Category: Lancelets and Tunicates view all from this category
Description Ciona intestinalis (vase tunicate) is a urochordata (sea squirt), a tunicate widely distributed in Northern European waters. As an invasive species, it has also spread to other parts of the world.
Since Darwin's time, sea squirts have been recognized as being possibly the closest invertebrate relative of humans. Its full genome has been sequenced, one that shares 80% of its genes with humans. During the 21st century it has become a major experimental model for developmental biologists.
Ciona intestinalis is a solitary tunicate with a cylindrical, gelatinous body, up to 14 cm long. The soft, smooth, translucent tunic (outer skin) is pale yellow or green in colour with orange body parts visible through the translucent tunic. Incurrent and excurrent siphons are easily seen near the tip of the organism.
The body of Ciona is bag-like and covered by a tunic, which is a secretion of the epidermal cells. The body is attached at a permanent base located at the posterior part, and the opposite bears two openings, the buccal and atrial siphons. The water is drawn into the ascidian through the buccal (oral) siphon and leaves the atrium through the atrial siphon (cloacal).
In their immature tadpole form, they resemble vertebrates.
Habitat Rocks, Piers, driftwood & pilings, Ocean or bay shallows.
Range Western Canada, Northwest, Alaska, New England, Eastern Canada, California.