The larval development of polychaeta from the Northern California coast. II.Nothria Elegans(family Onuphidae)

Abstract

The larvae of Nothria elegans, an onuphid polychaete common in northern California were reared in the laboratory from artificial fertilizations. At a temperature of 17.5°C, larvae developed rapidly and settled 6 days after fertilization. Development in the plankton is lecithotrophic, with feeding delayed until just prior to settlement. Setal and branchial characteristics of juveniles are different from those of adult N. elegans and present difficulties in identification of small onuphids taken from benthic samples. It is concluded that developmental strategies in the Onuphidae are dominated by a dependency on yolk reserves. N. elegans and 2 other onuphid species recorded in the literature have lecithotrophic development, whereas 7 other species are reported to develop directly with no planktonic phase at all.