Introduction to Fungi, Third Edition

674 ANAMORPHIC FUNGI
Table 25.1. Examples of the diversity of nematophagous fungi.
Genus Taxonomic affinity Mode of parasitism
Predatory fungi
Acaulopage, Stylopage Zygomycota Adhesive hyphae
Gamsylella, Dactylellina,
Arthrobotrys (incl. Dactylella,
Dactylaria, Monacrosporium,
Duddingtonia)
Drechslerella (incl. Arthrobotrys,
Dactylella, Monacrosporium)
Nematoctonus (Hohenbuehelia),
Pleurotus
Endoparasitic fungi
Haptoglossa
Orbiliaceae
(Ascomycota)
Orbiliaceae
(Ascomycota)
Pleurotaceae (euagarics
clade,Basidiomycota)
Plasmodiophoromycota
or Oomycota
Adhesive knobs, columns,
nets, non-constricting rings
Constricting rings
Adhesive or poisonous knobs
Gun cells (see Fig. 3.9)
Myzocytium, Nematophthora Oomycota Encysting zoospores
Catenaria Chytridiomycota Encysting zoospores
Harposporium, Drechmeria,
Verticillium, Hirsutella
Clavicipitaceae
(Pyrenomycetes,
Ascomycota)
Ingestion or attachment
of conidia
Egg and cyst parasites
Rhopalomyces Zygomycota Hyphal colonization of eggs
Pochonia chlamydosporia
Paecilomyces lilacinus
Clavicipitaceae
(Pyrenomycetes,
Ascomycota)
Ascomycota (incertae
sedis)
Hyphal colonization of cysts
Hyphal colonization of eggs
have a high saprotrophic potential, including
the ability to degrade cellulose, nematodes are
probably utilized mainly as a nitrogen supplement
(Barron, 1992).
In the endoparasitic nematophagous fungi
(see p. 680) there is no extensive mycelial
development outside the nematode host, and
these species must therefore be regarded as
obligate parasites in ecological terms. They
exist in the soil as spores which may either
become attached to the body of the host,
or become ingested. The spores then germinate
and penetrate the animal, developing a
mycelium within the body of the nematode.
Only reproductive hyphae (conidiophores) penetrate
to the outside of the dead colonized
nematode.
Parasites of eggs and cysts (p. 684) are found
in several different taxonomic groups. Typically
these fungi can be isolated from the soil or
rhizosphere as well as from nematode eggs or
cysts, and are therefore viewed as opportunistic
saprotrophs. The most thoroughly studied
representatives are Paecilomyces lilacinus and
Pochonia chlamydosporia (formerly Verticillium
chlamydosporium).