BASEODISCUS HEMPRICHII (EHRENBERG, 1831) (PHYLUM NEMERTEA) NEW DISTRIBUTIONAL RECORD FROM ANDAMAN AND NICOBAR ISLANDS, INDIA

Nemerteans or Ribbon worms (previously) known as Rhyncocoela and N emeteni) are soft bodied unsegmented worms. The earliest record of a nemertean worm is probably an general account by Olaus Magnus in 1555 of a long, grayish-blue marine worm. The first formal description of a species of N emertea did not happen until Gunnerus described the same species (as Ascaris longissima) in 1770 (Gibson, 1995). Most of the early information was given by Coe (1901, 1904, 1905, and 1940) which can be found in Hochberg and Luniansky (1998). A total of 1.149 species were described till today and have grouped into 250 genera (Gibson, 1995) and two classes. Gibson (1953) placed these species under orders : Archinemertea (3 genera, 28 species); Palaeonemertea (11 genera, 70 species); Heteronemertea (79 genera, 401 species); Hoplonemertea, Monostiliferous (91 genera, 500 species); Hoplonemertea, Reptantic-Polystiliferous (22 general, 45 species); Hoplonemertea, Pelagic-Polystiliferous (40 genera, 97 species); Bdellonemertea (1 genus, 5 species); Monotypic (3 genera). The fauna of the phylum N emertinea in India is least studied. Earlier record on the occurrence of N emetinean worm Eupolia hemprichi (Ehernberg, 1831) is from coasts of India (Punnett, 1903; Gravely, 1927; Patel et al., 1976). Another record was made stating a similar species of Gorgonorhyncus repeans was found in certain coast of India (Coe, 1917). There is also a reference of some unidentified nemertiean worms from Gulf of Kuchehh (Desai, 2010) and Neeleswarm, Kerala (Nandan, 1998), which, however was identified only to phylum level.


INTRODUCTION
Nemerteans or Ribbon worms (previously) known as Rhyncocoela and N emeteni) are soft bodied unsegmented worms.The earliest record of a nemertean worm is probably an general account by Olaus Magnus in 1555 of a long, grayish-blue marine worm.The first formal description of a species of N emertea did not happen until Gunnerus described the same species (as Ascaris longissima) in 1770 (Gibson, 1995).Most of the early information was given by Coe (1901Coe ( , 1904Coe ( , 1905Coe ( , and 1940) ) which can be found in Hochberg and Luniansky (1998).
The fauna of the phylum N emertinea in India is least studied.Earlier record on the occurrence of N emetinean worm Eupolia hemprichi (Ehernberg, 1831) is from coasts of India (Punnett, 1903; Gravely, 1927; Patel et  al., 1976).Another record was made stating a similar species of Gorgonorhyncus repeans was found in certain coast of India (Coe, 1917).There is also a reference of some unidentified nemertiean worms from Gulf of Kuchehh (Desai, 2010) and Neeleswarm, Kerala (Nandan, 1998), which, however was identified only to phylum level.
A specimen was obtained from Andaman Nicobar Islands, India during low tides in some intertidal regions, which was readily identified as a Heteronemertean Baseodiscus hemprichii (Ehernberg, 1831) as this species can be easily identified on the basis of external body coloration and pattern alone (Gibson, 1979).The present paper reports the first record of Baseodiscus   hemprichii (Ehrenberg, 1831) in Andaman and Nicobar Islands, India.A comprehensive synonym list is provided locality information in case of primary reference.

Materials examined:
The nemertiean sample was incidentally observed from the interitidal region of Kodiyaghat and also from rocky shores of south point, Andaman Nicobar Islands, India, collected in intertidal regions during evening low tides were the tidal amplitude was around 0.4 m.The nemertiean was found underneath dead corals and rock crevices.The specimen was collected by the author of this paper in Kodiyaghat (11°32'N, 92°43'E) using forceps and brought to lab in sea water were it was examined for length, breadth, coloration patterns in live condition and preserved in 4% formalin.The specimen was deposited in the Pondycherry University collection at Port Blair, Andaman and Nicobar Islands.
Description : In live condition the length of the nemartiean was 3 m, the breadth attained maximum of 6 mm near the fore gut and tapered to 1 mm in the tail region.The head was demarcated from the body by a transverse furrow.The body is slightly laterally compressed.The body color was white.A thick brown line started below the mouth with a 'T' shaped collar and extended the whole length of the body to the posterior end and a comparatively thin line was noticed in the ventral side beginning below the mouth without any 'T' shaped collar.The Snout region was also distinguished with the same brown color patch and only in the dorsal surface.
Habitat: The worm was found inhabiting in certain rocky shores, dead coral reefs and also in some sea grass beds under some boulders and holes.
Distribution: This species have been reported from all over the world.In India, this species shows continuous distribution from Gulf of Mannar to Gulf of Kuchchh (Patel et al., 1976).The present record shows the distribution of this nemetiean worm in Andaman and Nicobar Islands, India.
Discussion: The Nemertea (Minor phyla) is one of the least studied groups in Indian context.India being a mega biodiversity country lot more species to be identified and reported.Undertaking research in these groups may lead to invention of bioactive compounds as well as ecosystem service they provide.