Italian marine Gastrotricha: I. Six new and one redescribed species of Chaetonotida

The species Chaetonotus lacunosus Mock, 1979 is redescribed and refigured from specimens collected in littoral and shallow sublit‐toral sediments along the entire Italian coastline of the Mediterranean Sea and its adjacent waters. Six species new to science are described and figured: Chaetonotus apechochaetus, C. apolemmus, C. siciliensis, Halichaetonotus etrolomus, H. margaretae, and H. thalassopais. The proper nomenclature for Halichaetonotus decipiens (Remane, 1929) is noted, and a new combination is given: Musellifer delamarei (Renaud‐Mornant, 1968) n. comb.