title: Diminished foraging performance of a mutant zebrafish with reduced population of ultraviolet cones.
abstract: Ultraviolet (UV) cones are photoreceptors that sense light in the range 300-450 nm and are found in the retinas of non-mammalian vertebrates and small mammals. Despite their widespread presence across taxa, the functions that these cones exert in the lives of animals remain largely unknown. In this study, I used the zebrafish lor (lots of rods) mutant, characterized by a diminished UV cone population compared to that of wild-type zebrafish, to test whether its foraging performance differed from that of the wild-type (control). The mean location distance and angle (variables that are reliable indicators of foraging performance) at which control fish detected zooplankton prey were, on average, 24 and 90% greater than corresponding measures for lor fish. Such inferior foraging performance of the mutant could be explained by reduced contrast perception of the prey, resulting from the diminished population of UV cones and associated sensitivity. Thus, UV cones enhance the foraging performance of zebrafish, a crucial ecological function that may explain why small zooplanktivorous fishes retain UV cones throughout their lives.
authors.affiliation: Department of Biological Sciences, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia, Canada V5A 1S6 Department of Biology, University of Victoria, PO Box 1700, Station CSC, Victoria, British Columbia, Canada V8W 2Y2 inigo@sfu.ca.
authors.forename: Iñigo
authors.initials: I
authors.lastname: Novales Flamarique
mesh_terms: D000818:Animals; D005247:Feeding Behavior; D009154:Mutation; D017949:Retinal Cone Photoreceptor Cells / Q000502:physiology*; D014466:Ultraviolet Rays; D014796:Visual Perception; D015027:Zebrafish / Q000235:genetics / Q000502:physiology*
keywords: foraging; retina; ultraviolet cone; zebrafish