Research Items

Abstract

Origin of South American and African Freshwater Fishes WILLIAM A. GOSLINE (An. Acad. Brasil. Ciencias, 16, No. 3; 1944) criticizes some of the arguments advanced by biologists who have marshalled geological evidence to agree with their own interpretation of the biological data. While the author does not attempt to offer final conclusions concerning the African and South American freshwater fishes, he summarizes the evidence supplied by the best-known freshwater group, and suggests lines of further investigation. These are included under four heads. (1) The compilation of up-to-date revisions of the groups of fish involved, together with the presentation of phylogenies of these groups based on palæontological, anatomical and physiological data. These would show the relationship of the fishes between areas as compared with those within areas. (2) The demonstration from various sources of evidence that certain groups have originated and evolved in fresh water, and that salt water has always formed a complete barrier to their dispersal. (3) The determination, so far as is possible, of the geographical distribution—past and present—of these groups, together with their ecological limitations. (4) The correlation of all material from the above lines of investigation, special account being taken of the environmental needs affecting fish dispersal, with the derived data for other animal and plant groups and with geological and climatic history.