A review of the biospeleology of Meghalaya, India

This paper reviews the current state of knowledge of the biospeleology of the northeast Indian hill state Meghalaya. Since the early 1990s the Meghalayan Adventurers Association (based in Shillong), in partnership with European speleologists, has conducted a series of projects with the objective of mapping and documenting caves. To date over 320 km of cave passage have been mapped and much more remains to be discovered. The quantity and length of caves in Meghalaya exceeds that of any other known karst region of India. An exhaustive search of historical records yielded one highly detailed biological survey of a single cave in the west of the state and a few records of opportunistic specimen collection from caves at other locations. This data is supplemented by a review of numerous biological observations made during the Meghalayan Adventurers Association cave mapping program. Taxa with pronounced troglomorphic characteristics appear to be relatively common in the Jaintia Hills region of eastern Meghalaya and rare elsewhere in the state. In contrast, taxa with partial troglomorphy are widespread throughout Meghalaya. There is a range of taxa which occur regularly within caves and should be considered as significant components of the cave ecosystem regardless of troglomorphy. In some cases there is evidence of reproductive activity and opportunity for feeding which indicates that a proportion of the population complete their lifecycle within the caves and can be regarded as troglophiles. Sources of nutrition are primarily composed of flood borne debris, although dense colonies of bats (or cave-nesting swiftlets at some sites) can also contribute. The composition of cavernicole communities is not constant throughout the region and varies due to environmental and geographic factors. A major expansion of the limestone extraction industry is underway in the Jaintia Hills and elsewhere in Meghalaya. This will inevitably cause significant destruction and perturbation of cavernicole habitat. It would be prudent to implement formal studies to document the biospeleology of the region before significant loss or damage occurs.