New species of Bathydrilus Cook (Oligochaeta; Tubificidae) from British Columbia

Abstract

Bathydrilus litoreus n. sp., from intertidal habitats of British Columbia and Washington, is distinguished from other members of the genus by the combination of possessing histologically bipartite atria, atrial ducts, bilobed glandular sacs about the penial setae, patches of glandular epithelium between the dorsal setal bundles, and thickened epidermal pads ventrally in X. Bathydrilus torosus n. sp., from the intertidal of southwest Vancouver Island, is the only known shallow-water species of Bathydrilus to lack modified penial setae; it lacks dorsal patches of glandular epithelium and thickened epidermal pads ventrally in X but does possess atrial ducts and histologically bipartite, very muscular atria. Both B. litoreus and B. torosus lack copulatory sacs and pseudopenes. These are the first species of the genus to be described from the Northeast Pacific.