The oligochaete fauna in high mountain streams (Trentino, NE Italy): ecological and taxonomical remarks (original) (raw)

The oligochaete fauna in high mountain streams (Trentino, NE Italy): ecological and taxonomical remarks -Little literature has been produced on the oligochaete fauna in high mountain streams, where Oligochaeta generally do not exceed 10% of the zoobenthic community. In 13 stations within the Noce Bianco catchment (de la Mare Valley, Trentino, NE Italy, 46°N), 416 samples (260 kick and 156 drift) of aquatic invertebrates were collected, but Oligochaeta were found only in 88. A total of 1149 specimens were identified and ascribed to 28 taxa belonging to five families: Enchytraeidae, Haplotaxidae, Lumbriculidae, Naididae and Tubificidae. Enchytraeidae were the best represented family accounting, with 12 species, from 26% to 100% of the oligochaete communities. The enchytraeids Cognettia (mainly C. sp. and C. sphagnetorum) and Cernosvitoviella (mainly as immature specimens and C. atrata) were the two most frequent and abundant genera in both glacial and non-glacial sites. Clear differences between the two stream types were highlighted by the Principal Component Analysis. To be mentioned, the finding of Cernosvitoviella tridentina, new for science and the record of Cognettia cf. paxi and Stylodrilus parvus as new for the Italian fauna.