Diplopodomyces liguliphorus Santam., Enghoff & Reboleira, 2018

Santamaría, Sergi, Enghoff, Henrik & Reboleira, Ana Sofía P. S., 2018, New species of Troglomyces and Diplopodomyces (Laboulbeniales, Ascomycota) from millipedes (Diplopoda), European Journal of Taxonomy 429, pp. 1-20 : 6-8

Diplopodomyces liguliphorus Santam., Enghoff & Reboleira sp. nov.

MycoBank No: MB824137

Fig. 2

Diagnosis

The presence of a ligula-like protuberance on the perithecial apex is the most striking characteristic of this species which does not seem to be closely related to any other species in this genus.

Etymology

The species epithet means “bearing a tongue”, in relation to the perithecial protuberance.

Material examined

Holotype

SRI LANKA: s.d., on Spirobolida indet. (family uncertain), slide C-F-92267 .

Isotypes

SRI LANKA: Same data as holotype. Slides SS E575a and SS E575c ( BCB-Mycotheca).

Description

Cells II, III, VI and basal cell of primary appendage bright reddish coloured; the rest of the thallus is hyaline, except for the blackened foot.

Basal cell (I) two times as long as broad, typically obconical, narrow at the base and gradually broadening distally. Suprabasal cell (II) more or less trapezoidal and isodiametric. Cell III smaller than II, slightly longer than broad, laterally adnate and exceeding in length cell VI. Septum I-II horizontal. Septum II-III oblique, almost half in length than I-II. Septum II-VI very oblique, as long as septum I-II.

Primary appendage unbranched, variably bent, consisting of up to 8 cells, gradually tapering distally. Basal cell of primary appendage three times as long as broad, distinctly larger and darker than other cells of appendage. Typically a single flask-shaped antheridium without supporting cell is borne on the second cell of appendage. Spiny remains of spore apex (sx) conspicuous, stout, on the third cell, rarely on the fourth cell of appendage.

Perithecial stalk cell (VI) triangular to rhomboid, obliquely arranged above cell II and under the perithecial body. Secondary stalk cell (VII) and basal cells of perithecium (n, n’, m) hardly distinguishable. Perithecium fusiform, with a blunt apex which bears a small but evident, erect, rounded, ligulate protuberance (li), formed by a w4 perithecial wall cell.

Length from foot to apex of perithecium 119‒192 µm. Perithecium (including basal cells) 68‒121 × 21‒31 µm. Primary appendage (from primary septum to apex, undamaged) 76‒123 µm.

Remarks

Abundant thalli of the new species were scattered on legs and body rings (most on ventral side) of the frontal part of the millipede.

Rarely a second, additional antheridium was seen on the third appendage cell (an, Fig. 2D ). Interestingly, the nuclei appear to be conspicuous in all cells of the appendage and also inside the basal cell (I) of the receptacle when seen with DIC optics.

This species is well distinguished by the protuberant lip on the perithecium, the reddish colour in some receptacle cells, and poorly defined walls of the basal cells of the perithecium, a characteristic unknown in the tribe Laboulbenieae but found in other genera of other tribes.

Figures

Fig. 2. Diplopodomyces liguliphorus Santam., Enghoff & Reboleira sp. nov. A–B. Mature thalli with labelling of cells and other elements. C. Pair of young thalli focused to show the original spinous spore apex (sx). D. Mature thallus focused to show the antheridium (an). Scale bars: 50 µm. Photographs from: slides C-F-92267 (A‒B), SS E575c (C) and SS E575a (D).