Taxonomy and distribution of marine Enchytraeidae (Oligochaeta) in British Columbia

Abstract

Twenty-one species of marine enchytraeid oligochaetes within the genera Enchytraeus, Grania, Marionina, and Lumbricillus are confirmed as occurring on the Pacific Coast of Canada. Taxonomic reviews with redescriptions where necessary are provided for 48 species, bringing 13 into synonymy. A further three species were left as taxa inquirenda. Marionina is the least homogeneous of the genera, and further species revisions may change the present concept of the genus. Species habitat preference is largely intertidal, often with decomposing algae, but some subtidal species have been found. There appears to be a Pacific regional fauna.

Marine Oligochaeta of Jiaozhou Bay, Yellow Sea coast of China

“…The remaining species, Limnodriloides victoriensis, Enchytraeus kincaidi and Lumbricillus sp., are representatives of a northern, more exclusively temperate fauna in the Yellow Sea, the first two known also from the Northeast Pacific (Brinkhurst & Baker, 1979;Coates & Ellis, 1981), and E. kincaidi as well as several Lumbricillus species (one of which the present species is very likely to be) reported from the far east of the U.S.S.R. (Shurova, 1974(Shurova, , 1977(Shurova, , 1978(Shurova, , 1979.…”

“…International Code of Zoological Nomenclature). Enchytraeus saxicola, E. citrinus and E. metlakatlensis, the remaining three Enchytraeus species described from the North American west coast by Eisen (1904), were, however, regarded as indeterminable due to the lack of adequate types (Coates & Ellis, 1981). …”

In search ofMarionina(Clitellata, Enchytraeidae): A taxonomic history of the genus and re‐description of the type speciesPachydrilus georgianusMichaelsen, 1888

“…However, on account of the structural heterogeneity persisting in the taxon, they allowed broader limits to Marionina, such that delimitation of its species from those of other genera was made neither easier nor consistent. Suffice to say that since their revision, another 20 relocations of Marionina species have been proposed, involving as many as eight different enchytraeid genera (Lasserre 1966;Nurminen 1973;Coates & Ellis 1981;Coates 1983Coates , 1990Kasprzak 1986;Baroudi 1987;Rota 1995 In fact, no enchytraeid genus other than Marionina, as currently defined, admits variation in as many characters as the shape of the chaetae and their distribution along and around the body, the position of the head pore, shape of the brain, ganglionation of the ventral nerve cord, arrangement of the blood vessels, morphology and number of the pharyngeal glands and nephridia, shape of the testes and ovaries, structure and position of the penial bulbs, anatomy of the spermathecae and their connection to the gut (Xie & Rota 2001;Rota, personal observation).…”

“…For instance, a suprapharyngeal bifurcation of the dorsal blood vessel was only reported in nominal littoral species at the time of that cladistic analysis (Hesse 1893;Giere 1974;Coates & Ellis 1981;Coates 1989: p. 29), but eight non-marine species of Marionina are now known to possess this (homoplasious?) feature (Rota 1995;Xie & Rota 2001;Rota & Manconi 2004).…”

Taxonomy of North European Lumbricillus (Clitellata, Enchytraeidae)

“…One of the about 30 genera, Lumbricillus Ørsted, 1844, is primarily found in marine and freshwater habitats, but also in humid soils (Nielsen and Christensen 1959). It was established by Ørsted (1844), and Lumbricus lineatus Müller, 1774, the first enchytraeid ever described (Michaelsen 1889), was later regarded as its type species (Brinkhurst and Jamieson 1971; Coates and Ellis 1981). Ørsted (1842) had earlier referred Lumbricus lineatus to one of three groups constituting the “Lumbricillae”, and specifically to the group distinguished by having short, almost straight chaetae, “resembling stitching awls”, in both upper and lower bundles.…”