Gynodiastylidae


Gynodiastylidae is one of the eight most commonly recognised families of crustaceans of the order Cumacea. They are especially prevalent in the southern hemisphere, with some types described from Japan, Thailand and the Persian Gulf. Most are found at less than depth.

Anatomy

Gynodiastylidae have a small free telson, usually lacking terminal setae, though in some cases there may be two. The interior branch of the uropods is present on segments one through three. The number of free thoracic somites is never reduced. The first pereopods have a group of long rigid fibres on the propodus. Males have no pleopods. The flagellum of the second antenna does not reach further than the hindmost edge of the carapace. Females have a very small second antenna. They also have no exopods on their third maxillipeds. Because they lack exceptions to the two most important diagnostic characteristics, Gynodiastylidae have a pre-eminent place among monographic descriptions.