Use of Artificially Liberated Larvæ in Experiments on the Setting Behaviour of Spirorbis

Abstract

DURING a study of the systematics of the Spirorbinae (Serpulidae), it became clear that several forms are found characteristically on specific substrata. Whereas Spirorbis borealis Daudin occurs most abundantly on the brown alga Fucus serratus, Spirorbis tridentatus Levinsen (usually regarded as an ecophenotype of Spirorbis borealis ¹) is found only on stones and shells in dimly lit places. Another closely related form, which appears to be a distinct species previously confused with juvenile S. borealis, has been found in the Swansea area only upon the red alga Corallina officinalis. Evidently it was desirable to find by experiment whether the larvæ of these forms choose their characteristic substrata.