abstract

In zoos and aquariums the staple diet for most marine mammals is freshly thawed, previously frozen fish and squid. Feeding a variety of fish to captive piscivores can be a major challenge to institutions, due to cost and availability thereby making a readily available prepared fish analog-based diet very appealing. Past studies feeding the fish analog product (PMI Intl, St. Louis MO) to California sea lions and penguins have shown good acceptance of this product with no adverse effects. An increased gastrointestinal passage rate was observed when this product was the sole diet of bottlenose dolphins. Our study examines the effect of feeding 10-50% fish analog diet on beluga behavior and health.

Mystic Aquarium & Institute for Exploration currently houses three adult beluga whales whose health status is monitored closely via physical examinations, dietary records, hematology, gastric sampling, girth measurements and blubber thickness. In a seven month study the behavior of each animal was monitored daily and blood samples were collected twice monthly for hematological analysis. Each animal was used as its own control and all variables were compared during the feeding trial to pre- and post- study baseline values and/or to previous years' data from the same time period. All animals accepted the product immediately with no training required and feeding of this product did not appear to change animal behavior or health when increases in analog diet were administered gradually. Hematology changes noted during the course of the study were determined to be unassociated with administration of the fish-analog diet. We conclude that the fish analog product is an appropriate addition to beluga whale diets at the tested percentages.