Introduction to Fungi, Third Edition

AQUATIC HYPHOMYCETES (INGOLDIAN FUNGI)
689
Fig 25.13 Tetrachaetum elegans.The main axis of the conidium
bends and, at the point of curvature, two lateral arms arise
simultaneously.
obtained in cultures derived from a conidium.
The teleomorph is a species of Fibulomyces
probably belonging to the polyporoid clade.
Ingoldiella hamata (Fig. 25.17), a tropical
aquatic fungus, has large, dikaryotic conidia
with numerous clamp connections. The basidial
state is Sistotrema hamatum (polyporoid clade)
with eight-spored basidia. Single basidiospores
germinate to form monokaryotic mycelia on
which monokaryotic conidia develop. These
closely resemble dikaryotic conidia but lack
clamp connections.
There are other aquatic hyphomycetes with
basidiomycetous affinities indicated by the
possession of dolipore septa within the mycelium
and the conidium. Examples include
Dendrosporomyces prolifer and D. splendens which
have conidia with a strong morphological resemblance
to Dendrospora, and Tricladiomyces malaysianum
with spores resembling those of a
Tricladium but with dolipore septa (Nawawi,
1985).
25.2.2 Sigmoid conidia
A similar range of different types of conidial
ontogeny can be demonstrated for sigmoid
conidia.
Phialoconidia
Flagellospora curvula (Fig. 25.18a) has narrow,
sigmoid phialoconidia developing from phialides
on a sparsely branched conidiophore. A more
richly branched, penicillate arrangement of
phialides is found in F. penicillioides (Fig. 25.18b),
which has a Nectria teleomorph.
Fig 25.14 Varicosporium elodeae. Branched
blastoconidia formedby repeatedbranching of the lateral arms
which develop mostly from one side of the main axis.
include Taeniomyces (Fig. 25.16) which has a
conidium somewhat resembling a Tricladium,
but with a single clamp connection at the
septum lying between the two arms. The conidium
is dikaryotic, and the basidial state has been
Blastoconidia
Anguillospora has blastic, sigmoid conidia, but
evidence from the known teleomorphs indicates
that this form-genus is very heterogeneous,
including species from unrelated groups of
Ascomycota (see Table 25.2). There are also
differences in the mechanism of conidial
separation. Anguillospora longissima (Fig. 25.19)
has dark mycelium and conidia. The conidia
develop as club-shaped swellings from the
apices of conidiophores. The conidium becomes
septate and helically curved. Conidial separation
is rhexolytic, brought about by the collapse