The parasitic crustaceans of fishes from the Brazilian Amazon. 12. Ergasilus hydrolycus n.sp. (Copepoda: Poecilostomatoida) from Hydrolycus scomberoides (CUVIER)

Abstract

The female of Ergasilus hydrolycus n. sp. is described from specimens taken from the gills of an Amazonian fish, Hydrolycus scomberoides (CUVIER). The new species is similar to E. bryconis THATCHER, 1981, and to E. jaraquensis THATCHER & ROBERTSON, 1982, in the form of the body, antennae and legs, and in having a curved pectinate seta on the terminal segment of the first exopod. The new species is distinguished from the other two by having a single seta representing the fifth leg, instead of two, and by having a relatively larger antennal claw. Additionally, the pigmentation of E. hydrolycus n. sp., is limited to a single transverse band at the level of the mouth while in the other two species it is diffuse and distributed throughout the body. Also, the uropod of the new species has two main setae and that of E. bryconis has three. The new species is larger than E. jaraquensis