Peristodrilus
Peristodrilus (ref. ID; 5957 original paper)
Family Tubificidae: Subfamily Rhyacodrilinae (ref. ID; 7824)
Synonym Monopylephorus Lev. (in part) Brinkhurst, 1971 (ref. ID; 5957); Rhizodrilus Smith (in part) Hrabe, 1962 (ref. ID; 5957)
ref. ID; 5957
Tubificid oligochaetes with male ducts having vas deferens and long tubular atrium covered with prostate cells; atrium at first narrow then wide, leading directly to short eversible pseudopenes. Spermathecae with short ducts, long sac-like ampullae containing sperm in masses. Dorsal setal bundles with hair and pectinate setae, modified penial setae present. Coelomocytes numerous. Perister Mountain, S. Macedonia. Pyrenees Mountain and Massif Central, France. Freshwater, mountain streams and lakes. (ref. ID; 5957)
Type species
Rhizodrilus montanus Hrabe, 1962 (by monotypy) (ref. ID; 5957)
- Peristodrilus montanus nov. comb. (ref. ID; 5957 redescribed paper)
Syn; Monopylephorus montanus (Hrabe) Brinkhurst, 1971 (ref. ID; 5957); Rhizodrilus montanus Hrabe, 1962 (by monotypy) (ref. ID; 5957)
Synonym
Monopylephorus montanus (Hrabe) Brinkhurst, 1971 (ref. ID; 5957); Rhizodrilus montanus Hrabe, 1962 (by monotypy) (ref. ID; 5957)
Descriptions
Up to 14 mm long, 86 segments. Anteriorly 2-5 pectinate and 2-5 hair setae per dorsal bundle. Posteriorly the dorsal bundles contain 2-3 bifid and 1 (2) hair-like setae. Posterior to segment 40, 1, 2, setae per bundle. Anterior ventral setae 3-6 bifid setae per bundle, posteriorly 2-4 bifid setae. Up to 8 simple pointed setae present ventrally in XI. Spermathecal pores in X in ventral setal line, immediately posterior to 9/10. Male pores in XI in ventral setal line in posterior part of segment. Male funnel leads to narrow vas deferens which extends to segment XII where it enters atrium apically. Ental narrow portion of atrium extends posteriorly to XV where it widens considerably and extends anteriorly to the male pore. Vas deferens about 400 µm long, ental portion of atrium about 650 µm long, ectal portion 950 µm long. Vas deferens ciliated, covered with flat cells; in ental portion of atrium these flat cells become clumped to form small groups of prostatic cells. Prostatic cells of ectal portion of atrium similar to those of ental portion. Atrium terminates directly in short eversible pseudopenis. Coelomocytes numerous. (ref. ID; 5957)
Remarks
The male ducts in this species are unique in the Tubificidae. The vasa deferentia are covered with a layer of flat cells which unite to form small groups of cells near the beginning of the atria (in XII). Although Hrabe (1962) points out that the cell groups investing the atria are prostatic cells he does not comment on the nature of the cells covering the vasa deferentia. The distinction between vasa deferentia and atria is not marked. Peristodrilus montanus is characterized by apical entry of the vasa deferentia into the atira, modified penial setae, absence of ejaculatory ducts, and by the presence of pectinate and straight hair setae in the anterior dorsal bundles. The male ducts are very long. Although P. montanus is clearly a Rhyacodrilinae the combination of the above characteristics is unique within the subfamily. Peristodrilus montanus was originally known only from Golemo Lake in the Perister Mountains (hence the generic name). This region is known for its endemic supposedly preglacial relict species. It has now been recorded from the Pyrenees (Giani, as Rhyacodrilus coccineus) and from the Massif Central (Giani 1979). The types of P. montanus (Hrabe collection) have not been seen. (ref. ID; 5957)