The Effect of Fin–Clipping on the Cruising Speed of Goldfish and Coho Salmon Fry

Goldfish (Carassius auratus L.) and coho salmon fry (Oncorhynchus kisutch Walbaum) were acclimatized to temperatures of 20 °C. and 3 °C. respectively. The fish were placed, one at a time, once a day, for ten days, in a rotating annular chamber and the cruising speed was found. Then various fins were removed and the fish were given ten more trials. The mean cruising speeds before and after clipping were compared. The clipped fish suffered no loss in ability to swim at a constant rate. The data suggest that, for fish of a given weight and length, cruising speed is slightly improved by clipping. Any increased mortality in marked fish is due to loss of stability and control rather than loss in ability to swim steadily.