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

MycoBank number: MB 830734; Index Fungorum number: IF 830734; Facesoffungi number: FoF;

Typification: The holotype (FIG. 6h) was derived from the following: USA. TEXAS: Sutton County, 30.591°N, 100.138°W, ~300 m asl, 3-d-old culture of isolate Axs-31, originally isolated from freshly deposited feces content of female axis deer (Axis axis), Apr 2018, Radwa Hanafy. Ex-type strain: Axs-31. GenBank: MK881971 (D1–D2 28S rDNA).

Etymology: The species epithet “constrictus” refers to the observed constricted necks (point between sporangia and rhizoids) in the species endogenous sporangia (FIG. 6d–g). Obligate anaerobic fungus that produces globose polyflagellate    zoospores with  7 to  14   flagella. Zoospores germinate into monocentric thalli with highly branched anucleate rhizoidal systems. Exhibits both endogenous and exogenous monocentric thallus development. Endogenous sporangia produced from zoospore cyst enlargement develop into different shapes, including globose, tubular, clavate, and ellipsoidal. Endogenous sporangia display tightly constricted necks (point between sporangia and rhizoids) with narrow ports. Exogenous sporangia develop at the end of unbranched sporangiophores of varied lengths. Both short (from 6 to 20 μm) and long (up to 200 μm) sporangiophores are observed. The exogenous sporangia display ellipsoidal, ovoid, globose, constricted ellipsoidal, pyriform, bowling pin-like, and rhomboidal shapes. Sporangial necks are constricted with narrow port. A fine septum develops at the base of the sporangium at maturity. Zoospores are released through an apical pore followed by collapse of the sporangial wall.

Produces small, white, circular colonies (1 to 4 mm diam) with a brown central core of dense sporangial structures on agar, and a thick fungal biofilm growth in liquid media. The clade is defined by the sequences MK882043 (ITS1) and MK881971 (D1–D2 28S rDNA).

Additional specimens examined: USA. TEXAS: Sutton County, 30.591°N, 100.138°W, ~300 m asl, 3-d-old culture of isolate ADC-2, ADS-14, AXS-33, AXS-34, ADS-12, AXS-32, ADS-11, and ADS-21, originally isolated from freshly deposited feces content of female axis deer (Axis axis), Apr 2018, Radwa Hanafy. GenBank (D1–D2 28S rDNA): ADC-2 (MK881965), ADS-14 (MK881966), AXS-33 (MK881967), AXS-34 (MK1881968), ADS-12 (MK881969), AXS-32 (MK881970), ADS-11 (MK881972), and ADS-21 (MK881973).

Figure 6. Microscopic features of Ghazallomyces constrictus (clade 4, axis deer) strain Axs-31 (W-TX). Light (a–h, f, k, m–p) and scanning electron (i, j, l, q) micrographs. Light microscopy images were examined after staining with lactophenol cotton blue (a, d–h, k, m–p), as well as following staining of nuclei with DAPI (b). c. Overlay image. a. A polyflagellate zoospore. b–c. Monocentric thalli, with nuclei occurring in sporangia, not in rhizoids or sporangiophores. d–g. Endogenous sporangia with tightly constricted necks (arrows): d. Young globose sporangium. e. Young tubular sporangium. f. Mature clavate sporangium. g. Mature ellipsoidal sporangium. h–p. Exogenous sporangia: h. Young sporangium on a short, flattened sporangiophore (Sp); note the persistent empty zoospore cyst (Zc) and the rhizoidal system (R). i. Ovoid sporangium on short sporangiophore. j. Ellipsoidal sporangium on long sporangiophore. k. Ovoid sporangium on an eggcup-shaped sporangiophore (arrow). l. Globose sporangium. m. Constricted ellipsoidal sporangium with tightly constricted neck (arrow) on long sporangiophore. n. Pyriform sporangium; note the fine septum at the base of sporangium (arrow). o. Bowling pin-shaped sporangium. p. Rhomboidal sporangium with constricted neck (white arrow) and fine septum (black arrow); note the persistent empty zoospore cyst (Zc). q. Zoospores are released through apical pore followed by collapse of the sporangial wall. Sp = sporangiophore; Zc = zoospore cyst; R = rhizoid. Bars: a = 20 μm; b–q = 50 μm.