Agriosomyces longus Hanafy, Vikram B. Lanjekar, Prashant K. Dhakephalkar, T.M. Callaghan, Dagar, G. W. Griff., Elshahed & N.H. Youssef, sp. nov.

MycoBank number: MB 830738; Index Fungorum number: IF 830738; Facesoffungi number: FoF;

Typification: The holotype (FIG. 2g) was derived from the following: USA. TEXAS: Val Verde County, 29.369° N, 100.829°W, ~300 m above sea level (asl), 3-d-old culture of isolate MS-2, originally isolated from freshly deposited feces of male mouflon sheep (Ovis orientalis), Apr 2018, Radwa Hanafy. Ex-type strain: MS-2. GenBank: MK881996 (D1–D2 28S rDNA).

Etymology: The species epithet “longus” refers to the extremely long flagellum observed in zoospores of strain MS-2 (FIG. 2a).

Obligate anaerobic fungus that produces small, globose monoflagellate zoospores with an average diameter of 4 ± 1.1 μm. Zoospores are mainly monoflagellate, with rare occurrence of biflagellate spores. The average flagellum length was 22 ± 3.8 μm, approximately 5 to 6 times longer than the zoospore body. Zoospores germinate into monocentric thalli with filamentous anucleate rhizoidal systems. Both endogenous and exogenous sporangia are observed, which display no pleomorphism and both show globose morphology. In endogenous sporangia, the rhizoids are swollen below the sporangial neck, which is tightly constricted. Exogenous sporangia develop at the end of swollen sporangiophores, and the sporangial neck is constricted with a narrow neck port. Zoospores are released through dissolution and rupturing of the sporangial wall. Produces small, brown spherical colonies on agar, and a thin biofilm-like growth in liquid media. The clade is defined by the sequences MK882010– MK882013 (ITS1) and MK881996 (D1–D2 28S rDNA).

Additional specimens examined: Strain MS-2: USA. TEXAS: Val Verde County, 29.369°N, 100.829°W ~300 m asl, 3-d-old culture of isolate MS-4, originally isolated from freshly deposited feces of male mouflon sheep (Ovis orientalis), Apr 2018, Radwa Hanafy, GenBank: MK881997 (D1–D2 28S rDNA). Strain BGS-13: USA. TEXAS: Val Verde County, 29.369°N, 100.829°W ~300 m asl, originally isolated from freshly deposited feces of a female Boer goat (Capra aegagrus), Apr 2018, Radwa Hanafy, GenBank: MK881995 (D1– D2 28S rDNA amplicon).

Figure 2. Microscopic features of Agriosomyces longus (clade 1, mouflon–Boer goat) strain MS2 (W-TX). Light (b, e–h) and scanning electron (a, i) micrographs. c. DAPI staining for visualizing nuclei using a fluorescence microscope equipped with a Brightline DAPI high-contrast filter set. d. Overlay image. a. A monoflagellate zoospore (Z). b. A biflagellate zoospore. c–d. Monocentric thalli, with nuclei occurring in sporangia, not in rhizoids or sporangiophores. e–f. Endogenous globose sporangia with tightly constricted necks and subsporangial swellings (arrows). g–h. Exogenous globose sporangia; note the swollen sporangiophores (arrows). i. An empty sporangium (S) after zoospore (Z) release and rupturing of the sporangial wall. Bars: a = 5 μm; b = 20 μm; c–i = 50 μm.