Gastrotrichs from Lakes Bolsena, Chiusi and Montepulciano (central Italy), with the description of four new species

Abstract

Twenty‐one species of gastrotrichs were found in samples collected from Lakes Bolsena, Chiusi and Montepulciano. Four are new species: Chaetonotus (Zonochaeta) dracunculus, C. (Z.) cestacanthus, C. trispinosus and C. pungens. Two, C. poznaniensis and Aspidiophorus oculifer, were recorded for the first time in Italy. Sperms are reported in C. (Z.) dracunculus. Qualitative differences exist between gastrotrichs of Lake Chiusi, an eutrophic environment rich in vegetation, and those of Lake Bolsena, an oligotrophic environment with sandy bottom. There is a consistent relationship between the cuticular characteristics of a species and the habitat in which it was found: species with reduced scales and spines live interstitially in detritus, whereas species with elaborate scales and long spines live on the surface of plants.

Key words:

• Freshwater microfauna
• Gastrotricha Chaetonoti‐da
• Italian fauna
• Chaetonotus
• Aspidiophorus