D. Trigo et P. Lavelle, CHANGES IN RESPIRATION RATE AND SOME PHYSICOCHEMICAL PROPERTIES OF SOIL DURING GUT TRANSIT THROUGH ALLOLOBOPHORA-MOLLERI (LUMBRICIDAE, OLIGOCHAETA), Biology and fertility of soils, 15(3), 1993, pp. 185-188
Some physicochemical and biological measurements were carried out on t
he gut content and casts of Allolobophora molleri, an earthworm which
lives in humid soils of Northern Spain. In the anterior part of the gu
t, water (22% of moist weight of soil) and soluble organic matter (27.
4%) had been added to the ingested soil and pH had increased from 5.75
to 7.0. The amount of water-soluble compounds decreased sharply in th
e middle and posterior parts of the gut and were hardly detectable in
control soil or casts. The average O2 consumption, measured at 28-degr
ees- and 21-degrees-C, indicated respectively 2.75- to 12-fold increas
es in microbial respiration in the gut content compared to the non-ing
ested soil. These results extend the hypothesis of a mutualistic diges
tion in earthworms previously proposed for tropical endogeic species.