Cochlonemataceae
Overview
The six genera of the Cochlonemataceae, Amoebophilus, Aplectosoma, Bdellospora, Cochlonema, Endocochlus, and Euryancale previously were included in the Zoopagaceae (Bessey, 1950). Duddington (1973) created the Cochlonemataceae for those members of the Zoopagales that were parasites and he emended the Zoopagaceae so that it would only contain the predacious taxa, Acaulopage, Cystopage, Stylopage, Zoopage of the family.
The members of the Cochlonemataceae produce a thallus that is internal and no haustoria are produced, or the spore becomes the thallus and only the haustorium penetrates the host. The thallus may be more or less mycelial, as in Euryancale, somewhat swollen and cushion-shaped, such as Aplectosoma, or coiled, for instance Cochlonema and Endocochlus. In two genera, Amoebophilus and Bdellospora, the thallus is formed from the infecting spore, and only the haustorium is formed within the host. The spores of the Cochlonemataceae, especially in the catenulate taxa, Aplectosoma, Bdellospora, and Cochlonema, may be arthric and are probably similar to the sporangiospores formed by spp. of Piptocephalis and especially Syncephalis (Benjamin, 1979). The true nature of spore ontogeny (Benjamin, 1979) must await a transmission EM study of spore formation in members of the Cochlonemataceae and a comparison with TEM already completed on merosporangial development in other taxa of the Zygomycetes (Fletcher, 1972; Benny and Aldrich, 1975; Baker et al., 1977; Baker, 1979).
Members of the Cochlonemataceae can be isolated from any substrate (dung, soil, humus, rotting vegetation) that contains a suitable host animal (amoeba, nematode, rhizopods).
Classification
Cochlonemataceae Duddington, p. 233, 1973 [In Ainsworth, Sparrow, and Sussman. The Fungi Vol. 4B. (as Cochlonemaceae)].
Ecto- or endoparasites of amoebae, nematodes, or rhizopods. Only spore forming mycelium and spores produced outside host, or thallus and spores formed outside the host. Thallus formed inside host that is more or less mycelial or somewhat inflated and variously shaped and no rhizoids formed, or thallus external and formed from the infecting spore and only haustoria produced in the host. Spores are formed singly or in chains, sessile or on sporophores of various lengths. Zygospores hyaline, zygosporangium ornamentated, formed on apposed straight or coiled anisogamous suspensors, in some species a short protuberance arises from the larger suspensor.
Type genus: Cochlonema Drechsler.
A key to the genera of the Cochlonemataceae is provided by Duddington (1973). The following key is based on that presented by Duddington:
KEY TO THE GENERA OF COCHLONEMATACEAE
A. Thallus formed from an infecting spore that remains on the outside of the host, only haustoria produced in the host —— BAA. Thallus formed in the host, no haustoria produced —— E
B. Thallus a simple or sparingly branched coil —— CBB. Thallus cushion-shaped or more or less mycelioid —— D
C. Spores formed singly —— EndocochlusCC. Spores formed in chains —— Cochlonema
D. Thallus mycelioid; spores formed singly and successively on a lateral branch of the sporophore —— EuryancaleDD. Thallus more or less cushion-shaped; spores formed in chains —— Aplectosoma
E. Spore swells, becoming broadly ellipsoid during thallus formation; spores formed in long chains; haustoria branched 2-3 times —— BdellosporaEE. Spore does not swell during thallus formation, remaining cylindrical; spores formed singly or in chains of two to four, rarely more; haustoria cushion-shaped or lobate, not branched —— Amoebophilus
Synopsis of Genera
AMOEBOPHILUS Dangeard, 1910 (Botaniste 2: 51).
APLECTOSOMA Drechsler, 1951 (Mycologia 43: 173).
BDELLOSPORA Drechsler, 1935 (Mycologia 27: 25).
COCHLONEMA Drechsler, 1935 (Mycologia 27: 18).
ENDOCOCHLUS Drechsler, 1935 (Mycologia 27: 14).
EURYANCALE Drechsler, 1939 (Mycologia 31: 410).
Updated Feb 10, 2005