Ciona intestinalis

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Vase tunicate

Ciona intestinalis

Kingdom:	Animalia
Phylum:	Chordata
Subphylum:	Urochordata
Class:	Ascidiacea
Order:	Enterogona
Suborder:	Phlebobranchia
Family:	Cionidae
Genus:	Ciona
Species:	C. intestinalis

Binomial name

Ciona intestinalis
(Linnaeus, 1767)

Ciona intestinalis or vase tunicate is a Urochordata (sea squirt) whose genome has been sequenced and which has become, over the past decade, a major experimental model for developmental biologists. Four putative subspecies have been described.

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).

It is considered to be an invasive species and grows in dense aggregations on any floating or submerged substrate, particularly artificial structures like pilings, aquaculture gear, floats and boat hulls, in the lower intertidal to subtidal zones. Often grows with or on other fouling organisms.

Ciona intestinalis is a hermaphroditic broadcast spawner but cannot self-fertilize. Eggs and sperm, when released, can stay in the water column for 1 to 2 days while the larvae are free-swimming for 2 to 10 days.

Ciona intestinalis is thought to be spread to new areas mainly through hull fouling. Since it’s larvae can live for up to 10 days this species may also be transferred through the release of bilge or ballast water.

To avoid spreading this organism fish and shellfish harvesters should avoid transferring harvested shellfish and fishing gear to other areas. Gear should be thoroughly dried before transfer. Boat hulls should be inspected and, if necessary, thoroughly cleaned and disinfected with bleach or vinegar and dried before moving to other areas. Any organisms removed from boat hulls or gear should be disposed of on land. Bilge water should be released on land or disinfected.