Ultraviolet sensitivity in the torus semicircularis of juvenile rainbow trout (Oncorhynchus mykiss).
The spectral sensitivity of single units in the torus semicircularis (TS) of small (< 30 g) and large (> 60 g) juvenile rainbow trout, Oncorhynchus mykiss, was investigated. All examined units (n = 39) showed inputs from the long and medium cone mechanisms. In addition, a majority of units (28 of 39) in both size groups of fish had inputs from the UV cone mechanism, and both groups had several types of color-coded units. The TS of large trout differed from small fish by having a significantly higher proportion of luminance or non-color-coded units relative to color-coded units. Additionally, large fish had a reduced number of UV-sensitive units and an increased number of short-wavelength-sensitive units relative to small fish.
University of Victoria, Department of Biology, British Columbia, Canada.
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DJ
Coughlin
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Hawryshyn
D000818:Animals; D003118:Color Perception / Q000502:physiology; D005074:Evoked Potentials, Visual / Q000502:physiology; D008636:Mesencephalon / Q000502:physiology*; D017686:Oncorhynchus mykiss / Q000502:physiology*; D012160:Retina / Q000502:physiology; D017949:Retinal Cone Photoreceptor Cells / Q000502:physiology; D012684:Sensory Thresholds / Q000502:physiology; D013053:Spectrophotometry; D014466:Ultraviolet Rays