Conservation of Endemic Rain Forest Fishes of Sri Lanka: Results of a Translocation Experiment

Abstract: Four potentially endangered species of rainforest fishes, Barbus cumingi, Barbus nigrofasciatus, Barbus titteya, and Rasbora vaterofloris, endemic to streams of southwestern Sri Lanka, were translocated in 1981 into a depauperate stream system in the central hills. By 1985 all four species had established self-perpetuating populations in these streams, and had extended their ranges into adjacent stream Barbus nigrofasciatus, a generalist, was one of the most abundant species in these stream It was widely distributed throughout the stream system and in the slower sections of the Mabaveli Ganga (=Mabaveli River), and occupied a wide range of macro- and microhabitat types. The other three species were more specialized in their habitat and diet, and were thus patchily distributed. The microhabitats occupied by B. cumingi, B. titteya, and R. vaterifloris resembled the specialized microhabitats they occupy in their native stream Presumably because of their specializations, these three species were not as abundant as B. nigrofasciatus. Overall, the biology and distribution of the four species will enable them to survive spatially small-scale environmental perturbations The results suggest that trans locations are a feasible means of conserving other endemic fishes of Sri Lanka threatened with extinction. However, such translocations must be carefully planned with consideration for the indigenous community as well as the ecological requirements and genetic integrity of the target species.