IMIS

The present dataset reports distributional data on bryozoan specimens belonging to the Classes of Stenolaemata and Gymnolaemata collected in the Ross Sea and in Magellan Strait. It includes a total of 311 specimens corresponding to 282 MNA vouchers and belonging to 127 morphospecies. Out of these, 100 were classified to species level and 27 to genus level, representing 3 orders and 34 families.
In the last 30 years, several Italian expeditions have been conducted in the Ross Sea leading to the publication of contributions on different taxonomic groups. Among the different Phyla, Bryozoa was extensively studied until 2000 with papers reporting data on bryozoan species obtained during the first Italian Antarctic campaigns in Terra Nova Bay (i.e. 1988-1995) (Di Geronimo and Rosso 1990; Rosso 1990, 1991, 1992, 1994; Rosso and Sanfilippo, 2000). From 2000 onwards, new Antarctic campaigns were annually conducted and the number of new samples acquired by the Italian National Antarctic Museum (MNA, section of Genoa) progressively increased. However, no new taxonomical characterization was done until present on this material. Few samples from the Magellan Strait, collected during the VI Italian National Antarctic Program (PNRA) expedition in 1991, are also included here. The present study provides distributional data and taxonomic identification, at the lowest possible level, of bryozoans collected during thirteen scientific expeditions of the PNRA in the Ross Sea and the Magellan Strait.
Sampling was performed by using a variety of methods and gears such as dredges (Charcot dredge, Naturalist dredge, Triangular dredge and Picard dredge), Van Veen grabs of different volumes and, for opportunistic sampling, fishing long lines, mid water trawls (that accidentally touched the bottom due to a failure of the winches providing additional material), trammel nets and other fishing nets. In addition, during the XXV PNRA expedition, some samples were hand-collected by SCUBA diving.
The distributional data of Bryozoa came from different research expeditions, conducted between 1988 and 2014, and include 75 sampling stations, located between 18 and 711 metres of depth.
Once at the MNA, all specimens were classified at the lowest possible taxonomic level; only those that were classified at least at the genus level were included in the present dataset. Several researchers contributed in classifying the specimens, and the last taxonomic revision of the whole collection was conducted, in the past two years, by Chiara Lombardi, Silvia Cocito and Piotr Kuklinski. During all phases of sorting, classification and storage of samples at the MNA, quality control and data cleaning have been undertaken at various stages in order to produce high quality data, and make consistent cross-references between the database and samples’ labels.