To study anomaly among body components in the Mahisefid population situated in one of the spawning rivers, the abnormal fishes were sampled (n=10). Twenty six morphological properties were measured to be statistically (P<0.05) compared with normally caught fishes. The mentioned characters were standardized based on the total length. Eight ratios including standard length (SL), snout length (SNL), dorsal fin height (DFH), distance between pelvic fin to ventral fin (PV), distance between snout to anterior part of dorsal fin (PRB), distance between posterior part of dorsal fin to anterior part of caudal fin (POB), upper part of caudal fin length (UCFL) and mid part of caudal fin Length (CCFL) of abnormal fishes differed significantly (P<0.05) from those of healthy fishes. The morphological characters were classified at three components. Discriminant analysis showed the ratios of fork length and standard length were the significantly (P<0.05) variables to screen samples. Draining diverse pollutants and heavy metals to the receiving rivers, inbreeding and technical errors during propagation were the most important reasons threating the life cycle of Mahisefid populations.

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