Freshwater Ascomycetes - Species Monograph

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Genus	Species	Author
Jahnula	bipolaris	(K. D. Hyde) K.D. Hyde
Class	Order	Family
Dothideomycetes	Jahnulales	Inc. sed.

Genbank ID: 193036 MycoBank ID: 460475

Synonymy:

Jahnula bipolaris (K. D. Hyde) K.D. Hyde, Nova Hedwigia 68: 494. 1999.
≡ Ascagilis bipolaris K.D. Hyde Aust. Syst. Bot. 5: 111. 1992

Description

Habit:

Ascomata immersed or partially immersed in submerged wood.

Ascomata:

Ascomata 340–400 X 245–290 µm, globose to obpyriform, immersed to partially immersed in the substrate (wood), hyaline when young, becoming black translucent with age, membranous, with subtending and superficial stoloniferous hyphae, ostiolate, papillate.

Peridium:

Peridium about 30 µm wide, tissue of textura angularis to globosa in surface view, in longitudinal section about 6 cell layers wide, innermost layer of hyaline, thin walled, compressed cells, outermost layer of large, moderately thick-walled, pigmented, angular cells.

Beak:

Neck short, with short, inwardly growing, hyaline periphyses; apical region of the outer wall of the neck lined with angular cells.

Hamathecium:

Pseudoparaphyses septate, 3–4 µm wide, hyaline, anastomosing.

Ascus:

Asci 210–340 X 30–45 µm, fissitunicate, broadly cylindrical to obclavate, short pedicellate, with an apical chamber 4–6 X 7–8 µm and eight ascospores, which are overlapping uniseriate at ascus apex and base and 2–3 seriate in the middle

Ascospore:

Ascospores 45–55 X 18–20 µm (mean = 46 X 19 µm, n = 20), ellipsoidal to fusiform or slightly flattened on one side, light brown, one-septate, slightly constricted at the septum, multiguttulate; with gelatinous pads about 10–11 in diam, 2–3 µm high at the ascospore apices.

Sheath:

Ascospores with an oval to circular gelatinous sheath about 6–8 µm wide at the septum. Sheath is seen on ascospores within the asci but disappears upon discharge and contact with water or glycerin.

Appendage:

Gelatinous pads expanding in water, staining blue in aqueous nigrosin; with an oval to circular gelatinous sheath about 6–8 µm wide at the septum within the asci that disappears upon discharge and contact with water or glycerin.

Culture:

Colonies on (PYG) dark brown, diffuse, mycelium septate and thick walled; no anamorph observed.

Anamorph:

None observed.

Other info

Type & Location:

Ascagilis bipolaris K.D. Hyde Aust. Syst. Bot. 5: 111. 1992. Holotype: Australia: north Queensland, Millaa Millaa Falls, on submerged wood in freshwater, at the base of waterfal,1.i.1990. Kevin D. Hyde, BRIP 17155.

Other Specimens:

COSTA RICA: Heredia, La Selva Biological Station, Salto A60, 10°24'43''N, 84°1'0''W, UTM Zone 16, 826666mE, 1152499mN, water temperature 26 C, pH 5.5, on submerged, decorticated wood, 17 May 2000, JLA and RW A421-1. Sura 60, 10°25'48''N, 84°1'32''W, UTM Zone 16, 825685mE, 1154486mN, on submerged, soft, decorticated wood, water temperature 25 C, pH 5, 18 May 2000, JLA and RW A421-2. Panteno, 10°25'8''N, 84°0'22''W, UTM Zone 16 827814mE, 115391mN, on submerged, decorticated wood, water temperature 25 C, pH 5.5, 19 May 2000, JLA and RW A421-3. Sura 100, 6 February 2001, CMP A421-4. See World Records for other collections.

Substratum:

Submerged wood.

Habitat:

Freshwater lotic habitats.

Distribution:

Australia, Costa Rica, Hong Kong, Malaysia, Thailand

Pertinent Literature:

Hyde, K.D. 1992. Tropical Australian Freshwater Fungi. I. Some Ascomycetes. Aust. Syst. Bot., 5: 109–116. Raja, H.A. and C.A. Shearer. 2006. Jahnula species from North and Central America, including three new species. Mycologia 98: 319–332.

Comments:

Additional Pictures

Ascus
Ascospore discharge.
Ascoma with broad hyphae.
Ascus discharge.
Ascus apex.
Ascus apex.
Appendages stained with aqueous nigrosin.
Endoascus apex.

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