1. A ciliated, mucus-secreting groove or tube in the pharynx of certain aquatic animals, such as tunicates and amphioxus, that functions in filter feeding.
Usage: biology; zoology; technical term

Examples

• The endostyle of the tunicate secretes mucus to trap food particles from seawater.
• In amphioxus, the endostyle is homologous to the thyroid gland in vertebrates.
• The ciliated endostyle moves captured food toward the esophagus.
• Marine biologists study the endostyle to understand filter-feeding mechanisms in primitive chordates.