Validation of Male Pontella spinipes Giesbrecht, 1889 (Copepoda: Calanoida: Pontellidae) Based on Morphological and Mitochondrial COI Gene Sequence Analysis

Abstract

The neustonic copepods of the family Pontellidae - Pontella spinipes Giesbrecht, 1889 and P. diagonalis Wilson, 1950, both first described on the basis of female specimens exhibit very similar morphology and overlapping geographic ranges in the Indian Ocean. While several taxonomists have described males of each species, there has been no definitive evidence for female-male matching (link female and male of the same species) in the two species. In the present study, an analysis of mitochondrial cytochrome c oxidase subunit I (mtCOI) sequences in the specimens collected from the Arabian Sea revealed that female P. spinipes Giesbrecht, 1889, and male P. diagonalis sensu Silas and Pillai (1973) are genetically identical, providing evidence that the latter is actually P. spinipes. These findings emphasize that it is necessary to re-examine the female-male correspondence of other related species, formerly based on morphology alone, using molecular-genetic analysis as applied in the present study.