Indian Journal of Geo-Marine Sciences Vol. 44(6), June 2015, pp. 842-855 Biodiversity of marine mollusc from selected locations of Andhra Pradesh coast, South eastern India *S. Monolisha & J.K. Patterson Edward Suganthi Devadason Marine Research Institute, 44 Beach Road, Tuticorin - 628001, Tamil Nadu, India *[Email: [email protected]] Received 12 November 2013; revised 06 January 2014 Study on the diversity of molluscan fauna was carried out in eight locations along Andhra Pradesh coast. 70 species of mollusc including 44 species of Gastropods, 23 species of Bivalves and 3 species of Cephalopods were collected and documented. Shannon-Wiener diversity index (H') of Gastropods, Bivalves and Cephalopods ranged from 1.36 to 1.47, 1.11 to 1.21 and 1.06 to 1.43 respectively and Pielou’s Evenness index ranged from 0.90 to 0.94, 0.90 to 0.96 and 0.35 to 0.92 respectively. Total percentage varies within the class Gastropoda, Bivalvia and Cephalopoda. Gastropod existed with highest range of 60% followed by Bivalvia with 32 % and the lowest range existed to be the Cephalopods with 8%. Fishers α range varied from 0.44 to 7.22. Brillouin index range varied between 1.06 and 3.42. Among the eight locations, total density was observed higher in Location II (Vadrevu) with 15.12% and least density range in Location 8 (Nellore harbour) with 7.67% as this study site was highly polluted due to anthropogenic activities near harbour. Umbonium vestiarium, Cerithidea cingulata were observed to be the dominant and maximum in numbers and the bivalves Perna viridis and Donax faba were found to be maximum in diversity. [Key words: Diversity, Mollusc, Indices, Distribution, Andhra Pradesh] Introduction sustain these structural and functional resources In the geological time scale, molluscs cannot be over emphasized 8. evolved about 600 million years ago and this phyla Structurally molluscs are a heterogeneous is a very old monophyletic lineage, dating from group of animals with different structural form such before the Cambrian1, and is the second most as slugs, mussels, octopus and snails. Indian diverse of all animal phyla 2, 3, occurring in many coastline is rich in molluscan diversity. Some habitat types 4, 5. Phylum Mollusca constitutes literature is available on this diversity, notable dominant groups of animals and includes a variety among which are the works of Crichton (1941)9, of most conspicuous, animals, such as clams, Gravely (1941, 1942) 10, 11. The only comprehensive oysters, snails, squids and octopods 6. Mollusca are work on the molluscan fauna of the south eastern second only to Arthropoda in numerical abundance coast of India is by Satyamurthi (1952, 1956) 12, 13. 7. The number of species identified under phylum Present survey on the mollusc diversity in eight mollusca varies between 80,000 to 1, 00,000 around locations along Andhra Pradesh coast is carried out the world ocean. They are more abundant in the to provide the present status in the study area. littoral zones of tropical seas. Mollusc support economically in the fishery Materials and Methods sector and the ambiance of our coastal communities Current study involves identification and are frequently overlooked with diversity of these quantitative analysis of mollusc of Andhra pradesh marine organisms. Molluscan populations as a coast, South eastern India. Samples of mollusc were source of food, ornamental purposes and collected from eight locations covering four coastal commercial uses have brought them under the shade districts – Guntur, Prakasam, Krishna and Nellore of endangered species 7. The gastropods and bivalve during the period between November 2012 and fisheries are of sustenance nature and used for December 2012. The state of Andhra Pradesh is edible purpose, source of lime, as decorative shells situated between latitudes 13°40’N and 19°N and (or) for industrial purpose. Details on specific longitudes 80°E and 85°E. It is bordered by the Bay aspects of bivalves and gastropods management, of Bengal in the east, Orissa and Madhya Pradesh in biology, aquaculture and their relations to the north, Maharashtra in the north-west, Karnataka economic, public and ecosystem health are of in the west and south-west, and Tamil Nadu in the paramount importance but are at present lacking south. Sampling locations are illustrated in the aspect. Gastropods and bivalves have a significant Figure 1 and the study area include Location I- ecological role to play in the marine ecosystem. The Nizampatnam Harbour (15°90´ 24 N,80°66 E), importance of maintaining healthy molluscan Location II - Vadrevu port (15°81´67 N, 80°35´00 population and the type of information needed to E), Location III - Chirala fishing village (15°82´N, 80°35´ E), Location IV- Machilipatnam (16°25´56 MONOLISHA et al.: DIVERSITY OF MARINE MOLLUSC OF ANDHRA PRADESH COAST 843 N, 82°14´23 E), Location V - Bandar Harbour (16°18´43 N, 81°13´49 E), Location VI - Dumalapenta (14°90´20 N, 80°06´60 E) , Location VII - Isakapalli (15°00´12 N, 79°31´87E) and Location VIII - Nellore harbour (14°43´N, 79°97´E). This coastline was represented with thick patches of mangroves in deltaic regions of Krishna, Guntur and Nellore and the coastline represents estuaries, tidal creeks and channels, tidal flats, mudflats and sandy shores along the study area in all four districts. Visits were planned by considering the tidal activity. Samples were also collected from the bycatch obtained from trawl fishing nets. Quantitative analyses of the samples were carried out by collecting the specimens by the method of hand picking in transect of known area or using a quadrate of known size. At the same time the foulers like mussels and oysters were collected by Fig. 1: Map showing Locations I-VIII of Andhra Pradesh scrapping those using knives or spatula from a coast Results known unit area either using a quadrate. Further, the The present study was aimed on to assess in faunal bivalves were collected by hand digging the biodiversity of molluscan fauna in Andhra the substratum or by hand picking in different pradesh coast. The results have confirmed the places of each sampling regions 14. Specimens were presence of 44 species of Gastropods, 23 species of brought to laboratory, cleaned and identified using bivalves and 3 species of Cephalopods (Table 1). appropriate monographs. Data’s were collected Most of the species are commonly found in all the fortnightly throughout the study period. Information was reported mainly in form of still photographs and few empty molluscs were collected for 1.6000 identification purpose. This was to prevent undue 1.4000 killing of fauna. The number of species for a 1.2000 1.0000 particular region was utilized to determine the Gastropod Shannon Wiener index. Shannon Wiener index 0.8000 Bivalve 0.6000 value is then used to determine the diversity nature index Diversity Wiener - of Andhra pradesh coast and the level up to which 0.4000 Cephalopod the study area is free from the ever growing 0.2000 Shannon problem of pollution. Shannon-Wiener Diversity 0.0000 Index, H, was calculated using the equation H = -Σ Location I Location II Location III Location IV Location V Location VI Location VIILocation VIII Pi lnPi where Pi is the proportion of each species in locations (I-VIII). the sample 15. Shannon-Wiener diversity of Molluscan fauna in Andhra Pradesh coast is illustrated in the following figure -2. Shannon-Wiener diversity index (H') of Gastropods ranged from 1.36 to 1.47 ind.m-2 in Locations I to VIII, showing minimum range in Isakapalli (Location VII) and maximum range observed in Bandhar (Location V). In bivalves, Diversity index ranged from 1.11 to 1.21 ind.m-2 revealing minimum range in Isakapalli (Location VIII) and maximum range in Vadrevu port (Location II). Shannon-Wiener diversity index (H') of Cephalopods ranged from 1.06 to 1.43 ind.m-2 with minimum range observed in Machilipatnam (Location IV) and maximum 844 INDIAN J. MAR. SCI., VOL. 44, NO. 6 JUNE 2015 diversity range observed in Dumalapenta (Location (8.15%), Anadara rhombea (7.85%), Tellina VI). coarctata (7.61%), Sunetta meroe (5.93%), etc. High abundance of Perna viridis was noticed in ferro-cemented bridges near harbours, and Fig.2: Shannon-Wiener diversity index of molluscan fauna Isognomon sp., was observed attached to the barks in Andhra Pradesh coast of mangroves as substratum. 400 samples of Pielou’s Evenness index (Figure 3) of Cephalopods were counted and the most abundant Sepiella inermis Loligo molluscan fauna was carried out, Evenness index species includes (40.5%), -2 duvuaceili Sepia pharaonis ranged from 0.90 to 0.94 ind.m in gastropods, with (34.5%) and (25%). maximum range observed in Nizampatnam In the present study, 44 species of (Location I) and minimum range observed in gastropods, 23 species of bivalves and 3 species of Nellore Harbour (Location VIII), the Pielou’s index cephalopod was recorded from eight Locations of of bivalves ranged from 0.90 to 0.96 ind.m-2, four districts from Andhra Pradesh coast. Umbonium vestiarium, Cerithidea cingulata maximum value was observed in Nizampatnam were (Location I) and minimum range observed in observed to be the dominant and maximum in Perna viridis and Donax Bandhar, Dumalapenta and Iskapalli (Location V, numbers and the bivalves faba VI and VII). Pielou’s index of Cephalopods ranged were found to be maximum in numbers of from 0.35 to 0.92 ind.m-2, maximum range observed diversity. in Nizampatnam (Location I) and minimum range In Figure 4, Location wise total density was observed in (Bandhar Location V). analysed, Location II, III, V and I was highly During the study, 3184 gastropod and 1669 diverse with 15.12%, 14.53%, 13.52% and 13.31 %, bivalve samples were counted in eight sampling respectively.