Utilization of polychaete tubes as spawning substrate by the sea raven Hemitripterus villosus (Scorpaeniformes)

Abstract

The sea raven, Hemitripterus villosus, deposits its eggs on polychaete tubes (Salmacina sp.) in the coastal waters of Usujiri, southern Hokkaido, Japan. This is contradictory to investigations in the Bay of Peter the Great, Soviet Union, where eggs are deposited in narrow clefts. The egg masses are found among the bunchy worm tubes or between the base of the colony and the substrate. The spawning habit of H. villosus is distinct from ‘spawner in live invertebrates’ such as the little dragon sculpin Blepsias cirrhosus, which specifically associates with a sponge. That of H. villosus is classified as a ‘cavity spawner’.