Host Specificity, Settling, and Metamorphosis of the Two-tentacled Hydroid Proboscidactyla flavicirrata

Abstract

The colonial hydroid Proboscidactyla has been found only on the leathery tubes of marine sabellid worms (Uch ida and Okuda, 1941:433 ; Hand, 1954; Brinckmann and Vannucci, 1965: 367) . Nothing is known about the means by which this specific commensal association arises. In this paper I present observations on planula settling and metamorphosis, which indicate that larvae are caught in the tentacles of the sabellid worm and transferred to the rim of its tube.