Report on some monstrilloids (Crustacea: Copepoda) from a reef area off the Caribbean coast of Costa Rica, Central America with description of two new species

Monstrilloid copepods were collected during zooplankton surveys in the reef area of the Cahuita National Park, Caribbean coast of Costa Rica, Central America. These specimens represent three species, two of them undescribed. A male resembling the supposedly cosmopolitan Monstrilla grandis Giesbrecht, 1891 was recorded. Differences among populations from distinct geographic areas suggest that this species represents a complex. Some South American records are likely to be conspecific with the type material. Monstrillopsis cahuitae sp. nov. is related to congeners with an elongate, distally bilobed male genital apparatus, but can be distinguished by having six caudal setae. Cymbasoma alvaroi sp. nov. differs from its congeners by a combination of characters, including a rounded frontal process, the position of the oral papilla, the ornamentation of the cephalic area, and the length and shape of the fifth leg inner lobe. These are the first records of the monstrilloid fauna of the Costa Rican Caribbean.