Ancylistes was thought to be an unusual member of the aquatic Phycomycetes (Berdan, 1938) and was placed in the Ancylistales by Fitzpatrick (1930), along with fungi that were later included in the Lagenidiales (Oomycetes) by Sparrow (1973). Berdan (1938) discovered that actively discharged unispored sporangiola were formed by Ancylistes, which were similar to those produced by Conidiobolus spp. Waterhouse (1973) included Ancylistes in her list of genera of entomophthoralean fungi. Tucker (1981) and Ben-Ze’ev and Kenneth (1982) include Ancylistes, Conidiobolus, Meristacrum, and possibly Ballocephala and Zygnemomyces in the Ancylistaceae. Zygnemomyces is the only member of the family that has lost the ability to forcibly release its sporangia. Humber (1989) restricts the family to Ancylistes, Conidiobolus, and Macrobiophthora, genera that all use papillar eversion to forcibly release the sporangium. Ancylistes and Conidiobolus tend to produce their zygospores in line with the heterogamous gametangia but little else can be assertained from resting spore characteristics; zygospores of Macrobiophthora are angular in shape. As has been suggested from the family key and family description all members of the Ancylistaceae have a central nucleolus present in a relatively small, poorly staining nucleus (Tucker, 1981).

Ancylistaceae Schröter, 1893 [In Engler and Prantl, Die natürl. Pflanzenfam. 1(1): 92].

Saprobes or parasites of plants or animals. Mycelium nonseptate or irregularly septate. Sporophores unbranched, or rarely branched, one conidium formed per branch. Spores unitunicate, released forcibly by papillar eversion. Resting spores usually zygospores resulting from gametangial contact of neighboring hyphal cells or by scalariform conjugations between hyphae; formed in axis of hypha or in a conjugation tube. Nuclei small with a prominant nucleolus and lacking heterochromatin; usually difficult to observe during mitosis.

Type genus: Ancylistes Pfitzer.


A. Spores obovoid with a flattened base; resting spores angular in outline; parasitic on tardigrades or nematodes —— Macrobiotophthora

AA. Spore globose to obovoid, base conical to mammiform; resting spores globose to broadly ellipsoid in outline; saprobes or parasitic on animals other than nematodes and rotifers —— B

B. Parasitic on desmid algae; most infected by forcibly released spores or by contact with a sporophore of indeterminant length —— Ancylistes

BB. Saprobic or occasional pathogens of vertebrates or insects; hosts infected via forcibly released spores; sporophores determinant —— Conidiobolus

Synopsis of Genera

ANCYLISTES Pfitzer, 1872 (Monatsber. Königl. Preuss. Akad. Wiss. Berlin 1872: 396); 3 spp. (Berden, 1938—illus.; Sparrow, 1960—ILLUS. and key to spp.; Tucker, 1981—KEY TO SPP.).

CONIDIOBOLUS Brefeld, 1884 (Unters. Ges. Mykol. 6: 37); 22 spp. (Couch, 1939—ILLUS.; Drechsler, 1953a—ILLUS., 1953b—ILLUS., 1954—ILLUS., 1955a—ILLUS., 1955b—ILLUS., 1956—ILLUS., 1957a—ILLUS., 1957b—ILLUS., 1957c—ILLUS., 1960b—ILLUS., 1961—ILLUS., 1962—ILLUS.; Srinivasan and Thirumalacher, 1967b—illus. and key to spp.; King, 1976a—illus., 1976b—key to spp., 1977; Humber, 1981a; Ben-Ze’ev and Kenneth, 1982; Keller, 1987).
= Delacroixia Sacc. & Sydow, 1899 (Syll. Fung. 14: 457).
= Boudierella Cost., 1897 (Bull. Soc. Mycol. France 1897, p. 38), non Boudierella Saccardo.

Three subgenera:
= Conidiobolus Bref. subgen. Conidiobolus Bref..
= Conidiobolus Bref. subgen. Delacroixia (Sacc. & Syd.) Tyrrell & MacLeod, 1972 (J. Invert. Pathol. 20: 12).
= Conidiobolus Bref. subgen. Capillidium Ben-Ze’ev and Kenneth, 1982 (Mycotaxon 14: 431).

MACROBIOTOPHTHORA Reukauf, 1912 (Centralbl. Bakteriol., 1 Abt., Originale 63: 390) emend. Tucker, 1981 (Mycotaxon 13: 498); 2 spp. (Reukauf, 1912—illus.; Tucker, 1981—ILLUS. and KEY TO SPP.).

Updated Jan 31, 2009