|Sea Tulips, Pyura spinifera. |
A symbiotic sponge covers its surface.
Giribet et al., 2000
Tunicates (Sea squirts or Urochordata) are a subphylum of the Chordates. They are filter feeders, living mainly from plankton. The adults are sessile, stuck to rocks. They are called tunicates because the adult form is covered by a leathery tunic. This tunic supports and protects the animal. Many of them are colonial or semi-colonial in their adult stage. They are quite a large group, containing about 3,000 species. The adults live mostly on the sea floor, in the littoral zone.
Feeding[change | change source]
The sea squirt has two openings in its small body. One opening, called the oral siphon, sucks water into the animal; the other opening, called the atrial siphon, squirts water out of the animal. Inside is a little basket-like sieve which traps food: so these sea squirts are filter feeders. The Sea squirt can close the holes in its siphons, like a drawstring can close the opening in a bag.
Life cycle[change | change source]
When in its larval state, it looks like a tadpole and is sometimes called a tadpole larva. Like many sea creatures, a sea squirt larva looks very different from an adult sea squirt. The larva swims for a short time and then attaches itself to something on the sea floor, like a rock, transforming into its adult form. It usually stays in one place for the rest of its life.
Relationships[change | change source]
Discoveries[change | change source]
Scientists have also found out that some species can heal some damage done to them, over several generations. A similar process might be possible for humans.
References[change | change source]
|Wikispecies has information on: Urochordata.|
- Delsuc F., Brinkmann H., Chourrout D. & Philippe H. (2006). "Tunicates and not cephalochordates are the closest living relatives of vertebrates". Nature 439 (7079): 965–968. doi:10.1038/nature04336. PMID 16495997.
- Delsuc F., Tsagkogeorga G., Lartillot N. & Philippe H. (2008). "Additional molecular support for the new chordate phylogeny". Genesis 46 (11): 592–604. doi:10.1002/dvg.20450. PMID 19003928.
- Singh T. R., Tsagkogeorga G., Delsuc F., Blanquart S., Shenkar N., Loya Y., Douzery E. J. & Huchon D. (2009). "Tunicate mitogenomics and phylogenetics: peculiarities of the Herdmania momus mitochondrial genome and support for the new chordate phylogeny". BMC Genomics 10 (1): 534. doi:10.1186/1471-2164-10-534. PMC 2785839. PMID 19922605. http://www.biomedcentral.com/1471-2164/10/534.
- Sea Squirt, heal thyself: scientists make major breakthrough in regenerative medicine
- Solomon E. Berg L. & Martin D. 2002. Biology. Brooks/Cole.