Ultraviolet sensitivity in the torus semicircularis of juvenile rainbow trout (Oncorhynchus mykiss) (original) (raw)

Tbe spectral sensitivity of single units in the torus semicircularis (TS) of small ( < 30 g) and large ( > 60 g) juvenile rainbow trout, Oncorirynclsus mykiss, was investigated. AU examined units (n = 39) showed inputs from the long and medim cone mechanisms. In addition, a majorlty of units (28 of 39) in both size groups of fish bad inputs from the W cone mttcbanism, and both groups had several types of color-coded units. The TS of large trout differed from small fish by having a significantly bigher pro~~on of luminance or non-color-coded units relative to color-coded units. A~tion~y, large fish had a reduced number of W-sensitive units and an increased number of sbort-wavelengtbsensitive units relative to small fish.