Centroceras gasparrinii subsp. minor subsp. nov. (Ceramiaceae, Rhodophyta) in the North Adriatic Sea (Mediterranean): molecular and morphological characterization

In this study we examined several specimens previously identified as C. clavulatum from the North Adriatic Sea (Italy and Croatia) using morphological and molecular methods to understand which species is effectively present in this area of the Mediterranean Sea. Centroceras spp. were collected along the Italian (33 samples) and Croatian (7 samples) coasts of the North Adriatic Sea from 10 different sampling sites (Fig. 1) during March 2018-October 2018. For each sample, part was silica gel-dried for molecular analyses, and part was preserved in 4% formaldehyde/ seawater solution for morphological observations. When necessary, material was stained with 0.5% aqueous toluidine blue. Specimens were observed using a light microscope (Optika B-510PH, OPTIKA, Italy) equipped with a digital image acquisition system. A voucher specimen was deposited at PAD Herbarium, Botanical Garden Padova (Italy).