Inventario dei gastrotrichi marini italiani: una checklist annotata

Inventory of the Italian marine Gastrotricha: an annotate checklist. Thanks to the extensive research carried out in the past decade, the Italian marine gastrotricofauna is nowadays that best know worldwide. The heterogeneity of data acquired over more than a century, along with the difficulty of getting the original bibliography, often makes troublesome the integration of the old with the new information, a vital tasks without which comprehensive analysis are precluded. To overcome these problems we have tried to organize the available data in a format readily accessible to researchers, and technicians and decision-makers dealing with faunistic and/or marine ecology duty. Present data are organized in two series of complementary tables, one focused on the collecting locations (234), reporting the species found along with relative benthic zone of finding, the researchers involved, year of collection, and related bibliography; whilst the other is centered on the 189 species found so far (75 chaetonotids in 10 genera and 2 families; 114 macrodasyids in 22 genera and 6 families), and their geographic distribution reported by region, province and location. The most intensively investigated region is Tuscany with 50 localities involved and 97 species collected (9.4 ± 7.5 spp/loc), whereas the richest region is Campania with 101 species found in just 30 localities sampled (13.0 ± 8,1 spp/loc). The number of species per station is variable, ranging from 1 to 36, with a global mean of 8.5 ± 7.1 spp/loc. Halichaetonotus aculifer, present in 36% of the examined locations, results the most common chaetonotid, whereas among the macrodasyids, the most common species is Acanthodasys aculeatus, found in 28% of the investigated localities. The species geographic distribution is not homogeneous, however from dedicated tables it is possible to detect the coastal tract where the frequency of occurrence of a given species is higher. The Italian endemisms are 70 (36% of total species found), of which 32 exhibit a distribution confined to just one of the 15 investigated regions; the type localities are 53.