Occultibambusa aquatica H. Zhang & K.D. Hyde, Fungal Diversity 80: 81 (2016)
Index Fungorum number: IF552366; Facesoffungi number: FoF02439
Etymology: Refers to its aquatic habitat.
Holotype: MFLU 11-1141.
Saprobic on submerged wood in freshwater stream. Sexual morph: Ascomata perithecioid, 100–250 μm high, 180–280 μm diam., scattered or in small groups, immersed to semi-immersed, subglobose, with a flattened base, brown to dark brown, with minute ostiolate, central papilla, with rounded slot. Papilla up to 40 μm long, 50 μm diam., dark brown. Peridium carbonaceous and fragile, unequal in thickness, 35–45 μm thick at the sides, 25–35 μm thick at the base and near ostiole, composed of 5–7 × 1.5–2.5 μm, rectangular to polygonal celadon cells. Hamathecium comprises 2–3 μm wide, septate, hypha-like, numerous, branched, anastomosing, pseudoparaphyses embedded in mucilage. Asci 73–86 × 9–13 μm (x̄ = 78.2 × 11.1 μm, n = 10), 8-spored, bitunicate, fissitunicate, clavate, with a short furcate pedicel (5–8 μm), which elongates after discharge (up to 55 μm), apically rounded with a small ocular chamber (1–3 × 4–4.5 μm). Ascospores 19–25 × 3.5–6.5 μm (x̄ = 22.2 × 5 μm, n = 20), L/W 3.8–4.8 (mostly 4.5), mostly 2-seriate, narrowly fusiform with acute ends, 1-septate, not constricted at the septum, septum mostly median, upper cell slightly broader than lower cell, slightly swollen near the septum, straight to curved, brownish, with one large guttule in each cell, smooth-walled, thin-walled, surrounded by a 5–10 μm thick sheath. Germ tube mainly formed from both end cells. Asexual morph: Undetermined. (Descriptions from Hyde et al. 2016)
Culture characteristics: Ascospores germinating on WA within 12–24 h. Colonies on PDA, dense, dark grey, reaching up to 1 cm diameter at after 13 days at 25–28°C, raised, central embossing, velvety, aerial mycelium and entire edge smooth, clear.
Material examined: THAILAND, Chiang Rai, Hui Kang Pla Waterfall, on submerged bamboo, 16 November 2010, Huang Zhang a50 (MFLU 11-1141, holotype), ex-type living culture, MFLUCC 11-0006.
Notes: Occultibambusa aquatica is similar to O. bambusae in having clavate asci and 1-septate, fusiform, brown ascospores with a mucilaginous sheath. However, O. bambusae has larger ascomata (400–550 μm diam.) and larger ascospores (23.5–27.5 × 4.5–7 μm). A close phylogenetic relatedness is noted between O. aquatica and O. pustula in a monophyletic subclade basal to other Occultibambusa species (99 % MLBP, PP greater than 0.90). Occultibambusa aquatica has no statistical support to O. pustula and is similar in having fusiform, 1-septate ascospores, but the latter has raised and darker ascomata and hyaline to pale brown ascospores. (Notes from Hyde et al. 2016).
Freshwater distribution: Thailand (Hyde et al. 2016)
Fig 1. Occultibambusa aquatica (holotype). a Appearance of ascomata on host surface. b Vertical section through ascoma. c Peridium. d–f Asci. g, h Pseudoparaphyses. i, j Ascospores. k Ascospore stained with Indian ink. l Germinating ascospore. m, n Culture characters on PDA (m = from above, n = from below). Scale bars b = 100 μm, c = 40 μm, d, e, l = 20 μm, f = 30 μm, g, h, i–k = 10 μm
Hyde KD, Hongsanan S, Jeewon R, Bhat DJ, McKenzie EHC, Jones EBG, Phookamsak R, Ariyawansa HA, Boonmee S, Zhao Q, Abdel-Aziz FA, Abdel-Wahab MA, Banmai S, Chomnunti P, Cui BK, Daranagama DA, Das K, Dayarathne MC, de Silva NI, Dissanayake AJ, Doilom M, Ekanayaka AH, Gibertoni TB, Góes-Neto A, Huang SK, Jayasiri SC, Jayawardena RS, Konta S, Lee HB, Li WJ, Lin CG, Liu JK, Lu YZ, Luo ZL, Manawasinghe IS, Manimohan P, Mapook A, Niskanen T, Norphanphoun C, Papizadeh M, Perera RH, Phukhamsakda C, Richter C, André ALCM, Drechsler-Santos ER, Senanayake IC, Tanaka K, Tennakoon TMDS, Thambugala KM, Tian Q, Tibpromma S, Thongbai B, Vizzini A, Wanasinghe DN, Wijayawardene NN, Wu HX, Yang J, Zeng XY, Zhang H, Zhang JF, Bulgakov TS, Camporesi E, Bahkali AH, Amoozegar MA, Araujo-Neta LS, Ammirati JF, Baghela A, Bhatt RP, Bojantchev D, Buyck B, da Silva GA, de Lima CLF, de Oliveira RJV, de Souza CAF, Dai YC, Dima B, Duong TT, Ercole E, Mafalda-Freire F, Ghosh A, Hashimoto A, Kamolhan S, Kang JC, Karunarathna SC, Kirk PM, Kytövuori I, Lantieri A, Liimatainen K, Liu ZY, Liu XZ, Lücking R, Medardi G, Mortimer PE, Nguyen TTT, Promputtha I, Raj KNA, Reck MA, Lumyong S, Shahzadeh-Fazeli SA, Stadler M, Soudi MR, Su HY, Takahashi T, Tangthirasunun N, Uniyal P, Wang Y, Wen TC, Xu JC, Zhang ZK, Zhao YC, Zhou JL, Zhu L (2016) Fungal diversity notes 367–490: taxonomic and phylogenetic contributions to fungal taxa. Fungal Divers 80:1–270. https://doi.org/10.1007/s13225-016-0373-x