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 , 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 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 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 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 Actinopterygii 13 Ambassis commersoni Ambassidae Perciformes Actinopterygii 14 Carangoides malabaricus(Bloch Carangidae Perciformes Actinopterygii &Schneider,1801) 15 Gnathanodon speciosus Carangidae Perciformes Actinopterygii 16 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 & Molluscs in Ayiramthengu mangrove ecosystem Sl Species Family Order Class No PRAWNS 1 Penaeidae Decapoda Crustacea Penaeus indicus (H.Milne- Edwards 1837) 2 Penaeidae Decapoda Crustacea Metapenaeus dobsoni (Miers, 1878) 3 Metapenaeus affinis (H.Milne- Edwards 1837) Penaeidae Decapoda Crustacea

CRABS

1 Portunidae Decapoda Crustacea Portunus pelagicus (Linnaeus ) Infraorder: Brachyura

2 Portunidae Decapoda Crustacea Portunus sanguinolentus Herbst Infraorder:

Brachyura 3 Portunidae Decapoda Crustacea Scylla serrata (Forskal) Infraorder:

Brachyura 4 Ocypodidae Decapoda Crustacea Uca dussumieri (H.Milne- Edwards ) Infraorder: Brachyura MOLLUSCA 1 Cerithiidae Gastropoda Cerithihum sp. 2 Veneridae Bivalvia Meretrix sp.

Twenty three species of fishes belonging to crabs were common in the Ayiramthengu 18 families and 7 orders were collected mangroves. (Table 1). Of the 18 families, Cichlidae has Of the 23 species recorded, many the highest representation with 3 species species are commercially important as per followed by Cyprinidae, Carangidae and FAO, (1984) and Fish Base, (2003) (Table Mugilidae with 2 species each. The 3). The fish fauna of Ayiramthengu can be remaining 15 families were represented each classified into residents and migrants. The by a single species. Three prawn species resident species is the one which is (Penaeus indicus, Metapenaeus dobsoni, represented by some or all the size groups Metapenaeus affinis) and four species of during all the months of the year. The

SCIENCE CHRONICLE - A peer reviewed multidisciplinary science journal Vol .8 No.1&2 (2019) 35

RESEARCH ARTICLE ISSN: 2319-6955 migratory fishes enter and remain in the adapted to tolerate wide range of salinity estuary for short durations only. Migratory fluctuations. These groups of fishes fishes in Ayiramthengu are two types’ constitute the major stock of permanent marine and freshwater forms. Resident estuarine fishery resources and were present fishes were purely estuarine. Estuarine throughout the year. In the fish fauna fishes constituted the majority of fishes majority used as food fishes and some are living in the mangrove area. These fishes ornamental fishes. were mostly with marine affinities, were Table 3 : Characteristics Of Fishes Collected In Ayiramthengu Mangrove Ecosystem

Sl.No Scientific name Habitat Importance

1 Arius tenuispinis M, E C 2 Lagocephalus inermis M, E O 3 Etroplus maculatus E, FW O, LC 4 Etroplus suratensis E,FW O,C 5 Oreochromis mossambicus E,FW C,O 6 Scatophagus argus M, E O 7 Puntius carnaticus E,FW O,C 8 Puntius sarana E,FW O,C 9 Aplocheilus lineatus M, E O 10 Mugil cephalus M, E, FW C 11 Valamugil cunnessius M, E , FW C 12 Anabas testudineus E,FW LC 13 Channa striatus FW C 14 Xenentodon cancilla M,E C 15 Heteropnesteus fossilis FW C 16 Clarius betrachus FW C 17 Mystus gulio E, LC 18 Wallago attu E C 19 Secutor bindus M, E C 20 Ambassis commersoni M, E C 21 Carangoides malabaricus M, C 22 Gnathanodon speciosus M, E C 23 Gerres filamentosus M, E LC

M – Marine, E – Estuarine, FW – Freshwater, C – Commercial, O – Ornamental, LC – Less Commercial Importance

SCIENCE CHRONICLE - A peer reviewed multidisciplinary science journal Vol .8 No.1&2 (2019) 36

RESEARCH ARTICLE ISSN: 2319-6955

Like all other mangroves of Kerala, mangrove ecosystem showed migration rest Ayiramthengu mangrove is also known for of them was permanent residents. Migratory its rich flora and fauna. The rich and forms included marine and freshwater diversified life of this ecosystem is due to forms. Large number of juveniles of fishes high energy production capacity of was present throughout the mangrove area mangroves especially towards estuarine and (Resmi Vijayan, 2004). A study conducted marine fertility (Macnae, 1974). by Jisha. et al. (2004) at Ayiramthengu Visually the density of the fingerlings mangroves, Kollam district, Kerala, revealed or schooling of juvenile population in the the presence of 27 species of fishes mangrove waters is comparatively more belonging to 17 families. It is true that the than open waters. 16 species of fishes mangroves serve as ‘nature’s nursery’ for a occurring in the Asramam mangroves of variety of marine fishes and other animals of Kollam were reported by Mohandas (1993). food value to man. Many saline fishes are From Ayiramthengu mangroves 21 species believed to migrate to the mangroves, where of economically important fin fishes and they swarm their fingerlings and young their juveniles, 6 species of crabs, 3 species ones. It is generally argued that the of prawns, 3 species of molluscans, 3 mangroves are safer sites for the young species of birds and 1 species of semi ones, due to their intricately ramifying prop aquatic mammal were observed. The fish roots and the thousands of erect standing fauna in this mangrove ecosystem belonged breathing roots, which provides excellent to 4 orders such as Perciforrnes (18 species), shelter and protection from larger predators Pleuronectiformes (1 species), of the fishes and other fauna. Mangroves Gonorhychiformes (1 species) and have a rich and diverse assemblage of fish, Siluriformes (1 Species) (Resmi Vijayan, some with commercial value. Other fish 2004). The present study also revealed the species are important links in the mangrove presence of 23 species of fishes from the food web. Still others are only temporary same area. Fish fauna can be classified into residents that spend most of their life history residents and migrants. The migratory fishes elsewhere. In Ayiramthengu it was common enter and remain in the estuary for short to find large numbers of larvae and juvenile durations according to their salinity fish in net samples from mangrove area. tolerance. Fifteen species of finfishes in this The prawns, crabs and molluscs are also

SCIENCE CHRONICLE - A peer reviewed multidisciplinary science journal Vol .8 No.1&2 (2019) 37

RESEARCH ARTICLE ISSN: 2319-6955

abundant in this area. The present study also REFERENCES documented 3 species of prawns, 4 species  Day, F.1978. The Flshes of India (1 of crabs and two species of molluscs during and 2). Bertrand Quaritch, London.530 Pp. the study period(Table. 2). This may be due  FAO. 1984. Species Identification to the presence of high detritus in the water Sheets for Fishery Purposes. Western Indian in mangrove system and also due to the Ocean Fishing Area 51 (W. Fischer and G. meshwork of the root system of the Gianchi, Eds.). Food and Agricultural mangroves which provide a good nursery Organization of the United Nations. 105 Pp. ground for the growing organisms.  Fish Base .2003. World Wide Web Distribution of the juveniles within the electronic publication (R. Froese and D. mangrove is strongly influenced by salinity. Pauly, Eds.). http://www.fishbase.org, Among mangrove fauna, the crustaceans version 21 November 2003. specially the crabs, have shown greatest  Jagtap, T. G., Murthy, P and specialisations in relation to feeding, Komerpant, D. 2002. Mangrove respiration and vision. ecosystems of India: major biotic Human induced stresses such as constituents conservation and management, felling of mangrove trees for fuel, timber, In: Wetland conservation and management, poles, firewood and fishing and collection of Hosetti. B.B (Ed.), Pointer publishers, fish and prawn seeds, pollution etc. will lead Jaipur, India. 34-64 Pp. to the destruction of this productive  Jayaram, K.C. 1999. The mangrove forest. Many species collected freshwater fishes of the Indian region. 551 from this mangrove area are juveniles of pp. commercially important species. From this it  Jisha S., C.M. Aravindan and S.D. is very clear that these mangrove areas are Ritakumari. 2004. Checklist of fish fauna the breeding grounds of these organisms. of Ayiramthengu mangroves, Kollam Hence it is essential to take necessary district, Kerala, India. Seshaiyana .12 :2 . activities to aware the local population about  Mac Nae, W. 1974. Mangrove forest the need and significance of conserving and fisheries. FAO/UNDP Indian Ocean these ecosystems. Programme (Indian Ocean Fisheries commission) IOCF/ DEV/ 74/34, Rome.

 Manson, F.J., Loneragan, N.R.,

SCIENCE CHRONICLE - A peer reviewed multidisciplinary science journal Vol .8 No.1&2 (2019) 38

RESEARCH ARTICLE ISSN: 2319-6955

Skilleter, G.A., Phinn, S.R. 2005. An evaluation of the evidence for linkages between mangroves and fisheries: a synthesis of the literature and identification of research directions. Oceanogr. Mar. Biol. Annu. Rev., 43: 483–513.  Mohandas, A.1993. A comparative study of the Mangrove ecosystem in Kumarakom with that of Quilon to assess the man made changes. Ph.D thesis, University of Kerala. 300 Pp.  Naylor, R.L., Goldburg, R.J., Primavera, J.H., Kautsky, N., Beveridge, M.C.M., Clay, J., Folke, C., Lubchenco, J., Moony, H., Troell, M. 2000. Effect of aquaculture on world fish supplies. Nature. 405: 1017–1024.  Resmi Vijayan.2004. Certain aspects of the ecology of a mangrove ecosystem in Ayiramthengu. Ph. D. Thesis, MG University.250pp.  Satheeshkumar P. 2012. Mangrove vegetation and community structure of brachyuran crabs as ecological indicators of Pondicherry coast, South east coast of India. Iranian Journal of Fisheries Sciences .11(1) 184-203.

SCIENCE CHRONICLE - A peer reviewed multidisciplinary science journal Vol .8 No.1&2 (2019) 39