A zoospore is a motile
that uses a flagellum
. Also called a swarm spore, these spores are created by some protists
to propagate themselves.
Zoospores may possess one or more distinct types of flagella: ''tinsel'' or "decorated", and ''whiplash'', in various combinations.
*''Tinsellated'' (also known as ''straminipilous''
[) flagella have lateral filaments known as mastigonemes perpendicular to the main axis which allow for more surface area, and disturbance of the medium, giving it the property of a rudder, that is, the purpose of being used for steering.
*''Whiplash'' flagella are straight, to power the zoospore through its medium. There is also the 'default' zoospore, which only has the propelling, 'whiplash' flagella.
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.
In eukaryotes there are four main types of zoospore,
illustrated in Fig. 1 at right:
# Opisthokont. Posterior whiplash flagella, a characteristic of Chytridiomycota, and a proposed 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)
# Anisokont. Biflagellates zoospores with two whip types flagella of unequal length (Fig. 1c). These are found in some Myxomycota and Plasmodiophoromycota.
# Zoospores with a single anterior flagellum (Fig. 1d) of the tinsel type, characteristic of Hyphochytriomycetes.
# Heterokont. Biflagellate zoospores (Fig. 1e, f) with both whiplash(smooth) and tinsel type(fine outgrowths called mastigonemes) flagella attached anteriorly or laterally. These Zoospores are characteristic of Oomycota and other Heterokonts.
A zoosporangium is the asexual structure (sporangium) in which the zoospores develop in plants, fungi, or protists (such as the Oomycota)
Category:Fungal morphology and anatomy