New species of heterodrilus (oligochaeta, tubificidae) and records of H. maiusculus from the mediterranean sea

Abstract

The exclusively marine genus Heterodrilus is common in sandy sediments, particularly in tropical and subtropical seas. In this paper, H. maiusculus, previously known only from Saudi Arabia, is recorded from Corsica and Italy, and it is shown to have bifid pe-nial chaetae, a trait confirmed also for paratypic and topotypic material of the species. Two new species are described: H. ursulae sp.n. and H. tripartitus sp.n., both from Italy. Heterodrilus ur-sulae has trifid anterior chaetae, short, characteristically bent and bipartite atria, and long spermathecal ducts; H. tripartitus has bifid anterior chaetae and spermathecae with distinct vestibules, the latter feature being unique within the genus. © 2001 Taylor & Francis Group, LLC.