Four new species of Cletocamptus Schmankewitsch, 1875, closely related to Cletocamptus deitersi (Richard, 1897) (Copepoda: Harpacticoida)

Abstract

In 1897, Richard presented a brief and incomplete description of Mesochra (=Cletocamptus) deitersi from a site in the Naposta Grande River in Argentina. Since Richard's description, C. deitersi has been reported from inland brines as well as coastal estuaries and mangroves from North, Central and South America, India, China, Ethiopia, Hawaii, Australia, Iran and Malaysia. However, there is ample evidence to support the hypothesis that all these records belong to new and as yet undescribed species. Erroneous identification of specimens attributed to C. deitersi has been due to a high degree of polymorphism within and between populations, to the incompleteness of Richard's original description, and to the fact that Richard did not archive material for future comparisons. Recently, the existence of four extremely differentiated molecular lineages in specimens of Cletocamptus collected from the Salton Sea (California, USA), Jackson (Alabama, USA), Port Fourchon (Louisiana, USA) and Mazatlan (Sinaloa, Mexico), all previously identified with C. deitersi, was observed. Morphological differences among these populations are subtle but congruent with the patterns of genetic differentiation, suggesting, in fact, that each of these lineages belongs to different species.

Keywords:

• Copepoda
• Harpacticoida
• Cletocamptus
• taxonomy
• USA
• Mexico

Acknowledgements

The first author is indebted to Dr Frank Fiers from the Koninklijk Belgisch Instituut voor Natuurwetenschappen (Brussels, Belgium) and Dr Ernest Schockaert from the Limburgs Universitair Centrum (Diepenbeek, Belgium) for their support during a stay in Belgium. We are also grateful to Ms Sc. Ana C. Puello (CIAD-Mazatlán) for providing us with specimens of C. sinaloensis sp. nov. from El Yugo estuary, to Mr William G. Keel and Mr Chad T. Walter (Smithsonian Institution) for providing us with the USNM catalogue numbers, and to Berenit Mendoza Garfias (Institute of Biology of the National Autonomous University of Mexico) for the scanning microphotographs. This study is a contribution to project IN202400 and project G.0086.96 and was financed by the ‘Programa de Apoyo a Proyectos de Investigación y de Innovación Tecnológica (PAPIIT-UNAM)’ and by the Fund of Scientific Research Flanders. This contribution was greatly improved through the thorough revision and criticism of two anonymous referees to whom we are grateful.