Enhancement of Growth of Common Carp by Injection of a Homogenate of Carp Pituitary Glands

The growth rate of small (10-25 g), intact (i.e., not hypophysectomized) common carp (Cyprinus carpio) held at 35°C was enhanced by injections of pituitary material obtained from adult carp. Percentage increase over initial length and weight was dose-dependent by 4 weeks after the first injection. The dose-response curve for length increase due to the pituitary material was parallel to the curve demonstrated for injections of bovine growth hormone (bGH). The potency of bGH (determined in a previous study) was from 5.0 to 5.4 times greater per unit weight than the potency of the pituitary material. Condition factor of all fish increased slightly; the greatest increase was apparent among fish receiving the two lowest dosages and the least increase was noted among the control fish.