JFB jfb_12461 B Dispatch: June 19, 2014 Journal: JFB CE: Praveena Journal Name Manuscript No. Author Received: No of pages: 17 TS: suresh Journal of Fish Biology (2014) 0, 0–0 doi:10.1111/jfb.12461, available online at wileyonlinelibrary.com Imprint of monsoonal patterns on the ish assemblage in coastal waters of south-east India: a case study S. Biswas*, K. Jahir Hussain*, N. P. I. Das*, B. C. Russell† and K. K. Satpathy*‡ *Environment & Safety Division, Radiological Safety & Environmental Group, Electronics Instrumentation & Radiological Safety Group, Indira Gandhi Centre for Atomic Research, Kalpakkam, Tamil Nadu 603102, India and †Museum & Art Gallery of the Northern Territory, P. O. Box 4646 Darwin, NT 0801, Australia (Received 7 November 2013, Accepted 27 May 2014) The composition, species richness and diversity of a coastal ish assemblage from the Kalpakkam coast of south-east India are described along with temporal distribution patterns related to seasonal luctuations in dissolved oxygen, salinity, pH, chlorophyll-a, phytoplankton and zooplankton species richness and density. A total of 244 ish species belonging to 21 orders, 87 families and 163 genera were recorded. The ish assemblage was dominated by reef-associated species, followed by dem- ersal species. The majority of the species (63%) are widely distributed in the western Indo-Paciic as well as in the central Indo-Paciic. Jaccard’s coeficient analysis showed three distinct seasonal patterns of ish occurrence: pre-monsoon (PrM), monsoon (M) and post-monsoon (PoM). The max- imum number of species was during the PrM period, followed by the PoM and M periods. Species occurrence analysis showed Sardinella longiceps to be dominant during PrM and M periods, Leiog- nathus dussumieri during the M period and Secutor insidiator and Secutor ruconius during the M and PoM periods. Canonical correspondence analysis indicated that salinity and rainfall were the two most inluential environmental factors strongly correlated with temporal variation in the ish assem- blage. The physico-chemical conditions, in combination with factors such as higher food availability and shelter, might control the seasonal local distribution of the ichthyofauna in these Indian coastal waters. © 2014 The Fisheries Society of the British Isles Key words: environmental variables; ish community; Kalpakkam; seasonal effects; species composi- tion. INTRODUCTION Both seasonal variation of environmental factors and a suite of biological vari- ables inluence ish community composition in tropical regions where seasonal changes in climatic conditions inluence the hydrological variables, and have an impact on ish behaviour and species composition (Hossain et al., 2012). Amongst abiotic factors, water temperature (Allen, 1982; Szedlmayer & Able, 1996), pH (Nip & Wong, 2010; Mansor et al., 2012), salinity (Marais, 1982; Lalitham- bikadevi, 1993), dissolved oxygen (DO; Rakocinski et al., 1992; Fraser, 1997), ‡Author to whom correspondence should be addressed. Tel.: +91 4427480309; email: satpathy@igcar.gov.in 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 1 © 2014 The Fisheries Society of the British Isles