Nine new species of Dichogaster (Oligochaeta, Megascolecidae) from Guadeloupe (French West Indies)

Nine species belonging to two distinct groups within the genus Dichogaster Beddard, 1888 are described from material collected on the volcanic section of the island of Guadeloupe. The species Dichogaster arborea, D. caesitifusca, D. callaina, D. girija and D. basseterrensis all inhabit the leaf tanks of bromeliads and share the following anatomical characteristics: spermathecal pores on the trailing edges of segments, spermathecal axis differentiated into ampulla, internally fluted central chamber and duct, penial setae long and slender, testes and funnels free, prostomium undivided or divided by two grooves, simple single typhlosole and a pair of dorsal caeca on the mid-intestine. Dichogaster athena also inhabits bromeliads, but lacks the above characteristics and male reproductive organs, and is more similar to the remaining species. The three remaining species, D. guadeloupensis, D. matoubensis and D. musciphila , with lateral typhlosoles, no intestinal caeca, simpler spermathecal structure, prostomiums divided by a single groove and short penial setae, all inhabit soils of montane forests. The division of Dichogaster based on muscularity of the proventriculus wall is shown to be unsupportable, since thickness of the wall is size-related.