Complementary description of Peltidiumnayarit (Copepoda, Harpaticoida, Peltidiidae) and a new record at Revillagigedo Archipelago, Mexico.

Four adult females of a rare benthic/epiphytic harpacticoid copepod species of the genus Peltidium Philippi, 1839 were collected from insular zooplankton samples obtained at Revillagigedo National Park, Mexico. They were identified as Peltidiumnayarit Suárez-Morales & Jarquín-González, 2013 with type location (and the single previously known distribution site) at Playa Careyeros (20°46'59.46"N, 105°30'35.48"W), Nayarit, Mexico. We provide a complementary description of this species including new details of antennules, caudal rami, legs 1 and 5, and cuticular ornamentation using scanning electron microscopy observations. Peltidiumnayarit has a dark reddish-pink coloration allegedly mimicking the color of the macroalgae where they live, but specimens collected in the present study were obtained from sea surface zooplankton net tows. The record of Peltidiumnayarit in the Revillagigedo Islands represents the southwestern-most record of the genus in the Americas and the second record for Mexico.