Visual pigments of African cichlid fishes: evidence for ultraviolet visionfrom microspectrophotometry and DNA sequences

We have found evidence for ultraviolet visual capabilities in a Lake Malawi cichlid fish, Metriaclima zebra. Microspectrophotometry of single cones re vealed a visual pigment with peak sensitivity at 368 +/- 3 nm. M. zebra als o expresses a putative ultraviolet opsin gene whose sequence is closely rel ated to the SWS-1 opsin for other fishes. Several other African cichlids ha ve a functional copy of this UV gene in their genomic DNA, but do not appea r to express this gene as adults. These results suggest that ultraviolet vi sion is important for some cichlid fishes. UV wavelengths should therefore be included in future studies of cichlid vision, behavior and color pattern s. (C) 2000 Elsevier Science Ltd. All rights reserved.