Middle-East Journal of Scientific Research 14 (5): 587-597, 2013 ISSN 1990-9233 © IDOSI Publications, 2013 DOI: 10.5829/idosi.mejsr.2013.14.5.71212 Status of Scleractinian Diversity at Nancowry Group of Islands Andaman and Nicobar Islands 11Tamal Mondal, C. Raghunathan and 2K. Venkataraman 1Zoological Survey of India, Andaman and Nicobar Regional Centre, National Coral Reef Research Institute, Haddo, Port Blair-744 102, Andaman and Nicobar Islands, India 2Zoological Survey of India, Prani Vigyan Bhawan, M-Block, New Alipore, Kolkata-700 053, India Abstract: Andaman and Nicobar Islands represent a varied group of islands in its distributional pattern. Nancowry group in Andaman and Nicobar is comprised of 4 islands such as Camorta, Katchall, Nancowry and Trinket. These islands represent 274 species of scleractinian corals with 22.26% to 58.39% of species composition among themselves. Shannon-Weaver Diversity index (H¯ ) of Scleractinian corals of the islands was calculated as 5.62 to 6.85, indicating very high coral diversity at Nancowry Islands. Simpson’s species density index (D) ranged from 0.97 to 0.98 while Pielou’s Species evenness index (J’) showed 0.93 to 0.94 in these islands. The similarity index (QS) regulated low values 17.43% to 48.98% as most of the species were dissimilar between the islands. Key words: Scleractinian Diversity Density Evenness Nancowry group Andaman and Nicobar Islands INTRODUCTION land mass in the form of separation such as Sombrero channel at the southernmost, Revello channel in A scattered mountain chain of 572 islands between Katchall Island and Carmorta-Nancowry contributed for the formation of a biologically most Island where as Beyesford channel in between productive area as Andaman and Nicobar Islands, Carmorta-Nancowry Island and Trinket Island. presently designated as one of the 32 most important Such a kind of demographic situation of areas biological hot spots around the globe. Origin and protects or helps the highly diverse biological development of island’s tectonics of these areas gives organisms in its marine ecosystem. Scleractinian corals several shapes in the form of groups of islands within often called as rainforest of the sea, are among the the total numbers. Nancowry group of island is one of most ancient of ecosystem types of some 225 million the well recognized groups among all the areas, known years ago [1, 2]. The importance of coral reef as heart of Nicobar group due to its location at the ecosystems may be seen in their numerous ecological, central part among the 22 islands of Nicobar group. aesthetic, economic and cultural functions. The structure The Nancowry group comprised of four islands such of a reef provides homes and food for many types of Camorta, Katchall, Nancowry and Trinket. It is sub plants, fish and invertebrates [3]. This quantitative categorization part of Nicobar group which distributed documentation of scleractinian status is very essential from Car Nicobar to Great Nicobar Island. This group for the effective management and conservation of this of island is surrounded by Isle of Man at Northern unique marine ecosystem. The present study side, Teress and Bompoka Islands at North-western side documented as the status of diversity, density and and Miroe Island at the Southern side where as some evenness of coral species in four islands of Nancowry channels also have played a role for the making of these group of islands. Corresponding Author: Tamal Mondal, Zoological Survey of India, Andaman & Nicobar Regional Centre, National Coral Reef Research Institute, Haddo, Port Blair-744 102, Andaman & Nicobar Islands, India. 587 Middle-East J. Sci. Res., 14 (5): 587-597, 2013 MATERIAL AND METHODS Evenness of a community was described by the Pielou’s Evenness Index (J’). The formula of the index is Four islands of Nancowry group such as Camorta [12] Island (Lat: 08°02.178’N and Long: 93°33.103’E), Katchall Island (Lat: 07°58.952’N and Long: 93°24.351’E), J’=H’/H’max Nancowry Island (Lat: 07°59.517’Nand Long: 93°30.373’E) and Trinket Island (Lat: 08°06.260’N and Long: Where H' is the number derived from the Shannon 93°33.235’E) were surveyed during April 2012 to explore diversity. the Scleractinian corals and also to monitor the health Similarity Index is the simple measure of the extent status of those. Three reef areas were randomly selected to which two habitats species in common. It has been for each island to get precise data on species formulated below. quantification. “Manta tow” study method [4, 5] followed by Line Intercept Transect Method [6] and Quadrate S= (2C/a + b) X 100 methods [7] were applied to investigate the diversity of the scleractinian corals using Self Contained Underwater Where ‘C’= Number of species common at any two Breathing Apparatus (SCUBA) diving. Belt transect stations, ‘a’= number of species at one station and method was also employed to quantify the data of the ‘b’= number of species at the other station [13]. diverse scleractinian corals. Digital photography was made simultaneously (Sony-Cyber shot, Model-T900, RESULTS marine pack, 12.1 megapixels) to record the species content in the quadrate during the study. The species of Surveys and monitoring on scleractinian corals of corals were identified in conjunction with Veron [8] and Nancowry group of islands reveals a total number of Wallace [9]. 274 species. Among them 160 species of corals under Species diversity was calculated following 49 genera and 14 families at Camorta Island, 61 species Shannon-Weaver diversity index formula described of corals under 26 genera and 09 families at Katchall below [10]. Island, 93 species of corals under 38 genera and 13 families at Trinket Island and 134 species of corals under H¯= - pi loge pi 41 genera and 12 families at Nancowry Island were recorded (Table 1). The highest number of species was Where, pi = Proportion of number of individual of observed at Camorta Island whereas less number of a particular species and total number of individual of species at Katchall Island (Fig.1). all the species, H¯= diversity of a theoretically infinite The species diversity (H’) ranged from 5.62 to 6.85 population. at Katchall and Camorta Island respectively which are Simpson’s diversity index [11] is one of the truthful the highly significant values. Simpson’s density (D), indices to calculate the species diversity of any study in between 0.97 to 0.98, indicates a great deal of density site. It has been applied to calculate the species response among those study areas. Pielou’s evenness diversity of scleractinian corals of those islands. falls in between 0.93 and 0.94 (Fig. 2). Similarity Index The formula for the Simpson index is: (S) has been calculated between the islands and the values are depicted in Table 2. The maximum similarity s − D=1- ni( ni 1) index value (48.98%) was observed in between Camorta ∑i=1 ÷ NN( −1) and Nancowry Islands whereas lowest (17.43%) in between Katchall and Nancowry Islands (Table 2). Where S is the number of species, N is the total percentage cover or total number of organisms and n DISCUSSION is the percentage cover of a species or number of organisms of a species. In this form, D ranges from 1 to Undersea environment of Andaman and Nicobar 0, with 1 representing infinite diversity and 0 Islands offers a varied and complex animal lives of which representing no diversity. colourful coral reefs constitute the most fragile and 588 Middle-East J. Sci. Res., 14 (5): 587-597, 2013 Table 1: Species composition of Scleractinian Corals of Nancowry group of Islands. Sl. No. Scientific Name Camorta Katchall Trinket Nancowry FAMILY: ACROPORIDAE Genus - Acropora 1. Acropora gemmifera (Brook, 1896) + +- - 2. Acropora cuneata (Dana,1846) +-- - 3. Acropora vaughani Wells, 1954 - -+ + 4. Acropora forskali (Ehrenberg, 1834) +-- - 5. Acropora hyacinthus (Dana, 1846) +-- - 6. Acropora nasuta (Dana, 1846) +-- + 7. Acropora anthocercis (Brook, 1893) - +- - 8. Acropora valenciennesi (MED and H, 1860) - -+ + 9. Acropora divaricata (Dana, 1846) +-+ + 10. Acropora roseni Wallace, 1999 +-- - 11. Acropora striata (Verrill, 1866) +-- - 12. Acropora humilis (Dana, 1846) +-+ - 13. Acropora forskali (Ehrenbeerg, 1834) - -+ - 14. Acropora plana Nemenzo, 1967 - -+ - 15. Acropora torresiana Veron, 2000 - -+ - 16. Acropora tutuilensis Hoffmeister, 1925 +-- - 17. Acropora carduus (Dana, 1846) - -- + 18. Acropora pectinata Veron, 2000 - -+ - 19. Acropora insignis Nemenzo, 1967 - -+ + 20. Acropora sqarrosa (Ehrenberg, 1834) - -- + 21. Acropora sekiseiensis Veron, 1990 - -- + 22. Acropora yongei Veron and Wallace, 1984 - -- + 23. Acropora caroliana Nemenzo, 1976 - -- + 24. Acropora chesterfieldensis Veron and Wallace, 1984 - -+ + 25. Acropora abrotanoides (Lamarck, 1816) - -+ - 26. Acropora latistella (Brook, 1891) - -+ + 27. Acropora polystoma (Brook, 1892) - -- + 28. Acropora microclados (Ehrenberg, 1834) - -- + 29. Acropora copiosa Nemenzo, 1967 - -- + 30. Acropora robusta (Dana, 1846) +-- + 31. Acropora digitifera (Dana, 1846) - -- + 32. Acropora subuata (Dana, 1846) - -- + 33. Acropora cophodactyla (Brook, 1892) - -- + 34. Acropora horrida (Dana, 1846) - -- + 35. Acropora palmerae Wells, 1954 +-- + 36. Acropora selago (Studer, 1878) +-+ + 37. Acropora papillare Latypov, 1992 - -- + 38. Acropora elseyi (Brrok, 1892) - -- + 39. Acropora cerealis (Dana, 1846) +-- + 40. Acropora hemprichii (Ehrenberg, 1834) +-- + 41. Acropora tenuis (Dana, 1845) +-- + 42. Acropora bruggemanni (Brook, 1893) +-- + 43. Acropora echinata Dana, 1846 - -- + 44. Acropora