Aporrectodea caliginosa

(Savigny, 1826)

Description
Middle-sized to large, unpigmented earthworms. Body grey or pink, clitellum brownish. Chaetae paired. Two pairs of tubercula pubertatis, in XXXI and XXXIII, forming 8-shaped figures when joining edgeways; sometimes, in the biggest individuals, can be joined forming continuous ridge. Clitellum from XXVII, XXVIII or XXIX to XXXIV or XXXV. Length 55-170 mm, body diameter 4-7 mm, segment number 100-250. Usually well distinguishable from the other earthworms by its 8-shaped tubercula pubertatis in XXXI-XXXIII. In the related but rare species Aporrectodea limicola, somewhat similar tubercula lie in XXIII-XXXIV. In the largest individuals of Aporrectodea caliginosa, tubercula can be fused into continuous ridge (forma trapezoides); however, this form occurs mostly in dry habitats. The separate morphological and ecological forms of Aporrectodea caliginosa have been described under many different names.
Burrowing in soil.

Distribution
Western Palaearctic, introduced into many other temperate regions.

Ecology
The commonest earthworm in cultivated soil; not living in water but can often be washed into streams with rainwater, or thrown into water as discarded bait.

Reproduction
Sexual only. Eggs laid in cocoons.

Literature
Savigny, 1826: 180; Dugès, 1828: 289; Eisen, 1873: 43, 46; Evans, 1946: 98; Graff, 1953: 56, Figs 57-59; Bouché, 1972: 326, 333, 334, 337; Plisko, 1973: 102-108, Figs 102-109; Reynolds, 1977: 46-60, Figs 10-14; Chekanovskaya, 1981: 496-498, Fig. 252; Sims and Gerard, 1985: 54-57, Figs 13-14.

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