Force-Feeding Fish under Experimental Conditions

Abstract

IT is a common experience in aquarium management that fish in captivity vary greatly in the readiness with which they will accept food, and there is no doubt that the refractory species feed less readily after surgical operation. Surgery also lowers the general resistance of the subject, and the effects of inanition are more drastic. Over the past six years we have carried out thyroidectomies, and partial and total hypophysectomies on several hundred dogfish, and in the initial experiments, in which food was merely placed in the aquarium tanks, we experienced poor post-operative survival, usually of the order of 4 weeks and in no case exceeding 8 weeks. A review of the relevant literature showed this to be the experience of all previous workers with the exception of Matty¹, who thyroidectomized Scyliorhinus caniculus and reported that all the operated fish began to feed on strips of fresh squid muscle within a few days of the operation. He obtained post-operative survival times of “at least seventy-two days”.