A zoospore is a

motile Motility is the ability of an organism to move independently, using metabolic energy. Definitions Motility, the ability of an organism to move independently, using metabolic energy, can be contrasted with sessility, the state of organisms th ...

asexual

spore In biology, a spore is a unit of sexual or asexual reproduction that may be adapted for dispersal and for survival, often for extended periods of time, in unfavourable conditions. Spores form part of the life cycles of many plants, algae, f ...

that uses a

flagellum A flagellum (; ) is a hairlike appendage that protrudes from certain plant and animal sperm cells, and from a wide range of microorganisms to provide motility. Many protists with flagella are termed as flagellates. A microorganism may have f ...

for

locomotion Locomotion means the act or ability of something to transport or move itself from place to place. Locomotion may refer to: Motion * Motion (physics) * Robot locomotion, of man-made devices By environment * Aquatic locomotion * Flight * Locomoti ...

. Also called a swarm spore, these spores are created by some

protists A protist () is any eukaryotic organism (that is, an organism whose cells contain a cell nucleus) that is not an animal, plant, or fungus. While it is likely that protists share a common ancestor (the last eukaryotic common ancestor), the excl ...

bacteria Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among ...

, and

fungi A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately from ...

to propagate themselves.

Diversity

Flagella types

Zoospores may possess one or more distinct types of flagella - tinsel or "decorated", and whiplash, in various combinations. *Tinsellated (straminipilous) flagella have lateral

filament The word filament, which is descended from Latin ''filum'' meaning " thread", is used in English for a variety of thread-like structures, including: Astronomy * Galaxy filament, the largest known cosmic structures in the universe * Solar filament ...

s known as

mastigonemes Mastigonemes are lateral "hairs" that attach to protistan flagella. Flimsy hairs attach to the flagella of euglenid flagellates, while stiff hairs occur in stramenopile and cryptophyte protists.Hoek, C. van den, Mann, D. G. and Jahns, H. M. (1 ...

perpendicular to their main axis, which allow for more surface area, and disturbance of the medium, giving them the property of a

rudder A rudder is a primary control surface used to steer a ship, boat, submarine, hovercraft, aircraft, or other vehicle that moves through a fluid medium (generally aircraft, air or watercraft, water). On an aircraft the rudder is used primarily to ...

, that is, used for steering. *Whiplash flagella are straight, to power the zoospore through its medium. Also, the "default" zoospore only has the propelling, whiplash flagella. Both tinsel and whiplash flagella beat in a

sinusoidal A sine wave, sinusoidal wave, or just sinusoid is a mathematical curve defined in terms of the '' sine'' trigonometric function, of which it is the graph. It is a type of continuous wave and also a smooth periodic function. It occurs often in m ...

wave pattern, but when both are present, the tinsel beats in the opposite direction of the whiplash, to give two axes of control of

motility Motility is the ability of an organism to move independently, using metabolic energy. Definitions Motility, the ability of an organism to move independently, using metabolic energy, can be contrasted with sessility, the state of organisms th ...

Morphological types

eukaryotes Eukaryotes () are organisms whose cells have a nucleus. All animals, plants, fungi, and many unicellular organisms, are Eukaryotes. They belong to the group of organisms Eukaryota or Eukarya, which is one of the three domains of life. Bacte ...

, the four main types of zoospore are illustrated in Fig. 1 at right: # Posterior whiplash flagella are a characteristic of the

Chytridiomycota Chytridiomycota are a division of zoosporic organisms in the kingdom Fungi, informally known as chytrids. The name is derived from the Ancient Greek ('), meaning "little pot", describing the structure containing unreleased zoöspores. Chytrids ...

, and a proposed uniting trait of the

opisthokont The opisthokonts () are a broad group of eukaryotes, including both the animal and fungus kingdoms. The opisthokonts, previously called the "Fungi/Metazoa group", are generally recognized as a clade. Opisthokonts together with Apusomonadida and ...

s, a large clade of eukaryotes containing animals and fungi. Most of these have a single posterior flagellum (Fig. 1a), but the

Neocallimastigales Neocallimastigomycota is a phylum containing anaerobic fungi, which are symbionts found in the digestive tracts of larger herbivores. Anaerobic fungi were originally placed within phylum Chytridiomycota, within Order Neocallimastigales but late ...

have up to 16 (Fig. 1b). # Anisokonts are biflagellated zoospores with two whip types flagella of unequal length (Fig. 1c). These are found in some of the Myxomycota and

Plasmodiophoromycota The plasmodiophores (also known as plasmophorids or plasmodiophorids) are a group of obligate endoparasitic protists belonging to the subphylum Endomyxa in Cercozoa. Taxonomically, they are united under a single family Plasmodiophoridae, order P ...

. # Zoospores with a single anterior flagellum (Fig. 1d) of the tinsel type are characteristic of

Hyphochytriomycetes Hyphochytrids are eukaryotic organisms in the group of Stramenopiles (Heterokonta). Characteristics They are distinguished by an anterior tinsel flagellum on their zoospores. Also they have a rhizoidal or hypha-like vegetative system (hence the ...

. # Heterokont are biflagellated 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 the

Oomycota Oomycota forms a distinct phylogenetic lineage of fungus-like eukaryotic microorganisms, called oomycetes (). They are filamentous and heterotrophic, and can reproduce both sexually and asexually. Sexual reproduction of an oospore is the resul ...

and other

heterokont Heterokonts are a group of protists (formally referred to as Heterokonta, Heterokontae or Heterokontophyta). The group is a major line of eukaryotes. Most are algae, ranging from the giant multicellular kelp to the unicellular diatoms, which ...

Zoosporangium

A zoosporangium is the asexual structure (

sporangium A sporangium (; from Late Latin, ) is an enclosure in which spores are formed. It can be composed of a single cell or can be multicellular. Virtually all plants, fungi, and many other lineages form sporangia at some point in their life cy ...

) in which the zoospores develop in plants, fungi, or protists (such as the

References

External links