GC-MS analysis and identification of moult-specific metabolites in the haemolymph of male fiddler crab, Gelasimus hesperiae

• Aishwarya Nath, Jose Priya TA and Sudha Kappalli

Abstract

This study characterises the moult stage-specific haemolymph metabolite profile of the male brachyuran crab Gelasimus hesperiae using gas chromatography-mass spectrometry (GC-MS) to elucidate the metabolite shift across the moulting process. Haemolymph was collected from 24 healthy crabs, comprising eight individuals each at intermoult, premoult [D2], and postmoult stages, and pooled within each stage. A total of 229 metabolites were identified, of which 61, 13, and 85 were exclusively expressed at the intermoult, premoult, and postmoult stages, respectively. Bi-plot analysis revealed substantial variations in carbohydrates, amino acids, fatty acids, nucleic acids, vitamins, and their respective derivatives. Carbohydrates, proteins, and fatty acids declined from intermoult to premoult whereas, major biochemical components or their derivatives e...

Cymothoid isopods parasitic on fishes: current knowledge and future perspectives

• Saito, M., Fujita, H. (2026) 

Cymothoid isopods (Crustacea: Peracarida) are large ectoparasites of fishes. Mature females and males inhabit the buccal or branchial cavities, or burrow into the abdomen, or attach to the body surface of marine, brackish, and freshwater fishes. The mancae, which are released from the brood pouch of adult females, spend a planktonic period and develop into early juveniles infecting host fishes. Currently, 399 species in 49 genera of the family Cymothoidae have been recorded worldwide, including 46 species known from Japan and its adjacent waters. This paper provides a comprehensive review of cymothoid taxonomy, morphology, parasitology, molecular characteristics (cytochrome