163 BIODIVERSITY STATUS OF FISHES INHABITING RIVERS OF KERALA (S. INDIA) WITH SPECIAL REFERENCE TO ENDEMISM, THREATS AND CONSERVATION MEASURES Kurup B.M. Radhakrishnan K.V. Manojkumar T.G. School of Industrial Fisheries, Cochin University of Science & Technology, Cochin 682 016, India E-mail:
[email protected] ABSTRACT The identification of 175 freshwater fish- es from 41 west flowing and 3 east flowing river systems of Kerala were confirmed. These can be grouped under 106 ornamental and 67 food fish- es. The biodiversity status of these fishes was assessed according to IUCN criteria. The results showed that populations of the majority of fish species showed drastic reduction over the past five decades. Thirty-three fish species were found to be endemic to the rivers of Kerala. The distributions of the species were found to vary within and between the river systems and some of the species exhibited a high degree of habitat specificity. The diversity and abundance of the species generally showed an inverse relationship with altitude. The serious threats faced by the freshwater fishes of Kerala are mostly in the form of human interventions and habitat alter- ations and conservation plans for the protection and preservation of the unique and rare fish bio- diversity of Kerala are also highlighted. 164 Biodiversity status of fishes inhabiting rivers of Kerala (S.India) INTRODUCTION river. Habitat diversity was given foremost importance during selection of locations within the river system. Kerala is a land of rivers which harbour a rich The sites for habitat inventory were selected based on and diversified fish fauna characterized by many rare channel pattern, channel confinement, gradient and and endemic fish species.