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The World of Protozoa, Rotifera, Nematoda and Oligochaeta

Bryodrilus

Bryodrilus Ude, 1892 (ref. ID; 1257, 6026)

Family Enchytraeidae (ref. ID; 1257, 1928, 5971, 6026)
  1. Bryodrilus arctica (Bell, 1962) (ref. ID; 5971)
  2. Bryodrilus arctica Holmquist, 1968 (ref. ID; 5971)
  3. Bryodrilus diverticulatus Cern. (ref. ID; 6567)
  4. Bryodrilus ehlersi Ude, 1892 (ref. ID; 1257, 1928, 6026)
  5. Bryodrilus ehlersi glandulosus Dozsa-Farkas, 1990 (ref. ID; 6653)
  6. Bryodrilus parvus Nurminen (ref. ID; 6567)

Bryodrilus arctica Holmquist, 1968 (ref. ID; 5971)

Remarks

These specimens agree completely with the original description except for the following points. The origin of the dorsal blood vessel was XIII-XIV while the original description lists XII. This could represent added variability. The original description lists 51 as the segment number of the only specimen examined; we found a segment range of 52 to 58 in four specimens examined. We found regular discoidal lymphocytes, not the irregular type listed in the original description. This could be due to the fixing and preserving procedures used. We did not find a sudden enlargement of the gut or intestinal diverticula at the point where the esophagus merges into the intestine. This point has been one of controversy in deciding whether to place this taxon in Bryohenlea or Bryodrilus (see Bell 1962 and Holmquist 1968). At present we believe it may be variable characteristic by that in either cases, the species belongs in Bryodrilus. (ref. ID; 5971)

Bryodrilus ehlersi Ude, 1892 (ref. ID; 1257, 1928, 6026)

Descriptions

The species are 15 mm long. The anterior ventral bundles contain 6-7 setae (Ude gives 5, rarely 6). The nephridia are somewhat different from Ude's description and figure. The anteseptal portion is narrow and long, and the duct rises about the middle of the postseptal. The brain is concave in front, and not acutely cut, as Ude figures it. In the 6th segment there are four organs, two latero-ventral and two latero-dorsal, closely applied to the gut. The ventral pair are slightly further back than the others. The last pair of septal glands fills the 6th and 7th segments. The relations of the four peculiar glands in the 6th segment are not easy to determine in the living worm. Examination of transverse sections showed that the four glands do not open into the gut on the same level; and Ude's figures of this section are very diagrammatic. The differences between this form and the B. ehleisi of Ude, viz., size, number of setae in a bundle, brain, nephridia, etc., do not appear large enough at present to justify the creation of a new species. (ref. ID; 1928)