#crustacean

• Amphipod — A small malacostracan crustacean belonging to the order Amphipoda, characterized by the absence of a carapace, a laterally compressed body, and legs structurally adapted for different functions (some for walking, others for swimming or jumping). Most species live in marine or freshwater environments (such as the beach flea or the genus Gammarus), playing an essential ecological role in aquatic food webs.
• Amphithoe — An ancient proper noun designating a Nereid in Greek mythology, daughter of Nereus and Doris, a marine nymph personifying the agility and swift movement of ocean waves; in zoology, the term represents the taxonomic genus 'Amphithoe' (frequently spelled Ampithoe), grouping various species of marine amphipod crustaceans known for constructing algal tubes.
• Arthropods — The scientific and taxonomic designation assigned to the largest phylum of invertebrate animals (Arthropoda), consisting of species with a segmented body, bilateral symmetry, and jointed appendages. Members of this group, which inhabit absolutely all living environments on the planet, periodically undergo the molting process to allow body growth restricted by the external crust.
• Astaciculture — A specialized branch of aquaculture and zootechnics dealing with the study, breeding, controlled growth, and commercial exploitation of freshwater crayfish (crustaceans of the Astacidae family); this technological process includes setting up artificial hatcheries, optimizing water quality, controlled feeding, and ecological species selection for economic capitalization or restocking natural hydrographic basins.
• Astaciform — Having the shape, appearance, or anatomical structure resembling that of a crayfish (of the genus Astacus); a morphological adjective used in biology to describe the exterior appearance of certain fossil or contemporary crustaceans presenting a robust cephalothorax, segmented abdomen, and prominent claws.
• Astaco- — A scientific combining form (prefixoid) extracted from the Greek language (from 'astakos'), used in rare scientific, zoological, and paleontological terminology to refer to crayfish, decapod crustaceans of the Astacidae family, or to describe anatomical and fossil structures belonging to or closely related to this group of aquatic organisms.
• Astacoid — Resembling a crayfish or the species of the Astacus genus in form, structure, or general appearance; a morphological adjective used to describe fossil specimens, crustacean larvae, or external anatomical characters (such as the carapace or claws) reminiscent of the river crayfish's structural configuration.
• Astacomorph — Having the shape, external structure, or morphological appearance resembling a crayfish (of the genus Astacus); (as a plural neuter noun, Astacomorpha) an infraorder of decapod crustaceans that includes freshwater crayfish and lobsters, structurally characterized by large chelae on the first pair of legs and a well-developed abdomen.
• Astacus — Lowercase spelling form for the taxonomic genus Astacus (freshwater crayfish); used in regular text or in binomial species names (such as Astacus astacus, the European crayfish) to denote decapod crustaceans with a rigid exoskeleton and large claws. It represents a fundamental morphological unit in the study of European freshwater fauna, serving as an excellent ecological indicator for the purity of running waters.