Zoospore

Flagella types

Zoospores may possess one or more distinct types of flagella: tinsel or "decorated", and whiplash, in various combinations.

Both tinsel and whiplash flagella beat in a sinusoidal wave pattern, but when both are present, the tinsel will beat in the opposite direction of the whiplash, to give 2 axes of control of motility.

Morphological types

In eukaryotes there are four main types of zoospore, illustrated in Fig. 1 at right:

1. Opisthokont. Posterior whiplash flagella, a characteristic of Chytridiomycota, and a proposed a uniting trait of the Opisthokonts, a large clade of eukaryotes containing animals and fungi. In most of these, there is a single posterior flagellum (Fig. 1a), but in Neocallimastigales, there are up to 16 (Fig. 1b)
2. Anisokont. Biflagellate zoospores with two whip type flagella of unequal length (Fig. 1c). These are found in some Myxomycota and Plasmodiophoromycota.
3. Zoospores with a single anterior flagellum (Fig. 1d) of the tinsel type, characteristic of Hyphochytriomycetes.
4. Heterokont. Biflagellate zoospores (Fig. 1e, f) with both whiplash and tinsel type flagella attached anteriorly or laterally. These Zoospores are characteristic of Oomycota and other Heterokonts.

Zoosporangium

A zoosporangium is the asexual structure (sporangium) in which the zoospores develop in plants, fungi, or protists (such as the Oomycota)