Search

The coagulation property of hemolymph is one of the characteristic indicators of the immune function of crustaceans. This article focuses on the abnormal phenomenon of wild Charybdis japonica, where the hemolymph cannot coagulate in the Qinhuangdao Sea area. The pathogens were isolated and purified, and three dominant strains, N1, N2, and Q1, were obtained. These strains were identified as Vibrio natriegens, V. fortis, and Metschnikowia bicuspidata through morphological observation, physiological and biochemical experiments, and 16S rDNA or ITS sequence analysis. Subsequently, drug sensitivity and probiotic antagonism analyses were performed. Considering the potential for cross-species transmission of crustacean pathogens, the isolated pathogens may bring potential hazards to Portunus trituberculus, an important aquaculture economic species in China. Therefore, artificial infection and histopathological analysis were conducted on P. trituberculatus. The results of drug sensitivity and antagonism assays revealed that stain V. natriegens exhibited susceptibilities towards antibiotics such as streptomycin and norfloxacin, but 10 probiotics had no antagonistic effect on it; strain V. fortis exhibited susceptibilities to antibiotics such as tetracycline and chloramphenicol, moreover, strain V. fortis showed inhibitory effects on Bacillus velezensis and B. amyloliquefaciens. Strain M. bicuspidata exhibited drug susceptibility towards polymyxin B and showed inhibitory effects on B. toyonensis, B. velezensis, and B. amyloliquefaciens. The results of artificial infection tests using V. natriegens, V. fortis, and M. bicuspidata in P. trituberculatus showed cumulative mortality rates of 100%, 75%, and 35%, respectively, after 120 hours of infection. The hemolymph of the deceased P. trituberculatus following injection with strain V. natriegens or V. fortis exhibited a light blue and did not coagulate normally. Conversely, the hemolymph of the deceased crabs following injection with strain M. bicuspidata appeared milky white and normal coagulation. Histopathology examination demonstrated that strains V. natriegens, V. fortis, and M. bicuspidata can all induce lesions in several tissues. This study is the first to isolate V. natriegens and V. fortis from crustaceans, and the infection tests on the P. trituberculatus can replicate the symptoms, such as hemolymph noncoagulation. Based on these findings, it is speculated that the pathogens capable of casing hemolymph noncoagulation syndrome in P. trituberculatus may originate from wild C. japonica. The drug resistance and probiotic antagonism test results can provide a theoretical basis for precise medication and offer insights into the development and application of probiotic preparations targeting the three pathogens. [ABSTRACT FROM AUTHOR]

Background: Two specimens of the genus Hippolyte were examined from the caridean collections of the Marine Biological Museum, Chinese Academy of Sciences. These specimens were captured in the South China Sea in 1987. Detailed inspection revealed that their morphological features closely match the (re)descriptions of Hippolyte australiensis, especially in the presence of a long, distinct lateral carina on the rostrum, a dorsally unarmed rostral border, and four prominent terminal spines on the dactylus of the last three pereiopods. New information: The discovery of Hippolyte australiensis in Chinese waters represents a significant expansion of its geographic distribution from the South Pacific to the North Pacific. Furthermore, an additional taxonomical report of H. australiensis is provided since its retrieval in 2001. [ABSTRACT FROM AUTHOR]

DNA was extracted from tissue samples from specimens of newly-collected Bathynomus kensleyi from Queensland and subsequently the COI and 16S rRNA sequences were successfully cloned. The holotype of B. kensleyi was also sampled for COI only. Comparison of the sequences showed that, for the COI sequences, B. jamesi and B. kensleyi have more than 59 different DNA positions amongst 596 known reading sequences. The Kimura two parameter (K2P) distance analysis confirmed that B. jamesi and B. kensleyi are two species. Indian records of Bathynomus are reviewed and three of the four identified species from India are shown to be misidentifications. Bathynomus decemspinosus, B. doederlini and B. kensleyi are found to not occur in India and the only accepted record is that of Bathynomus keablei Lowry & Dempsey, 2006. We conclude that, based on molecular analysis and morphological comparisons, the correct species identity of Indian species other than Bathynomus keablei remains unknown. [ABSTRACT FROM AUTHOR]

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]

Copyright of Spanish Journal of Palaeontology is the property of Socieadad Espanola de Paleontologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Twenty-one specimens of Portunus sp. first crab were obtained from plankton samples collected from the Obhur Creek, Central Red Sea, Saudi Arabia. These specimens have been morphologically described herein. The setal patterns of the first crabs of the present specimens were compared with those of the first crabs of P. sanguinolentus. Presence of two to three rows of setae on the coxa of maxillule and coxa and basial of the first maxilliped are found in both the species of Portunus first crabs compared herein. These features seem to be taxonomically significant as these features are found in one of the other genera of Portunidae – Thalamita. [ABSTRACT FROM AUTHOR]

To determine the Amphipoda (Crustacea) fauna of the inland waters of Western Anatolia, Marmara and the Turkish Thrace Region, field studies were conducted between May 2014 and March 2019. Seven field studies were conducted. Samplings were conducted at 291 localities and amphipod specimens were found at 127 of them. As a result, 11 amphipod species (Echinogammarus stocki G. Karaman, 1970, Gammarus aequicauda (G. Karaman, 1970), Gammarus anatoliensis Schellenberg, 1937, Gammarus arduus G. Karaman, 1975, Gammarus balcanicus Schäferna, 1923, Gammarus dorsosetosus Mateus & Mateus, 1990, Gammarus gonensis Özbek, 2016, Gammarus komareki Schäferna, 1923, Gammarus lacustris G.O. Sars, 1863, Gammarus pulex pulex (Linnaeus, 1758), Gammarus uludagi G.S. Karaman, 1975) were determined. The new records can be listed as: E. stocki for Ekinanbarı, G. anatoliensis for Uşak, G. arduus for Bolu and Düzce, G. balcanicus for Kocaeli and Sakarya, G. dorsosetosus for Bolu, G. gonensis for Istanbul and Manisa, G. komareki for Düzce and Kocaeli, G. lacustris for Istanbul, G. pulex pulex for Bolu, Kırklareli, Kocaeli, Sakarya and Uşak, and G. uludagi for Aydın, Bilecik, Sakarya and Yalova provinces. The observed morphological features and the detailed drawings of the determined taxa are presented. Additionally, a map showing the distribution of the obtained species is also given. [ABSTRACT FROM AUTHOR]

In order to understand the role of lower order tributaries in the population structuring of the freshwater anomuran crab Aegla parana Schmitt, 1942, a study on the distribution of demographic categories was carried out along Negro River and in its tributary Totó River that belong to Upper Iguaçu Basin, southern Brazil. Two collection points were established along the main channel of Negro River, in a 7.00 km long stretch, and three points in the entire creek Totó River with 6.61 km long. The animals were captured with Surber net and baited traps and had the carapace length (CL) measured. A total 146 crabs were obtained from Negro River and 361 from Totó River, performing 507 analyzed aeglids. From the point 1 of Negro River, males measured 27.68 ± 12.68 mm CL and females 18.98 ± 5.88 mm CL; from point 2 of the same river, the values were 24.45 ± 13.70 mm CL and 27 ± 8.50 mm CL, respectively. There was a positive and direct relationship between the mean CL of the aeglids from Totó River and the distance of the collection points from its source. Males: point 1 (source of the creek): 7.90 ± 1.23 mm CL; point 2: 9.55 ± 3.06 mm CL; point 3: 9.91 ± 2.62 mm CL. Females: point 1 (source): 6.68 ± 1.70 mm CL; point 2: 9.01 ± 1.94 mm CL; point 3: 10.49 ± 2.57 mm CL. The sexually immature aeglids are distributed mainly in the lower order tributary (= Totó River), and the mature ones in the main channel of Negro River, indicating that this population perform ontogenetic migrations from tributary to the main river. The spatial partition can be explained under three aspects that are quite contrasting between Negro River and Totó River: 1. substrate architecture; 2. depth of the water column and 3. quality of available food. [ABSTRACT FROM AUTHOR]

A new species of the genus Cyphocaris Boeck, 1871, is described. The material examined was collected during the "Acoustics along the Brazilian Coast" (Abraços 1) project, by micronektonic trawls at a targeted depth of 525 m, off the Rocas Atoll, Rio Grande do Norte state, Brazil. Cyphocaris boecki sp. nov. can be grouped with the eyed species in the genus but differs from them--except for C. faurei K. H. Barnard, 1916 and C. latirama, Hendrycks & Conlan, 2003--in presenting a dorsally smooth pereonite 1. However, the new species can be distinguished from both by its maxilliped inner plate with two robust apical setae, pereopod 7 basis with weakly produced posterodistal lobe, telson lobes without setae, spines or apical nails, and other characters that are individually discussed among them. The new species can be readily differentiated from C. pedroi Sorrentino, Alves, Johnsson & Senna, 2016, also described from Brazil, by presenting eyes, a rounded lateral cephalic lobe, very elongated antenna 2 almost reaching body length, and pereopod 5 basis, with apically acute spur reaching about two-thirds of the propodus. This is the second record of the genus for Brazilian waters. [ABSTRACT FROM AUTHOR]

The meiobenthic harpacticoids of the Persian Gulf and the Gulf of Oman has been almost unknown. During October 2014 to September 2016, interstitial and phytal harpacticoids were collected from tide pools in 30 different localities along the Iranian coast of the Persian Gulf and the Gulf of Oman. The new information on the distribution of 26 species and 12 families is provided, here. The most species-rich family was Laophontidae with seven species, followed by Miraciidae with four species. In this paper, all the species were considered new records for the area. Furthermore, the first checklist of meiobenthic Harpacticoids is provided. [ABSTRACT FROM AUTHOR]

Copyright of Iheringia. Série Zoologia is the property of Fundacao Zoobotanica do Rio Grande do Sul and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A representative of the family Cambaridae (Decapoda) was recorded for the first time in Bulgaria. This is the North American spiny-cheek crayfish Faxonius limosus, considered as an invasive alien species of European Union concern. A total of 92 specimens (42 males and 50 females) were found in the Danube tributaries, the rivers Topolovets, Voinishka and Archar in northwestern Bulgaria, in 2015-2016. The morphometric characters of all specimens were studied and no significant differences were found between the three populations and between the males and females. Furthermore, the morphometric features distinguishing F. limosus from the native crayfish species of the genera Astacus, Pontastacus and Austropotamobius in Bulgaria were presented. We assume that F. limosus was introduced in Bulgaria through the Danube River, coming downstream from the Serbian and Romanian sectors, where this species have been recorded earlier. Our results also indicate an early stage of establishment of the species in the Bulgarian sector of the Danube River. The further spread of F. limosus upstream of the Danube tributaries and in the inland waters will threaten the native crayfish populations in Bulgaria. Therefore, urgent measures in accordance with the Regulation (EU) No 1143/2014 need to be taken at national and regional level in order to prevent the range extension and the negative impact of this invasive alien species in Bulgaria. [ABSTRACT FROM AUTHOR]

The present study reports the occurrence of the pistol shrimp, Alpheus euphrosyne from the South-Eastern Arabian Sea. Identification of the species was based on morphological and molecular examination. One male and two female specimens were collected from the experimental fishing vessel FV Sagar Harita, operating in the Arabian Sea off the south-west coast of India during May 2016. [ABSTRACT FROM AUTHOR]

Since scorpions exist almost all over the world, some expected body differences exist among the species: undoubtedly, the most evident is the shape and size of their pincers or chelae. The scorpion chela is a multifunctional body component (e.g. attack/defense, mating and protection from the environment) that leads to the development of different stresses in the cuticle. How such stresses in the cuticle are accommodated by different chelae shape and size is largely unknown. Here we provide new comparative data on the hierarchical structure and mechanical properties of the chela cuticle in two scorpion species: Scorpio Maurus Palmatus (SP) that has a large chela and Buthus Occitanus Israelis (BO), with a slender chela. We found that the SP exocuticle is composed of four different sublayers whereas the BO exocuticle displays only two sublayers. These structures are different from the exocuticle morphologies in crustaceans, where the Bouligand morphology is present throughout the entire layer. Moreover, the scorpion chela cuticle presents an exclusive structural layer made of unidirectional fibers arranged vertically towards the normal direction of the cuticle. Nanoindentation measurements were performed under dry conditions on transversal and longitudinal planes to evaluate the stiffness and hardness of the different chela cuticle layers in both scorpions. The chela cuticle structure is a key factor towards the decision of the scorpion whether to choose to sting or use the chela for other mechanical functions. Many arthropods such as lobsters, crabs, stomatopods, isopods, and spiders have been the subject of research in recent years, and their hierarchical structure and mechanical properties extensively investigated. Yet, except for a limited number of pre-1980 publications, comparatively little work has been devoted to the terrestrial scorpion. The scorpion chela is a multifunctional part of the body (e.g. attack/defense, mating and protection from the environment) that involves the development of various stresses in the cuticle. How these stresses in the chela cuticle are managed by different chelae shape and size is still unknown. The lack of a single study that integrates morphological characterization of the entire hierarchical structure of the scorpion chela cuticle, and local mechanical properties, significantly affects the scientific knowledge regarding important structural approaches that can be used by nature to maximize functionality. [ABSTRACT FROM AUTHOR]

Located in the Cantabrian Sea (NE Atlantic), El Cachucho is the largest offshore Marine Protected Area (MPA) in Spain. One of the most abundant keystone megafauna species occurring in this MPA is a yellow gorgonian of genus Placogorgia Wright and Studer (1889), occurring in relatively high densities in steep slopes with rocky outcrops at depths ranging 500–1200 m. Here, we describe a new species of isopod, Astacilla andresmeixidei sp. nov., living in association with a specimen of a yellow gorgonian collected at 525 m depth. Females of the new species are characterised by a trapezoidal pereonite 4 with a middorsal bifurcate tubercle on posterior margin; males have a rectangular pereonite 4 with small tubercles irregularly distributed and pereonite 3 with a midventral process. The new species is distinguished from the most morphologically similar species Astacilla gorgonophila Monod (1925) by its dorsal sculpture, having a shorter antenna 2 with a flagellum of three articles plus a claw, and also by its geographic and bathymetric distribution. Phylogenetic analysis using the mitochondrial marker COI confirmed that the new isopod is a member of the family Arcturidae and placed it in a clade, recovered with low support, including other species of the genus Astacilla Cordiner, 1793. As with other previously described arcturids, we suggest that A. andresmeixidei sp. nov. is a commensal of the gorgonian using its branches to reach higher in the water column and thus increase its chances to get more particulate organic matter. Our morphological analyses on the gorgonian host, suggest that it belongs to the genus Placogorgia although in our phylogenetic results using the nuclear marker msh1 the gorgonian shows affinities with the genus Paramuricea Kölliker (1865). This taxonomic inconsistency is discussed. • A new deep-sea Astacilla species is described from the Cantabrian Sea (NE Atlantic). • The new isopod was found in association with a keystone gorgonian (Placogorgia sp.) • We provide morphological and phylogenetic evidence for the isopod and the gorgonian. [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]

Highlights • A new species of amphipod genus Bathyceradocus was found in NW Pacific. • It is the fourth wood-associated amphipod species collected at abyssal depths. • The species exhibits high molecular diversity that may indicate the existence of stable population over long time. Abstract During the expedition to the abyssal plain of Kuril-Kamchatka (KuramBio I) wood fragments were collected at seven stations. One of the wood-falls harboured a group of amphipods belonging to the genus Bathyceradocus known to be associated with this type of habitat. Morphological study of the collection revealed that the crustaceans belong to species new to science. The species presently described differs from known congeners in the armature of the mandibular palp, the shape of gnathopod 2, the shape of coxa 4 as well as the shape of the basis of pereopods 5–7. The studied collection consists of females (one ovigerous), two males and juveniles, so size-specific variation is also provided. It is the first record of Bathyceradocus in the Northwest Pacific and the fourth wood-associated amphipod species found in abyssal depths. Because the material was available for genetic study, cytochrome c oxidase I subunit (COI) sequences were analysed and six haplotypes were distinguished. There was relatively high intraspecific variation taking into account that all individuals came from a single station. [ABSTRACT FROM AUTHOR]

The mantis shrimp superfamily Squilloidea, with over 185 described species, is the largest superfamily in the crustacean order Stomatopoda. To date, phylogenetic relationships within this superfamily have been comprehensively analysed using morphological data, with six major generic groupings being recovered. Here, we infer the phylogeny of Squilloidea using a combined dataset comprising 75 somatic morphological characters and four molecular markers. Nodal support is low when the morphological and molecular datasets are analysed separately but improves substantially when combined in a total-evidence phylogenetic analysis. We obtain a well resolved and strongly supported phylogeny that is largely congruent with previous estimates except that the Anchisquilloides -group, rather than the Meiosquilla -group, is the earliest-branching lineage in Squilloidea. The splits among the Anchisquilloides - and Meiosquilla -groups are followed by those of the Clorida -, Harpiosquilla -, Squilla - and Oratosquilla -groups. Most of the generic groups are recovered as monophyletic, with the exception of the Squilla - and Oratosquilla -groups. However, many genera within the Oratosquilla -group are not recovered as monophyletic. Further exploration with more extensive molecular sampling will be needed to resolve relationships within the Oratosquilla -group and to investigate the adaptive radiation of squilloids. Overall, our results demonstrate the merit of combining morphological and molecular datasets for resolving phylogenetic relationships. The phylogenetic relationships within Squilloidea, the largest superfamily of mantis shrimps, have only been comprehensively studied using morphology. Here we present the first total-evidence phylogenetic analysis for the group, and within Stomatopoda. Our results show the merit in using a combination of morphological and molecular data to improve nodal support and resolve phylogenetic relationships. [ABSTRACT FROM AUTHOR]

Phenotypic plasticity and polyphenism, in which phenotypes can be changed depending on environmental conditions, are common in insects. Several studies focusing on physiological, developmental, and molecular processes underlying the plastic responses have revealed that similar endocrine mechanisms using juvenile hormone (JH) are used to coordinate the flexible developmental processes. This review discusses accumulated knowledge on the caste polyphenism in social insects (especially termites), the wing and the reproductive polyphenisms in aphids, and the nutritional polyphenism and sexual dimorphism in stag beetles. For the comparison with non‐insect arthropods, extensive studies on the inducible defense (and reproductive polyphenism) in daphnids (crustacean) are also addressed. In all the cases, JH (and methyl farnesoate in daphnids) plays a central role in mediating environmental stimuli with morphogenetic processes. Since the synthetic pathways for juvenoids, i.e., the mevalonate pathway and downstream pathways to sesquiterpenoids, are conserved across pancrustacean lineages (crustaceans and hexapods including insects), the evolution of developmental regulation by juvenoids that control molting (ecdysis) and metamorphosis is suggested to have occurred in the ancestral arthropods. The discontinuous postembryonic development (i.e., molting) and the regulatory physiological factors (juvenoids) would have enabled plastic developmental systems observed in many arthropod lineages. In phenotypic plasticity and polyphenism, in which phenotypes can be changed depending on environmental conditions, similar endocrine mechanisms using juvenile hormone (JH) are used to coordinate the flexible developmental processes. This review discusses accumulated knowledge on the caste polyphenism in social insects, the wing and the reproductive polyphenisms in aphids, the nutritional polyphenism and sexual dimorphism in stag beetles, and the inducible defense (and reproductive polyphenism) in daphnids. In all the cases, JH plays a central role in mediating environmental stimuli with morphogenetic processes, to construct adaptive phenotypes to the environments. [ABSTRACT FROM AUTHOR]

Faxonius barrenensis (Rhoades, 1944) is endemic to the Green River system of Kentucky and Tennessee, USA and closely related to Faxonius mirus (Ortmann, 1931), which is restricted to Tennessee River tributaries in Tennessee and Alabama. A crayfish with morphological affinities to these species (Faxonius sp.) occurs in the Red River system (Cumberland River Drainage) of Kentucky and Tennessee. Whether the latter represents a disjunct population of F. barrenensis, F. mirus, or a distinct species, has not been tested. Whether the shared morphological traits reflect shared ancestry or convergence is unknown. We used molecular and morphological data, including two mitochondrial (COI and 16S) and two nuclear (28S and GAPDH) genes and a standard suite of phenotypic measurements to examine the phylogenetic relationships and the taxonomic status of Faxonius sp. relative to F. barrenensis, F. mirus, and other species of Faxonius Ortmann, 1905. All gene datasets recovered focal taxa as a clade, implying their morphological similarities likely reflect shared ancestry. In all mitochondrial and combined gene trees, Faxonius sp. was recovered as genetically divergent from F. barrenensis and F. mirus. Faxonius sp. is phenotypically distinguished from F. barrenensis and F. mirus based on several characteristics including shorter rostrum, longer abdomen, wider areola, and straight margins on both mandibles (toothed in F. mirus; toothed and straight in F. barrenensis); Form I males have a strong angular shoulder on the gonopod, in comparison to F. barrenensis. Given these findings, we describe Faxonius sp. as Faxonius bellator n. sp. Faxonius bellator n. sp. has been collected at only four localities, suggesting it has a small range and warrants conservation concern. [ABSTRACT FROM AUTHOR]

A new species of aorid amphipod, Bemlos seisuiae sp. nov. is described from deep muddy bottom off Tanabe Bay, Japan. The new species is characterized by its conspicuously slender and elongated pereopods 3–6. The aorids reported from deep water are reviewed, and their morphological adaptations to deep water are discussed. [ABSTRACT FROM AUTHOR]

Grooming behaviors that decrease fouling have been documented in various animals. The result of autogrooming has been frequently documented, with the behaviors and time spent grooming being highly variable in taxa. Setae are important in removing fouling as well as optimizing sensory reception and movement in crustaceans. Mantis shrimps (Stomatopoda) are marine crustaceans that are divided into two groups (smashers and spearers) based on the morphology of their foraging appendages. While other behaviors and structures in mantis shrimps have been intensely studied (foraging, agonistic, reproduction), grooming has been studied in detail in only a few species. We studied grooming behaviors in both groups and describe the morphologies of the grooming appendages and body regions frequently groomed. Smasher and spearer mantis shrimps were predicted to have distinct grooming behaviors and morphologies of their grooming appendages because they inhabit different environments. The grooming behaviors of smasher and spearer species were recorded and described by grooming frequency and duration, grooming mechanism, and the groomed body regions being documented. The first maxillipeds, the only grooming appendage, and frequently groomed body regions (eyes, antennae, and antennules) were observed using a scanning electron microscope. Compared to spearers, smashers groom their bodies more frequently, for longer durations, have a higher density of grooming setae, and are more fouled even though they may live in habitats with less free-suspended sedimentation. Spearers could therefore be structurally better adapted with their first maxillipeds and remove environmental fouling more efficiently for their specific habitats. Compared to various other crustaceans, mantis shrimps have relatively little fouling on their appendages and have low grooming-time budgets. [ABSTRACT FROM AUTHOR]

Barona arcuata, n.gen et n.sp., a left forewing of a relatively large cockroach of the Order Blattaria, is described from mesosaur-bearing lagoonal shales of the Mangrullo Formation (north-eastern Uruguay). While most of the insect remains recovered from the Mangrullo Formation come from sandy limestones, associated to scarce isolated mesosaur bones and pygocephalomorph crustaceans, the cockroach wing here described was found in the overlaying green to brownish, gray and dark black shales associated to intercalated bentonites and evaporitic gypsum crystals. Barona arcuata shares some features with typical Late Carboniferous taxa such as its general venation pattern and outline of the wing, four main and powerful veins arising close together from near the base of the wing, Sc simple forked, pectinate, reaching the costal border through a long fork, R and M bifurcating and terminating in the wing margin above and below the apex respectively, short and narrow CuA, and the presence of a broad interspace between CuP and AA. Cross venation seems to be absent or it was not preserved. Some characters might relate Barona arcuata to the Late Carboniferous-Early Permian Neothroblattinidae such as the presence of sigmoidal veins in the anal area, a condition not found in any of the remaining representatives of the Palaeozoic Blattaria. Intriguingly, the Uruguayan blattarian also presents a strong similarity with Qilianiblatta namurensis Zhang, Schneider & Hong, 2012 from the Westphalian of China, clearly a smaller taxon that is also difficult to relate to any of the preexistent families. The apparent plesiomorphic venation pattern of the new species which is reminiscent of that present in the oldest known blattarians, is in agreement with a Permo-Carboniferous (Gzhelian-Asselian) age for the Mangrullo Formation also supported by the presence of a macrofloral assemblage dominated by arborescent lepidondendrids and other lycopsids and the pygocephalid-like morphology of the pygocephalomorph crustaceans from the same levels. [ABSTRACT FROM AUTHOR]

Polychelidan lobsters are one of the rare groups of decapod crustaceans which were first discovered as fossils long before being identified in extant deep-sea environments. As for other decapods, their fossil record is highly incomplete, which complicates the reconstruction of their evolutionary history. Another problem that hinders better knowledge of the group is familial assignments, which can be difficult in the absence of a complete revision of known fossil taxa. As a result, only three fossil Polychelidae have been identified to date, the oldest dating back to the Callovian (Middle Jurassic). In the present study, we consider two rarely studied species, Palaeopolycheles crymensis Levitski, 1974 from the Toarcian-Aalenian (Early-Middle Jurassic) of Crimea (Ukraine), and Eryon neocomiensis Woodward, 1881 from the Valanginian (Early Cretaceous) of the Outer Carpathians (Czech Republic). Our reinvestigations indicate they present several characters typical of Polychelidae, and are actually morphologically quite similar to extant species, notably in the structure of the anterior part of the carapace and the small ocular incisions. Two new genera are erected to accommodate them: Tauricheles gen. nov. (type species Palaeopolycheles crymensis) and Woodwardicheles gen. nov. (type species Eryon neocomiensis). The reinvestigations show that: (1) the evolutionary history of Polychelidae is much older than previously considered; (2) Polychelidae have inhabited deep water for a long time; (3) both species are probably autochthonous or parautochthonous to turbiditic palaeoenvironments; (4) Woodwardicheles neocomiensis comb. nov. is one of the rare benthic macrofossils of the Silesian Basin. http://zoobank.org/urn:lsid:zoobank.org:pub:CE6FEEA7-4162-4AE2-9413-11FD38FE04B9 [ABSTRACT FROM AUTHOR]

Metapenaeopsis sibogae inhabits the South Pacific and Southeast Asia and is an emerging fisheries resource. However, studies on the population biology of M. sibogae are scant, and their morphometric relationships have not been examined. Thus, we studied the relative growth of M. sibogae, hypothesizing that its morphological sexual maturity can be estimated based on abrupt shifts in allometry. The relationships of body length (BL) and body weight (BW) with carapace length (CL) were determined by the least squares method. Data for each sex were repeatedly partitioned into two size-delimited subsets (early and late phases), considering a CL value as a hypothesized transition point. Analysis of the sum of squared residuals indicated that two separate linear BL/CL models fit the data better than a single linear model showing clear transition points in both males (13.2 mm CL) and females (15.0 mm CL). The changes in allometry in the BL/CL relationships between early- and late-phased males and females were indicated by a 20.5 and 21.5% decrease in the slope, respectively. These transition points could be associated with sexual maturity. The growth rate of BW vs. CL slowed significantly after morphological sexual maturity was reached in both sexes, demonstrating the existence of dimorphic growth. [ABSTRACT FROM AUTHOR]

The external morphology of the larval steps in the development of the Anomuran crab Allopetrolisthes punctatus is described using material obtained under laboratory conditions and from field samples. All stages are presented with photos taken with a scanning electron microscope. For the first time in this species, and in a similar way as described for the whole family Porcellanidae, it was possible to identify one prezoea, two zoeal and one megalopa stages. The main difference between the zoeal stages is the translucid spine in the center of the telson of the zoea II, surrounded by five gross setae at each side. Also, we also studied first juvenile stages to know the size at which sexual pleopods appear, which in our samples it occurred at 1.97 mm of carapace length. [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]

The parasitic copepod, Lernanthropinus trachuri (Brian, 1903) (Copepoda, Siphonostomatoida, Lernanthropidae) was found on the Mediterranean horse mackerel, Trachurus mediterraneus in Bandırma Bay, Turkey. The aim of this study is to present female Lernanthropinus trachuri with morphological characters with photos from Turkey. The details unseen in photos were supported with drawings. All parasites were firmly attached to the gill filaments of the host. This parasite is also specific for the genus Trachurus (Costa et al 2017). Therefore, this parasite may use as biomonitor or tag species for fish stock studies in Turkey. [ABSTRACT FROM AUTHOR]

Aliaporcellana spongicola sp. n. from the Philippines and Indonesia is described. The new species has been frequently photographed by divers because of its striking coloration, but has not been described yet. Aliaporcellana spongicola sp. n. is in fact a widespread commensal of barrel sponges of the genus Xestospongia and other sponges. Morphological characters and ecological information of all described species of Aliaporcellana, and of other porcellanids associated with sponges and soft corals, suggest that all members of the genus are commensals, and that similar morphological adaptations to dwelling on these hosts have evolved independently in different evolutionary lines within Porcellanidae. [ABSTRACT FROM AUTHOR]

Hyalella maya n. sp. from a sinkhole (cenote) in Quintana Roo, Mexico, is described herein, based on morphological characters. It is the third species recorded in Mexico and the second species of Hyalella found in the Aktun-Ha sinkhole. It can be distinguished from its closest species, Hyalella azteca from Veracruz, by the shape of the palp of maxilla 1, the number of setae in the posterior margin of the basis, the relative palm length and the truncate process of gnathopod 2 in males, the number of setae in the lobe of the basis of pereopod 7, and the shape and setation of the telson. Those characters have been found to be useful for species distinction in the complex by González and Watling (2002). The main differences between Hyalella cenotensis and Hyalella maya n. sp. are: the presence of eyes, the number of articles in the flagellum in antennae 1 and 2, the relative length of antennae to the total body length, the relative length of the rami in uropod 3 to the peduncle length, and the number of setae in the telson. [ABSTRACT FROM AUTHOR]

Studies on relative growth and sexual maturity are important to understand the reproductive biology of a species. The aims of this study were to determine the relative growth and to estimate the size of Panopeus occidentalis at morphological sexual maturity, as well as to confirm whether this species demonstrates heterochely or handedness. Individuals were collected every two months from March 2013 to July 2014 in the intertidal estuarine zone of Cananeia, São Paulo, Brazil. The following measurements were taken: carapace width (CW), carapace length (CL), right and left cheliped propodus length (CPL), right and left cheliped propodus height (CPH), right and left cheliped propodus width (CPW), abdomen width (AW), and first pleopod length (FPL). The morphometric relationship used to estimate the size at morphological sexual maturity were CW vs. AW for females and CW vs. FPL for males; these comparisons yielded estimated CW values of 15.60 mm and 16.67 mm, respectively. Heterochely was observed but handedness was not present. The species has a major cheliped on one side, but the side is not constant. This study provides the first insights on the relative growth, sexual maturity, heterochely, and handedness on a population of P. occidentalis in a conserved area. [ABSTRACT FROM AUTHOR]

Subterranean habitats include mainly aerated ("dry") and flooded-karst or volcano-karst caves as well as interstitial waters; the term "cave" also includes narrow fissures. Such habitats can be classified as terrestrial cave and fissure habitats, cave and fissure waters, and interstitial waters. Only woodlice (Isopoda) can be present in terrestrial subterranean habitats, but all orders of Crustacea are represented in aquatic habitats. Springs are also a source of subterranean aquatic fauna. Most subterranean crustaceans are members of Copepoda, Amphipoda, and Isopoda. Sampling tools include hand nets, mini hand nets, nets for wells, filter bottles, the Bou-Rouch pump, traps, and the use of artificial substrates. Preservation of the material depends on the final use of the specimens for morphological or molecular analyses, or for some special purposes. [ABSTRACT FROM AUTHOR]

We validated the morphological hybrid index (MHI) described by Simovich et al. (2013) for detecting hybrids between the endangered San Diego fairy shrimp Branchinecta sandiegonensis (Fugate, 1993) and the versatile fairy shrimp B. lindahli (Packard, 1883) through morphological and genetic analysis of 662 individuals. This index uses species-specific character states for "spines" (dorsolateral projections) on thoracic segments 3-11 in adult females. In non-admixed (non-hybrid) populations, the character states for segment 8 correlate poorly with the remaining segments, and the overall morphological hybrid index score (MHI score). Only 22% of non-admixed B. sandiegonensis display the expected character state for segment 8 compared to nearly all B. lindahli. Eliminating this character in principal component analyses increases the proportion of variation explained by PC1 from 57.3% to 69.5%. The revised MHI, however, still shows slight variation in populations of B. sandiegonensis and B. lindahli that have no genetic evidence of admixture. Hybrid populations possess considerably more variation in MHI score, and this variation is heavily skewed towards B. lindahli phenotypes. We suggest using the revised MHI and genetic characters in future experimental field studies to improve an understanding of the processes that initiate and maintain hybridization in this system. [ABSTRACT FROM AUTHOR]

Palaeopalaemon newberryi Whitfield, 1880 is redescribed based upon a large collection of specimens including those collected in the nearly 40 years since P. newberryi was last evaluated. Previously undescribed aspects of its morphology include a large, pectinate maxilliped; the dactylus of pereiopod I; a triangular sternal field; well-preserved antennae, including an endopod with an antennulate flagellum; and a broad, roughly triangular scaphocerite. Phylogenetic analysis supports the position of P. newberryi as a lobster and suggests that Palaeopalaemonoidea is the sister taxon of Polychelida. Palaeopalaemon newberryi is distinct from Angustidontus, and pectinate claws shared by the two taxa may be a convergent morphology and not phylogenetically informative. Palaeopalaemon newberryi probably exhibited a benthic habit. [ABSTRACT FROM AUTHOR]

Niphargus sarii sp. n. was collected from Jo-Khanem Spring in Ilam Province. This species hypothesis is based on the analysis of morphological characters and 28S ribosomal DNA sequences. In this paper, we describe the morphological traits of this new species. Then, its taxonomic status within the genus is discussed in comparison to the 15 known Iranian species. Results revealed that N. sarii sp. n. is phylogenetically close to N. sohrevardensis. This species is easily distinguished from other Iranian species by some characters, in particular the equal length of rami in uropod I, lack of lateral robust setae on telson and the situation of dactylus to posterior margin of propodus in gnathopod II. [ABSTRACT FROM AUTHOR]

Abstract: Wire‐mesh traps are extensively used to harvest blue crabs Callinectes sapidus but also capture over 40 other species. Numerous studies have evaluated bycatch reduction devices (BRDs) to reduce the incidental capture of one species, the diamondback terrapin Malaclemys terrapin, since 1992. Despite decades of research, widespread adoption of BRDs as a conservation action has not occurred, which partly stems from seemingly conflicting results from a multitude of BRD designs along the U.S. Atlantic and Gulf of Mexico coasts. In this study, we developed a simple scoring system to assess the probability of trap entry by legal‐sized (≥12.7‐cm carapace width; n = 736) blue crabs as well as trap exclusion of diamondback terrapins (n = 985) based on morphometric measurements for both species. Probability of entry or exclusion for each legal‐sized blue crab and diamondback terrapin was assessed for each of 8,196 theoretical BRD sizes encompassing the range of BRD widths and heights actually tested since 1992. Predictive relationships for trap entry or exclusion for each theoretical BRD size were evaluated as a function of three geometric BRD attributes: BRD area (cm2), diagonal BRD opening (cm), and the ratio of BRD width to height. Comparison of observed (35 data sets) versus predicted (entry or exclusion probabilities for BRDs) catches for both species revealed that BRDs have performed as predicted for legal‐sized blue crab catch (slope = 0.99; >81,000 crabs) but have captured considerably fewer diamondback terrapins than predicted based on BRD size alone (slope = 0.28; 1,430 diamondback terrapins). Analyses also substantiated superior (i.e., >30% better) diamondback terrapin exclusion potential for a BRD we designed that measured 5.1–6.4 cm (height) × 7.3 cm (width). Increasing the width of this BRD by 0.4 cm would also achieve a 99% capture probability for legal‐sized blue crabs, comparable to other widely tested and marketed BRD designs. [ABSTRACT FROM AUTHOR]

Abstract: To estimate genetic parameters for main growth traits measured in different scales in Chinese mitten crab, a total of 1600 and 4857 individuals from 20 families were observed for body weight, body length, body width, and body depth at two measuring periods. With multivariate animal models for absolute growth, the heritabilities for these growth traits were estimated to be low and moderate at the sampling and harvesting periods, respectively, while pairwise ratios between body length, width, and depth indicated low inheritance. This suggested that the shape of the crabs can be genetically improved with family selection. Genetic correlations, which all exceeded 0.68, were consistently higher in the harvesting period than in the sampling period. A random regression model was constructed to genetically analyze multiple allometries that were used to define the relative growths of these growth traits. As a result, the heritabilities for the allometry scalings were estimated as 0.893, 0.909, and 0.488 of body length, depth, and width to body weight, respectively. Genetic correlations of the allometry scalings, which ranged from −0.975 to 0.097, considerably differed among three morphological traits. According to the genetic parameters of the allometry scalings of morphological traits to body weight, synchronous growth of body shape with body weight might be genetically regulated through selective breeding for their relative growths. [ABSTRACT FROM AUTHOR]

Squat lobsters are prevalent in chemosynthetic environments but have been insufficiently studied in mud volcano habitats. An abyssal species, Munidopsis taiwanica Osawa, Lin & Chan, 2008 was recently collected in a mud volcano field in the Mariana Trench at a depth greater than 5000 m, which represents a new distributional record. Its diagnostic characters are presented in this study. In-situ observation suggested that M. taiwanica was closely associated with this chemosynthetic environment and probably exhibited camouflage behaviour by attaching seafloor sediments onto its body. Munidopsis taiwanica is the first confirmed species of squat lobster found in the mud volcano environment, and currently represents the deepest record (5491 m) of squat lobsters in the world. [ABSTRACT FROM AUTHOR]

The marine fauna of decapod Crustacea, in all its diversity, can be negatively affected as a result of environmental changes, both on a local or a global scale. The present study aims to report the existence of Cyrtograpsus angulatus Dana, 1851, on the northern Patagonian coast, while concurrently describing some other decapod species associated with the various habitats. C. angulatus was originally described from the Chilean coast north of 36°43′S, and the present study revealed its presence down to 44°S. In the estuaries investigated, C. angulatus is the exclusive decapod species, whereas in coastal zones it can coexist with other species of marine decapods. Nevertheless, according to the null model of the co-occurrence of species, the species associations tested did not show any structured pattern. Some ecological and biogeographical patterns in relation to this species and its biocoenoses are discussed. [ABSTRACT FROM AUTHOR]

A new species of deep-water barnacle belonging to the family Scalpellidae is described from the western central Pacific. Based on the presence and absence of radial stripes on the surfaces of the plates, the 23 species of the genus Amigdoscalpellum can be divided into two groups. In the species group with radial stripes, the new species here described, A. dorsituberculatum sp. nov., differs from other species by the dorsal part of the carina being round and arched, the roof without lateral ribs and median furrow; the infra-median latus wider triangular, its length on the basal margin greater than its height; and by the vestigial form of the caudal appendage. A key to the species of Amigdoscalpellum is provided. [ABSTRACT FROM AUTHOR]

White-clawed crayfish Austropotamobius pallipes (Lereboullet, 1858) are one of five crayfish species indigenous to Europe, and the only crayfish species to occur in Ireland. With no known invasive species posing a risk, the Irish population is of considerable conservation importance, particularly in a European context. While there are a number of capture techniques described for crayfish population studies, many have a number of limitations associated with them. There is a need therefore to evaluate new and emerging techniques, so as to assess their efficacy for monitoring A. pallipes populations. Artificial refuge traps (ARTs), an alternative passive capture method, were evaluated against three other widely used capture techniques during the summer months of 2015. Results indicate ARTs to be an effective technique for sampling crayfish, and suggest that, in combination with other capture methods, ARTs could depict accurate population structures, and reduce some of the sampling effort and bias associated with crayfish monitoring. [ABSTRACT FROM AUTHOR]

We present an updated checklist of the Diaptomidae of China, based on a literature review and on original field data from all over China during 2012-2016. A total of 19 genera and 56 species have been recorded. Neutrodiaptomus has the highest species richness (10 species), followed by Arctodiaptomus (9 species). Only one species each of Eudiaptomus, Mixodiaptomus, Eodiaptomus, Dentodiaptomus, Dolodiaptomus, Allodiaptomus, Karstodiaptomus, Metadiaptomus and Paradiaptomus was found. The taxonomic status of 16 species was revised: one wrongly attributed genus, Argyrodiaptomus, was corrected to Sinodiaptomus. First records for China include Arctodiaptomus parvispineus and one new cave-dwelling genus, Karstodiaptomus, is added. One Latin name from Shen & Sung’s book (1979) is corrected. Remarks on nomenclature and taxonomic issues are supplemented with information on the geographical distribution of the various species within China. [ABSTRACT FROM AUTHOR]

We investigated how surface mating affects the characteristics of chimneys (diameter, height, and thickness) and burrows (total length, horizontal length, total depth, volume and shapes) in Uca rosea (Tweedie, 1937). In U. rosea, surface mating is the main mating mode, and females incubate eggs inside their own burrows. We investigated 73 randomly selected burrows with chimneys (36 females, and 37 males). We observed that chimney and burrow characteristics, except for burrow/chimney diameter, were greater in females than in similar-sized males. The burrows were I- and J-shaped, with a higher number of J-shaped burrows in females and a higher number of I-shaped burrows in males. J-shaped burrows were longer and deeper, had greater volumes, and had higher and thicker chimneys, than I-shaped burrows. Chimney characteristics were positively correlated with burrow characteristics. Our results indicate that U. rosea female burrows are used for breeding, and male burrows are used for temporary stays. [ABSTRACT FROM AUTHOR]

In crustaceans, successful reproductive processes, such as the transition from juvenile to adult, exhibit important morphological changes that can be detected by analyzing relative growth. This study describes the relative growth of body structures in Nematopalaemon schmitti and its secondary sexual characteristics, and also estimates the morphological sexual maturity of this species in a region influenced by upwelling. The carapace length (CL), second pleuron length (PlL), cheliped carpus length (CaL), cheliped propodus length (PrL) and the length of appendix masculina (AML) of the shrimp were measured. The relationships that best demonstrated the changes in allometric coefficient between demographic categories were AML vs. CL for males, and PlL vs. CL for females. The estimated CL for morphological sexual maturity in males was 8.51 mm and 9.30 in females. Our results showed the appendix masculine and the second pleuron were secondary sexual characteristics that play roles in reaching the morphological sexual maturity necessary for reproductive success and to assure the life cycle of this species. [ABSTRACT FROM AUTHOR]

The crab genus Perisesarma De Man, 1895 has been shown to be a polyphyletic taxon comprising morphologically heterogeneous species. Some members of the genus have a close phylogenetic relationship with the sister genus Parasesarma De Man, 1895, with which it shares many morphological similarities, except for the existence of an epibranchial tooth in Perisesarma. This study uses morphological and molecular approaches to reconstruct phylogenetic relationships of Perisesarma and related genera and to evaluate the phylogenetic importance and taxonomic usefulness of the epibranchial tooth. As genetic markers we use two mitochondrial and one nuclear gene. A comparative morphological analysis reveals that a clean separation between species of Parasesarma and Perisesarma is not possible, because of intermediate conformations of the epibranchial tooth. In our molecular analysis, most species of Perisesarma cluster solidly together with species of Parasesarma, but without being reciprocally monophyletic. Morphology and genetics also indicate that the West African species of Perisesarma and the Indo-Pacific P. fasciatum are markedly different from all other species of the genus. Therefore, we here suggest with robust double support a new classification, transferring most species of Perisesarma to Parasesarma and the three West African representatives and P. fasciatum into new genera, thereby restricting the genus Perisesarma to the type species P. dusumieri. [ABSTRACT FROM AUTHOR]

In crustaceans, successful reproductive processes, such as the transition from juvenile to adult, exhibit important morphological changes that can be detected by analyzing relative growth. This study describes the relative growth of body structures in Nematopalaemon schmitti and its secondary sexual characteristics, and also estimates the morphological sexual maturity of this species in a region influenced by upwelling. The carapace length (CL), second pleuron length (PlL), cheliped carpus length (CaL), cheliped propodus length (PrL) and the length of appendix masculina (AML) of the shrimp were measured. The relationships that best demonstrated the changes in allometric coefficient between demographic categories were AML vs. CL for males, and PlL vs. CL for females. The estimated CL for morphological sexual maturity in males was 8.51 mm and 9.30 in females. Our results showed the appendix masculine and the second pleuron were secondary sexual characteristics that play roles in reaching the morphological sexual maturity necessary for reproductive success and to assure the life cycle of this species. [ABSTRACT FROM AUTHOR]

During the last three decades, strong progress was made in the taxonomy of the family Chydoridae (Crustacea: Cladocera), and the results of these revisions have become a valuable confirmation of the non-cosmopolitanism in the cladoceran distribution. But, to date, delineation between several chydorid genera (Pleuroxus Baird, 1843, Picripleuroxus Frey, 1993, Alonella Sars, 1862 and Disparalona Fryer, 1968) has been intuitive rather than based on careful diagnostics. Disparalona is a cladoceran genus with a complicated and confused taxonomy. We compiled a checklist of all formal taxa belonging to this genus in current understanding. Our study comprises a taxonomic revision of the North American, African and East Asian populations of D. cf. hamata with the aim of clarifying their species and generic status. We redescribe D. hamata (Birge, 1879) based on material from North America and D. chappuisi (Brehm, 1934) based on material from Africa. The latter is common in tropical-subtropical Asia, with a distribution range reaching the Far East of Russia. The second taxon from Africa is provisionally identified as D. cf. striatoides (Šrámek-Hušek, 1946), which was described initially from the Czech Republic. Further comparison is needed for a final conclusion on conspecifity of European and African populations provisionally placed to this taxon. At the current level of knowledge Mixopleuroxus Hudec, 2010 must be accepted as a subgenus of the genus Disparalona. The diagnoses of Disparalona s. str. and D. (Mixopleuroxus) are provided. Disparalona s. str. includes D. ikarus Kotov and Sinev, 2011, D. leei (Chien Shing-ming, 1970), D. rostrata (Koch, 1841) and D. smirnovi Sinev, 2015, while D. (Mixopleuroxus) includes D. hamata, D. chappuisi and D. striatoides. D. leptorhyncha (Daday, 1905) and D. caudata Smirnov, 1996 are not described adequately, but they also probably belong to the latter subgenus. The status of D. acutirostris (Birge, 1879) must be clarified in the future. [ABSTRACT FROM AUTHOR]

A colourful crab currently referred to as Parasesarma indiarum (Tweedie, 1940) is a relatively common species in Southeast Asian mangroves and has been recorded from Singapore, Malaysia, and Indonesia. The present study compares the material from Singapore and Peninsular Malaysia to the type specimens from Ambon, and recognises two species based on their morphology and genetic distances. The structure of the chelar dactylar tubercles and molecular data support the distinction of specimens originating from Peninsular Malaysia and Singapore from those of Ambon corresponding to P. indiarum sensu stricto. We here describe them as a separate species, Parasesarma peninsulare new species, and compare it with allied congeners. [ABSTRACT FROM AUTHOR]

The Indo-West Pacific pinnotherid crab genus, Ostracotheres H. Milne Edwards, 1853, was recognised for species with a simple, unadorned carapace without marginal lamellae, and a spatulate maxilliped 3 propodus with a rounded or subtruncate apex. Prior to the present study, the genus included: O. tridacnae (Red Sea; type species), O. affinis (Mauritius, Djibouti), O. cynthiae Nobili, 1906a (Red Sea); O. spondyli Nobili, 1905 (Persian Gulf); O. subglobosus (Baker, 1907) (southern Australia); O. holothuriensis Baker, 1907 (southern Australia); O. subquadratus Sakai, 1939 (Japan); and O. tomentipes Takeda & Konishi, 1994 (Japan). Reconsideration of species assigned to Ostracotheres shows they differ considerably in other aspects such as carapace physiognomy, pereopod article proportions, and gonopod structure (where known), suggesting the genus is not monophyletic. Thus, Ostracotheres is revised based on type and other material. Ostracotheres sensu stricto is restricted to O. tridacnae and O. cynthiae. Ostracotheres tridacnae is confirmed as a senior synonym of O. savignyi H. Milne Edwards, 1853, and appears to be restricted to the Red Sea as a commensal of tridacnine clams; records of O. tridacnae from southeast Africa are referred to Afropinnotheres dofleini (Lenz in Lenz & Strunck, 1914). Similarly, O. cynthiae appears to be restricted to the Red Sea as a commensal of ascidians; the single record of O. cynthiae from Indonesia requires confirmation but its published account is not consistent with O. cynthiae sensu stricto. A new genus, Austrotheres, is proposed for O. holothuriensis and a new species from eastern Australia. Ostracotheres subglobosus and O. subquadratus, considered by some to be conspecific, are shown to be separate valid species, with the identity of the latter fixed by a neotype selection; both are transferred to a new genus, Discorsotheres, together with O. spondyli and a new species from the tropical western Pacific. Ostracotheres affinis and O. tomentipes are referred to a new genus Latatheres, with the identity of the former fixed by a neotype selection. Keys to the species of the genera studied herein and to pinnotherid genera with a 2-segmented maxilliped 3 palp are provided. [ABSTRACT FROM AUTHOR]