Lepeophtheirus simplex sp. n., a caligid copepod (Siphonostomatoida) parasitic on "botete" (bullseye puffer, Sphoeroides annulatus) in Sinaloa, Mexico.

A new species of caligid copepod, Lepeophtheirus simplex sp. n., parasitic on bullseye puffer, Sphoeroides annulatus (Jenyns) in Sinaloa, Mexico is described. The new species is distinguished from its congeners by the possession of (1) a maxillule with simple dentiform process; (2) a sternal furca with sharply pointed, curved tines; (3) a 2-segmented exopod of leg 3 with simple, slender spine on proximal segment; (4) a 3-segmented exopod of leg 4 with a long proximal, outer spine; and (5) the terminal claw of male antenna with a large, tridentate, medial protuberance.