Certain effects in the habits of schooling fishes, as based on the observation of Jenkinsia. American Museum novitates ; no. 382

Abstract

"1. Jenkinsia will not normally approach a dark, solid object closer than a certain distance, which is probably equal to its limit of visibility. 2. Schools of Jenkinsia, with their vacuities over and around solid objects, are interpreted in the mechanical terms of a positive mutual attraction of the fish for each other and a common negative reaction toward any other, generally dark, body. 3. It is possible that these effects might be reduced to different aspects of the same reaction. 4. Further study should throw light on the reactions of some pelagic fishes to larger objects in motion as well as the apparently 'intelligent' rounding up by larger fishes of schools, reducing them to purely mechanical performances which would be, nevertheless, useful"--P. 5.