| Abstract: | Monstrilloid copepods were collected from the oceanic island Isla del Coco in the Eastern Tropical Pacific; two undescribed species were found, one of Cymbasoma and one of Monstrillopsis. The first species, represented by females only, is distinguished by the structure of its fifth legs, the antennular armature and the position of the ovigerous spines. The new Monstrillopsis, represented by male specimens, is distinguished by its genital lappets and details of the antennule armature. The isolation of this island, 532 km from the mainland, and the limited dispersal means of monstrilloids suggest potential endemism of these species. A recent record of Cymbasoma tumorifrons from the Mexican Pacific was found to represent a new species of Cymbasoma. It can be distinguished from C. tumorifrons, probably a Mediterranean form, by its body shape and antennular armature. These findings double the number of monstrilloid species known from the Eastern Tropical Pacific. |
