Freshwater Ascomycetes - Species Monograph

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Genus	Species	Author
Lucidascocarpa	pulchella	A. Ferrer, Raja & Shearer
Class	Order	Family
Dothideomycetes	Unknown	Unknown

Synonymy:

None

Description

Habit:

On submerged decomposing wood.

Ascomata:

Ascomata on wood, scattered to aggregated, numerous, superficial to partially immersed with white, glistening necks protruding from the substrate. Venter globose to subglobose, 105–200 x 90–180 µm in diameter, white, glistening.

Peridium:

Peridium 10–14 µm wide, composed of 5–7 cell layers, cells thin-walled, elongated, hyaline. Tissue of textura angularis in surface view.

Beak:

Beak 160–280 x 38–50 µm, hyaline, cylindrical, curving irregularly, periphysate, with short hyphae protruding from the surface.

Hamathecium:

Pseudoparaphyses absent.

Ascus:

Asci 145–150 x 28–30 µm (mean = 144 x 29 µm, n = 20), clavate, pedicellate, straight or at times slightly curved toward the base with gelatinous material deposited around the apex of the endoascus, containing 8 overlapping, obliquely biseriate ascospores. Dehiscence fissitunicate, ectotunica rupturing at the apex and becoming strongly wrinkled and curled inwards, endotunica elongating to a quarter length of the ascus.

Ascospore:

Ascospores 36–50 x 12–16 µm (mean = 40 x 13, n = 50), seven-septate, hyaline, ellipsoidal to fusiform, verruculose, multiguttulate in a dictyose pattern, end cells lacking guttules, staining blue in aqueous nigrosin, surrounded by a large gelatinous sheath.

Sheath:

Sheath gelatinous ca. 2 µm wide in ascus, expanding in water to 28–60 µm wide at the mid region, 68–128 µm long at ascospore apices, germinating from ascospore apices.

Appendage:

None.

Culture:

Colonies on potato dextrose agar (Difco), slow growing, 0.5 cm diam in 4 wk at 24 C, dark brown, compact, with little aerial mycelium.

Anamorph:

Anamorph not observed.

Other info

Type & Location:

ECUADOR: NAPO, Yasuni National Park, Tiputini River, 9º10’N, 79º51’W, water temperature 26 C, pH 5.5–6, on submerged decorticated wood, 4 April 2004, A. Ferrer, A-566-1. (ILL). HOLOTYPE.

Other Specimens:

COSTA RICA, Caño Negro Reserve, Frio Stream, on submerged, decorticated wood, 10˚53’ N, 84˚45’W, water temperature 28 C, pH 5, xx December 2005, A. Ferrer, and M. Salazar, AF280-1; Barra del Colorado and Tortuguero National Park, Las Palmas stream, on submerged, decorticated wood, 10˚53’ N, 84˚45’W, water temperature 28 C, pH 5, xx December 2005, A. Ferrer, and M. Salazar, AF280-1; La Selva, Sarapiqui River, on submerged, decorticated wood, 10˚26’ N, 84˚01’W, water temperature 25 C, pH 5, xx January 2006, M. Salazar, AF280-1.

Substratum:

Submerged decorticated wood.

Habitat:

Flowing water habitats.

Distribution:

Costa Rica, Ecuador, Peru

Pertinent Literature:

Ferrer, A., H.A. Raja and C.A. Shearer. 2008. Lucidascocarpa pulchella, a new ascomycete genus and species from freshwater habitats in the American tropics. Mycologia 100: 642–646.

Comments:

Additional Pictures

Ascospore sheath stained with aqueous nigrosin.
Discharging ascus.
Ascus apex.
Ascospore and sheath stained in aqueous nigrosin.
Ascospores with sheath and wall roughening (stained in aqueous nigrosin).
Asci and ascospores.
Fragmentation of ascospore sheath.
Ascospore germinating on agar.

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