Redescription and First Molecular Characterization of Lernanthropus caudatus Wilson, 1922 (Copepoda: Lernanthropidae): A Comparative Integrative Analysis.

PURPOSE: The aim of this study was to redescribe and provide the first molecular characterization of the copepod Lernanthropus caudatus Wilson, 1922 (Copepoda: Lernanthropidae) collected from three sparids (Archosargus probatocephalus, A. rhomboidalis, and Lagodon rhomboides) from the Yucatán Peninsula. METHODS: Fish were collected from two coastal lagoons and offshore of the northern part of the Yucatán Peninsula, Mexico. Copepods were morphologically studied using light microscopy. Sequences of the cox1 mtDNA gene were generated for L. caudatus collected from the three sparid species. These sequences were compared to those available in the GenBank dataset for 18 species of Lernanthropidae, and a phylogenetic tree was built. RESULTS: The generated cox1 mtDNA sequences of four isolates of L. caudatus clustered together in a well-supported monophyletic clade. The intraspecific genetic divergence among isolates was, on average, 1%. The phylogenetic analysis yielded L. tylosuri as a sister group of L. caudatus, albeit with very low nodal support and with a genetic divergence of 21% between them; moreover, the cox1 interspecific divergence between L. caudatus and all the other species of Lernanthropus varied between 20 and 24%. CONCLUSION: The specimens of L. caudatus correspond morphologically with the diagnosis of the species originally published in 1922 as well with a redescription published in 2003; however, some morphometric traits are added in our study, and molecular data of the copepod is provided for the first time, including sequences from the type host, A. probatocephalus.