What struck the Slavs in the fish?

СomSlav and Protoslav *ryba has no generally accepted etymological explanation. Among existing hypotheses, that of Pogodin / Uhlenbeck seems to be the most convincing. They suggested a genetic identity of Slav. *ryba with Deutsch Raupe ‘shaggy caterpillar’ (< I.-Eur. *rūb(h)- ‘dig, tear’), but gave no explanation for it. The present article substantiates this hypothesis by proposing a motivation for Slav.*ryba, a derivative from from I-Eur. *rūb(h)- ‘dig, tear’, based on the scaly quality of the animal’s tegument, cf. *rytyi ‘with pockmarks’.