Multi-gene phylogeny reveals a new genus and species of Hapalidiales (Rhodophyta) from Antarctica: Thalassolithon adeliense gen. & sp. nov.

• Published in: Phycologia
• Main Authors: RICCARDO TRENTIN, EMANUELA MOSCHIN, ALESSANDRO GRAPPUTO, FABIO RINDI, STEFANO SCHIAPARELLI, ISABELLA MORO
• Other Authors: Trentin, Riccardo, Moschin, Emanuela, Grapputo, Alessandro, Rindi, Fabio, Schiaparelli, Stefano, Moro, Isabella
• Format: Article in Journal/Newspaper
• Language: English
• Published: Taylor and Francis Ltd. 2023
• Subjects: Coralline red algae; Molecular phylogeny; Morpho-anatomy; Ross Sea; Species delimitation models; Taxonomy; Terra Nova Bay; Adélie Cove; Antarctic; New Zealand; Antarc*; Antarctica
• Online Access: https://hdl.handle.net/11577/3473809; https://doi.org/10.1080/00318884.2022.2147745

Non-geniculate coralline algal specimens were collected in 2013 during the XXVIII Italian Expedition to Antarctica in Adélie Cove (Terra Nova Bay; Ross Sea) and deposited in the collections of the Italian National Antarctic Museum (MNAIT, Section of Genoa). Specimens were characterized through a polyphasic approach combining DNA sequence data obtained for four genes (psbA, rbcL, 18S rDNA and cox1) with morpho-anatomical observations. DNA sequences revealed that all specimens belonged to the same species. Phylogenetic reconstructions unambiguously recovered this alga as a member of the order Hapalidiales, but without any close relationship to a genus of this order currently recognized on a molecular phylogenetic basis. Instead, it formed a well-supported lineage with specimens named ‘Hapalidiales sp. ZH-Twist-2019’, collected in New Zealand, for which no formal assignment at genus level has been proposed. Species delimitation methods (ABGD, PTP, GMYC) applied to the psbA dataset indicated that the Adélie Cove coralline alga is a distinct species from all other known hapalidialean species for which such sequences are available. A new genus, Thalassolithon gen. nov., is proposed for T. adeliense sp. nov.