Microbes and Plants - Freshwater Ecology: Concepts and Environmental Applications - page 141

FIGURE 8.8 Selected algal genera, with scale bar length: (A) Euglena (a Euglenophyte), 20

m; (B) Peridinium (a Dinoflagellate), 20 m; (C) Ceratium (a Dinoflagellate), 20 m; and

(D) Chara (a Charophyte) large view 2 cm, close-up 500 m (reproduced with permission

from Prescott, 1982).

molds), Phycomycetes (algal fungi), Ascomycetes (filamentous fungi), Basi-
doiomycetes (column fungi), and Deuteromycetes (imperfect fungi). Most
fungi are saprophytes, meaning they live on dead organic matter. The sys-
tematics of the fungi are based on their reproductive features and mor-
phology, except for the Dueteromycetes, in which no reproductive struc-
tures have been found. As molecular techniques are applied to fungi,
the taxonomy of the Deuteromycetes will probably be resolved more
satisfactorily.
Of the groups of fungi, only the Phycomycetes are predominantly
aquatic. In general, they are unicellular. The Phycomyctes include many
parasitic species that are pathogens of planktonic algae, small animals, and
the eggs of crustacean larvae and fish (Rheinheimer, 1991). The As-
comycetes and Deuteromycetes (particularly the aquatic Hyphomycetes)
are often abundant on decaying leaves and wood (Fig. 8.11). The