Styelidae

Styelidae is a family of tunicates, also known as sea squirts, belonging to the order Stolidobranchia. These sessile marine invertebrates are found in all the world's oceans, from shallow coastal waters to the deep sea. Styelidae are characterized by their leathery or cartilaginous test, which is often tough and opaque. The body is typically vase-shaped and attached to a substrate such as rocks, shells, or even man-made structures.

Members of this family are filter feeders, drawing water through their oral siphon, extracting food particles, and expelling the filtered water through the atrial siphon. Styelidae exhibit a wide range of sizes and shapes, with some species being solitary and others colonial. Their coloration can vary greatly, from drab browns and grays to vibrant reds, oranges, and blues, often depending on their habitat and diet. Reproduction is typically sexual, with individuals releasing sperm and eggs into the water column, though some species are hermaphroditic and can self-fertilize. Larval stages are free-swimming before settling and metamorphosing into the adult form. They play an important role in marine ecosystems as filter feeders and as a food source for various organisms.