A new species of Cymbasoma (Crustacea: Copepoda: Monstrilloida) from the Pacific coast of Costa Rica, Central America

摘要

A new species of monstrilloid copepod belonging to the genus Cymbasoma Thompson is described from a female specimen collected in Bahia Culebra, an embayment on the Pacific coast of northwestern Costa Rica, in Central America. The new taxon, C. concepcionae, n.sp., is part of a group of species of Cymbasoma with a fifth leg represented by a single lobe armed with three setae. An overall comparison of this morphological group is presented. The new species is distinguished mainly by a combination of characters including a short inner seta on the fifth leg, a slightly globous genital double somite, and transverse cuticular striations nearly encircling the cephalic area. Moreover, the species can be easily recognized by a distinctive cluster of rounded cuticular processes on the middle ventral margin of the fifth pedigerous somite and on the anterior half of the genital double somite. The intercoxal sclerite of the first swimming leg shows a peculiar ornamentation not previously described within the group. This is the first record of a monstrilloid copepod species from marine waters of Costa Rica and of Central America, and the fourth species of Cymbasoma recorded from the Eastern Tropical Pacific.