Decapoda

Part of speech: noun

Definitions

1. A diverse order of crustaceans characterized by having ten limbs, typically including species such as crabs and shrimp
2. Organisms within this classification exhibit notable variations in size, habitat, and behavior
3. This group plays significant ecological roles in aquatic environments, often serving as both predators and prey in the food web

Etymology: "Decapoda" is a Modern Latin coinage, built from two Greek elements: "deka," meaning ten, and "pous," meaning foot, or "podos" in its combining form. The name refers to the ten walking legs that crabs, shrimps, lobsters and their relatives share, with the first three pairs of legs often modified into mouthparts or claws. Naturalists needed a single label for this group, and they drew on classical Greek vocabulary the way they did for most scientific names of the period. The name is a technical coinage, not an ancient word, so the Greeks themselves never used it. Its meaning is literal and visible: anyone who counts the legs of a shrimp or lobster can see why the term fits. The more recent part of the story is the group's classification, which has been revised repeatedly as biologists have compared anatomy and genetics, so the exact membership of the order has shifted over time.

Synonyms: ten-footed crustaceans