The Apygophora had uniramus cirri and no anus. The Pygophora had biramus terminal cirri and an anus and was further divided into two families, Lithoglyptidae and Cryptophialidae. Kolbasov (2009) revised the superorder Acrothoracica on the basis of morphological examinations of females, dwarf males, and cyprids and rearranged the acrothoracican species into two new orders, Lithoglyptida and Cryptophialida. The present study is the first attempt to reconstruct the phylogenetic relationships of acrothoracican barnacles by sequencing two mitochondrial (cytochrome C oxidase I and 16S ribosomal DNA) and two nuclear (18S ribosomal DNA and histone H3) markers of 8 of the 11 genera comprising 23 acrothoracican species. All monophylies of the eight acrothoracican genera sampled in this study were strongly supported. The deep interfamilial relationship constructed is consistent with the recent morphological phylogenetic relationship proposed by Kolbasov, Newman, and Høeg (Kolbasov, 2009) that Cryptophialidae (order Cryptophialida) is the sister group to all other acrothoracicans (order Lithoglyptida). According to an ancestral character state reconstruction analysis, the posterior lobes of females; armament of opercular bars, attachment stalk, lateral projections of the body, and aperture slits in dwarf males; and habitat use appear to have phylogenetic importance. [ABSTRACT FROM AUTHOR]

We use mitochondrial (mtCOI) and nuclear (nH3) sequence data to investigate differentiation of Eudiaptomus hadzici , a freshwater copepod endemic to the Western Balkans. E. hadzici has a disjunct distribution and morphological differences were observed at regional scale. In the current study 6 out of 7 known populations are included. We applied several species delimiting approaches, distance based methods (K2P p- distance and Automatic Barcode Gap Discovery, ABGD) using the mtCOI, Bayesian phylogeny and the Bayesian method implemented in bPTP and BPP programs using the concatenated sequences of both genes. Phylogenetic and species delimitation analyses all suggest that the nominal species E. hadzici consists of four isolated, cryptic evolutionary lineages in the Western Balkans. Each of the four lineages inhabits a single lake or a group of lakes in close proximity. They exhibit major differences in secondary sexual characters, e.g. right antennule in males. Denticulation of spine on 13th segment is substantially distinct among the four lineages, having different number and shape of tooth-like protrusions. Gene flow and dispersal are restricted to very small spatial scale, but with local differences, implying that diverse historical and contemporary processes are operating at small spatial scales in E. hadzici . In order to further examine spatial and temporal diversification patterns, we constructed a dated species tree analysis using * BEAST. Due to lack of reliable calibration points and taxa specific evolutionary rates, two evolutionary rates were applied and the faster one (2.6% myr) seems more plausible considering the geological history of the region. The divergence of E. hadzici lineages is dated from Early Miocene onwards with geographically close lineages diverging more recently, Late Miocene to Pleistocene and Pleistocene, respectively. Overall, our findings shed light on cryptic genetic complexity of endemics in one of European biodiversity hotspots. Moreover, this study represents one further example of integrative taxonomy, linking DNA methodology and classical taxonomy based on morphology. Therefore, it lays groundwork for future taxonomy and biogeography of freshwater microcrustaceans in the region. [ABSTRACT FROM AUTHOR]

An anomopod branchiopod crustacean that displays many structural similarities to the extant generaScapholeberisandMegafenestra(family Daphniidae), fortuitously preserved in amber of Early Cretaceous age, is described. Although most of its appendages have been lost, preservation of several structures is vastly better than in most ‘orthodox’ fossils of these delicate animals. The well-preserved carapace suggests that, like extant representatives of these genera, but in no other daphniid, the animal exploited the surface film, beneath which it suspended itself by means of the straight ventral margins of its functionally bivalved carapace, each of which was armed with a row of close-set setae. Unlike the postabdomen of all the many extant anomopods, which is unsegmented, that of the fossil species, which was well preserved, was segmented; its distal half, or rather more, being clearly divided into four segments. Its topographically ventral margin was armed with pairs of very long spines (relatively longer than in any extant species), and the paired, hook-like terminal spines, clearly homologous with the claws of living species, were modified in a way that has no exact parallel in extant forms. The distal segment shows signs of annulations and may have had slight independent mobility. It is suggested that the long ventral spines of the postabdomen facilitated levering the animal forward over soft substrata. Its minute size reflects the fact that it is a first instar. Moreover, it was possibly squeezed out of the brood pouch prematurely when its parent became trapped in resin. The difficulty of assigning a place to the fossil in the phylogeny of the anomopods, all of which, including fossil forms of greater antiquity, have an unsegmented postabdomen, is briefly noted. The possibility that this attribute represents a very ancient atavism is tentatively suggested. [ABSTRACT FROM AUTHOR]

Indocarisgen. nov. with two new species,Indocaris imbricatasp. nov. andIndocaris inopinatasp. nov., and also for the already knownIndocaris tirupatiensis(Ranga Reddy 2011a) comb. nov. – all from the groundwaters in peninsular India. The highly diagnostic synapomorphy of the new genus is a composite character associated with the male leg 4 basis: five or six prominent, imbricate, enlarged, petal-like spinules, arranged as a semi-whorl at the insertion of the endopod and increasing in size from internal to external. Another distinctive feature of the same appendage is that its one-segmented endopod is dilated or bulbous in the proximal half, produced distally into an incurved spiniform or horn-like structure about as long as the corresponding first exopodal segment, and ornamented with three or four fine spinules on the subproximal outer margin. The three species also share a unique constellation of other salient morphologic features, which along with the phylogenetic position ofIndocarisgen. nov. within the family Parastenocarididae are discussed.Indocarisgen. nov. has closest phylogenetic affinity with the NeotropicalRemaneicariJakobi, 1972. A short note on the ecology and biogeography of the parastenocaridid species of the Indian subcontinent is provided besides a key for their identification. [ABSTRACT FROM AUTHOR]

Although crustaceans vary extensively in genome size, little is known about how genome size may affect the ecology and evolution of species in this diverse group, in part due to the lack of large genome size datasets. Here we investigate interspecific, intraspecific, and intracolony variation in genome size in 39 species of Synalpheus shrimps, representing one of the largest genome size datasets for a single genus within crustaceans. We find that genome size ranges approximately 4-fold across Synalpheus with little phylogenetic signal, and is not related to body size. In a subset of these species, genome size is related to chromosome size, but not to chromosome number, suggesting that despite large genomes, these species are not polyploid. Interestingly, there appears to be 35% intraspecific genome size variation in Synalpheus idios among geographic regions, and up to 30% variation in Synalpheus duffyi genome size within the same colony. [ABSTRACT FROM AUTHOR]

Phylogenetic analysis of most species within Necrocarcinoidea based upon 55 adult morphological characters supports the inclusion of 5 families within the superfamily. Two new genera are recognized within Necrocarcinidae, Arcticocarcinus n. gen. and Elektrocarcinus n. gen., and numerous new combinations have resulted. Necrocarcinoidea exhibited diversity peaks in the Albian (Early Cretaceous) and Campanian (Late Cretaceous), and displayed niche partitioning at the family level. Most Paleogene occurrences of Necrocarcinoidea are in carbonate rocks of Northern Europe. [ABSTRACT FROM AUTHOR]

Paraeuchaeta hebes is one of the most important carnivorous copepods in the coastal upwelling system off Galician waters (Ría de Vigo, NE Atlantic). A suctorian epibiont of the genus Pelagacineta was found attached to the surface of these copepods. The abundance and distribution on the copepod surface were analysed, taking into account the sex of the crustacean, revealing some preference for females and also a different attachment point in both sexes. The morphological study allowed us to identify a new species of this Suctoria epibiont as Pelagacineta hebensis. Moreover, the 18S rRNA gene was partially sequenced to inspect the phylogenetic position of Pelagacineta hebensis within the subclass Phyllopharyngea. The maximum-likelihood ( ML) tree obtained was consistent with the morphological and with previous molecular studies and showed that P. hebensis belongs to the order Endogenina, as a sister clade of the few taxa sequenced within this order. Including new genetic data to the Endogenina will allow building new hypothesis about the evolution of the most derived clade of suctorians. [ABSTRACT FROM AUTHOR]

The Australian freshwater crayfish species, Cherax quadricarinatus Von Martens, 1868, is an important commercial and invasive species that is also being increasingly used as a model organism to address important and interesting questions in crustacean biology. Through deep sequencing of the transcriptome of C. quadricarinatus from the hepatopancreas and four other tissues, we examine the evolution of endogenously transcribed cellulase genes and provide new insights into controversial issues regarding the nutritional biology of crayfishes. A cluster assembly approach yielded one of the highest quality transcriptome assemblies for a decapod crustacean to date. A total of 206,341,872 reads with an average read length of 80 bp were generated from sequencing the transcriptomes from the heart, kidney, hepatopancreas, nerve, and testis tissues. The assembled transcriptome contains a total of 44,525 transcripts. A total of 65 transcripts coding for carbohydrate-active enzymes (CAZy) were identified based on hidden Markov model (HMM), and a majority of them display high relative transcript abundance in the hepatopancreas tissue, supporting their role in nutrient digestion. Comprehensive phylogenetic analyses of proteins belonging to two main glycosyl hydrolase families (GH9 and GH5) suggest shared ancestry of C. quadricarinatus cellulases with other characterized crustacean cellulases. Our study significantly expands the number of known crustacean-derived CAZy-coding transcripts. More importantly, the surprising level of evolutionary diversification of these proteins in C. quadricarinatus suggests that these enzymes may have been of critical importance in the adaptation of freshwater crayfishes to new plant-based food sources as part of their successful invasion of freshwater systems from marine ancestors. [ABSTRACT FROM AUTHOR]

We describe the sperm ultrastructure of two sympatric rock shrimps, Sicyonia dorsalis and Sicyonia typica, and compare them in a molecular context to provide new insight into the sperm morphology of the Sicyoniidae. To accomplish this, the vasa deferentia of males of both species were fixed and prepared for transmission electron microscopy and light microscopy cytochemistry. Sperm of S. typica exhibit an oval main body and a short subacrosomal complex region with convoluted membrane pouches, a crystalline lattice and a well-developed large granule anterior to the spike, as previously described for Sicyonia carinata. In contrast, the ultrastructure of S. dorsalis sperm features an elongated complex subacrosomal region above the main body and a flat nucleus, and small cytoplasmic membrane vesicles are not present. Although S. dorsalis sperm are similar to those of Sicyonia ingentis, the spike of S. dorsalis is shorter than S. ingentis. A phylogenetic tree was built by Bayesian inference based on 19 sequences of 16S rDNA of some representatives of the genus. Our findings show that sperm analysis of these shrimps reflects their phylogenetic history and that such analysis is very useful for taxonomic studies. Species with corresponding sperm ultrastructure are in the same clade of the proposed phylogeny. Moreover, it is possible to detect different groups within the genus based on the presence of at least two distinct morphological patterns of ultrastructure in the spermatozoa of Sicyonia. [ABSTRACT FROM AUTHOR]

A new species of deep-sea yeti crab, Kiwa araonae, is described from a hydrothermal vent field, Mujin ("Misty Harbor"), at a depth of about 2000 m on the Australian-Antarctic Ridge (AAR), Southern Ocean. The Mujin vent field (62°11.79S), in a large, unexplored gap in the Circum-Antarctic Ridge system, is the most southern record for a yeti crab to date. Kiwa araonae n. sp. is the fourth described species in the family Kiwaidae Macpherson, Jones and Segonzac, 2005, and the second known from the Southern Ocean. This new species differs morphologically from its three congeners by the having a nearly flat branchial region, relatively short rostrum, third sternite with parallel lateral margins, slender chela, straight fingers of the chela, and propodi of pereiopods 2-4 with three corneous spines on the flexor margins. The Bayesian phylogenetic tree and the genetic distance based on the mitochondrial 16S rRNA gene (408 bp) clearly indicate the distinctiveness of this species. The discovery of Kiwa araonae in the AAR suggests a possible biogeographic connection of the Southern Ocean vent faunas. The presence of a new hydrothermal vent field with endemic species in the AAR provides additional information on the global biogeography of deep-sea vent faunas. [ABSTRACT FROM AUTHOR]

The complete mitochondrial genome sequenced from the floral egg crab Atergatis floridus (Linnaeus, 1767) and the determination of the position of the species in the reconstructed phylogenetic tree of the infraorder Brachyura using the protein coding mitochondrial genes are presented. Results show the mitochondrial genome length of A. floridus is 16,435 bp with nucleotide distribution as 33.4% A, 20.3% C, 10.5% G and 35.8% T. The structure of the complete mitochondrial genome of the species is the same as with the previous xanthid record. The result of the phylogenetic analysis suggests that A. floridus is the closest species to other Xanthidae species in the brachyuran records. This is the first complete mitochondrial genome record from the genus Atergatis. [ABSTRACT FROM AUTHOR]

In this study, the complete mitochondrial genome (mitogenome) of Caridina multidentata is reported for the first time. These data demonstrate that the C. multidentata mitochondrial genome is a 15,825 bp circular molecule and encodes the typical 37 metazoan mitochondrial genes [13 protein-coding genes (PCGs), 22 transfer RNA genes (tRNAs), two ribosomal RNA genes (rRNAs)] and an A + T-rich control region. The genome composition was highly A + T biased 63.45% and showed negative AT-skew (−0.131) and slightly possitive GC-skew (0.018). The complete mitogenome provides essential and important DNA molecular data for further phylogenetic and evolutionary analysis for shrimps. [ABSTRACT FROM AUTHOR]

A reference genome is important for genomic and phylogenomic analysis, but except for a brachiopod Daphnia pulex , other crustacean genomes have not been completely sequenced. As one of the most economically important crustaceans, decapod shrimps have attracted great attentions worldwide. But the highly complexity block us from completing shrimp genomes. To explore the decapod shrimp genomes, we performed phylogenomic and comparative genomics analyses of pancrustaceans using transcriptome data. A group of 85 single-copy genes were collected from two shrimps and seven genome-available arthropods for phylogenetic analysis. It was found that the two major members of Pancrustacea, Hexapoda and Crustacea, fall into respective monophyletic clades. D. pulex and shrimps were estimated divergent at about 395 Myr and the gene family compositions were significantly different between them. The gene families involved in ion binding, peroxidase activity and cytoskeletal part were significantly expanded in shrimps, which were considered tightly associated with the seawater environment adaptation. When comparing the two shrimps, gene families involved in synapse in Litopenaeus vannamei and cellular component in Penaeus monodon showed significant expansion, which implies the nervous system of L. vannamei and cellular structure of P. monodon might be adaptively evolved respectively. [ABSTRACT FROM AUTHOR]

The article discusses a study which investigated the distribution patterns, genetic diversity and phylogenetic affinities and colonization histories of freshwater amphipods across the Tibetan Plateau based on a sampling and genetic data from two mitochondrial markers. Topics include a description of the Holarctic amphipod genus Gammarus and the sampling sites of Gammarus lacustris.

The family Ocypodidae is a group of intertidal brachyuran crabs found in tropical to temperate seas worldwide. While the family has historically included many subfamilies, most of these have now been given separate family status within the superfamily Ocypodoidea. The most recent classification recognises only two subfamilies, the ghost crabs: Ocypodinae Rafinesque, 1815; and the fiddler crabs: Ucinae Dana, 1851. The ghost crabs comprise 21 species in two genera, Ocypode Weber, 1795, and Hoplocypode Sakai & Türkay, 2013. The fiddler crabs are the most species-rich group of this family with 104 species, all belonging to the single genus Uca Leach, 1814, with 12 recognised subgenera. The present study supports 13 groups (= genera) belonging to three revised subfamilies. This result is based on molecular evidence from the nuclear 28S rDNA, and the mitochondrial 16S rDNA and cytochrome oxidase subunit I (COI). The family now also includes the monogeneric Ucididae Števčić, 2005, recently recognised as a separate family for Ucides Rathbun, 1897, herein relegated to a subfamily of the Ocypodidae. Uca (and thus Ucinae) is shown to be paraphyletic, belonging to two widely divergent clades. Uca (Uca) s. str. from the Americas and Afruca Crane, 1975, from the East Atlantic cluster with Ocypode and Hoplocypode, and thus constitute a revised Ocypodinae. The American broad-fronted group with the Indo-West Pacific subgenera, forming a distinct clade, for which the subfamily name Gelasiminae Miers, 1886, is available. Australuca Crane, 1975, and Hoplocypode Sakai & Türkay, 2013, are not supported, and are treated as synonyms of Tubuca Bott, 1973, and Ocypode, respectively. All other subgenera of Uca are here recognised as full genera. The three constituent subfamilies of the Ocypodidae are thus as follow: Ocypodinae (Afruca; Ocypode; Uca s. str.); Gelasiminae (Austruca Bott, 1973; Cranuca Beinlich & von Hagen, 2006; Gelasimus Latreille, 1817; Leptuca Bott, 1973; Minuca Bott, 1954; Paraleptuca Bott, 1973; Petruca Shih, Ng & Christy, 2015; Tubuca; Xeruca Shih, 2015); and Ucidinae Števčić, 2005 (Ucides). [ABSTRACT FROM AUTHOR]

Coral-associated fauna is a relatively understudied topic. Hence, the nature of the relationship between an associated organism and its host is usually unknown. In the present study, the obligate associations between gall crabs (Decapoda: Cryptochiridae) and mushroom corals (Scleractinia: Fungiidae) are reviewed from a phylogenetic perspective. Based on field surveys, examination of museum material and a literature review, a total of 35 fungiid species have been found that act as hosts for four gall crab species. Fungiid-associated gall crabs appear to be more geographically widespread than previously known, with new records showing their occurrences from the Red Sea and western Indian Ocean all the way to the central Pacific Ocean. The obligate nature of the association between cryptochirids and their hosts makes them an ideal model taxon to test for possible cospeciation events. The congruence between their phylogenies was tested by using the program Jane 4.0, resulting in cospeciation and duplication events between the crabs and their host corals. The sharing of several closely related host coral species by the same gall crab species or genus may provide support to models indicating phylogenetic relationships within the Scleractinia. [ABSTRACT FROM AUTHOR]

The subterranean genus Niphargus is one of the most species-rich genera among freshwater amphipods in the world, distributed in the Western Palearctic. Thus far, taxonomic and phylogenetic research has focused mainly on the European half of the genus range. In this study, 25 populations of Niphargus from Iran, Lebanon and the Crimean Peninsula were investigated. Bayesian inference based on 28S, H3 and COI gene sequences suggests that populations from the area belong to four different clades. Three species from Crimea and one species from Iran are nested at basal nodes, indicating their rather ancient origin. The rest of the species are younger and belong to two separate clades. One Crimean species is a sister-species to east Romanian species. The second clade includes one species from Lebanon and all but one population from Iran. The origin of this clade corresponds to marine transgression between the Black Sea and Mediterranean approximately 12 Mya. This clade was further investigated taxonomically. Revision of qualitative morphological traits and unilocus species delimitation methods using COI suggest that this clade comprises 12-16 species, of which only three have been described so far. Multilocus coalescence delimitation methods (using fragments of COI, 28S, H3 and ITS) strongly supported 11 of these species. The remaining populations comprise at least two species complexes that require further and more detailed taxonomic research. [ABSTRACT FROM AUTHOR]