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Within Malacostraca, legs are diversified variously throughout the groups. Most conspicuous is the transformation of anterior thoracopods, especially the first, into maxillipeds involved in feeding. However, the concept of a maxilliped is not precise, because it relates to a vague combination of morphological and functional deviation from a locomotory limb. Although general homology of the first thoracopod (maxilliped or not) is beyond doubt, special homology (synapomorphy) of the anteriormost maxillipeds remains uncertain. For better insights, we studied the musculature and exoskeletal structures of the first thoracopods in Anaspidacea, Euphausiacea, Lophogastrida, Mysida and Stygiomysida, using three-dimesional reconstruction of laser scanning microscopy and micro-computed tomography data. Our analysis shows high muscular and skeletal complexity of the first thoracopods. We herein reject the term 'maxilliped' for Anaspidacea and Euphausiacea, because their first thoracopods differ little from the posterior limbs, although specific correspondences between these taxa might represent synapomorphies. The 'mysidacean maxilliped' is morphologically well derived from the posterior thoracopods and appears synapomorphic for the mysidacean subtaxa. A comparison with other Peracarida additionally shows correspondences indicating a homologous 'peracaridan maxilliped'. In contrast, we consider the peracaridan maxilliped not to be homologous to the decapodan maxilliped. As a distinction, we propose the term 'unguiped' for the peracaridan first thoracopod. [ABSTRACT FROM AUTHOR]

A mass mortality assemblage of mysid crustaceans is herein reported from the Cenomanian (Late Cretaceous) sublithographic limestone of Hakel (Lebanon). The studied specimens documented a mass mortality event attesting mysid swarm behaviour, herein briefly described and discussed. Though their poor preservation does not allow a specific assignment, this new record is remarkable, resulting the first formal report of Mysida Boas 1883 (Crustacea, Malacostraca) from the rich crustacean fossil fauna from the Late Cretaceous of Lebanon and from the worldwide Cretaceous record.

Here, we provide the first complete mitochondrial genomes for two higher taxa of Peracarida, Lophogastrida and Stygiomysida. We examined Lophogaster typicus as a representative of Lophogastrida and Spelaeomysis bottazzii as a representative of Stygiomysida. Both mitogenomes have all typical metazoan genes (13 protein‐coding genes, two ribosomal RNA genes and 22 transfer RNAs). The mitogenomes have a length of 15,076 bp in L. typicus and 14,806 bp in S. bottazzii. Gene order differs markedly from the hypothetical pancrustacean/malacostracan ground pattern in both species, and in L. typicus, all genes were encoded on the heavy strand. This is the first time this is described for a crustacean. We also reconstruct eumalacostracan phylogenies using a data set consisting of 98 species based on alignments comprising all protein‐encoding genes as well as the protein‐encoding genes and the two ribosomal RNAs. We find support for the monophyly of Mysidacea based on species from all three higher taxa (Mysida, Lophogastrida, Stygiomysida). Moreover, our analyses also support a monophyletic Peracarida with Amphipoda or Amphipoda + Mysidacea as the sister group to the remaining Peracarida. [ABSTRACT FROM AUTHOR]

Historically, the native mysid Neomysis mercedis was a key source of food for fish in the San Francisco Estuary (SFE). Following the introductions of the over-bite clam and many invasive zooplankton species in the mid-1980s, populations of native zooplankton species plummeted, including N. mercedis. In July 1993, Hyperacanthomysis longirostris, an invasive mysid, was first documented in the SFE, and it quickly became the most abundant mysid in the upper estuary. Since 2011, the California Department of Fish and Wildlife has sampled mysid abundance throughout the upper SFE concurrently with their Fall Midwater Trawl, which targets juvenile Striped Bass. We analyzed data from these mysid trawls to investigate environmental correlates of N. mercedis and H. longirostris abundance. We found that H. longirostris was found at higher temperatures significantly more often than N. mercedis, and there was a trend towards greater frequency of H. longirostris at higher salinities. Increases in water temperature over time, coupled with H. longirostris’s smaller size at maturity and lower food needs may partially explain its success in the SFE.

Neomysis awatschensis is an important prey item for various fishes in Lake Kasumigaura, Japan. There is, however, a contradiction concerning the major food sources of this mysid species: whether "bottom mud", "particulate organic matter (POM) including phytoplankton", or "mesozooplankton" is the main diet, and this uncertainty may be due to differences in the methodology used to determine the prey items in previous studies. This study examined the main food sources of N. awatschensis by combining three methods to eliminate methodological biases: DNA metabarcoding, microscopy and stable isotope analysis. Planktonic diatoms and green algae sequences were the main taxa detected by DNA metabarcoding and microscopy on the fecal pellets. The δ15N values of the mysids were similar to those of phytoplankton feeders rather than carnivorous planktonic crustaceans. These results suggest that diatoms and green algae were the major food sources for N. awatschensis in Lake Kasumigaura during the investigation period, and that its trophic level is as low as that of herbivores. However, the partial contribution of other "POM" (e.g., benthic diatoms) is also implied, considering the dispersion in δ13C values. Mesozooplankton prey, such as copepods, were detected both using DNA metabarcoding and microscopy, but they could not be a major food source due to the low nitrogen stable isotopic signature of the mysids. The opportunistic feeding habits of N. awatschensis possibly explain the consistent dominance of this species in the lake, where the ecosystem structure was substantially changed because of successive desalination. [ABSTRACT FROM AUTHOR]

Historically, the native mysid Neomysis mercedis was a key source of food for fish in the San Francisco Estuary (SFE). Following the introductions of the over-bite clam and many invasive zooplankton species in the mid-1980s, populations of native zooplankton species plummeted, including N. mercedis. In July 1993, Hyperacanthomysis longirostris, an invasive mysid, was first documented in the SFE, and it quickly became the most abundant mysid in the upper estuary. Since 2011, the California Department of Fish and Wildlife has sampled mysid abundance throughout the upper SFE concurrently with their Fall Midwater Trawl, which targets juvenile Striped Bass. We analyzed data from these mysid trawls to investigate environmental correlates of N. mercedis and H. longirostris abundance. We found that H. longirostris was found at higher temperatures significantly more often than N. mercedis, and there was a trend towards greater frequency of H. longirostris at higher salinities. Increases in water temperature over time, coupled with H. longirostris's smaller size at maturity and lower food needs may partially explain its success in the SFE. [ABSTRACT FROM AUTHOR]

According to the results of surveys performed in the years 2003–2008, the species composition of the Peracarida (Crustacea, Malacostraca) fauna of the Barents Sea was determined. In total, 323 species were identified within the study area. Sixty-four species of Peracarida were noted for the Barents Sea for the first time. The most significant refinements concerned the orders Isopoda, Cumacea, and Tanaidacea. The main features of the quantitative distribution of Peracarida were revealed; it was found that the richest accumulations were confined to mixed silty–sandy bottom sediments of the shallow waters and the slopes of troughs. In the Barents Sea, eight Peracarida faunistic complexes have been identified, which are confined to specific environmental conditions. Generally, boreal–arctic species prevail in the biogeographic structure, the share of the boreal species exceeds that of the arctic species (28 and 21%, respectively). The zone of combining the ranges of the arctic and boreal species has shifted eastwards and northwards compared to the period of 1968–1970; this is a consequence of the ongoing "warm" hydrological period in the Barents Sea. [ABSTRACT FROM AUTHOR]

Studying the colonization, distribution, demographics, and abundance of invasive species is important for understanding their invasion biology, including the conditions required for establishment. This information can also be used to reduce their risk of spread. Opossum shrimp Mysis diluviana Audzijonyte and Väinölä, 2005, is an invasive species in lakes and reservoirs of the western United States and Canada. Four lakes in western Wyoming, USA, were stocked with this nonnative crustacean in 1971, but no Mysis surveys have been conducted in Wyoming since 1981. We determined presence/absence, demographics, and abundance of Mysis in these and six nearby lakes that could have been invaded using vertical net tows and environmental DNA analysis. Environmental conditions were compared in lakes with and without Mysis, and we evaluated the potential for Mysis to disperse downstream. Mysis (> 500 individuals/m2) persisted in two of the four stocked lakes and nowhere else. Both of the lakes with established populations had daytime light levels on the bottom below the visual feeding threshold for fish, and the hypolimnia were oxygenated. Hierarchical cluster analysis of lake physicochemical conditions grouped these two lakes with four others, all of which were deep (46-185 m), with high oxygen concentrations (> 3 mg/L) on the bottom, and relatively low light intensities (< 0.2 lx) near the bottom. A second cluster of lakes that all lacked Mysis, and appeared to be less suitable, were shallow (< 20 m), had severe hypolimnetic hypoxia, and higher light levels (= 590 lx) near the bottom. The interaction of strong light penetration with lake depth, compounded by strong clinograde oxygen profiles, would prevent the formation of a daytime predation refuge from fish in these lakes, reducing the likelihood of Mysis invasion. Given that only half of the purposeful introductions in Wyoming were successful, and that there have been no new invasions in nearly 50 years, future range expansion by the species in the region is unlikely without human facilitation. [ABSTRACT FROM AUTHOR]

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The female of Heteromysoides simplex Hanamura & Kase, 2001 is described for the first time based on material collected from a submarine cave on Ie-jima Island, Ryukyu Islands, southwestern Japan. Morphological descriptions and illustrations of this specimen are given. [ABSTRACT FROM AUTHOR]

A new mysid, Mysidella hoshinoi sp. n. is described from Izu-Oshima Island, Sagami Sea, central Japan. This species differs from its congeners in having a posterodorsal finger-like papilla on the eyestalk, five peculiar spines terminating in plumed seta on outer margin of carpopropodus of endopod of first thoracopod, and uropodal endopod bearing 27 spines on inner margin. [ABSTRACT FROM AUTHOR]

The spread of Mysis diluviana, a small glacial relict crustacean, outside its native range has led to unintended shifts in the composition of native fish communities throughout western North America. As a result, biologists seek accurate methods of determining the presence of M. diluviana, especially at low densities or during the initial stages of an invasion. Environmental DNA (eDNA) provides one solution for detecting M. diluviana, but building eDNA markers that are both sensitive and species-specific is challenging when the distribution and taxonomy of closely related non-target taxa are poorly understood, published genetic data are sparse, and tissue samples are difficult to obtain. To address these issues, we developed a pair of independent eDNA markers to increase the likelihood of a positive detection of M. diluviana when present and reduce the probability of false positive detections from closely related non-target species. Because tissue samples of closely-related and possibly sympatric, non-target taxa could not be obtained, we used synthetic DNA sequences of closely related non-target species to test the specificity of eDNA markers. Both eDNA markers yielded positive detections from five waterbodies where M. diluviana was known to be present, and no detections in five others where this species was thought to be absent. Daytime samples from varying depths in one waterbody occupied by M. diluviana demonstrated that samples near the lake bottom produced 5 to more than 300 times as many eDNA copies as samples taken at other depths, but all samples tested positive regardless of depth. [ABSTRACT FROM AUTHOR]

The article provides information on the collection and processing of the marine species mysids, stygiomysids, and lophogastrids. Mysids or opossum shrimps are crustaceans that occur in vast number throughout the waters of the world. The article discusses their ecology, collection methods to document the species, and preservation techniques.

Total length, and the length of carapace and telson, are generally used to measure the size of mysid crustaceans. However, this method may not be as accurate for measuring these animals, since mysids commonly bend their abdomen when they are collected and preserved. Besides, the fragile carapace of mysids may result in less accurate outputs in such size measurements. The aim of this study was to determine the relationship between carapace length and statolith diameter in Mysida. The carapace length and statolith diameter were measured in 1199 individuals of Neomysis nigra Nakazawa, 1910. The statolith diameter was significantly correlated with carapace length. It is suggested that the statolith diameter of mysids could be used as an alternative measurement for characterizing body size in these crustaceans. [ABSTRACT FROM AUTHOR]

We studied the spatial and temporal distribution pattern of three marine mysids (Chlamydopleon dissimile, Metamysidopsis elongata atlantica and Mysidopsis coelhoi) from the Cananeia-Iguape Coastal System, southeast Brazil, in relation to environmental variables and zooplankton abundance. We also analysed mysid reproductive traits, and tested their tolerance to salinity gradients in laboratory experiments. Salinity was identified as a major factor influencing mysid spatial and temporal distribution, selectively limiting their distribution within the estuary. Chlamydopleon dissimile and M. coelhoi were common, but occurred at low abundances throughout the year, whereas the numerically dominant M. elongata atlantica had abundance peaks in spring, when thermohaline conditions were more favourable. Mysid brood size varied interspecifically; the occurrence of juveniles throughout the year indicated that mysids breed continuously in the region. The high biomass of M. elongata atlantica observed in spring confirms the importance of mysids in coastal regions' food webs. [ABSTRACT FROM AUTHOR]

The neustal is a specific habitat of oceans, which significantly differs in abiotic parameters from the waters below. One of the most significant components of the coastal neustonic fauna is the benthohyponeuston migrating diurnally between benthic and neustonic realms. Data on this fauna are fragmentary and contradictory, partly due to lack of the criteria to distinguish benthohyponeuston from other benthopelagic animals diurnally migrating to the bulk water from the seafloor. We propose a criterion to quantify the degree of aggregation/avoidance of the neustal zone, reveal four distinct ecological groups and describe patterns of their overnight dynamics. Benthohyponeuston appears in open water at sunset, its biomass most rapidly increases one hour after sunset. Cumaceans, mysids and polychaetes make significant contribution during first three hours after sunset. Decapods are important around midnight and 3 h later. Amphipods are significant overnight. By analogy with the benthopelagic species, we define the benthohyponeuston as benthic animals, which are associated with the neustal zone at least at one stage of their life cycle. This association is necessary for reproduction, dispersal or feeding – that represent three basic pathways connecting neustonic and benthic/benthopelagic coastal communities below. The data on benthohyponeuston and patterns of its overnight dynamics will help in a better understanding of vertical migrations in the coastal zone and in estimating diurnal fluxes of organic matter. [ABSTRACT FROM AUTHOR]

The term "taxonomic impediment" is widely used in the biodiversity literature. The taxonomic impediment consists of several problems: the incomplete knowledge of the largely unknown global biodiversity, the insufficient number of experts and their unbalanced distribution across the globe and the taxonomic infrastructures that are not meeting the demands yet. It is difficult to examine how severe the problem in the development of taxonomic knowledge is, because there might be a big taxonomic gaps in knowledge in some groups, like many invertebrates, but small in some vertebrate taxa. As an example of an invertebrate taxon, the online WoRMS database was queried for amphipod crustaceans, and data for the cumulative increase of species numbers, species description rates and data from the taxonomic community were extracted. The increase of species numbers over time is strong and the species description rates are high since the 1960s. Within the group of 30 most productive amphipod taxonomists during the past 15 years, 9 are retired, 2 are on temporary contracts, 1 is a freelancer, 8 stopped working on amphipods leaving 9 out of 39 permanently employed. There is a strong geographical bias with 21 of the 30 taxonomists originating from Australia, Europe, North-America and Japan especially within the group of highest productivity. The taxonomic effort of amphipodologists was compared with the situation in Cumacea and Mysidacea. [ABSTRACT FROM AUTHOR]

The acute toxicity of three organophosphate pesticides (diazinon, chlorpyrifos, pirimiphos-methyl) two chlorinated biocides (endosulfan, pentachlorophenol) and a nonsteroidal anti-inflammatory drug (diclofenac) was tested on <24 h neonates of saltwater mysidacea ( Siriella armata) in laboratory acute toxicity test. The 50 and 10 % lethal effective concentrations (LC and LC), NOEC and LOEC values were calculated. The three organophosphate pesticides showed an apparently biphasic dose-response profile, supporting that its mechanism of action in crustaceans differ from other organic compounds. The biphasic pattern of response was confirmed using the common aquatic ecotoxicological model Daphnia magna. According to the 96-h LC values for S. armata, the ranking of toxicity was chlorpyrifos (0.13 µg/L) < pirimiphos-methyl (1.3 µg/L) < endosulfan (3.2 µg/L) < diazinon (4.03 µg/L) < pentachlorophenol (262.2 µg/L) < diclofenac (2919 µg/L). In general, mysids resulted at least one order of magnitude more sensitive than model daphnia, which stresses the need for using marine species for the derivation of seawater quality standards. [ABSTRACT FROM AUTHOR]

Mysidopsis zsilaveczi sp. nov. shows colour patterns on the eye that mislead the observer in thinking that the eyes are facing upwards, largely irrespective of their actual orientation, and have resulted in local divers naming these animals 'stargazer mysids'. To date, only males of the new species could be sampled. Within the species-rich genus Mysidopsis G. O. Sars, 1864 the males of M. zsilaveczi are characterized, besides their unique colour patterns, by a subdivided antennal scale; by a small, mid-dorsal protuberance on the carapace; by endopods of all pleopods having a large, expanded, plate-like exite on the basal segment; by the comparatively large, two-segmented endopod of pleopod 1; by uropodal endopods that extend well beyond the telson; and by having a linguiform telson with spines all along its lateral margins. The new species also shows diverse, very small, lobe-like structures on basis and dactylus of thoracic endopods 3-8. Closely similar structures were for the first time also found in Mediterranean material of M. angusta G. O. Sars, 1864 and M. gibbosa G. O. Sars, 1864. This new species raises the number of southern African Mysidopsis species to nine, confirming the coastal waters of this subcontinent as being one of the major hotspots of diversity in this genus. An updated key to the Mysidopsis species from southern Africa (Namibia plus South Africa) is provided. [ABSTRACT FROM AUTHOR]

Seagrass meadows are important ecosystems on shallow coastal waters, maintaining a high diversity of species. Mysids are the dominant taxa of suprabenthic organisms associated with seagrass meadows in temperate coastal waters, where they are an important food resource for the coastal fishes. Five meadows of Cymodocea nodosa were sampled off the east and west of Gran Canaria Island in spring and autumn 2011 to describe associated suprabenthos and to determine seasonal changes in the abundance of suprabenthos assemblages. Mysids, decapods and amphipods made up 95% of total suprabenthos abundance, which was more abundant in spring (May) than in autumn (November). A total of 29 species were identified, 12 amphipod, 11 decapod and 6 mysid species. The mysid Leptomysis lingvura did not show seasonal differences, while Anchialina agilis showed greater abundance in May at all localities. For the other mysid species, abundances were higher in May than November, although significant differences varied among localities. The dominant amphipod, Apherusa vexatrix , and the dominant decapod, Hippolyte spp., also showed significant differences in density between seasons, being higher in May at all localities. From these results, we conclude that there is an overlap between the natural life cycle of the seagrass C. nodosa and associated suprabenthos. [ABSTRACT FROM AUTHOR]

We studied the influence of mysid species number on their feeding rates to test how the structure of the mysid assemblage may affect carbon fluxes in the Cananeia estuary. Three types of experiments were conducted at the laboratory in order to: (i) evaluate mysid feeding rates and selectivity on the natural zooplankton assemblage; (ii) determinate mysid functional responses to varying food density using Artemia sp. nauplii as food; and (iii) check inter- and intraspecific predation between mysids. For the former two experiments, three mysid species were incubated isolated or combined (2 species: Metamysidopsis elongata atlantica+Mysidopsis coelhoi; 3 species: M. e. atlantica+M. coelhoi+Chlamydopleon dissimile), comprising 5 treatments. The three mysid species had opportunistic feeding behavior on the natural zooplankton assemblage, but there was evidence of avoidance of medium-size prey (300-400μm) mostly comprised of Oithona spp., probably due to a combination of small size and prey swimming patterns. Ingestion rates showed a non-linear increase with increasing food concentrations, suggesting a type II functional response for all mysid species and combination of species. There were both positive (complementarity effect) and negative effects of species combinations on the investigated response. Negative interactions were probably linked to intraguild predation as confirmed by experiment (iii), which resulted in a reduction of mysid predation over the zooplankton. [ABSTRACT FROM AUTHOR]

The aim of the study was to determine the biological characters typical of Neomysis integer, to investigate and update issues of its biology, ecology, and distribution in the southwestern Baltic Sea, and to compare biological properties of N. integer collected during eight study seasons in 2006-2007 in the region from Świnoujście to Darłowo. No link was established between N. integer size and sample collection site. The population attained sizes within the range of 2.64 to 18.84 mm. The size at which females achieved sexual maturity varied seasonally. A mean of 34 eggs was noted in the marsupium. The mean wet weight of N. integer was 0.011 g. Three generations were confirmed at most of the study sites. [ABSTRACT FROM AUTHOR]

Foram realizados experimentos para avaliar previamente o potencial tóxico de duas amostras de efluente derivado de petróleo a ser lançado no canal de S. Sebastião, através de um emissário submarino que está sendo construído no Terminal Marítimo "Almirante Barroso" (TEBAR). As amostras (denominadas Efluente-A e -B) foram fornecidas pela PETROBRÁS e foram testadas com jovens e adultos de Promysis atlântica (Crustacea, Mysidacea). Em relação ao Efluente-A, concentrações entre 1% e 5% alteram significativamente a taxa de mortalidade dos animais em curto intervalo de tempo (24-96 horas). No caso do Efluente-B concentrações de 0,075% (96 horas) estão no limite máximo de exposição que não afeta a sobrevivência dos jovens da mesma espécie. Os testes demonstraram serem as duas amostras (Efluentes A e B) bastante diferentes uma da outra, sendo a segunda cerca de dez vezes mais tóxica que a primeira. Além disso, a toxicidade dos efluentes varia também em função do armazenamento. Outros possíveis efeitos dos efluentes sobre o ecossistema são discutidos.Preliminary experiments were carried out to estimate the potential toxicity of an effluent derived from petroleum to be dumped into São Sebastião channel through a submarine emissary which is being built at the Maritime Terminal "Almirante Barroso" (TEBAR). Two simulated samples of this effluent (denominated A and B) were supplied by PETROBRÁS. The toxicity of sample A was tested with young and adult Promysis atlántica (Crustacea, Mysidacea) and the toxicity of sample B only with young individuals of the same species. In relation to Effluent-A, concentrations between 1% and 5% increase significantly the rate of mortality of animals in short term tests (24-96 hrs). The results also indicated that, in this case, adults are less resistant than youngs. Concentrations of 0.075% of Effluent-B are at the maximum limits of no effect observation for short term expositions of young animals (96 hrs). The two effluent samples are different from each other. Both of them are very toxic, but the second is about 10 times more toxic than the first one. The toxicity of the samples also varies in function of time of storage. It seems that this variation is not predictable as the results indicated that the toxicity increased with storage for sample A and diminished for sample B. Other possible effects of the effluent on the ecosystem are discussed.

The mercury bioaccumulation and population dynamics of the mysid Mesopodopsis slabberi was assessed along a mercury gradient in Ria de Aveiro (Portugal). M. slabberi is one of the most important mysid species in European temperate coastal shallow waters playing a key ecological role. Nevertheless, no references were found concerning the possible consequences of the Hg on the trophodynamics of these coastal ecosystems. M. slabberi showed a clear bioaccumulation along the Hg gradient and through life, with mature females reaching the highest concentrations. In terms of population structure, higher densities and biomasses of M. slabberi were assessed in the most contaminated areas contrarily to the least polluted areas. Despite the mercury accumulation in its tissues no strong negative effects on the structure and population dynamics of the species were observed. However, mysids might be important in the transfer of metals from the sediments and zooplankton to higher trophic levels such as fishes, most of them with commercial interest. [ABSTRACT FROM AUTHOR]

This paper presents the results of a detailed comparative description of the morphological characters of N. integer obtained during eight research seasons in 2006-2007 period from the region stretching from Świnoujście to Darłowo. An attempt was made to assess the suitability of the studied characters for establishing to which populations individuals belong, to identify secondary sex traits and to detect differences in the body shape of these shrimp-like crustaceans. Most of the measurable characters in all of the samples discrimination analysis indicated the characters which differentiated the compared groups were telson length, lower abdomen width, exopodite uropod length, cephalothorax width below the carapace, cephalothorax width above the carapace and the height of fourth and fifth abdominal segment connections. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, the non-target effects of tebufenozide were evaluated on the estuarine crustacean, the opposum shrimp Neomysis integer (Leach, 1814). Tebufenozide is a synthetic non-steroidal ecdysone agonist insecticide and regarded as potential endocrine-disrupting chemical (EDC). N. integer is the most used crustacean in ecotoxicological research in parallel to Daphnia sp. and has been proposed for the regulatory testing of potential EDCs in the US, Europe and Japan. Major results were: (i) cDNAs encoding the ecdysteroid receptor (EcR) and the retinoid-X-receptor (RXR), were cloned and sequenced, and subsequent molecular phylogenetic analysis (maximum likelihood and neighbor-joining) revealed that the amino acid sequence of the ligand binding domain (LBD) of N. integer EcR (NiEcR) clusters as an outgroup of the Crustacea, while NiRXR-LBD clusters in the Malacostracan clade (bootstrap percentage=75%). (ii) 3D-modeling of ligand binding to NiEcR-LBD demonstrated an incompatibility of the insecticide tebufenozide to fit into the NiEcR-ligand binding pocket. This was in great contrast to ponasterone A (PonA) that is the natural molting hormone in Crustacea and for which efficient docking was demonstrated. In addition, the heterodimerization of NiEcR-LBD with the common shrimp Crangon crangon (Linnaeus, 1758) RXR-LBD (CrcRXR-LBD) was also modeled in silico. (iii) With use of insect Hi5 cells, chimeric constructs of NiEcR-LBD and CrcRXR-LBD fused to either the yeast Gal4-DNA binding domain (DBD) or Gal4-activation domain (AD) were cloned into expression plasmids and co-transfected with a Gal4 reporter to quantify the protein–protein interactions of NiEcR-LBD with CrcRXR-LBD. Investigation of the ligand effect of PonA and tebufenozide revealed that only the presence of PonA could induce dimerization of this heterologous receptor complex. (iv) Finally, in an in vivo toxicity assay, N. integer juveniles were exposed to tebufenozide at a concentration of 100μg/L, and no effects against the molting process and nymphal development were scored. In conclusion, the in vitro cell reporter assay, based on NiEcR-LBD/CrcRXR-LBD heterodimerization in Hi5 cells and validated with the natural ecdysteroid hormone PonA, represents a useful tool for the screening of putative EDCs. As a test example for non-steroidal ecdysone agonist insecticides, tebufenozide had no negative effects on NiEcR/RXR receptor dimerization in vitro, nor on the molting process and nymphal development of N. integer at the tested concentration (100μg/L) in vivo. [Copyright &y& Elsevier]

Pelagic Mysidacea and Decapoda have important roles in marine ecosystems. However, information on their life histories is extremely limited. This study aimed to evaluate the life cycles of pelagic Mysidacea and Decapoda in the Oyashio region, Japan. Production of the four dominant species was estimated by combining body mass (DM) data and abundance data. Mysidacea belonging to 5 species from 5 genera occurred in the study area. Their abundance and biomass ranged between 11.7-50.1 ind. m-2 and 1.2-7.9 g wet mass (WM) m-2 respectively. Six species from 6 genera belonged to Decapoda, and their abundance and biomass ranged between 9.0-17.3 ind. m-2 and 3.0- 17.3 g WM m-2 respectively. Based on body length histograms, there were two to four cohorts for the three dominant mysids and one dominant decapod on each sampling date. Life histories of the two numerically dominant mysids (Eucopia australis and Boreomysis californica) followed similar patterns: recruitment of young in May, strong growth from April to June, and a longevity of three years. Life cycles of the two minor species (the mysid Meterythrops microphthalma and the decapod Hymenodorafrontalis) were not clear because of their low abundance. The timing of recruitment of the young and the strong juvenile growth for the two dominant mysids corresponds with the season when their prey is abundant. The annual production of the dominant mysid species was 14.0 mg DM m-2 (B. californica) and 191.8 mg DM m-2 (E. australis). Annual production/biomass (P/B) ratios ranged between 0.242 (H. frontalis) and 0.643 (M. microphthalma). Compared with other re gions, the Oyashio region showed high production and low P/B ratios. The high production in the Oyashio region may be related to the high biomass of these species. Because of the low temperature conditions (3°C), pelagic mysids and decapods in the Oyashio region may have slower growth, longer generation times and lower P/B ratios than in other oceans. [ABSTRACT FROM AUTHOR]

The zooplankton assemblage in the permanently open Sundays Estuary, on the south-east coast of South Africa, was studied seasonally. Samples were collected once per season between winter 2007 and autumn 2009 by means of boat-based plankton tows. A total of 19 taxa was recorded. Numerically, the copepodPseudodiaptomus hesseidominated the zooplankton, withParacartia longipatellaandHalicyclopssp. also contributing significantly to the assemblage. Mysids were dominated byMesopodopsis wooldridgeiandRhopalopthalmus terranatalis. Among the Brachyura,Hymenosoma orbicularelarvae andParatylodiplax edwardsiilarvae were prevalent. Zooplankton density varied with season, site and salinity zone, as has been reported in previous studies of temperate estuaries worldwide. Density peaked in summer, with means of 3 331 ind. m−3in 2008 and 8 031 ind. m−3in 2009. Highest densities ofP. longipatellaoccurred in the lower estuary (Sites 1–3) andP. hesseiin the upper estuary (Sites 8–10). Highest density occurred in the euhaline zone, due largely to the high density ofP. longipatella. Site 1, closest to the mouth, typically supported the highest diversity of zooplankton. Patterns in zooplankton density and diversity resulted from the combined influence of salinity, temperature and fresh water inflow. [ABSTRACT FROM AUTHOR]

Copyright of Revista Mexicana de Biodiversidad is the property of Universidad Nacional Autonoma de Mexico, Instituto de Biologia 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.)

The paper analyzes published and original data on the current distribution of alien species of malacostracan crustaceans including representatives from the orders Amphipoda, Mysidacea, Isopoda, Cumacea, and Decapoda in the Gulf of Finland (eastern part of the Baltic Sea). Thus far, 12 alien species of allochthonous origin have been recorded in this area. Also, seven species of malacostracans are known as actively spreading species in neighboring regions and therefore as potential invaders to the Gulf of Finland. The invasion history of the alien species and possible vector of their expansion from the original areas to the study area are discussed. [ABSTRACT FROM AUTHOR]

The article focuses on the study concerning the co-existence of large populations of several mysid species in oligotrophic underwater marine caves located on the French Mediterranean coast. It examines the carbon and nitrogen stable isotope compositions of species to determine their trophic relationships. It shows that hemimysis speluncola feeds mainly on zooplankton and phytoplankton outside the cave.

The article explores the current distribution of freshwater opossum shrimp Mysis Salem in Ireland. Results reveal that M. Salem was recorded from eight lakes and two unique groups were detected in each lake, juvenile and adults. Based on its deep-water habitat, M. Salem has been under-recorded in Ireland, and its distribution may extend to other Irish lakes. The abundance of M. Salem in most lakes seem low and its status may be threatened by such factors as climate change.

Copyright of Environmental Research, Engineering & Management / Aplinkos Tyrimai, Inžinerija ir Vadyba is the property of Institute of Environmental Engineering 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.)

Mysid crustaceans, representing 27 species belonging to 21 genera, are reported from the Exclusive Economic Zone (EEZ) of India; one of these species, Pseuderythrops abrahami sp. nov., is described as new. The new species is easily distinguished from all the known species of the genus Pseuderythrops by the irregularly lobed cornea of the eye, narrow upturned rim of the anterior region of carapace and the absence of distal suture on the antennal scale. Three species, Boreomysis plebeja, Anchialina media and Synerythrops intermedia, are new records for Indian waters. Rhopalophthalmus indicus and Euchaetomera glyphidophthalmica are recorded for the first time from the Bay of Bengal. The morphological differences shown by the present specimens from the published descriptions are discussed and a note on the distribution of each species is given. [ABSTRACT FROM AUTHOR]

biogeographic analysis of the Black Sea and Caspian Sea basin and adjacent Aegean Sea and the Sea of Marmara was conducted based on the distribution of 55 mysid species. The Black and Caspian Sea basin proper is inhabited by 35 mysid species belonging to 12 genera, among them 26 species and 3 genera are endemic to the region. Ponto-Caspian and Caspian species are predominant. The explored areas were included into two provinces of the Mediterranean subrealm of the East-Atlantic Subtropical realm and three provinces of the Ponto-Caspian realm. [ABSTRACT FROM AUTHOR]