A NOTE ON THE OCCURRENCE OF NON-STYGOBITIC FISHES IN A CAVE IN ANDHRA PRADESH, PENINSULAR INDIA

摘要

What with its vast territory, ancient and varied geomorphology, hydrology, and climate, the Indian subterranean domain has given rise to numerous natural caves and cavities of varied shapes and sizes. A small tract such as the Tungabhadra River Valleyin Andhra Pradesh alone has more than one hundred caves (Prasad 1996). Generally characterized by perpetual darkness, low energy input and remarkable constancy of temperature and humidity, caves are inhabited by highly diversified organisms, ranging from protozoans to mammals besides bacteria and fungi. The typical cave/groundwater dwellers have originated from their extinct/extant epigean ancestors of marine, freshwater or terrestrial habitats at different times and in different ways. Hence, the subterranean realm (stygon) has come to be regarded as a promising place to look for insights into biological adaptation and speciation (Rouch 1986). That the Indian caves harbour rich biodiversity can be gauged by the fact that a recent preliminary study ofjust a single collection from the sandy bottom of a cave (Kotumsar Cave) has led to the discovery of three new taxonomically and biogeographically significant stygobitic crustacean taxa, together with a new amphipod family (Ranga Reddy 2006; Messouli etal. 2007; Ranga Reddy and Defaye 2009). Nevertheless, groundwater biology as a whole has received scant attention in India (Ranga Reddy 2002, 2004).