Abstract
Seven new species of terrestrial Enchytraeidae (Oligochaeta) are described from soils of the southern Brazilian Atlantic rain forest. They were found in the framework of the German-Brazilian project SOLOBIOMA, which studied rain forest recovery. Specimens were investigated in vivo and as stained whole mounts. Three species belong to a new genus, named Xetadrilus. Xetadrilus is similar to Guaranidrilus Cernosvitov, 1937 and Tupidrilus Righi, 1974; it differs in the absence of lateral chaetae from segment VIII on and in peculiar structures of the prostomium: ganglia, inner papillae, and a frontal epithelial recess. Further peculiarities are small body size, absence of oesophageal appendages, and a variable pattern of pharyngeal glands. The three species are named X. maacki, X. aphanus, and X. fabryi. Three further nominal species are transferred to Xetadrilus: Marionina pituca Righi, 1974, Marionina righiana Xie & Rota, 2001, and Stercutus ugandensis Bell, 1954. The other four new species belong to Guaranidrilus, the species-richest genus at the sampling sites. They are named G. andreolii, G. marquesi, G. cingulatus, and G. hoeferi. All species have elongate transverse epidermal gland cells, three pairs of post-pharyngeal ganglia, and a dorsal vesicle in the nephridial postseptale. These traits may be included in the genus diagnosis. In all species described here, most of the species-specific taxonomic traits are found in non-reproductive structures, which means that specimens of all age groups can be identified to the species level, juveniles included.
NSTL