Three genera formerly included in Ancylistaceae, Ballocephala, Meristacrum, and Zygnemomyces, have been transferred to Meristacraceae (Humber, 1989) because these fungi all produce a simple, upright conidiophore bearing several conidia.

Meristacraceae Humber, Mycotaxon 34: 456. 1989.

Parasites of soil invertebrates. Mycelium in host walled, coenocytic initially, later septa are formed and cells disarticulate. Conidiophore simple, bearing several conidia discharged by papillar eversion, by fluid discharge by a swollen subtending cell, or passively released from a short pedicel. Resting spores (zygospores) the result of conjugation of neighboring hyphal cells or scalariform conjugations between adjacent hyphae. Nuclei small (3-5 ┬Ám) with a prominant central nucleolus and no heterochromatin; nuclei difficult to observe during mitosis.

Type genus: Meristacrum Drechsler.


A. Sporophore nonseptate —— B

AA. Sporophore becoming transversely septate —— Meristacrum

B. Sporophore one celled; spores pedicellate not forcibly released; on nematodes —— Zygnemomyces

BB. Sporophore producing short, lateral basally septate, swollen outgrowths bearing single spores, which are forcibly discharged; on tardigrades —— Ballocephala

Synopsis of Genera

BALLOCEPHALA Drechsler, 1951 (Bull. Torrey Bot. Club. 78: 199); 3 spp. (Drechsler, 1951—ILLUS.; Richardson, 1970—illus.; Pohlad and Bernard, 1978—illus. and key to spp.; Tucker, 1981—KEY TO SPP.).

MERISTACRUM Drechsler, 1940 (J. Wash. Acad. Sci. 30: 250) emend. Tucker & Humber, 1981 (In Tucker, Mycotaxon 13: 494); 2 spp. [Drechsler, 1940—ILLUS., 1960a—ILLUS.; Miura, 1973—illus.; Couch et al., 1979—ILLUS. as Tabanomyces mil’koi (Dudka & Koval) Couch, Andreeva, Laird & Nolan; Tucker, 1981—KEY TO SPP.; Saikawa, 1989—ultrastructure].
= Pseudocoelomomyces Nam & Dubitskii, 1977 (Akad. Sci. Kazakh. S. S. R., Inst. Zool., Alma Alta 1: 576).
= Tabanomyces Couch, Andreeva, Laird & Nolan, 1979 (Proc. Natl. Acad. U.S.A. 76: 2302; fide Humber, 1981a).

ZYGNEMOMYCES Miura, 1973 (Rept. Tottori Mycol. Inst. 10: 520) emend. Tucker, 1981 (Mycotaxon 13: 495); 2 spp. (Miura, 1973—illus.; Tucker, 1981—ILLUS. and KEY TO SPP.).

Updated Jan 31, 2009