1Department of Zoology, Mar Thoma College Tiruvalla, Kerala, India
2Department of Zoology, Catholicate College, Pathanamthitta, Kerala, India
Applied Ecology and Environmental Sciences.
2022,
Vol. 10 No. 11, 691-701
DOI: 10.12691/aees-10-11-5
Copyright © 2022 Science and Education PublishingCite this paper: Cheriyan P. Letha, Oommen Manu. Fish Assemblage Pattern in Relation to Physico-Chemical Parameters of the Meenachil River, Southern Western Ghats, Kerala, India.
Applied Ecology and Environmental Sciences. 2022; 10(11):691-701. doi: 10.12691/aees-10-11-5.
Correspondence to: Cheriyan P. Letha, Department of Zoology, Mar Thoma College Tiruvalla, Kerala, India. Email:
lethapc@hotmail.comAbstract
Meenachil River originates from the biodiversity hotspot Western Ghats, home to varied and diverse fish fauna endemic to the region. The fish composition of the upper, middle and lower stretches of the Meenachil River was investigated from 2015 to 2019 to explore the fish assemblage patterns and the associated environmental factors. Thirty-nine species belonging to 20 families, 11 orders, and 31 genera were collected during the study. Order Cypriniformes ranked first with 16 species, followed by Siluriformes and Anabantiformes, each with five species. Three major assemblage patterns were differentiated in Meenachil River, the “mountainous species,” inhabiting the upstream, “piedmont species,” the midstream; and the “downstream species,” the lower stretches. Canonical Correspondence Analysis reflected altitude as the most significant factor influencing the assemblage pattern of fishes in the Meenachil River. Nemacheilus triangularis, Garra mullya, Barilius gatensis, Barilius bakeri and Haludaria fasciata, with a strong negative correlation to salinity, TDS, and conductivity, supported their partitioning and distribution restricted only to the high altitude areas of the river. Piedmont species positively correlated to dissolved oxygen levels were Mystus montanus, Rasbora daniconius, Devario aequipinnatus, Mastacembelus armatus and Salmostoma acinaces. Glossogobius giuris, Systomus sarana, Hyporamphus limbatus, Mystus gulio, Mystus oculatus, Etroplus suratensis, Parambassis dayi and Gerres setifer showed very strong positive correlations to salinity, TDS and conductivity were restricted to the downstream. Megalops cyprinoides is an anadromous species migrating between Vembanadu Lake and the lower stretches of the river. Etroplus maculatus, Parambassis thomassi, Aplocheilus lineatus, Dawkinsia filamentosa, and Xenentedon cancila have general distribution in the river not significantly influenced by any of the environmental parameters studied. Deviations from the existing structural pattern in fish assemblages can be used to assess the ecological status of the river and its fish fauna.
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