Allocation of pyloric caecum reserves in FED and starved sea stars, Pisaster giganteus (Stimpson): somatic maintenance comes before reproduction

Abstract

Pyloric caeca were removed through the raytips of sea stars, Pisaster giganteus (Stimpson), beginning their seasonal period of gonad growth. Four months later their feeding rate, gonad growth, and gametogenic activity were lower than those of intact animals, while body growth rate remained the same. Removal of only the raytips also depressed feeding rate and gonad growth. When sea stars were starved, gonad growth and gametogenic activity were lower in animals without pyloric caeca, but body weight loss was the same as in intact animals. We conclude that when food is abundant, materials are utilized to enhance somatic and gonad growth. With decreasing reserves, due either to reduced food intake and/or pyloric caecum removal, somatic maintenance and growth have priority over gonad growth in material and energy allocation. Such a pattern of resource allocation is appropriate for long-lived iteroparous animals, such as these sea stars.