Diversity and Distribution of Echinoderms of Great Nicobar Biosphere Reserve: Andaman and Nicobar Islands

Abstract

Diversity and distribution of echinoderms were estimated on Great Nicobar Biosphere, Andaman and Nicobar Islands. The field surveys were conducted at 10 sites of Great Nicobar Biosphere during 2015–2019 and yielded a total of 49 echinoderm species under 5 classes. The maximum number of species (42) was recorded at B. Quarry and minimum (8) obtained at Vijay Nagar. Most of the echinoderms encountered belonged to classes Echinoidea (regular and irregular urchins, 19 species), Ophiuroidea (brittle stars, 11 species), Asteroidea (sea stars, 9 species), Crinoidea (feather stars, 6 species) and Holothuroidea (sea cucumbers, 4 species). Among the five reported classes, Ophiuroidea was recorded with maximum 12 species and class Holothuroidea was recorded with at least four species. Among the recorded shallow-water echinoderms, class Echinoidea was more dominant in terms of species richness. In five recorded class of phylum Echinodermata, class Holothuroidea, four species are under IUCN (International Union for Conservation of Nature) status; Actinopyga mauritiana (Quoy & Gaimard, 1834) is listed under vulnerable (VU) and Holothuria (Halodeima) atra, Holothuria (Mertensiothuria) leucospilota and Stichopus chloronotus are under at least concern (LC) under IUCN. The current work also provides ten new distribution records of echinoderms, Colobometra perspinosa (Carpenter, 1881), Nardoa novaecaledoniae (Perrier, 1875), Gymnolophus obscura (Ljungman, 1867), Breviturma brevipes (Peters, 1851), Echinometra oblonga (Blainville, 1825), Tripneustes gratilla (Linnaeus, 1758), Stomopneustes variolaris (Lamarck, 1816), Brissus latecarinatus (Leske, 1778), Metalia sternalis (Lamarck, 1816) and Maretia planulata (Lamarck, 1816) to Great Nicobar Biosphere Reserve.