Vacuolonema iberomarrocanum G. S. Hentschke et J. Morais 2025, gen. et sp. nov.

Vacuolonema iberomarrocanum G. S. Hentschke et J. Morais gen. et sp. nov. Figs. 1–16 Description In culture, filaments intensely entangled or sometimes forming fascicles with few filaments (4–6). Trichomes isopolar, cylindrical, flexuous not branched, sometimes motile. Trichome ends rounded, not tapered toward the ends. Sheaths very thin, hyaline, visible only after releasing hormogonia. Cells longer than wide, 5–11 μm long, 0.9–1.3 μm wide. Cross-wall with adjacent vacuole-like structures, when observed under transmission electron microscopy. Under optical microscope, these structures are visible as hyaline or dark regions next to the cross-walls or apices of the trichomes. Under SEM (BSED), these structures appear as bright dots. Cell content olive-green, with two parietal thylakoids. Without necridia. Hormogonia short, few celled. Type: — PORTUGAL. Olhos d’Água Beach, Albufeira, 37.089 73 oN, 8.191 017 oW, 02 May 2007, Rui Seabra et Vitor Ramos (holotype PO-T5172!, Metabolically inactive state (lyophilized) of the strain LEGE 07170). Habitat: Benthic. LEGE 07170 is marine from a wave-exposed tide puddle at Olhos d’Água Beach, Albufeira, Portugal (37.08973 oN, 8.191 017 oW). LEGE 191244 is from a tidal shallow rockpool (or rocky substratum) in the coast of Essaouira, Morocco (31.51253°N, 9.77297°W). Etymology: Vacuolo is derived from the Latin “ vacuus ” meaning “empty”. Refers to the genus’ distinctive feature, which are the vacuole-like structures at the cross-walls. Nema is from the Greek “nēma,” meaning “thread” or “filament.” Ibero refers to the Iberian Peninsula. “ marrocanum” is derived from indicating the region where the species is found. The suffix “ anum ” is used to denote geographic origin and is neutral in gender. Reference strain: LEGE 07170 Material analyzed: LEGE 07170 and LEGE 191244 GenBank accession numbers: 16S rRNA and 16S–23S ITS: KU 951854 (LEGE 07170), PQ155757 (LEGE 191244)