Zoogeography of Indian freshwater fishes
The geographical distribution of 89 genera of primary freshwater fishes of India is discussed. It is shown that the fish fauna comprises three components: Indian, Indo-Chinese and Malayan, with indigenous Gondwana elements and intrusive genera. The Indo-Chinese element is dominant, whereas the Malayan element is comparatively poor. The original peninsular fauna is found as relicts in isolated hill tops where suitable ecological niches are found. There were faunal transgressions from the eastvia the Assam gateway and also from the west. The biogeography of the peninsula and the distribution patterns of the various genera are discussed. It is surmised that a major part of the fauna may have had an origin in the Indo-Chinese amphitheatre radiating and intruding in all directions. A list of the 89 fish genera is also appended.