zoöspore

A zoöspore is a type of motile asexual spore produced by certain algae, fungi, and protists. The term derives from the Greek words *zoon* (ζῶον), meaning "animal," and *spora* (σπόρα), meaning "seed," reflecting its ability to move independently through flagella or cilia. Unlike non-motile spores, zoöspores possess one or more whip-like appendages that enable locomotion, facilitating dispersal and colonization of new environments.

Zoöspores are commonly found in groups such as the Oomycetes (a filamentous fungus-like lineage), certain green algae (e.g., *Chlamydomonas* and *Spirogyra*), and slime molds. In these organisms, they play a critical role in reproduction and survival. For example, in the water mold *Phytophthora infestans*, which causes late blight in potatoes, zoöspores are released into water and swim toward host plants, infecting them to propagate the species.

The formation of zoöspores typically occurs through meiosis or mitotic division, depending on the organism. After germination, they may develop into new individuals or contribute to sexual reproduction cycles. Some zoöspores are encased in protective walls, allowing them to remain dormant until favorable conditions return.

While zoöspores are essential for the life cycles of many organisms, they also serve as important biological indicators. Their presence in aquatic ecosystems can reflect water quality and the health of algal populations. Additionally, certain pathogenic species that produce zoöspores, such as those causing plant diseases, pose significant agricultural and ecological challenges.