Pleosporales » Aquasubmersaceae » Aquasubmersa

Aquasubmersa japonica

Aquasubmersa japonica A. Hashim. & Kaz. Tanaka

Index Fungorum number: IF551422; Facesoffungi number: FoF00956

Etymology: named after the country of origin, Japan.

Holotype: HHUF 30469


Saprobic on dead wood. Sexual morphAscomata 180–210(−300) μm high, 115–175(−230) μm diam., scattered to grouped, subglobose, immersed to semi-immersed. Ostiole 10–16 μm high, short papillate, lacking a clypeus. Peridium 20–30 μm wide, composed of 4–7 layers of flattened, 8–12.5 × 2.5–5.5 μm, thin-walled cells of textura angularis, black at the outside. Hamathecium comprising numerous, 2–4.5 μm wide, hyaline, septate, branched pseudoparaphyses. Asci (60–)66–93 × (4.5–)5.5–8 μm ( = 76 × 6.2 μm, n = 17), 8-spored, bitunicate, cylindrical, with a short pedicel (9–14 μm long), apically rounded, with an ocular chamber. Ascospores 20–26 × 4–5.5(−6) μm ( = 23.2 × 4.6 μm, n = 65), L/W (3.7–)4–6(−6.5) ( = 5.1, n = 65), biseriate, hyaline, broadly fusiform with rounded ends, straight, with a mostly median septum (0.45–0.54;  = 0.50, n = 65), smooth, guttulate when young, with an entire sheath; sheath when fresh condition diffuse, gelatinous, up to 10 μm wide, later becoming sharply delimited firm sheath of 1.5–4 μm thick. Asexual morph: Coelomycetous. Conidiomata pycnidial, globose to subglobose, up to 215 μm high in section, 115–195 μm diam., scattered, semi-immersed, solitary, black to brown. Ostiole 53–80 μm high, short papillate, circular, dark-brown, central. Peridium 20–25 μm wide, composed of 9.5–12.5 × 3–7.5 μm, polygonal, hyaline to brown cells; Conidiophores reduced. Conidiogenous cells holoblastic, 9–12 × 5.5–6.5 μm, lageniform, hyaline, smooth. Conidia ellipsoidal, 17–22(−23) × (7–)8–9 μm ( = 19.4 × 8.4 μm, n = 50), L/W 1.9–2.7 ( = 2.3, n = 50), hyaline, smooth, guttulate when young. (Descriptions from Ariyawansa et al. 2015)


Culture characteristics: Ascospores formed in culture are similar to those on natural substrate.


Material examined: JAPAN, Okinawa, Isl. Ishigaki, Banna Park, on dead wood, 16 July 2011, K. Tanaka & K. Hirayama KT 2862 (HHUF 30469, holotype), ex-type living culture, MAFF 245219; ibid. KT 2863 (HHUF 30470, paratype), living culture, MAFF 245220. JAPAN, Okinawa, Isl., Iriomote, Oomija River, on submerged wood, 12 July 2011, K. Tanaka & K. Hirayama KT 2813(HHUF 30468, paratype), living culture, MAFF 245218.


Notes: The asexual characters of A. japonica show a good match with the generic concepts of Aquasubmersa. The conidia of A. japonica differ in being slightly larger than those of A. mircensis (18.3 × 9.4 μm; Zhang et al. 2012). ITS sequence differences between our materials of A. japonica and the ex-type strain of A. mircensis (NR 121545) were found at 27–28 positions with three gaps. Notes from Ariyawansa et al. (2015).



Ariyawansa HA, Hyde KD, Jayasiri SC, Buyck B, Chethana KWT, Dai DQ, Dai YC, Daranagama DA, Jayawardena RS, Lücking R, Ghobad-Nejhad M, Niskanen T, Thambugala KM, Voigt K, Zhao RL, Li GJ, Doilom M, Boonmee S, Yang ZL, Cai Q, Cui YY, Bahkali AH, Chen J, Cui BK, Chen JJ, Dayarathne MC, Dissanayake AJ, Ekanayaka AH, Hashimoto A, Hongsanan S, Jones EBG, Larsson E, Li WJ, Li QR, Liu JK, Luo ZL, Maharachchikumbura SSN, Mapook A, McKenzie EHC, Norphanphoun C, Konta S, Pang KL, Perera RH, Phookamsak R, Phukhamsakda C, Pinruan U, Randrianjohany E, Singtripop C, Tanaka K, Tian CM, Tibpromma S, Abdel-Wahab MA, Wanasinghe DN, Wijayawardene NN, Zhang JF, Zhang H, Abdel-Aziz FA, Wedin M, Westberg M, Ammirati JF, Bulgakov TS, Lima DX, Callaghan TM, Callac P, Chang CH, Coca LF, Dal-Forno M, Dollhofer V, Fliegerová K, Greiner K, Griffith GW, Ho HM, Hofstetter V, Jeewon R, Kang JC, Wen TC, Kirk PM, Kytövuori I, Lawrey JD, Xing J, Li H, Liu ZY, Liu XZ, Liimatainen K, Lumbsch HT, Matsumura M, Moncada B, Nuankaew S, Parnmen S, de Azevedo Santiago ALCM, Sommai S, Song Y, de Souza CAF, de Souza-Motta CM, Su HY, Suetrong S, Wang Y, Wei SF, Wen TC, Yuan HS, Zhou LW, Réblová M, Fournier J, Camporesi E, Luangsa-ard JJ, Tasanathai K, Khonsanit A, Thanakitpipattana D, Somrithipol S, Diederich P, Millanes AM, Common RS, Stadler M, Yan JY, Li XH, Lee HW, Nguyen TTT, Lee HB, Battistin E, Marsico O, Vizzini A, Vila J, Ercole E, Eberhardt U, Simonini G, Wen HA, Chen XH, Miettinen O, Spirin V, Hernawati (2015) Fungal diversity notes 111–252—taxonomic and phylogenetic contributions to fungal taxa. Fungal Divers 75:27–274.

Zhang Y, Crous PW, Schoch CL, Hyde KD (2012) Pleosporales. Fungal Divers 52:1–225


Figure 1. Aquasubmersa japonica. a, b. Appearance of ascomata on substrate, c. Ascoma in longitudinal section d Peridium, e. Pseudoparaphyses, f. Ascus, g, h. Ascospores with mucilaginous sheath, i. Ascospore in India ink, j, k. Conidiomata in culture, l. Conidioma in longitudinal section, m. Peridium of conidioma, n. Conidiogenous cell and immature conidium, o–r. Conidia, a, b, e, h, i. from HHUF 30469; c, d, g. from HHUF 30470; f from HHUF 30468; j–r. from culture MAFF 245220. Scale bars: a, b = 200 μm, c, f, l = 20 μm, d, e, g–i, m–r = 10 μm, j, k = 300 μm. (Image from Ariyawansa et al. 2015).


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