The angular distribution of the light produced by some mesopelagic fish in relation to their camouflage

Abstract

The angular distributions of luminescent light produced by two oceanic fish, Argyropelecus affinis and Chauliodus sloani , were measured in two vertical planes, one containing the antero-posterior axis of the fish and the other at right angles to this axis. These distributions of light were of the kind required to match, over a wide range of angles of viewing, the external daylight field in the ocean. These observations give strong support to the hypothesis that the function of many photophores is to give camouflage.