Antarctic hydrographic fluctuation as suggested by animals that reach Ceylon

• Published in: Proceedings of the Royal Society of London. Series B. Biological Sciences
• Format: Article in Journal/Newspaper
• Language: English
• Published: The Royal Society 1960
• Subjects: Antarctic; Colombo; The Antarctic; Antarc*
• Online Access: http://dx.doi.org/10.1098/rspb.1960.0071; https://royalsocietypublishing.org/doi/pdf/10.1098/rspb.1960.0071

Various records of antarctic and southern cold temperate zone species entering the Ceylon area appear in the Colombo Museum bulletin Spolia Zeylanica , in the check list of the birds of Ceylon, and in the administration reports of the Marine Biologist of Ceylon. A study of these data reveals that fluctuating hydrographic conditions of the antarctic and southern cold temperate zone might be responsible for the periodic advent into Ceylon and its seas of the animals from the above-mentioned zones. They might also exert a direct influence upon the decrease or increase of various marine animals of economic importance and affect meteorological conditions which in turn exert their influence both on the land and its fauna and flora. The following data are now set down for consideration: (1) The pearl oyster Perlamater vulgaris appears in fishable numbers for one, two or three years then dies off and almost becomes extinct for 6 to 20 year periods before again appearing in large numbers. (2) Fishes such as the Mako shark, the sunfishes Mola mola and Ranzania laevis and the swordfish Xiphias gladius are seasonal in their appearance and are rarely captured (Deraniyagala 1936).