Porifera collection of the Italian National Antarctic Museum (MNA) - Data

Study Extent

The distributional data considered here originated from 331 different sampling stations ranging between 17 and 1100 metres of depth

Sampling

Sampling was performed on a total of 331 different sampling stations (Figures 1, 3, 4, 5) through the deployment of a variety of sampling gears, mainly dredges (Charcot dredge, Naturalist dredge, Triangular dredge and Picard dredge) and Van Veen grabs of different volumes. Some samples were also opportunistically collected by long fishing lines, mid water trawls (that touched the bottom due to a failure of the winches), trammel nets and other fishing nets that provided additional material to standard techniques. Some samples, from the XIV, XV, XVII, XVIII, XXIII and XXV PNRA expeditions, were hand-collected by SCUBA diving. In one case (i.e. Sycetta antarctica (Brøndsted, 1931), MNA 8847) the specimen was collected beached and sampling coordinates refer to the coastline. In another case, i.e. Lycopodina cf. vaceleti (Van Soest and Baker 2011), the specimen record is based on a georeferenced ROV video frame (Figure 6) and no physical samples are available. Once the material has been acquired by the MNA after sorting and shipment activities, all the specimens were classified to the lowest possible taxonomical resolution. In the years, different researchers have contributed to the classification of the specimens: Homoscleromorpha were studied by Maurizio Pansini and Antonio Sarà; Demospongiae and Hexactinellida were studied by Rachel Downey, Antonio Sarà, Marco Bertolino, Maurizio Pansini and Barbara Calcinai; Calcarea were studied by Hans Tore Rapp. The present dataset has been formatted in order to fulfil the Darwin Core standard protocol required by the OBIS scheme (http://iobis.org/data/schema-and-meta-data) and according to the SCAR-MarBIN Data Toolkit (available at http://www.scarmarbin.be/documents/SM-FATv1.zip). The dataset was uploaded in the ANTOBIS database (the geospatial component of SCAR-MarBIN). Vouchers are now preserved in 90% ethanol (~53% of the entire collection), frozen (~23%), or dried (~24%).

Quality Control

Specimens were identified at the finest possible taxonomic resolution and only those that have been classified at least at the genus level were included in the present dataset. During all the 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 sample labels. The MNA uses an SQL-based database (Specify 6) and a R-Shiny web application to manage its collections and link all the data (photos, glass slides, etc.) to the physical samples.

Method steps

1. Due to the large amount of researchers that managed the material before the acquisition of the collection by the MNA, all the specimens and distributional records were rechecked and then imported in the museum database. During this phase it emerged that only ~75% of the Porifera collection fulfilled the expected minimum set of data fields to be included in GBIF. The remaining ~25% of the material present in the MNA collection can be divided in a ~7%, represented by material not yet classified, and another ~18% represented by old materials that cannot be ascribed to a specific sampling station due to missing labels or incomplete information about sampling. Georeferencing on board each of the different research vessels is based on the interpolation of GPS satellite receivers and a gyrocompass. Station coordinates and sampling events were recorded during sampling activities based on various GPS systems.

This dataset focuses on all classes (Calcarea, Demospongiae, Hexactinellida and Homoscleromorpha) of the Phylum Porifera (Kingdom Animalia), and includes a total of 807 specimens belonging to 144 morphospecies (with 95 taxa classified at species level and 49 at genus level), and representing 12 orders and 30 families)

1. Porifera
   rank: phylum
2. Calcarea
   rank: class
3. Demospongiae
   rank: class
4. Hexactinellida
   rank: class
5. Homoscleromorpha
   rank: class

The specimens were collected in the Ross Sea sector of the Southern Ocean in a bathymetric range from 17 to 1100 meters of depth