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 hypophy sectomized) common carp (Cyprinus carpio) held at 35C 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.