Pseudoderbesia eckloniae Huisman & Verbruggen 2020, sp. nov.

• Main Authors: Huisman, John M., Verbruggen, Heroen
• Format: Other/Unknown Material
• Language: unknown
• Published: Zenodo 2020
• Subjects: Biodiversity; Taxonomy; Plantae; Chlorophyta; Ulvophyceae; Bryopsidales; Bryopsidaceae; Pseudoderbesia; Pseudoderbesia eckloniae; Antarc*; Antarctica
• Online Access: https://doi.org/10.5281/zenodo.12216071; http://treatment.plazi.org/id/BD10879FFF85FFB47C55FBB926D14237

Pseudoderbesia eckloniae Huisman & Verbruggen, sp. nov. (Fig. 1) HOLOTYPE. — PERTH 09134638. Collected at Cape Peron, Western Australia (32°16.18’S, 115°41.178’E), epiphytic on Eckloniaradiata at 2 m depth, 9.I.2019, J. M.Huisman 9.1.19.1A-C (three specimens mounted on sheet) (Fig. 1B). PARATYPE. — PERTH 09134646. Loc. id. , 30.XII.2018, J. M.Huisman 30.12.18 . ETYMOLOGY. — The epithet “eckloniae ” refers to the species’ only known host, Ecklonia radiata . DESCRIPTION Thallus grass green, forming a velvety layer on the surface of degrading branches of Ecklonia radiata (Fig. 1A), spreading laterally for up to 10 cm, siphonous, with dichotomously branched upright axes arising from a stoloniferous base (Fig. 1C). Stolons terete, 35-50 µm in diameter, attached by elongate, terete rhizoidal siphons. Upright axes dichotomously (rarely trichotomously) branched 4-7 times when mature, dichotomies mostly at similar levels but occasionally unequal, with slight constrictions commonly present at branch bases (Fig. 1D). Upright axes proximally 50 µm in diameter when young, 120-200 µm in diameter when mature; distal branches markedly narrowing, with ultimate branches 12-25 µm in diameter. Chloroplasts numerous, elongate to ovate, each with a single pyrenoid (Fig. 1E). Reproduction not observed. MOLECULAR ANALYSIS The rbc L gene of four samples of the new species was sequenced following the procedures of Verbruggen et al. (2009) and submitted to GenBank (MT108929). The four sequences of Pseudoderbesia eckloniae , sp. nov., were identical and only one was included for further analysis. The sequence was aligned with those of Bryopsidineae used in Leliaert et al. (2014) and Lambia antarctica (Skottsberg) Delépine (Cremen et al. 2019). A maximum likelihood phylogenetic tree was inferred with RAxML 8.2.10, using a GTR+G+I model and 100 standard bootstraps (Stamatakis 2014). The phylogenetic tree (Fig. 2) shows that the genus Pseudoderbesia is related to Lambia Delépine and Bryopsis J.V.Lamouroux, but the exact relationships ...