Morphology and DNA sequences reveal a new species of <i>Clavellotis</i> (Copepoda: Lernaeopodidae) as a parasite of three species of sparids in the Yucatán Peninsula, Mexico

Species of genus <i>Clavellotis</i> (Castro-Romero & Baeza-Kuroki, ) are parasites of marine fishes across the world. During the course of a survey on the metazoan parasites of marine fish across the Yucatán Peninsula, Mexico, specimens of a lerneapodid copepod consistent with the concept of <i>Clavelotis</i> were collected from the gills of three species of sparids, and were described as a new species using morphological and molecular characters. <i>Clavellotis mayae</i> n. sp. represents the second species of the genus reported in Mexican coastal waters. The new species morphologically resembles <i>C. dubius</i> and <i>C. sebastidis</i> in the trunk shape but can be readily distinguished by having a short maxilla which is separated to its distal end, a sub-oval and conspicuously larger aliform process, and a distal margin of the trunk bearing pronounced subcircular flaps covering the attachment sites of the egg sacs. The new species further differs from all other known congeners by having a short genital process and mandibles without secondary dentition. Molecular analyses through 28S rDNA and <i>cox</i>1 sequences further corroborate all these morphological distinctions and support the taxonomic placement of the new species within <i>Clavellotis</i>. The relationships of this species with other congeners are discussed in light of molecular evidence.