Effects of Temperature on the Incidence of Scoliosis and Cataract in Chum Salmon Fry Caused by Tryptophan Deficiency

Abstract

So far, scoliosis caused by tryptophan (TRP) de- ficiency has been noted only in salmonids which are coldwater fishes, but not in warmwater fishes. This suggests that environmental temperature has some rela- tion to the incidence of scoliosis or that this is a parti cular phenomenon occurring only in salmonids. In this study, therefore, chum salmon fry were reared for 4 weeks on a TRP-deficient diet at three different water temperatures, and the incidence of scoliosis was com- pared among the three groups to confirm our assump- tions. At the same time, the cataract which is known to be one of the symptoms of tryptophan deficiency was also checked. The experimental conditions, experimental fish, tes diet and sampling methods for serotonin (5-HT) analysis were the same as reported previously.1)