CURRENT PRACTICES IN AQUATIC ANIMAL SUPPLEMENTATION

Abstract

Aquatic animals have been managed under human care for centuries. Limitations in the variety of foods available to feed to these animals, as well as the use of frozen fish products in current dietary protocols makes supplementation of some nutrients necessary.  Limited research has been performed related to species specific requirements for vitamins or minerals and there are few standardized recommendations for these species other than for thiamin and vitamin E, for which recommendations are based on deficiencies created under controlled situations in pinnipeds.  In recent years, advances have been made in the way fish are caught, processed, stored, thawed and fed to animals. Additionally many facilities analyze their feeder fish items for caloric content and base their diets on calories consumed instead of strictly on an as fed weight basis. However, vitamin supplementation practices often have not been modified to reflect these changes. Finally, more recent nutritional concerns have arisen; many facilities have experienced cases of iron storage disease in both pinniped and cetacean species and vitamin C supplementation may contribute to this pathology by enhancing the absorption of dietary iron. An Aquatic Animal Nutritional Survey was distributed to zoos and aquariums worldwide focusing on marine mammals, penguins and sharks.  Results were returned from over 70 facilities. The range of supplements being fed to aquatic animals is significant and much of the variation is due to the manner in which supplements are being dosed. Although over-supplementation of water soluble vitamins may be tolerated by these species, over-supplementation of some fat soluble vitamins is potentially harmful. These data can inform and be used to improve feeding practices of aquatic animals.