Abstract
Eclipidrilus pacificus n. sp., from northwestern USA, is distinguished from other Eclipidrilus by having a single atrium with midventral male pore, small penis, prostomium without a proboscis, and non-spiraling atrial musculature. Most populations also differ from congeners in having paired spermathecal pores anterior to the ventral chaetae, but specimens from the Columbia River have variable number and placement of the spermathecae. An unusual spiral orientation of the atrial musculature has previously been used to define Eclipidrilus. However, orientation of the atrial muscle layers varies among the previously described species, and does not provide a distinctive synapomorphy for the genus as a whole. Consequently, the genus is redefined to include species having elongate-petiolate atria with an inner, near-transverse muscle layer and an outer, longitudinal to spiral muscle layer.References
Boveri-Boner, Y. (1920) Beiträge zur vergleichenden Anatomie der Nephridien niederer Oligochäten. Universität Zürich, Gustav Fischer, Jena, 52 pp.
Brinkhurst, R.O. (1989) A phylogenetic analysis of the Lumbriculidae (Annelida, Oligochaeta). Canadian Journal of Zoology, 67, 2731–2739.
Brinkhurst, R.O. (1991) Ancestors. Mitteilungen aus dem Hamburgischen Zoologischen Museum und Institut, 88, 97–110.
Brinkhurst, R.O. (1998) On the genus Eclipidrilus Eisen, 1881 (Lumbriculidae, Clitellata), including a description of Eclipidrilus ithys sp. nov. Canadian Journal of Zoology, 76, 644–659.
Chekanovskaya, O.V. (1962) Aquatic Oligochaeta of the USSR, Akademiya Nauk SSSR Publishers, Moscow, Leningrad. English Translation 1981. Amerind Publishing Co. Pvt. Ltd, New Delhi. 513 pp.
Collado, R., Martinez-Ansemil, E. & Giani, N. (1993) Les Oligochètes aquatiques de la Péninsule Ibérique: description de Stylodrilus curvithecus n. sp. (Lumbriculidae) et de Mesenchytraeus lusitanicus n. sp. et redescription de Cognettia hibernica Healy (Enchytraeidae). Annales de Limnologie, 29(2), 129–138.
Cook, D.G. (1966) In Studies on North American aquatic Oligochaeta. III. Lumbriculidae and additional notes and records of other families. R.O. Brinkhurst and D.G. Cook. Proceedings of the Academy of Natural Sciences of Philadelphia, 118, 1–33.
Cook, D.G. (1967) Studies on the Lumbriculidae (Oligochaeta) in Britain. Journal of Zoology (London), 153, 353–368.
Cook, D.G. (1971) Family Lumbriculidae. In: Brinkhurst R.O. & Jamieson B.G.M. Aquatic Oligochaeta of the World, Oliver and Boyd, Edinburgh, 200–285.
Cook, D.G. (1975) Cave-dwelling aquatic Oligochaeta (Annelida) from the eastern United States. Transactions of the American Microscopical Society, 91(1), 24–37.
Eisen, G. (1881) Eclipidrilidae and their anatomy. A new limicolide Oligochaeta. Nova Acta Regiae Societatis Scientiarum Upsaliensis, Ser. 3, 11, 1–10.
Eisen, G. (1895) Pacific Coast Oligochaeta. I. Memoirs of the California Academy of Sciences, 2, 84–90.
Fend, S.V. & Brinkhurst, R.O. (2000) New species of Rhynchelmis (Clitellata, Lumbriculidae), with observations on the Nearctic species. Hydrobiologia, 428, 1–59.
Fend. S.V. and Rodriguez, P. (2003) Eremidrilus n. gen. (Annelida, Clitellata, Lumbriculidae) and new species from California, U.S.A. Canadian Journal of Zoology, 81, 515–542.
Giani, N. & Rodriguez, P. (1994) New species of the genus Trichodrilus (Oligochaeta, Lumbriculidae). Zoologica Scripta, 23(1), 33–41.
Holmquist, C. (1976) Lumbriculids (Oligochaeta) of northern Alaska and Northwestern Canada. Zoologische Jahrbücher Systematik, 103, 377–431.
Hrabç, S. (1970) Notes on the genera Stylodrilus and Bythonomus (Lumbriculidae, Oligochaeta). Spisy PÕírodovçdecké fakulty University J.E. Purkynç v Brnç, 515, 283–309.
Hrabç, S. (1984) Two atavistic characters of some Lumbriculidae and their importance for the classification of Oligochaeta. Hydrobiologia, 115, 15–17.
Hrabç, S. & Ñernosvitov, L. (1927) Über eine neue Lumbriculiden-Gattung Anastylus parvus n. g. n. sp. aus Karpathorußland. Zoologischer Anzeiger, 71, 203–207.
Pennak, R.W. (1989) Fresh-water invertebrates of the United States: Protozoa to Mollusca. 3rd edition. John Wiley & Sons, Inc., New York.
Rodriguez, P. & Giani, N. (1995) A preliminary review of the taxonomic characters used for the systematics of the genus Trichodrilus Claparède (Oligochaeta, Lumbriculidae). Hydrobiologia, 278, 35–51.
Smith, F. (1896) Notes on species of North American oligochaetes II. Bulletin of the Illinois State Laboratory of Natural History, 4, 396–421.
Smith, F. (1900) Notes on species of North American Oligochaeta. IV. On a new lumbriculid genus from Florida, with additional notes on the nephridial and circulatory systems of Mesoporodrilus asymmetricus Smith. Bulletin of the Illinois State Laboratory of Natural History, 5, 459–479.
Smith, F. (1919) Lake Superior lumbriculids, including Verrill’s Lumbricus lacustris. Proceedings of the Biological Society of Washington, 32, 33–40.
Sokolskaya, N.L. (1977) A new species of the genus Eclipidrilus (Oligochaeta, Lumbriculidae) from the Chukchi Peninsula. Zoologicheskiy zhurnal, 56(2), 296–300.
Sokolskaya, N.L. (1983) On the fauna of the tubificids and lumbriculids (Oligochaeta: Tubificidae, Lumbriculidae) of the Chukchi Peninsula. Sbornik Trudov Zoologicheskogo Muzeya MGU, 20, 120–143.
Wassell, J.T. (1984) Revision of the lumbriculid oligochaete Eclipidrilus Eisen, 1881, with descriptions of three subgenera and Eclipidrilus (Leptodrilus) fontanus n. subg., n. sp. from Pennsylvania. Proceedings of the Biological Society of Washington, 97, 78–85.
Westheide, W. (1999) Ultrastructure and functional significance of intestinojunctional spermathecae in enchytraeids (Oligochaeta, Annelida). Hydrobiologia, 406, 199–211.