Search

Two earthworm species, one exotic (Pontoscolex corethrurus) and the other one native (Glossoscolecidae sp.) from Veracruz, Mexico, were cultivated under laboratory conditions, to collect their castings every 48 h, measure cast production rates and their effects on soil chemical conditions and the concentration of several plant-available nutrients. Both species were cultivated in an Alfisol (La Víbora) and P. corethrurus was also raised in two other soil types, a Vertisol (Plan de las Hayas) and an Andosol (Los Tuxtlas), to measure pH, C, N, C/N, NO 3, NH 4, Na, K, Ca, Mg, CIC, available- totaland resin-P, Al, Fe, Cu, Zn, Mn in the casts and control soil. P. corethrurus surface cast production was highest in soils with low organic matter content. In the Alfisol, Glossoscolecidae sp. produced less casts than P. corethrurus, but promoted the availability of most plant nutrients, especially K, Na Mg, Mn, Fe, K and NH 3. Pontoscolex corethrurus promoted the concentration of most parameters compared with the control in the Andosol and Vertisol; in the Alfisol, about half the parameters were significantly affected. Pontoscolex corethrurus has a high capacity to adapt to different soils and modify their chemical characteristics, promoting the availability of several plant nutrients; this is especially important in organic matter-poor soils, such as the Alfisol. [ABSTRACT FROM AUTHOR]

The checklist of earthworm species of Colombia and the patterns of distribution are presented. Data was obtained from collections made from 1872 to 2002. The information come from sporadic taxonomic registers and from some systematic studies conducted in hydrographic basins and savanna regions; both highlight the high diversity of the Andes mountainous areas. Most collections (93.2%) were carried out in the Andean region. The Colombian Oligochaeta comprises 113 species placed in nine families, 30 genera and six subgenera, of which 90 are native and 23 exotic. Most of the species are endemic of the Glossoscolecidae family. Andiodrilus is represented by the greatest number of species (25), while Martiodrilus with 19 species shows the highest habitat diversity, including forests, pastures and even the páramo. Only two species of this family were cosmopolitan (P. corethrurus and O. elegans) currently inhabiting anthropic environments. The species of the other families, excepting Tumak hamenni and Dichogaster medellina, were eurytopic. [ABSTRACT FROM AUTHOR]