Mucus excretion and carbon turnover of endogeic earthworms

摘要

Mucus excretion of endogeic earthworms, by the body surface to burrow walls and by the intestine to casts, was investigated using uniformly14C-labelled adult or subadult specimens ofOctolasion lacteum(Örley) in laboratory incubations in soil from a beechwood on limestone. The daily loss of C due to mucus excretion from the body surface and in casts was calculated as 0.2 and 0.5 of total animal C, respectively. The C loss due to mucus excretion by subadult or adult individuals ofO. lacteumis assumed to account for 63 of total C losses (including mucus excretion and respiration) of the earthworms. In a second experiment we studied the incorporation of14C from labelled soil, again from a beechwood on limestone, into the tissue of the endogeic earthworm speciesAporrectodea caliginosa(Savigny). The results of this experiment indicate the existence of two C pools, one more labile and one more stable, in earthworms. It is assumed that the C investment for respiration and mucus excretion is derived from the labile C pool of endogeic earthworms