Vejdovskyella comata

(Vejdovsky, 1884a)

Description
Small transparent worms. Prostomium as a low cap, with eyes. Dorsal chaetae beginning from VI, strikingly thick and stiff in comparison with worm's body. 4-8 long (170-420 µm), thick curved hair chaetae per dorsal bundle, with two rows of coarse serrations; besides these, 1-8 straight sharp single-pointed needle chaetae, 47-90 µm long. Ventral chaetae by 3-6, with slightly longer upper tooth, in II 80 µm long, further rearward 51-92 µm. They are absent from V, or also from IV, leaving a false impression that dorsal chaetae begin from V or IV. In mature individuals single hooked penial chaetae. Length 2-8 mm, segment number in zooids 12-24, in single individuals 24-34. Lack of any enlarged ventral chaetae distinguishes Vejdovskyella comata from its European congeners. The synonym Nais hamata Timm, 1883 is chronologically older than Bohemilla comata Vejdovsky, 1884 (the year 1883, usually recorded for the latter, is rather the year of submission but not of issuing the publication). However, the former name has not been in use for more than a century and is thus invalid.
Crawling on substratum.

Distribution
Holarctic.

Ecology
In freshwater.

Reproduction
Mostly asexual, by paratomy (budding). Mature individuals and sexual reproduction rare or seasonal.

Literature
Timm, 1883: 152-153, Pl. XI Fig. 24; Vejdovsky, 1884a: 218; Sperber, 1948: 137-140, Figs 15C-F, 26A; Sperber, 1950: 65-66, Fig. 17C-F, Pl. II Fig. 3; Brinkhurst and Jamieson, 1971: 347-349 (partim), Fig. 7.10A-E; Chekanovskaya, 1981: 204-206, Fig. 85; Hrabe, 1981: 50, Pl. 8 Figs 1-4; Kasprzak, 1981: 117-118, Figs 308-313.

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