PHYSIOLOGICAL ABNORMALITY AND THE TISSUE VITAMIN-K LEVEL OF MUMMICHOGFUNDULUS-HETEROCLITUS FED WITH A VITAMIN-K FREE DIET

Mummichog Fundulus heteroclitus Linnaeus were reared during the spawni ng season with a vitamin K free diet for 11 weeks. Most of the male fi sh died during the experiment, while female fish seldom died. The mena quinone-4 (MK-4) content in the tissues markedly decreased during the experimental feeding. In contrast, none of the male or female fish (co ntrol fish) which were fed a diet supplemented with menadione sodium b isulfite (MSB) died. After 11 weeks, MK-4 was found to have accumulate d in various tissues of the control fish, especially in the gonadal ti ssue, except for the liver tissue. In the kidney tissue of the female fish fed a vitamin K free diet, a large number of immature erythrocyte s were observed. This suggests that the female fish had been affected by hematoporia and/or hematopoiesis brought about by a deficiency in v itamin K. However, larval mortality was not affected by the vitamin K deficiency. These results suggest that vitamin K intake is necessary f or mummichog, particularly for the male fish during the spawning seaso n even though they can continue to grow without any vitamin K suppleme nt.