Taxonomic study of the genus Eudactylopus (Crustacea, Copepoda, Harpacticoida) from India and updated checklist of marine Harpacticoid copepods from India

Abstract

the southeastern coast is most speciose, with up to 50% of species record. However, northwest region is found to be less explored, as it contains less than 10% recorded species. The present checklist accommodates detailed information on locality, geographical coordinates, habitat and the source of recorded taxa. Comparisons also made with existing checklists from other regions.; Three new species of the genus Eudactylopus Scott A., 1909 from Murud Beach, India, are studied in details. Before this study, six species of the genus Eudactylopus Scott A., 1909 were recorded from India. These three species are very similar to previously identified Eudactylopus spectabilis (Brian, 1923), Eudactylopus robustus (Claus, 1863), and Eudactylopus andrewi Sewell, 1940. However, they differ in many detailed characters such as: 1) body ornamentation 2) the chaetotaxy of P5 and P6 3) the relative proportions and site of the origin of the setae of the exopod of the female P5 4) shape of the rami of P5 5) number of antennules segments. This study results also confirm the significance of these characters in the taxonomy of the genus Eudactylopus. These characters may be helpful in separating other species within the genus as well. Furthermore, a checklist of marine harpacticoids recorded from India is presented. Records from adjacent Island (Andaman and Nicobar Island) are also included. This list comprises 270 species; the species recorded in the Indian shelf belong to 33 families, and 113 genera currently known from India. The most abundant family is Miraciidae consisting of 45 species, followed by the Laophontidae 30 species, Ectinosomatidae 26 species, Paramesochridae 19 species, Ameiridae 15 species, Thalestridae 11 species, Tetragonicipitidae 11 species, Canuellidae 10 species, and Peltidiidae 10 species. Up to 10 harpacticoid, families were represented by less than 10 species. 50 species are endemic to India. There are approximately 10 to 12 species, which have peculiar or restricted distribution. The results show that the species distribution among Indian shelf is asymmetrical