Halofilum salinum (Dangeard) Darienko et Pröschold 2017

Darienko, Tatyana & Pröschold, Thomas, 2017, Toward a monograph of non-marine Ulvophyceae using an integrative approach (Molecular phylogeny and systematics of terrestrial Ulvophyceae II.), Phytotaxa 324 (1), pp. 1-41 : 18-19

Halofilum salinum (Dangeard) Darienko et Pröschold comb. nov. ( Fig. 10A )

Basionym: Heterogonium salinum Dangeard 1911 , Bull. Soc. Bot. France 58: 311, fig. 1.

Synonym: Pirula salina (Dangeard) Printz 1927 , Chlorophyceae in Engl. Natürl. Pflanzenfam. 225.

Diagnosis: Filaments are short, usually not more than 2–4 cells. The filaments are very fragile and easily disintegrated. They can be observed only in very young cultures (not older than several days). Cells are pear-shaped with a relatively thick cell wall. The chloroplast is parietal and usually covers 2/3 of the cell. The pyrenoid is present and surrounded by 2–4 large starch grains. Mature vegetative cells are 6.0–12.0 μm long × 5.0–9.0 μm wide and are uninucleate. Reproduction occurs by budding. Young cells are approximately 4.0 μm × 3.0 μm.

Differs from other species by SSU-ITS sequences and reproduction by budding.

Habitat: unknown

Type locality: unknown (only known from a culture vessel containing sea water).

Lectotype (designated herein): Fig. 1 in Dangeard (1911).

Epitype (designated herein): The strain SAG 1.95 is permanently cryopreserved in a metabolically inactive state (cryopreserved in liquid nitrogen) in the SAG, University of Göttingen, Germany.

ITS-2 DNA Barcode: HAL 1 in Figs S2.

Comment: The formation of short filaments was observed only on SWES agar plates under an inverted microscope. The filaments are very fragile and immediately disintegrate by preparation on a microscopy slide.

Figures

FIGURE 1. Molecular phylogeny of the Ulvophyceae based on SSU rDNA sequence comparisons. The phylogenetic tree shown was inferred using the maximum likelihood method based on a data set of 1770 aligned positions of 106 taxa using PAUP 4.0b10. For the analysis, the GTR+I+G (base frequencies: A 0.23760, C 0.22733, G 0.28379, T 0.25128; rate matrix A-C 1.0063, A-G 2.3095, A-T 1.3005, C-G 0.7427, C-T 4.0954, G-T 1.0000) with the proportion of invariable sites (I = 0.5552) and gamma shape parameter (G = 0.4527) was chosen, which was calculated as the best model by Modeltest 3.7. The branches in bold are highly supported in all analyses (Bayesian values> 0.95 calculated with PHASE and MrBayes; bootstrap values> 70% calculated with PAUP using maximum likelihood, neighbor-joining, maximum parsimony and RAxML using maximum likelihood). The sister group of the Oltmannsiellopsis-clade was chosen as outgroup. The clade designations was given after the represented genera. The strains originally assigned as Dilabifilum and Pseudendoclonium basiliense are marked with * and # behind the accession number, respectively. The generic names after taxonomic revision are given in white boxes.

FIGURE 10. Overview about the morphology of the investigated Halofilum strains grown on SWES medium. A. H. salinum SAG 1.95, B. H. helgolandicum SAG 2.95, C. H. ramosum SAG 2050, D. H. ramosum SAG 2235; E. H. ramosum ULVO-19, F. ULVO-28.