Erseus, C. (1980). Taxonomic studies on the marine genera Aktedrilus Knöllner and Bacescuella Hrabe (Oligochaeta, Tubificidae), with descriptions of seven new species. Zoologica Scripta. 9:97-111.
279872
Erseus, C.
1980
Taxonomic studies on the marine genera Aktedrilus Knöllner and Bacescuella Hrabe (Oligochaeta, Tubificidae), with descriptions of seven new species
Zoologica Scripta
9:97-111
Publication
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The taxonomy and morphology of Aktedrilus Knollner, 1935 and Bacescuella Hrabé, 1973 (subfamily Phallodrilinae), both common genera of the marine, littoral meiofauna, were studied on the basis of material from various geographical areas. A. monospermathecus Knöllner, 1935 is redescribed from France and Scotland. A. magnus sp.n., A. brevis sp.n., A. curvipenis sp.n. and A . floridensis sp.n. are described from Italy, Brazil, France and Florida, respectively. Two very closely related forms are described from the Pacific: A. locyi sp.n. (California) and A. parvisprostatus sp.n. (Great Barrier Reef). B. mediterranea sp.n. is described from Italy, and new European records are given for B. arctica Erséus, 1978 and B. parvithecata Erséus, 1978. Both genera are characterized by having two pairs of prostate glands, well developed penes, and unpaired, mid-dorsal spermatheca (if present). The species of Bacescuella transfer their sperm by means of external spermatophores, structures that are not developed in Aktedrilus. The eight species of Aktedrilus are largely distinguished by means of the morphology of the spermatheca, penes and prostates. The four species of Bacescuella differ principally from each other in the length of the vasa deferentia, and in the morphology of the prostates and copulatory organs. Most Bacescuella species lack spermatheca.