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Peaks in northern bottlenose whale, Hyperoodon ampullatus, strandings are found between August and September in the UK and August and November in The Netherlands, consistent with a hypothesized southward migration. However, results on diet suggest that several whales stranded during these months were not travelling from northern latitudes prior to stranding. We analysed the stomach contents of ten whales stranded in the north-east Atlantic (Scotland, N = 6, England, N = 1, Ireland, N = 2 and The Netherlands, N = 1). All but one of the analysed whales (live-stranded in the River Thames in January 2006) stranded between August and October. Food remains consisted almost entirely of cephalopod mandibles. Twenty-one cephalopod species (16 families) were recorded, the most abundant taxa being Gonatus spp., Teuthowenia spp. and Taonius pavo. No fish and few crustacean remains were found. Small amounts of cephalopod flesh were found in three of the stomachs and none in the others. Given that cephalopod beaks can remain within the stomach for several days, and that there was no evidence of inshore feeding (no coastal species were present among the prey), the whales may not have fed for several days prior to stranding. Three whales had remains of warm-temperate water cephalopods (e.g. Vampyroteuthis infernalis, Heteroteuthis sp.) in their stomachs, while three individuals showed a high diversity of prey in their stomachs, suggesting that several of the whales could have been either travelling north or consistently feeding in temperate latitudes prior to stranding. As previously recorded in other deep diving teuthophagous cetaceans, two animals had ingested small amounts of plastic debris.

Quinones are one of the major pigment groups that provide such bright colors to feather stars (Echinodermata, Crinoidea). These secondary metabolites also act as defensive molecules rendering crinoids unpalatable and repellent to other organisms. However, feather stars are usually associated with numerous symbiotic organisms, amongst which the ectocommensal snapping shrimp Synalpheus stimpsonii. We investigated the chemical stimulus allowing host selection in S. stimpsonii through the combination of behavioral tests, chemical extractions, and mass spectrometry analyses. The individuals of S. stimpsonii used in the experiments were sampled around the Great Reef of Toliara (Madagascar) where they are found in association with two crinoid species: Comanthus wahlbergii and Phanogenia distincta. The chemical attractiveness of the two crinoid hosts and a non-host species, Cenometra bella, was tested in an olfactometer. The three crinoids produced attractive kairomones allowing the snapping shrimp to recognize them. Mass spectrometry analyses on purified extracts of P. distincta revealed the presence of three different anthraquinones (rhodoptilometrin, comantherin, and a new crinoid anthraquinone). Compared to the existing literature, this anthraquinonic cocktail is specific to P. distincta. When these extracts were injected in the olfactometer, they triggered similar attracting behavior suggesting that crinoid anthraquinones are kairomones allowing host selection for S. stimpsonii. This hypothesis is also supported by the fact that shrimps were chemically attracted by pure commercial anthraquinones. In addition to their traditional defensive role (allomones), anthraquinones would, therefore, also function as kairomones, maintaining the symbiosis between S. stimpsonii and its crinoid hosts.

Powdered crab and lobster shells (crustacean meal) obtained from fisheries are used as soil amendments to promote plant health and defense. In this study, a commercial crustacean meal amendment used to promote the health of lettuce, tomato, and other crop plants was applied to roots of lettuce and tomato seedlings. Gene expression profiling of the treated roots was assessed by RNA sequencing (RNA-seq) at 24 h after application relative to a 0 h time point. The RNA-seq analyses revealed upregulation of different types of genes in both tomato and lettuce roots at 24 h. Gene ontology analyses revealed increased expression of genes associated with oxidoreductases/metal ion binding in tomato roots at 24 h, while there was predominantly increased expression of genes associated with cell wall organization, lyases, and hydrolases in lettuce roots at 24 h. The types of defense-related genes expressed were also markedly different. In tomato roots, the most highly induced gene (log2 fold change 13.84, P ≤ 0.001) encoded a defense-associated miraculin-like protein, but transcripts of a similar gene were not induced in lettuce roots. Interestingly, phenylpropanoid pathway genes relating to cell wall biogenesis and lignification were significantly upregulated in both lettuce and tomato roots, suggesting that strengthening of plant cell walls is a common response to crustacean meal application. This research provides insight into gene expression patterns in the roots of lettuce and tomato in response to crustacean meal, improving our understanding of how this amendment could aid in plant health. [Formula: see text] The author(s) have dedicated the work to the public domain under the Creative Commons CC0 “No Rights Reserved” license by waiving all of his or her rights to the work worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law, 2022.

La Trobe University Faculty of Science, Technology and Engineering Murray Darling Freshwater Research CentreMDFRC item.Caridean shrimps are an integral component of lowland river ecosystems in south-eastern Australia, but their distributions may be affected by flow alteration. Monthly shrimp samples were collected from slackwaters in three hydrologically distinct sections of the heavily regulated Campaspe River and the less regulated Broken River for three consecutive years. The distributions of Paratya australiensis, Caridina mccullochi and Macrobrachium australiense, along with their life history in river sections with different hydrology are outlined. Paratya australiensis and M. australiense occurred in all sections, but C. mccullochi was absent from sections of the Campaspe River that received irrigation flows during summer/autumn. Shrimp larvae were most abundant in summer (December–February) and juvenile recruitment continued through to mid autumn (April). Breeding and recruitment of P. australiensis occurred for longer than other shrimps. Apart from large adult and berried M. australiense, all life stages of shrimps commonly occurred in slackwaters, particularly the larval and juvenile stages. Irrigation flows in summer/autumn probably adversely affect the size, extent and arrangement of slackwaters, at a time when they may be critical habitats for C. mccullochi larval development and recruitment. Dams and weirs in the Campaspe River may have influenced shrimp abundance and the timing of breeding.

La Trobe University Faculty of Science, Technology and Engineering Murray Darling Freshwater Research CentreMDFRC item.Small ephemeral pools in the Murray-Darling basin, Australia, that dry annually lack fish and are dominated by microfauna. Community size structures and species diversity are very variable and many ponds contain one or more of the large calanoid copepods, Boeckella major, Boeckella pseudochelae and Hemiboeckella searli. Gut content analysis showed that these species were omnivores with B, major being the most carnivorous and B. pseudochelae the least. B. major guts contained 21 animal taxa (cladocerans, calanoid and cyclopoid copepodids, nauplii and rotifers), H. searli contained 15 taxa (calanoid, cyclopoid and harpacticoid copepods, nauplii and rotifers) and B. pseudochelae 8 taxa (small cladocerans, nauplii and rotifers). Mean numbers of animals per gut differed significantly between the large calanoids and in B. major, B. pseudochelae and H. searli were, respectively, 2.9, 0.6 and 0.2. In B. major "Rotifers" were positively selected, "Copepodites" and "Others" neutrally selected and "Cladocera" and "Nauplii" negatively preferred. In H. searli "Copepodites", "Nauplii" and "Rotifers" were neutrally selected, and "Others" negatively preferred. B. pseudochelae showed negative preference for "Cladocera", "Nauplii" and "Others", and "Rotifers" were neutrally selected. At sites containing B. major, species diversity was significantly reduced and community size structure (measured as mean and median log-length, % of sizes >500 mu m) was significantly larger than it was at sites lacking large calanoids or with only B. pseudochelae and H. searli. It is hypothesised that predation by B. major may be an important force structuring the communities of these habitats.

Aquatic organisms have to produce proteins or factors that help maintain a stable relationship with microbiota and prevent colonization by pathogenic microorganisms. In crustaceans and other aquatic invertebrates, relatively few of these host factors have been characterized. In this study, we show that the respiratory glycoprotein hemocyanin is a crucial host factor that modulates microbial composition and diversity in the hepatopancreas of penaeid shrimp. Diseased penaeid shrimp (Penaeus vannamei), had an empty gastrointestinal tract with atrophied hepatopancreas, expressed low hemocyanin, and high total bacterial abundance, with Vibrio as the dominant bacteria. Similarly, shrimp depleted of hemocyanin had mitochondrial depolarization, increased reactive oxygen species (ROS) levels, and dysregulation of several energy metabolism-related genes. Hemocyanin silencing together with ROS scavenger (N-acetylcysteine) treatment improved microbial diversity and decreased Vibrio dominance in the hepatopancreas. However, fecal microbiota transplantation after hemocyanin knockdown could not restore the microbial composition in the hepatopancreas. Collectively, our data provide, to our knowledge, new insight into the pivotal role of hemocyanin in modulating microbial composition in penaeid shrimp hepatopancreas via its effect on mitochondrial integrity, energy metabolism, and ROS production.

Anelasma squalicola is a parasitic barnacle of members of the deep-water shark families Etmopteridae, Pentanchidae and Scyliorhinidae. We report the first published confirmation of this species in the Eastern Pacific Ocean, based on material collected off Costa Rica, its first record as a parasite of the Ninja lantern shark, Etmopterus benchley (Etmopteridae), and a new size record for the host. The information presented herein expands the knowledge (distribution and host usage) of this enigmatic species.

We assessed fiddler crabs' (Minuca burgersi) ability to secrete metallic contaminants through ecdysis under controlled conditions. We fed them with contaminated food with different copper (Cu) and lead (Pb) amounts and measured their concentration in the released and renewed exuviae. We found a significant reduction in the average concentrations of Cu and Pb in the released and renewed exuviae-eliminating the exoskeleton in the ecdysis process helps in the metal detoxification mechanism of these animals. A portion of the concentration of metals is retained in the crustaceans' exuvia, and thus, they can be used to analyze bioaccumulation in ecosystems. Our results also reinforce the need for attention to the contamination characterization in crustaceans before and after ecdysis to avoid underestimation effects.

The subarctic NE Pacific is comprised of several oceanographic regimes, in which regional variability in sea surface temperature (SST), satellite chlorophyll a, and crustacean zooplankton biomass influence the production rates of crustacean zooplankton. Traditional methods for estimating zooplankton production rates are labour/time intensive and restricted to select copepod species. A practical field alternative is the ‘chitobiase method’, which yields community-level biomass production rates (BPR) analogous to traditional moulting rate methods. BPR was measured along the west coast of Vancouver Island and in the subarctic NE Pacific during 2005, 2009–2011, and 2015–2018. Generalized additive modelling identified SST and the developing crustacean zooplankton biomass as key drivers of BPR variability. BPR varied positively with the proportion of developing copepod biomass relative to that of non-copepod crustacean zooplankton biomass. Our analysis indicates that BPR variation is associated with zooplankton community composition, but that high zooplankton biomass is not necessarily predictive of high BPR. Specifically, higher BPR is associated with a higher relative biomass of large-bodied, cold-water indicator species, and a lower biomass of non-copepod crustaceans.

Two new amphipods for Norway Melita nitida and Corophium multisetosum (Crustacea; Amphipoda) were registered in brackish waters in the Tista Estuary in Halden, southeastern Norway. Both species were found in the samples from Tista’s outlet into the Idde Fjord, C. multisetosum in the beach zone and M. nitida at about 4 m depth. Melita nitida is a North American species first found in Europe in the Netherlands in 1998, and since then dispersed into the Baltic Sea via the Kiel Canal and now also found several places on the German Baltic Sea coast and in the Black Sea. Corophium multisetosum was collected even before the 1920s in Western Europe, and is considered native for Europe, whereas its relationship to North America is more ambiguous. From the British Isles and the Netherlands, it seems to have spread to Germany, Poland, Denmark and Sweden, and at present Norway. Until now the two species were found in small numbers at the Norwegian sites and their influence on the total benthic community is probably negligible in this initial phase. The Tista Estuary in Halden apparently appears to be a hotspot for alien brackish water species in Norway. Generally estuaries, with their combination of brackish water jointly with their unsaturated ecological niches and intensive international ship traffic, seem to possess the highest potential infection rate for aquatic systems with alien acrozoobenthic species.

Decapod crustaceans are ecologically and economically important invertebrates but are vulnerable to anthropogenic pressures and climate change. Understanding their spatial ecology is essential for their management and conservation, with telemetry emerging as a useful tool to quantify space-use and movements. Here, we synthesized the use of telemetry to study decapods among articles published from 1971 to 2019 (n = 102 studies), by taxonomic group of the study species, study location, objectives, number of animals tagged and their tag recovery rate, types (and trends) of telemetry used, and IUCN conservation status. These studies revealed insight into the behaviours and roles of decapods across habitats and geographic regions. The most common study species were crayfish and lobsters (41%, Astacidea), and these studies also had the highest number of individuals tagged per study (mean = 149 individuals). Most studies (86%) were conducted in the northern hemisphere. Acoustic tags were the most commonly used equipment (66% of studies) and were first employed in 1971, followed by radio-telemetry (mid-1990s), passive integrated transponders (mid-2000s), and data storage tags (late 2000s). Almost half (48%) of studies focused on species that had a conservation status of Least Concern, perhaps reflecting an applied science focus on animals of commercial interest rather than conservation importance. The positive allometric relationship between body length and movement rate (exponent = 0.86) demonstrates the type of broader ecological insight that combining these studies can provide. Tracking decapod movements will likely become increasingly important for managing fisheries, protecting sensitive species, and understanding invasion biology.

Ten species belonging to the families Paraphronimidae and Vibiliidae were collected during a deep-water survey off western Mexico: two species of Paraphronima and eight species of Vibilia. This represents about 40% of all known species of these two genera world-wide. A total of 419 males and 607 females were obtained in 39 samples from localities in the Gulf of California (33) and off southwestern Mexico (6). Vibilia armata was by far the most frequently (32 localities) and most abundantly (687 specimens, 67% of the total) collected species, followed by V. longicarpus (231 specimens in nine localities) and P. crassipes (35 specimens in 9 localities). Co-ocurrence of species of Vibilioidea in our samples was very low, with maxima of seven and five species collected in the same sample, once each. Considering previous records, a total of 16 species of Vibilioidea (almost 70% of all known species) have now been reported from western Mexico: two species of Paraphronima and 14 species of Vibilia, including V. australis occasionally reported in the area as its junior synonym, V. wolterecki.

Three new species in the genus Niambia are described from southern African caves: N. botswanaensissp. nov. from Diviner’s Cave (Botswana), N. ghaubensissp. nov. from Ghaub Cave and N. namibiaensissp. nov. from Märchen Cave (Namibia). All these species show troglomorphic traits such as absence of body pigmentation and eyes. These are the first troglobitic species recorded in the genus. Most of the other species of Niambia are epigean and occur in semi-arid environments in the Afrotropical Region.

Ostracods are one of the most suitable organisms because of their ecological and morphological preferences for habitat types to study the diversity between streams and lakes. Here, 24 streams and 16 lakes were sampled in 2019 to evaluate the species compositions between streams and lakes. Environmental heterogeneity in the sense of the physico-chemical variables was found among the habitats. 24 of the 29 species with 923 individuals were found in the lakes when 13 species with 898 individuals were found in the streams. Eight species were common in both habitat types. Species contributing about 70.81% to the significant differences in the species composition between the habitats showed cosmopolitan characteristics. Species variation among the replicates of lakes were higher than streams. Results indicated that the species composition was probably associated to dissolved oxygen in lakes, while electrical conductivity in streams. Relationship amid elevational range and ostracod species richness was negative in lakes when there was no clear relationship in the streams. Overall, results suggested that determination of influential regional factors in different aquatic bodies can provide important contributions to the estimation of which habitat types can be chosen by species, and the using of species as bioindicators.

A new genus and species, Mauritiorchestia fayetta gen. nov., sp. nov., of talitrid amphipod is described from beaches in Mauritius. Mauritiorchestia differs significantly from the closely related genus Platorchestia in the maxilla 1 palp (absent in Mauritiorchestia, vestigial in Platorchestia) and in the dactylus of gnathopod 1 (simplidactylate in Mauritiorchestia, cuspidactylate in Platorchestia).

Five species of the family Odiidae (Amphipoda), including four new species, are recorded from Japan: Metodius cyanomaculatus sp. nov.; M. leucomaculatus sp. nov.; Postodius albifacies sp. nov.; P. sanguineus sp. nov.; and Antarctodius japonicus Ariyama, 2011. Morphological characters and coloration of these species are described in detail. Metodius gen. nov. is established for the two new species and is characterized by the very short and bare palp of the maxilla 1 and the large gnathopod 2 propodus. Keys to the odiid genera and the Postodius species in the world are provided. The genera can be distinguished from one another by the shapes of maxilla 1, maxilliped, pereopod 7, and telson. The Postodius species differs in the shapes of gnathopod 2, and pereopods 3, 7. Female of A. japonicus is firstly recorded. In this species, the presence of an accessory flagellum and a gill on the coxa 7 is confirmed.

Lanceola loveni antarctica and L. sphaerica are rare deep-sea species known from very few specimens. Until recently (Zeidler 2019) L. loveni antarctica was known only from the types, seven specimens (7–27 mm), from the Indian Ocean Sector of the Antarctic (Vinogradov 1962). Similarly, L. sphaerica, originally described as a variety of L. clausi (Vinogradov, 1957), based on two damaged specimens, a female (8.0 mm) and a male (9 mm), from the Kurile-Kamchatka region of the NW Pacific, later elevated to full species status by Vinogradov (1970) upon the discovery of a well-preserved male (5 mm) from the same general region, was until then known only from these three specimens. The recent discovery of several specimens of both species in the USNM (Zeidler 2019) has now made it possible to provide a more detailed redescription of these rare species, including some new distribution records.

The setal abundances and distributions of the spider crab Libinia are examined, using two species. These spider crabs decorate their bodies with environmental materials and camouflage from predators. These decorations attach to hooked setae, but other types setae are prevalent in body regions where decorations occur. Adult crabs undergo a terminal molt and lose the ability to regrow setae. Little is known about setal changes over the lifetime in these crabs and if hooked setae abundance decreases with age, resulting in a loss of camouflage strategy in larger individuals. The objective of this study is to determine the prevalence and abundance of hooked and non-hooked setae in the decorated body regions and if these setal patterns vary by species and body size. Scanning electron microscopy is used along with computer software to describe, count, and measure the setal coverage of hooked and non-hooked setae in body regions. Small individuals have more hooked setae than larger individuals and the two species have different setal abundances of hooked and non-hooked setae. Non-hooked setae cover much surface areas of crabs, attach decorations, and remain on the crabs even when hooked setae are damaged and broken. Setal morphologies and fouling are described among different sized crabs and the two species, with setal types and morphologies being similar but fouling being different. Large individuals likely employ a different camouflage strategy than small individuals due to losing hooked setae but retaining non-hooked setae.

Epibiotic associations in the plankton community have been documented along the west and east coast of India. This report indicates a higher predominance of epibiosis along the east coast compared to the west. A total of 28 ciliates and one diatom species were reported epibiotic on the various planktonic host in the east coast, whereas only 17 ciliates and two diatoms were listed as epibiotic along the west coast. Ciliates formed the prevalent epibiotic species mainly on zooplanktonic crustacean host. Females of the host organisms were more infected due to their higher number in the population. The host specificity of various epibionts are also well-defined. The abundance of epibiotic organisms results from global warming and eutrophication and acts as indicators of ecosystem shifts.

Lipophilic toxins were investigated in different benthic compartments of Paranagua Bay, southern Brazil. Relatively low concentrations of okadaic acid (OA) were frequently reported in macrophyte extracts (maximum 0.64 ng g-1), mainly in sheltered estuarine areas, correlated with the cell abundance of toxigenic benthic dinoflagellates, Prorocentrum lima. Non-conjugated OA was also detected in benthic marine animals, mostly during summer-autumn 2016. Higher OA concentrations were found in the viscera of Genidens genidens fish (24.3 ± 3.7 ng g-1) and in soft tissues of Mytella guyanensis bivalves (21.3 ± 2.13 ng g-1), whereas lower levels were less frequently reported in many other benthic feeders, including cephalopods, gastropods, crustaceans and fishes. Although OA concentrations were below the levels associated with acute human intoxication, possible chronic effects to benthic animals and their consumers cannot be disregarded due to the frequent presence of this biotoxin in various fishery resources. Human health risks are substantially enhanced for small-scale fishing communities and other socioeconomically vulnerable populations.

Leptalpheus lirai sp. nov., a new species of symbiotically living, infaunal alpheid shrimp, is described based on a single specimen from the Gulf of Santa Fe, Sucre, Venezuela. The new species belongs to an informal group of nine species within the genus Leptalpheus Williams, 1965, which is characterised by the presence of well-developed adhesive disks on the major chela. In addition, Leptalpheus axianassae Dworschak & Coelho, 1999 and Fenneralpheus chacei Felder & Manning, 1986 are recorded for the first time from Venezuela (Anzoátegui and Sucre, respectively), the latter also representing the first record of the genus Fenneralpheus Felder & Manning, 1986 for the country. These records bring to 11 the number of alpheid genera, and to four the number of species of Leptalpheus, known in Venezuelan marine waters.

Salinity is a key factor that structures biodiversity on the planet. With anthropogenic change, such as climate change and species invasions, many populations are facing rapid and dramatic changes in salinity throughout the globe. Studies on the copepod Eurytemora affinis species complex have implicated ion transporter gene families as major loci contributing to salinity adaptation during freshwater invasions. Laboratory experiments and population genomic surveys of wild populations have revealed evolutionary shifts in genome-wide gene expression and parallel genomic signatures of natural selection during independent salinity transitions. Our results suggest that balancing selection in the native range and epistatic interactions among specific ion transporter paralogs could contribute to parallel freshwater adaptation. Overall, these studies provide unprecedented insights into evolutionary mechanisms underlying physiological adaptation during rapid salinity change.

Freshwater prawn are promising candidates for aquaculture and knowledge of food and feeding habit is must for successful culture. Present study investigates the feeding mechanism and role of appendages in feeding behaviour of freshwater prawn, Macrobrachium lamarrei. Mostly preferred food was dried prawn powder and least preferred was groundnut cake. Prawns showed cannibalistic behaviour frequently in lab. Antenna and antennules were the main sensory appendages which help in locating and orientation while I & II chelate legs were used for detection, catching and transferring of food up to the mouth. Maxillipedes, maxilla and maxillula played the supportive role. Mechanism of feeding and functional role of different appendages in feeding behaviour have been discussed.

The Southern Ocean (SO) is the least understood environment on earth, but anthropogenic impacts related to climate change, fishing activities and tourism are already well-established in the region. Herein, we investigate biodiversity patterns in the Atlantic Sector of the SO by investigating a considerable number of samples collected from a wide depth range (89–6224 m). Three topics are addressed: (1) which taxa occur in the SO; (2) if there are distinct shelf, slope and abyssal faunas; and (3) which abiotic parameters explain the ostracod assemblages. We also tested putative ecological preferences of ostracod genera, widely used in palaeoceanographical reconstruction. For this, almost 5000 living ostracods from 51 epibenthic sledge samples were identified to 140 species. Statistically significant differences were observed among the faunas from the shelf, slope and abyssal faunas, indicating that the shelf fauna survived in refugia during the glacial periods of the Quaternary. Our analyses showed that the main variables influencing ostracod distribution is depth, followed by nitrate and phosphate. Temperature, salinity and oxygen content do not seem to be as important as previously proposed. Putative ecological preferences of ostracod genera, for example, low oxygen for Cytherella, could not be confirmed, suggesting that this topic requires further investigation.

Sub-Antarctic fur seals, Arctocephalus tropicalis, are widely distributed in the southern hemisphere, breeding on islands north of the Antarctic Convergence in the South Atlantic, South Indian, and Southwestern Pacific Oceans. At their breeding grounds, sub-Antarctic fur seals feed on a variety of fish, cephalopods, crustaceans, and occasionally, on penguins. According to the literature, the species feeds mainly on squid and fish, in the southern Brazilian coast, during the non-breeding period and far away from its breeding colonies. Here, we present records of predation on penguins by sub-Antarctic fur seals off southern Brazilian coast (29°20′S, 49°43′W to 33°44‵S, 53°22′W). We examined the gastrointestinal contents of 61 sub-Antarctic fur seals collected from 1987 to 2019. Remaining of penguins were found in the gastrointestinal tracts of three adult males (4.9%). We identified feathers, and other bird parts by comparing them specimens from scientific collections and illustrations in the literature. Seabirds found in the gastrointestinal tracts of the three sub-Antarctic fur seals were most probably Magellanic Penguins, Spheniscus magellanicus. To our knowledge, this is the first study reporting predation on penguins by sub-Antarctic fur seals far from their breeding colonies. Although penguins are not among the main prey of sub-Antarctic fur seals, our results suggest that they occasionally feed on penguins during the non-breeding period along the southern coast of Brazil.

Body color in insects changes according to the living environment and physiological stresses possibly involved in endocrine factors. To date, 3 predominant bioactive peptides, Corazonin, Elevenin, and pigment-dispersing factor (PDF), have been illuminated to be involved in the body color in insects and crustaceans. Here, we examined the possibilities that these 3 factors would contribute to body color changes via melanization in the two-spotted cricket, Gryllus bimaculatus, whose body color changes according to population density drastically. Quantitative analyses revealed the higher transcriptional levels of Corazonin and Elevenin in the crowded-conditioned crickets, whereas the transcriptional level of PDF was higher in the isolated-conditioned crickets. However, the body color was not changed by knockdown of Corazonin, Elevenin, and PDF by RNA interference. The present data indicated that coloration mechanisms in G. bimaculatus is differently controlled from the previous observation in Locusta migratoria, a closely related orthopteran species.

Analysis of Cladocera (Crustacea: Branchiopoda) subfossil remains in lake sediments features prominently in paleolimnological studies. It is well known, however, that species composition in a taphocoenosis (assemblage of subfossil remains in sediments) does not represent perfectly that of the original living community (biocoenosis) from which it came. We analyzed the representation of different Cladocera skeletal components in sediments of 27 Russian water bodies to compare two methods of enumerating relative abundances of cladoceran remains: (1) recording the number of most abundant fragments of each taxon to represent the number of individuals, and (2) recording each fragment of a taxon as belonging to an individual specimen. Overall, for all cladoceran taxa and all water bodies sampled, proportions of different skeletal components differed from what would be expected based on those in live individuals. Carapaces were the most abundant component in 23 of 27 water bodies. Head shields were common, but predominated in only four samples, whereas postabdomens were rare, accounting for

It is widely accepted among the Cladocera (Crustacea) taxonomists that almost all “cosmopolitan” taxa are represented by some un-revised complexes of cryptic species. But many macro taxa of the cladocerans are still unrevised. The aim of this work is to analyze the taxonomic status of Oriental populations of the genus Bosminopsis Richard, 1895 (Anomopoda: Bosminidae) based on morphological characters. We have studied populations from India, Myanmar, Cambodia, Thailand, Laos, Vietnam, Philippines, Malaysia and Papua New Guinea and concluded that Oriental populations belong to a single species, Bosminopsis africanus (Daday, 1908), initially described from Africa. Analysis of literature data confirms that is widely distributed through whole Oriental zone. A single large mucro, or the mucro accompanied by an additional small spine in both sexes, is the main trait which differentiates B. africanus from B. zernowi Linko, 1901 distributed in more northern regions of Eurasia.

Two species of the marine harpacticoid family Pseudotachidiidae (Copepoda) are reported from subtidal sediments in the Southern Sea of Korea. Psammis wellsi sp. nov. (Danielsseniinae) is most closely related to P. longisetosa Sars, 1910 but differs from its European congener in the ventral ornamentation of the female genital double-somite, the dorsal ornamentation of the second abdominal somite in the male, the armature of the proximal endite of the maxillary syncoxa, the relative setal lengths and general shape of the female P5, and the relative length of the inner seta of the male P5 endopodal lobe and P6. The female of Pseudomesochra tatianae Drzycimski, 1968 is redescribed in detail, constituting the only other record of the species since its discovery at the type locality in western Norway. East Asian records of members of the four subfamilies currently recognized in the Pseudotachidiidae are summarized. Published and other records of the 23 described species in the Pseudomesochrinae are collated and their armature patterns of P1–P5 are tabulated and corrected where necessary. Pseudomesochra affinis (Sars, 1920) is removed from its synonymy with P. longifurcata T. Scott, 1902 and formally reinstated as a valid species. An updated female-based key to the 19 valid species of Pseudomesochra T. Scott, 1902 and four species of Keraia Willen & Dittmar, 2009 is presented.

Two new species in the genus Nannopus Brady, 1880 (Copepoda: Harpacticoida) from intertidal mudflats of the Yellow Sea along the Korean peninsula, Nannopus cylindricus sp. nov. and N. robustus sp. nov., are described. Nannopus cylindricus belongs to the group of Nannopus species with seven elements on P4 exp-3. Within this group, it is closest to a cryptic species complex related to N. ganghwaensis Vakati, Kihara & Lee, 2016 based on an inflated caudal seta IV. However, N. cylindricus differs from the other species in this complex with respect to caudal seta V (inflated and heavily cylindrical at its base in N. cylindricus, inflated only in the N. ganghwaensis cryptic complex). Nannopus robustus belongs to the group of species displaying two setae on P2 enp-2. Within this group, N. robustus is closely related to N. serratus Vakati & Lee, 2017 based on the presence of one endopodal naked seta arising from a stem-like protrusion on the mandibular palp. However, N. robustus can be distinguished from N. serratus based on the following characters: outermost distal spine on P2 exp-3 (extremely strong, smooth and recurved in N. robustus, moderately strong, denticulate and normal-shaped in N. serratus, and spine 1.6 times as long in N. robustus as in N. serratus), P2 exp-2 inner seta (absent in N. robustus, present in N. serratus), shape of caudal seta V (anterior part distinctly cylindrical in N. robustus, normal-shaped in N. serratus), and ornamentation of caudal seta VI (naked in N. robustus, pinnate in N. serratus). An updated key to the 17 valid species of Nannopus is provided.

The lanthanides are considered emerging contaminants but information on their long-term toxicity to aquatic species under environmentally relevant conditions is scarce. We aimed to fill this gap by evaluating the long-term adverse effects of gadolinium on the freshwater model—crustacean Daphnia magna. The exposure of D. magna for up to 39 days to 0.1 mg Gd/L (a 21-days chronic toxicity NOEC value derived by us formerly) in the lake water had no negative effect (p > 0.05) on vitality, size and reproduction of parent animals as well as their offspring. Thus, assumingly the current Gd contamination levels of surface waters pose no hazard to aquatic crustaceans that in general are very sensitive to various pollutants. Moreover, presence of 0.1 mg Gd/L in the lake water even mitigated the long-term toxic effect of 0.2 mg Ni/L (studied as a model co-contaminant) to D. magna’s vitality and productivity.

Two new copepod species from two caves in northeastern and southern Thailand are described. Elaphoidella isana sp. nov. and Schizopera paktaii sp. nov. were collected from the unsaturated zone of freshwater pools fed only by dripping water. They are closely related to E. intermedia Chappuis, 1931 and S. validior Sars, 1909, respectively. Elaphoidella isana sp. nov. can be distinguished from its closest relative by the armature of P4 and P5, and by the ornamentation of caudal rami. Schizopera paktaii sp. nov. differs from its relative S. validior in the armature of P1, P5 and caudal rami.

The dietary composition and nutritional alteration resulting from time and size of thornback ray, Raja clavata, were investigated in the present research. For this purpose, the individuals were obtained from the commercial bottom trawl vessels operated around Gokceada Island, North Aegean Sea, Turkey between February 2019 and February 2020. The female:male ratio was found to be 1:0.79. The vacuity index was calculated for males, females and both individuals to be 5.8%, 4.7%, and 5.3%, respectively. The major food item groups were determined to be decapod crustaceans, teleost fish, and cepholopoda with IRI% (Index of Relative Importance) values of 77.72, 7.05, and 0.25, respectively. The best-represented food item was found to be Goneplax rhomboides. The prey types, abundance, and biodiversity were observed to change with the increasing lengths of R. clavata. The trophic level (TLw) of R. clavata was calculated to be 3.27, and it was observed that the TLw values were increased with the increasing individual length. The diet overlap was found to range from 40 to 49 cm and 50 to 59 cm TL in autumn and winter. The highest prey biodiversity was found in the length group of 70-85 cm TL and during spring. This study presents detailed findings on the feeding behaviour of R. clavata. In the future, food competition between the species should be monitored to develop a better understanding of the diet overlap. Thus, more comparisons should be conducted between the studies performed in varied geographical areas.

The study of the composition and properties of the internal environment (hemolymph) of crustaceans grown in various conditions has an important ecological and physiological aspect, since a number of characteristics of the physiological status of objects can be used to assess the state of the environment, thus, they can be included in the number of bioindicators. However, the nature of the observed differences between objects grown under different conditions, the features of homeostatic regulatory mechanisms and the limits of the reference values of individual homeostasis constants are often not known. To formulate recommendations regarding the technological process of growing objects of warm-water aquaculture, taking into account the assessment of environmental conditions in dynamics through the analysis of indicators of the state of individuals — bioindicators — it is necessary to compare the state of individuals kept in different conditions. The object of the study was the Australian red claw crayfish Cherax quadricarinatus (Von Martens, 1868), cultivated under various conditions of intensive and semi-intensive cultivation. The studies have revealed that throughout the entire period of cultivation, individuals grown in ponds retained a high level of total protein, cholesterol and β-lipoproteins, in contrast to crayfish cultivated in pools. The values of these indicators as bioindicators indicate a high degree of compliance of the growing conditions with the needs of the studied object. Comparative assessment of fluctuations in the ratio of hemolymph shaped elements in the hemocyte composition between cancers grown under different conditions did not reveal significant differences. It was found that significantly higher growth rates are characteristic of crayfish grown in ponds, in contrast to the group of individuals cultivated in pools. The comparative analysis of bioindicators in different growing conditions presented by the authors of the article supplements information that is of significant interest for monitoring the growing conditions of this representative of warm water aquaculture, which will be valuable for specialists engaged in crustacean breeding.

The emerging threat of marine microplastics (mp) has quickly led to a growing body of research seeking to understand their biological impacts. In a crucial step towards understanding the effects of microplastic exposure on larval development, mud crab larvae (n=90/treatment) were reared through their five developmental stages (z1, z2, z3, z4 and megalopae) under four treatment levels of 50 μm polyethylene terephthalate fibers (0, 0.1, 1, and 10 mp/mL). Three experiments were conducted, each with a unique duration of microplastic exposure: (i) full exposure (z1-megalopae), (ii) early exposure (z1-z3), and (iii) late exposure (z3-megalopae). These exposure durations allowed us to assess the vulnerability of specific developmental stages and differentiate between acute and chronic effects of microplastic exposure. Survival, body size, and stage duration were recorded throughout each experiment. Our research findings indicate a decrease in body size as microplastic concentrations increased. Furthermore, results indicate that the time spent at each developmental stage increased in treatments with higher microplastic concentrations. Both effects occurred throughout all developmental stages. Decreases in body size were observed while plastic was present and disappeared upon the subsequent molt after microplastics were removed. However, stage duration delays remained consistent after larvae were exposed to high levels of microplastics. These results lend additional evidence to the hypothesis that microplastic exposure may impact an organism's energy budget. Ingestion rates of microplastic fibers were low, suggesting that the cause of these effects cannot be explained by ingestion alone. Future research will concentrate on identifying the specific causes behind these effects. Also see: https://micro2022.sciencesconf.org/426941/document, In MICRO 2022, Online Atlas Edition: Plastic Pollution from MACRO to nano

The article presents the analysis of biological parameters of parthenogenetics of Artemia crustaceans of the hypergaline reservoirs of Kazakhstan. In the lakes under study there are shown the changes of the total crustacean biomass decreasing from high-productive to low-productive. Most of the reservoirs with Artemia in Kazakhstan are characterized by the presence of Artemia parthenogenetic populations with the absence or extremely small presence of males. The aggregation of males in significant numbers may indicate the tension of the ecological situation in the reservoirs and the desire of the population to increase the survival and stability of the offspring. It has been stated that all age periods of crustacean maturation are found in the reservoirs. At the same time, the basis of Artemia populations in all studied lakes are the youngest stages - nauplius, which form 53-86% of the total number of Artemias. In lakes Artemia crustaceans are presented by bisexual parthenogenetic race, with all age stages of development during the summer - autumnal period of observations. The hydrochemical mode of hypergaline lakes of Karabassky floods is favorable for activity of Artemia Branchiopoda crustaceans. The size of crustacean biomass populations in Lake Balhash change on seasons ranging from low to very high. Lake No. 1 is highly productive in Artemias in the summer, and lake No. 2 - in the spring. Such difference in temporary aspect is caused by existence of various generations in the populations of the crustaceans on seasons. The data obtained prove the high potential of the studied small reservoirs of the Balkhash region in relation to autumn plankton cysts

This study, included the feeding of Clausocalanus furcatus of crustacean zooplankton (Calanoida), by studying the structure of the mandible and the gut content of this previous species to determine their favorite food. 93 samples have been collected vertically in period between March and October 2020. The samples were also accompanied with different hydrophysical and hydrochemical measurements in three regions that differ from each other with their environmental properties. The number of members of (C.furcatus) that were studied reached (64) individuals, of which (44) are female and (20) are male. On the other hand, determining the morphology, studying its structure, and knowing the content of the gut of the aforementioned species helped in expanding knowledge about the conditions and strategies of feeding it under the influence of environmental factors. The number of algae species (phytoplankton) that C.furcatus fed reached (9) species, of which (6) belong to the Dinophyceae, (2) species to Bacillariophyceae earth, and (1) only one species to the group Cryptophyceae. The highest average number of Dinophyceae was (1755), followed by Bacillariophyceae (505) individuals, then the group of Cryptophyceae (189) individuals.

BACKGROUND Chemometrics can be used to analyze a wide range of food products for authentication, quality control, differentiation and the determination of nutrition quality. Owing to the scarcity of studies relating to the intrinsic physico-chemical characteristics of penaeid shrimps caught on the Nigerian coast, the aim of this research was to estimate the energy-supplying nutrients, mineral elements and functional characteristics of Farfantepenaeus notialis from the Lagos Lagoon. METHODS The proximate composition was determined using the AOAC method while the energy-providing nutrients were multiplied by the Atwater factors. The samples were digested in HNO3/HCl for mineral determination and the functional properties were estimated using optical measurements. RESULTS Higher concentrations of moisture, crude protein, crude fat, and carbohydrate were recorded in the flesh while crude fibre and total ash were higher in the exoskeleton samples. The flesh had higher total metabolisable energy (1524 kJ 100 g-1) and utilizable energy due to protein (36.49 kJ). All the investigated minerals (Ca, Mg, K, P and Na) were more concentrated in the exoskeleton. In both samples, Na/K and Na/Mg ratios were within acceptable ideal ranges of 1.4-3.4 and 2-6, respectively. All values of the MSI (calculated) were lower than their comparative standard index values, having positive contrasts in both exoskeleton and flesh samples. The exoskeleton sample had better functional properties, but the flesh sample was higher in swelling strength. CONCLUSIONS In addition to good flesh quality, F. notialis contains considerable amounts of energy-providing nutrients. As the content of fibre is very low, F. notialis may be ideal as a weaning food for children.

We describe Expanathura monile sp. nov. from Iriomote Island, Okinawa, Japan, northwestern Pacific. This species resembles E. collaris, E. macronesia, and E. haddae in having very broad uropodal rami, a broad telson, and a moderately shortened pleopod 1 endopod, but differs from these three species in the female having (1) the head with a dorsal V-shaped band of brown pigmentation, (2) the antennular flagellum with 3–4 articles, (3) antennal peduncular article 2 with an outer triangular projection, (4) the uropodal endopod longer than wide, (5) the uropodal exopod with an acute triangular projection, (6) an oval telson, and (7) the posterolateral setae on the telson similar in length. We present a revised key to known species in the genus Expanathura and briefly discuss the male polymorphism observed in E. monile.