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How are tunicates important in marine food chains?

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Bright blue sea squirt Rhopalaea crassa with yellow-edged openings grows on a coral reef among various corals in the Philippines. — tunicate Blue spot sea squirt (*Clavelina moluccensis*), a colonial tunicate.

Tunicates are vital components of marine ecosystems, serving as an essential link in the food chain. By acting as filter feeders, they play a significant role in processing organic matter within their environments.12

Many tunicates, such as those in the class Appendicularia, utilize specialized structures to net food from the water, while others use their gill slits as a filtering apparatus to capture nutrients. Because they are found in great numbers throughout the world's oceans—ranging from polar regions to the tropics—they represent a widespread food source for various marine organisms. Through their position in the food web, they indirectly contribute to human food sources as well. Additionally, some tropical species live symbiotically with unicellular plants and blue-green algae, which can provide them with supplemental nutrition.234516