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The World of Protozoa, Rotifera, Nematoda and Oligochaeta

Aulodrilus

Aulodrilus Bretscher, 1899 (ref. ID; 1257, 3692, 6913, 6972)

Family Tubificidae (ref. ID; 1257, 5876, 5939, 6208, 6597, 7854)

Family Tubificidae: Subfamily Aulodrilinae Brinkhurst, 1971 (ref. ID; 6913) reported author and year? (ref. ID; 6560)

Family Tubificidae: Subfamily Tubificinae Eisen (ref. ID; 6972)

ref. ID; 1663

Dorsal and ventral setae different. Ventral setae bifurcate, dorsal setae bifurcate or mixture of two or three types. Four bundles of an indeterminate number each per segment. Worm usually reddish. Coelomocytes sparse or absent. Without gills. Prostates and atria of different form. Atrium with one or two prostate glands, or prostate glands. Prostates solid. (ref. ID; 1663)

ref. ID; 6972

The taxonomy of this genus is confused, and several species have been discovered in Japan that have yet to be described (A. Ohtaka, Tomioka, Japan, personal communication). There is a particular problem with a series of taxa with oar-shaped dosal chaetae in mid and posterior segments, beginning with A. pigueti Kowalewski. Five synonyms of A. pigueti were suggested by Brinkhurst and Jamieson (1971), including A. prothecatus Chen from China. The species differ in regard to the position of the gonopores (more or less median, depending on the development of a transitory median bursa) and the degree to which lateral teeth or other details can be seen on the oar chaetae. The former characters should be investigated on mated specimens, which often proves difficult as these species appear to reproduce asexually in many instances (especially in more temperate latitudes). The latter would be best observed under scanning electron microscopy, but this will not help elucidate old taxa where the types are missing. Giani et al. (1984) clearly illustrated the male ducts of several Aulodrilus species and showed that there are true penes present in the cosmopolitan A. pluriseta (Piguet, 1906) and A. limnobius, in contrast to earlier descriptions of the same taxa which suggested there were eversible penes. Considerable caution should be exercised in accepting older descriptions at face value until they are confirmed from new material. The following descriptions should be regarded as preliminary as they are based on in adequate material. (ref. ID; 6972)
  1. Aulodrilus americanus Brinkhurst & Cook, 1966 (ref. ID; 6651) reported author and year? (ref. ID; 5939)
  2. Aulodrilus japonicus Yamaguchi, 1953 (ref. ID; 6651, 7098, 7854) reported author and year? (ref. ID; 6648)
  3. Aulodrilus limnobius Bretscher, 1899 (ref. ID; 3692, 5939, 6913, 7854)
  4. Aulodrilus pectinatus Aiyer, 1928 (ref. ID; 3692)
  5. Aulodrilus pigueti Kowalevski, 1914 (ref. ID; 6601, 6972), Kowalevsky, 1914 (ref. ID; 3692) or Kowalewski, 1914 (ref. ID; 6913, 7098, 7254, 7854) reported author and year? (ref. ID; 1861, 5939)
    Syn; Aulodrilus prothecatus Chen, 1940 (ref. ID; 6972); Aulodrilus remex Stephenson, 1921 (ref. ID; 6972)
  6. Aulodrilus pleuriseta Piguet, 1906 (ref. ID; 1257, 2378, 6208, 7854)
  7. Aulodrilus pluriseta Piguet, 1906 (ref. ID; 1257, 3692) reported year? (ref. ID; 3446, 6597, 6913, 7817) reported author and year? (ref. ID; 5939)
  8. Aulodrilus prothecatus Chen (ref. ID; 6600)
    See; Aulodrilus pigueti (ref. ID; 6972)
  9. Aulodrilus remex Stephenson, 1921
    See; Aulodrilus pigueti (ref. ID; 6972)

Aulodrilus japonicus Yamaguchi, 1953 (ref. ID; 6651, 7098, 7854) reported author and year? (ref. ID; 6648)

Remarks

This species was originally described by Yamaguchi (1953) from Sapporo, northan Japan. It was once dubiously synonymized with A. pluriseta (Piguet) by Brinkhurst (1971), and later considered as a distinct species by Hrabe (1981), also by Finogenova and Arkhipova (1994). Nevertheless, the taxonomic relation between them is stil unclear because considerable differences can be found among the descriptions of diagnostic chaetal apparatus in A. japonicus by different authors. (ref. ID; 7098)

Aulodrilus pigueti Kowalevski, 1914 (ref. ID; 6601, 6972), Kowalevsky, 1914 (ref. ID; 3692) or Kowalewski, 1914 (ref. ID; 6913, 7098, 7254, 7854) reported author and year? (ref. ID; 1861, 5939)

Synonym

Aulodrilus prothecatus Chen, 1940 (ref. ID; 6972); Aulodrilus remex Stephenson, 1921 (ref. ID; 6972)

Descriptions

A. pigueti is a cosmopolitan species that prefers silty substrata in mesotrophic waters. (ref. ID; 1861)

Dorsal chaetae of II 4 or 5, probably simple-pointed, on III 8, some bifid with thin upper teeth and 1 short hair chaeta, on IV and V 11 bifids or some simple-pointed, 2 short hair chaetae. On genital segments only 7 or 8 chaetae per bundle of which only 1 or 2 are hairs, on X-XIV also 2 hairs but 1 oar-shaped and 2 bifid chaetae. From XV on, 3 oar-shaped and 2 hair chaetae per bundle. The number of ventral chaetae varies in a similar manner (5 in II, 8 in III, 11 in IV and V, single penials in glandular sacs in VII, 5 or 6 in posterior bundles). Spermathecae (in VI) with quite long ducts with a narrow lumen, ampullae cylindrical with a wide lumen, transition being abrupt. Ampullae contain bundled sperm. Position of spermathecal pores uncertain but probably median to chaetal line. Male pores very close together in VII, in front of what appears to be a median bursa and closer than the large single penial chaetae. Penis sacs elongate, atria spherical with basal prostate gland stalks, vasa deferentia about as long as atria plus penis sacs. (ref. ID; 6972)

Dorsal chaetae from II-IV (V) bifid with the upper tooth shorter and thinner than the lower, 2-4 (9) per bundle; they are replaced gradually by oar-shaped and hair chaetae from IV or VI-VIII, and there may be as many as 4 of each form on some segments. Ventral chaetae up to 11 per bundle, with the upper tooth shorter and thinner than the lower and the nodulus distal. (ref. ID; 7254)

Remarks

This description is in close agreement with that of A. remex by Stephenson (1921, 1923) and Aiyer (1928, 1929). The former even includes the presence of simple-pointed chaetae in anterior bundles. The authors of these descriptions were unaware of the description of A. pigueti by Kowalewski (1914, cited in Brinkhurst and Jamieson 1971). Chekanovskaya (1962) concluded that pigueti and remex were identical. Ohtaka (1987) indicated that A. pigueti and A. prothecatus Chen are synonymous. A second, immature specimen from the same location has only 2-4 dorsal chaetae in II-IV, an oar-shaped chaetae are found from VI on, accompanied by hair caetae. These number only 3 or 4 and 2 per bundle, respectively. The anterior ventral bundles have only 3 or 4 chaetae, some simple-pointed, but all are bifid by VIII. (ref. ID; 6972)

Material examined

1 specimen (dissected) Zhujiang River, Huang-zhu-qi, Guangzhou, Guangdong Province, 1985. Qi Sang collection. (ref. ID; 6972)

Aulodrilus pleuriseta Piguet, 1906 (ref. ID; 1257, 2378, 6208, 7854)

Descriptions

The chaetae are long and thin; in the ventral bundles there are 8-10 per bundle (Kowalewski 1914), with the upper tooth thinner and shorter than the lower to which it is closely applied. In the dorsal bundles there are 6-7 hair chaetae regularly alternating with the crotchets, of which there are 8 or sometimes more, up to 10. The upper tooth of the dorsal crotchets is thinner and shorter than the ventral, both being poorly developed. There is a set of fine teeth between the main teeth. There are no specialised chaetae. Posteriorly bundles contain 3 crotchets in both dorsal and ventral, and 3 hair chaetae dorsally. Worms are usually small, 10-17 mm. (ref. ID; 6208)