Distolomyces euxinus W.Rossi & Mishustin, 2024

Mishustin, Ruslan I., Khodosovtsev, Alexander Y. & Rossi, Walter, 2024, New species and new records of Laboulbeniales (Ascomycota) from countries surrounding the Black Sea, Cryptogamie, Mycologie 20 (11), pp. 139-149 : 141-142

Distolomyces euxinus W.Rossi & Mishustin , sp. nov.

( Fig. 2 )

TYPE MATERIAL. — Ukraine • Odesa oblast, Bilhorod-Dnistrovskyi district , 6 km SE of Prymorske village; 45°40’32”N, 29°52’8”E; 7-8.VI.2023; leg. Y. Khalaim; holotype: FI [slide WR4586a ] .

ADDITIONNAL EXAMINED MATERIAL. — Ukraine • Odesa oblast, Bilhorod-Dnistrovskyi district, 6 km SE of Prymorske village; 45°40’32”N, 29°52’8”E; 7-8.VI.2023; leg. Y. Khalaim; FI [slides WR4583 , WR4584 , WR4585 , WR4586b ], KER, LWKS [ L00463 , L00464 , L00465 , L00466 , L00467 , L 00468 , L00509-L00517 ]; on the antennae of Labidura riparia (Pallas, 1773) ( Dermaptera , Labiduridae ).

Georgia • Kvemo Kartli, Gardabani municipality, Kumisi, shore of Lake Kumisi ; 41°35’1”N, 44°51’35”E; 26.IV.2022; leg. R. Mishustin; KER [slides #L00157, L00158 , L00160 ]; on antennae (mainly) and mouthparts of L. riparia (#i00126-1) .

ETYMOLOGY. — From Euxinum Mare, the Latin name of the Black Sea.

INDEX FUNGORUM. — IF901676.

DESCRIPTION

Thallus mostly hyaline, except the lower cell of the appendage and, sometimes, the outgrowths originating from cell II and the preapical appendages. Basal cell of the receptacle (cell I) longer than broad, subtrapezoidal in outline. Suprabasal cell (cell II) much smaller, slightly broader than long, cell III similar to cell II and placed next to it, giving rise apically to a free appendage formed of three superposed cells: the lower elongate, tapered and distinctly extended above the insertion of the bicellular antheridial branchlet; the median very long and flexuous; the terminal is an elongate antheridium bearing laterally a small spine and ending in a long, tapering tip which can reach the height of the tip of the perithecium; a second antheridium is seldom present. Cell III usually bears also three outgrowths variable in length, from digitiform to barely protruding, and also variable in color, from almost hyaline to light brown. Perithecium subsessile, asymmetrical, similar in outline to a lemon wedge with the lower half slightly broader, tapering above to a relatively small conical tip subtended dorsally by two paired rounded bumps and on both sides by two symmetrically diverging, slender and curved, horn-like appendages. An abortive perithecium is frequently seen. Length from foot to perithecial apex 80-105 µm; outgrowths of the receptacle 0-13 µm; free appendage 55-70 µm; perithecium 45-80 × 15-25 µm; preapical appendages about 13 µm.

NOTES

The above description is based on the numerous thalli from Ukraine; the fewer examined Georgian thalli are slightly larger on average (95-130 µm from foot to perithecial apex), and, when present, have shorter outgrowths of the receptacle.

Distolomyces euxinus W.Rossi & Mishustin , sp. nov. is allied to D. forficulae (T.Majewski) I. I. Tav. , reported from several European countries on the earwig Forficula auricularia L., 1758 ( Santamaría &Pedersen 2021). The new species is easily distinguishable for the outgrowths on the receptacle, which are usually conspicuous although rarely absent, and for the much longer and slenderer appendage, the lower cell of which is much paler (vs blackened in D. forficulae ) and distinctly extended above the insertion of the antheridial branch.

Figures

FIG. 2. – Distolomyces euxinus Rossi & Mishustin, sp. nov. from the type slide. Scale bars: 25 µm.