A functional interpretation of coxal morphology in Epimeria cornigera (Crustacea: Amphipoda: Paramphithoidae)

Coxal plates 1–5 of Epimeria cornigera form a closely interlocking series keyed by the head such that ventral flexion of the peraeon is severely curtailed. The clamp formed by coxae 4 and 5 is interpreted as an adaptation facilitating copulation in a species with feeble gnathopods and non-prehensile antennae. The morphology of the posterior three pairs of peraeopods can also be regarded as an adaptation for gripping the female. Other possible functions (e.g. predator deterrence and feeding grip) of coxal structures are also examined.