RECORD OF Ostrea puelchana D’ORBIGNY, 1842 (BIVALVIA: OSTREIDAE), AS NEW EPIBIONT IN Eriphia gonagra (FABRICIUS, 1781) (CRUSTACEA: ERIPHIIDAE) FROM NORTHEASTERN BRAZIL

In this paper, we describe the first association of the ostreid species Ostrea puelchana d’Orbigny, 1842, as new epibiont in Eriphia gonagra (Fabricius, 1781), with material collected in Northeastern Brazil. The specimens of E. gonagra were collected manually in November of 2020 during the low tide in the Barra de Catuama beach, State of Pernambuco. Among 10 specimens collected, only one adult male showed the presence of two commensal specimens of O. puelchana adhered in the epibranchial and antero-lateral regions of the basibiont (right side). The presence of the epibiont O. puelchana on the new host E. gonagra expands the range of the crustacean species potentially used as hosts by this oyster along the Brazilian coast. Keywords: marine invertebrates, biological interactions, Pernambuco, commensalism, beachrocks.

Isobaric Tags for Relative and Absolute Quantitation-Based Proteomics Analysis Provides a New Perspective Into Unsynchronized Growth in Kuruma Shrimp (Marsupenaeus japonicus)

Unsynchronized growth is a common phenomenon in farmed crustaceans. The underlying molecular mechanism of unsynchronized growth of crustaceans is unclear. In this study, a comparative proteomic analysis focusing on growth differences was performed using kuruma shrimp Marsupenaeus japonicus, an economic crustacean species, as the model. The study analyzed kuruma shrimp at fast growth stage and steady growth stage from both fast growth group and slow growth group by an Isobaric tags for relative and absolute quantitation (iTRAQ)-based quantitative proteomic analysis method. A total of 1,720 proteins, including 12,291 peptides, were identified. Fifty-two and 70 differentially expressed proteins (DEPs) were identified in the fast growth stage and steady growth stage, respectively. Interestingly, 10 DEPs, including 14-3-3-epsilon-like, GPI, GPD1, MHC-1a, and MHC-1b, were presented in both growth stages. In addition, all these 10 DEPs shared the same expression tendency at these two growth stages. The results indicated that these 10 DEPs are potential growth biomarkers of M. japonicus. Proteins associated with faster growth of M. japonicus may promote cell growth and inhibit cell apoptosis through the Hippo signaling pathway. The fast growth group of M. japonicus may also achieve growth superiority by activating multiple related metabolic pathways, including glycolysis, glycerophospholipid metabolism and Citrate cycle. The present study provides a new perspective to explore the molecular mechanism of unsynchronized growth in crustacean species.

A freshwater crab (Barytelphusa sp.) feeding on a catfish (Pterocryptis sp.)

The freshwater crab, Barytelphusa cunicularis (Westwood, 1836), is a common and widespread crustacean species inhabiting freshwater streams throughout India except the northeast. It is an omnivore that feeds on small crustaceans, gastropods, insects and aquatic vegetation. This species is commonly collected as a food commodity and is also often reared in captivity for the same purpose. In captivity, these crabs seem to prefer animal-based food and are generally fed about 10% of their total biomass in prawn and rice flakes daily. Observations of B. cunicularis feeding in nature are scant in the literature, and to the best of my knowledge there have not been any reports of the species feeding on fish. Herein I report the first observation of B. cunicularis feeding on a Malabar silurus, Pterocryptis wynaadensis, a type of catfish.

Diversity of Groundwater Crustaceans in Wells in Various Geologic Formations of Southern Poland

Data on Crustacea from underground waters accessed through wells are limited in Poland. A recent study was undertaken to determine diversity and factors influencing the crustacean communities inhabiting wells drilled in three bedrocks, Jurassic limestone, Cretaceous marls and flysch. A total of 23 crustacean species and subspecies were recorded belonging to Copepoda, Ostracoda, Amphipoda and Bathynellacea. Only four species of low abundance, however, were stygobionts. Our studies showed that abundance and species number of Copepoda and Ostracoda were affected by bedrock geology (with higher abundances and species richness in wells of Cretaceous marls), and in the case of copepods, also by sampling season. Furthermore, this paper lists all species of Crustacea recorded from inland groundwater habitats of Poland based published over the last 133 years. The most species-rich group was Copepoda with 43 representatives (four stygobites), followed by Ostracoda and Amphipoda with a total of 37 and 12 species, respectively (each with nine stygobites). In addition, two species of Isopoda (one stygobite) and one Bathynellid appear in the checklist. The checklist identifies geographical (and environmental) gaps which require further research.

Phylogenetic analysis of TALE superclass homeobox genes in amphipod crustaceans

TALE class genes are a group of developmentally conserved transcription factors found in animals. Here, we describe the identification and phylogenetic analysis of TALE class genes in amphipod crustaceans. We identified 241 putative TALE class genes from 56 amphipod crustacean species. Phylogenetic analysis of the genes revealed six subclasses. We provide a list of FASTA sequences of the genes identified. Results from this work may inform future evolutionary and comparative genomics studies on animal development.

Planktonic associations between medusae (classes Scyphozoa and Hydrozoa) and epifaunal crustaceans

Jellyfish are known to carry various epibionts, including many of the subphylum Crustacea. However, the associations between gelatinous zooplankton and other invertebrates have been chronically overlooked. Crustacea, a massive clade of economically, ecologically, and culturally important species, includes many taxa that utilize gelatinous zooplankton for food, transport, and protection as both adults and juveniles. Here we compile 211 instances of epifaunal crustaceans recorded on Hydromedusae and Scyphomedusae from a century of literature. These include 78 identified crustacean species in 65 genera across nine orders found upon 37 Hydromedusa species and 48 Scyphomedusae. The crustacean life stage, location, nature of the association with the medusa, years, months, and depths are compiled to form a comprehensive view of the current state of the literature. Additionally, this review highlights areas where the current literature is lacking, particularly noting our poor understanding of the relationships between juvenile crabs of commercially valuable species and medusae.

High-Throughput Screening of Psychotropic Compounds: Impacts on Swimming Behaviours in Artemia franciscana

Animal behaviour is becoming increasingly popular as an endpoint in ecotoxicology due to its increased sensitivity and speed compared to traditional endpoints. However, the widespread use of animal behaviours in environmental risk assessment is currently hindered by a lack of optimisation and standardisation of behavioural assays for model species. In this study, assays to assess swimming speed were developed for a model crustacean species, the brine shrimp Artemia franciscana. Preliminary works were performed to determine optimal arena size for this species, and weather lux used in the experiments had an impact on the animals phototactic response. Swimming speed was significantly lower in the smallest arena, whilst no difference was observed between the two larger arenas, suggesting that the small arena was limiting swimming ability. No significant difference was observed in attraction to light between high and low light intensities. Arena size had a significant impact on phototaxis behaviours. Large arenas resulted in animals spending more time in the light side of the arena compared to medium and small, irrespective of light intensity. The swimming speed assay was then used to expose specimens to a range of psychotropic compounds with varying modes of action. Results indicate that swimming speed provides a valid measure of the impacts of behaviour modulating compounds on A. franciscana. The psychotropic compounds tested varied in their impacts on animal behaviour. Fluoxetine resulted in increased swimming speed as has been found in other crustacean species, whilst oxazepam, venlafaxine and amitriptyline had no significant impacts on the behaviours measured. The results from this study suggest a simple, fast, high throughput assay for A. franciscana and gains insight on the impacts of a range of psychotropic compounds on the swimming behaviours of a model crustacean species used in ecotoxicology studies.