A Study on Some Ecological Aspects of Snow Trout (Schizothorax pelzami) from Laiinsoo River in Northeastern Iran

Samples of Schizothorax pelzami were collected by electroshocker from Laiinsoo River (n=150) in northeastern Iran in January 1995. The growth and diets rates of S.pelzami were examined. For 30 specimens in Laiinsoo River, the length-weight relationships were estimated as W= -12.108 × L3.134 (r =0.999) for females and W= -10.594 × L2.796 (r = 0.849) for males. Stomach contents were examined to determine the kind, number, and volume of organisms present. Classification of the stomach contents of individual fish in Laiinsoo River revealed different groups of benthic invertebrates. Chironomidae, were the most abundant benthic invertebrates among the categories of organisms collected. The Ivelev index showed that odonata, at 1; Chironomidae (Larva), at 0.6, and Simulidae (larva), at 0.5, were the most important food items for S. pelzami. The ratio of male to female for specimens caught from Laiinsoo River was 2.5:1.