Subterranean Fishes of the World

4770

1959

Cave Notes. Publication of Cave Research Associates

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The discovery of the blind cave fish almost 25 years ago 1n Aigamas Cave in South West Africa by the late K. P. Jordan and the sUbsequent description of the new form by E. Trewavas constituted the total scientific history of this fish until Dr. Jubb's recent paper (TREWAVAS, E. Dr. Karl Jordan's expedition to South West Africa and Angola. Novitates Zooloeicae. vol. 40, P. 70-71. 1936). Although the existence of the fish of Algamss Cave was known to the local people, it was not until Jubb had the opportunity to stUdy several specimens of ClaTis cavernlcola that attention was paid to the origin and natural history of the species. In his informative article he reviews the earlier knowledge of the fish and discusses his own observations. He found, for example, that the fish eat insect skeletons excreted by baboons that also inhabit the cave. Equally important however is the present distribution of the genus of closely related species now isolated in certain areas of the same karst. Jubb proposes that the catfish were formerly distributed throughout the region, but as the river went underground +t trapped these fishes in caves and sinks. One close ~elative, Claris duroerilll, lives 1n the nearby Cunene and Okauango rivers, while a third member of the complex is found isolated in the Wondergat, an open cave, and like C. c8vernicola shows tendencies to become cave-adapted. This integration of biological and geological findings is reminiscent of the work of Hubbs and Miller 1n relating Pleistocene/ Recent drainage and fish distributions in our own country (HUBBS, C.L. and R.R. MILLER. The Great Basin: II. The zoological evidence: Correlation between fish distribution and hydrographic history in the desert basin of western United States. Utah University Bulletin. vo L, 38, #20. p , 18-166. 1948). The history of the recent fish here and in Africa reflects the paleo-geographic situation. Certain outstanding examples such as the genus Claris demonstrate the value of these studies in measuring the rate of speciation in cave fish. R. Graham.

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