Freshwater Ascomycetes - Species Monograph

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Genus	Species	Author
Megalohypha	aqua-dulces	A. Ferrer & Shearer
Class	Order	Family
Dothideomycetes	Jahnulales

Genbank ID: 435401

Synonymy:

Description

Habit:

Ascomata superficial on wood, stalked or sessile.

Ascomata:

Ascomata on wood 240–300 x 200–250 mm, superficial, globose to obpyriform, ostiolate, papillate, hyaline, membranous, connected to the substrate by a brown, septate stalk strongly constricted at the septa, 20–25 wide and up to 450 mm long; sessile ascomata connected to the substrate by superficial, broad, brown, septate, stoloniferous hyphae.

Peridium:

Peridium about 15 mm thick, in longitudinal section composed of 1–2 layers of hyaline, thin-walled cells.

Beak:

Papillae 55 x 45 mm, short, cylindrical, with inwardly growing, hyaline periphyses, wall composed of outwardly diverging globose, thin walled cells.

Hamathecium:

Hamathecium of pseudoparaphyses 3–4 mm wide, filamentous, septate, hyaline, branched and anastomosing above the asci.

Ascus:

Asci 110–160 x 35–60 mm, fissitunicate, clavate or ellipsoid, short pedicellate, with or without an apical chamber, eight-spored.

Ascospore:

Ascospores 40–55 x 19–22 mm (mean = 48.3 x 18.8 mm, SD = 2.8 x 0.91 mm, n = 30), irregularly arranged, ellipsoidal, acutely tapered at apices, brown to dark brown, one septate, septum appearing as a very dark band, both cells of equal size, rough walled, with longitudinal sulcate striations, lacking appendages or a gelatinous sheath.

Sheath:

None observed.

Appendage:

None observed.

Culture:

Colonies on potato dextrose agar (PDA; Difco) effuse, with little aerial mycelium, slow growing, reaching a diameter of 1.2 cm in 4 weeks, dark brown and producing a pale yellow pigmentation of the surrounding agar. Hyphae brown, smooth, strongly constricted at the septa, 25 to 40 mm wide.

Anamorph:

None observed.

Other info

Type & Location:

PANAMA. COLON PROVINCE: Soberania National Park, Juan Grande River, 9°8ÕN, 79°43ÕW, 12 January 2003 on submerged decorticated wood, A. Ferrer, AF005-1. (ILL). HOLOTYPE.

Other Specimens:

PANAMA. COLON PROVINCE: Soberania National Park, Frijoles River, 9°8ÕN, 79°43ÕW, on submerged decorticated wood, 12 May 2003. A. Ferrer, AF005-2. THAILAND. KRABI PROVINCE: Than Bok Khorani National Park, Stream at Nature Trail, 8°23.6ÕN, 98°44.1ÕE, on submerged wood, 26 January 2006. S. Sivichai, SS3792.

Substratum:

Habitat:

Distribution:

PANAMA (COLON), THAILAND (KRABI)

Pertinent Literature:

Ferer and Shearer 2007

Comments:

Additional Pictures

Ascus.
Immature discharged ascus stained with aqueous nigrosin.
Fissitunicate dishcarge.
Fissitunicate discharge.
Broad hyphae.
Broad hyphae from culture.
Ascospore longitudinal striations.
Stalked ascoma.
Young asci.

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