Possible Mechanism for the Endocrine Control of Breeding in a Cirripede

Abstract

THE breeding of the barnacle Balanus balanoides (L.) is controlled by light and temperature; a temperature below a critical value of 10° C and a light periodicity of less than 12 h/day are necessary before the barnacle will breed 4–8 weeks later¹. As part of the cyclic activity of the oviducal glands during the natural breeding phase of B. balanoides 2–3 weeks before fertilization an elastic sac is formed within each gland² which envelops the eggs as they pass down the oviduct, forming a membrane binding the egg mass together.