Zooxantellene

Zooxantellene is not a widely recognized term in the scientific literature. It may be a misspelling or informal coinage related to zooxanthellae, the photosynthetic algae that live in partnership with marine invertebrates. The following overview uses zooxanthellae as the central reference point, since no established entity named “zooxantellene” has a clear, broadly accepted definition.

Zooxanthellae are dinoflagellates that form symbiotic associations with a range of marine hosts, most notably scleractinian corals, but also some sea anemones, jellyfish, and flatworms. These algae reside within host tissues, usually in endodermal cells, where they perform photosynthesis and translocate a portion of their photosynthetic products—such as sugars and organic compounds—to their hosts. In return, the zooxanthellae receive a protected environment and access to inorganic nutrients. This mutualism is a major energy source for reef-building corals and contributes to reef growth and calcification, particularly in nutrient-poor tropical waters.

Taxonomy and distribution: historically, zooxanthellae referred to several lineages within the family Symbiodiniaceae, including the genera Symbiodinium, Cladocopium, and Durusdinium. Taxonomic revisions in recent decades have refined these groups, and many corals host diverse clades that differ in light tolerance and thermal sensitivity.

Ecological significance and threats: the zooxanthellae–host symbiosis is central to coral reef ecosystems but is sensitive to environmental stress, especially elevated temperatures and light loads. Coral bleaching occurs when corals expel their symbionts, risking reduced growth, diminished reef structure, and ecosystem decline.