Mutualism between earthworms and soil microflora

The gut mucus production of different earthworms species has been measured in order to verify the mutualistic hypothesis between earthworms and soil m icroflora. Earthworms of different origin (tropical and temperate) and ecol ogical category (endogeic, anecic and epigeic), individuals of the same spe cies occuping different soils, and earthworms of different species from the same soil, have been studied. intestinal mucus production suggests the exi stence of the mutualistic digestion system. The mucus percentage in the gut was greater in the epigeic than in both anecic and endogeic. Nevertheless, the relative enrichment was higher in the endogeic species. The organic ma tter content of the substratum seems to play a regulating role in the mutua listic system, because the greater the substratum organic matter content th e lower the relative enrichment. Generally, in temperate zones more mucus w as added to the substratum, suggesting that the low temperature do necessar y a greater microflora stimulation.