RESEARCH ARTICLE ISSN: 2319-6955 A STUDY ON MEGAFAUNAL DIVERSITY IN AYIRMTHENGU MANGROVE ECOSYSTEM, KOLLAM DISTRICT, KERALA DEEPTHI G.R. AND REEJA JOSE Department of Zoology, Bishop Moore College, Mavelikara- 690110 Correspondence to:[email protected] Abstract: Mangrove forests are regarded as the most dynamic and bio diverse wetlands on world. Ayiramthengu mangrove ecosystem in Kollam District is a very good example of natural reserve of biological diversity. The present study documented the aquatic faunal diversity of Ayiramthengu mangroves, Kollam District, Kerala. Twenty three species of fishes belonging to 18 families have been collected. Of the 18 families, Cichlidae has the highest representation with 3 species followed by Cyprinidae, Carangidae and Mugilidae with 2 species each. The fish fauna of Ayiramthengu mangrove is composed of marine, estuarine and freshwater fishes. The present study also documented 3 species of prawns, 4 species of crabs and two species of molluscs during the study period. Many species collected from this mangrove area are juveniles of commercially important species. From this it is very clear that these mangrove areas are the breeding grounds of these organisms. Hence it is essential to take necessary activities to aware the local population about the need and significance of conserving these ecosystems. KEYWORDS: Mangrove ecosystem, Ayiramthengu, Megafaunal diversity INTRODUCTION Kerala is profusely well-off with marine, backwaters. An important characteristic of brackish water and fresh water resources. backwaters is their biological diversity, These water bodies are inhabited by a wide which refers to the diversity of various variety of aquatic fauna and flora and the species of living organisms, plants and State occupies one of the leading positions animals, the presence of various ecosystem in the aquatic biodiversity. An outstanding services, and genetic diversity. In Kerala the feature of the Kerala’s coastal zone is the brackish water resources includes the lower presence of a large number of perennial or reaches of rivers, the brackish water lakes, temporary estuaries popularly known as the backwaters and the adjacent low lying SCIENCE CHRONICLE - A peer reviewed multidisciplinary science journal Vol .8 No.1&2 (2019) 31 RESEARCH ARTICLE ISSN: 2319-6955 fields and prawn filtration fields, mangrove invertebrates and vertebrates. They are swamps etc. productive habitats and may support coastal Mangroves are particular ecosystems fisheries for prawns and fishes (Manson et developed along estuarine sea coasts and al., 2005). Some animals found within river mouths in tropical and subtropical mangrove environments are vulnerable or regions of the world, mainly in the intertidal threatened as a result of human activities in zone. Hence, the ecosystem and its the coastal zone. Worldwide, about 30% of biological components are under the all commercial fish species are mangrove- influence of both marine and freshwater dependent (Naylor et al., 2000). Mangroves conditions. This has led to the grouping of a are the breeding and nursery grounds for a wide array of plant and animal species of number of marine organisms including the special adaptations suited to the ecosystem. commercially important shrimp, crab, shell It acts as an ecotone between terrestrial and fishes and many fishes (Satheesh kumar, estuarine ecosystems. The ecosystem is also 2012). considered as most productive and Total area of mangroves in India is about biodiverse providing significant functions in 4461km2, constituting 0.41% of countries the coastal zones as buffer against erosion, geographical area (Jagtap et al., 2002). The storm surge and tsunamis. Mangroves are mangrove vegetation of Kerala covers an known as “kandal kadu” in Malayalam. In area of about 17 sq km spreading the entire lndia mangroves occur along both the backwater systems, lagoons and some of the Western and Eastern coasts. In Kerala intertidal areas different districts. mangroves are distributed in all the districts Mangroves are unique habitats which except Idukki, Pathanamthitta, Palakkad and function as nursery ground for several Wayanad. Mangroves provide excellent valuable species of finfishes and shellfishes habitat for migratory birds, serve as and they play a critical role in supporting breeding ground for many species of fishes marine food chains, protecting coastal areas and prawns helps in controlling pollution, and in improving water quality. Mangrove rutting of husks etc. ecosystems are productive wetlands found in Mangrove roots become home to tropical and subtropical regions which terrestrial as well as marine plants, algae, provide suitable shelter for both marine and SCIENCE CHRONICLE - A peer reviewed multidisciplinary science journal Vol .8 No.1&2 (2019) 32 RESEARCH ARTICLE ISSN: 2319-6955 terrestrial organisms. India. The mangrove ecosystem is a part of Mangrove ecosystem has the highest level of Kayamkulam estuary (lat. 9° 07’ - 9° 16’ N productivity among natural ecosystems, and and long. 76° 20’ - 76° 28’ E), which is a performs several ecosystem services. The narrow stretch of tropical backwater on the continued exploitation of mangroves west coast of Peninsular India. The worldwide has led to habitat loss, changes in mangrove vegetation at Ayiramthengu is species composition, loss of biodiversity and formed as outer edge in the sheltered regions shifts in dominance and survival ability. of the estuary. This area lies in the Alappad Worldwide, about half of the mangroves panchayat of Kollam district, Kerala. The have been destroyed. The increase in the protected area of Ayiramthengu has a total biotic pressure on mangroves in India has area of 55 acres. There is a brackish water been mainly due to land use changes and on fish farm adjacent to the estuarine tract. At account of multiple uses such as for fodder, present, the mangrove area is under the fuel wood, fibre, timber, alcohol, paper, control of Fisheries Resource Management charcoal and medicine. Along the west coast Society (sponsored by Department of alone, almost 40% of the mangrove area has Fisheries, Gov. of Kerala). The present been converted to agriculture and urban study was conducted from March 2015 to development. Our understanding of the March 2017. natural processes in this vulnerable and Collection of samples fragile ecosystem is far from adequate. The The specimens for the present study were present study is an attempt to expose the collected from the Ayiramthengu mangrove status of megafaunal diversity in ecosystem during every month. Arthropods Ayiramthengu mangrove ecosystems and molluscs from the mangrove areas were Kollam District of Kerala and also to study collected and procured from local fisherman the taxonomy of collected specimens. for the present study. The species-level MATERIALS AND METHODS identification will be done using books, Study site monographs, reprints, CD ROMs available The Ayiramthengu mangrove (lat. 9° on respective groups. Fishes were collected 02’ - 9° 16’ N and long. 76° 20’ - 76° 32’ E) by using cast nets and hand nets from the is situated in Kollam district of Kerala, mangrove areas. Some fishes were procured SCIENCE CHRONICLE - A peer reviewed multidisciplinary science journal Vol .8 No.1&2 (2019) 33 RESEARCH ARTICLE ISSN: 2319-6955 from the fisherman. Identification of fish (1984) and Jayaram (1999). The species- fauna in the study area was carried out by level identification will be done using following Day (1978), FAO species books, monographs, reprints, CD identification sheets for fishery purposes ROMs available on respective groups. RESULT AND DISCUSSION 1. FISH DIVERSITY Table 1: Classified List of Fishes in Ayiramthengu mangrove ecosystem Sl. Fish Species Family Order Class No. 1 Puntius carnaticus Cyprinidae Cypriniformes Actinopterygii 2 Puntius sarana Cyprinidae Cypriniformes Actinopterygii 3 Aplocheilus Aplocheilidae Cyprinodontiformes Actinopterygii lineatus(Valenciennes,1846) 4 Mugil cephalus Linnaeus,1758 Mugilidae Mugiliformes Actinopterygii 5 Valamugil cunnessius Mugilidae Mugiliformes Actinopterygii 6 Xenentodon cancilla (Hamilton, 1822) Belonidae Beloniformes Actinopterygii 7 Arius tenuispinis Ariidae Siluriformes Actinopterygii 8 Heteropnesteus fossilis(Bloch, 1794) Heteropneustidae Siluriformes Actinopterygii 9 Clarius betrachus Clariidae Siluriformes Actinopterygii 10 Mystus gulio(Hamilton, 1822) Bagridae Siluriformes Actinopterygii 11 Wallago attu(Bloch &Schneider,1801) Siluridae Siluriformes Actinopterygii 12 Secutor bindus Leiognathidae Perciformes Actinopterygii 13 Ambassis commersoni Ambassidae Perciformes Actinopterygii 14 Carangoides malabaricus(Bloch Carangidae Perciformes Actinopterygii &Schneider,1801) 15 Gnathanodon speciosus Carangidae Perciformes Actinopterygii 16 Gerres filamentosus Gerreidae Perciformes Actinopterygii 17 Etroplus maculates(Bloch, 1795) Cichlidae Perciformes Actinopterygii 18 Etroplus suratensis(Bloch, 1790) Cichlidae Perciformes Actinopterygii 19 Oreochromis mossambicus Cichlidae Perciformes Actinopterygii 20 Scatophagus argus(Linnaeus, 1766) Scatophagidae Perciformes Actinopterygii 21 Anabas testudineus(Bloch, 1792) Anabantidae Perciformes Actinopterygii 22 Channa striatus(Bloch, 1793) Channidae Perciformes Actinopterygii 23 Lagocephalus inermis Tetraodontidae Tetraodontiformes Actinopterygii SCIENCE CHRONICLE - A peer reviewed multidisciplinary science journal Vol .8 No.1&2 (2019) 34 RESEARCH ARTICLE ISSN: 2319-6955 Table : 2 Classified List of Arthropods &