Ciona savignyi (lat.) - a type of shellfish from the class of ascidium . It lives in shallow water around Japan . In addition, it is distributed on the western coast of North America , where it is considered as an invasive species.
| Ciona savignyi |
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| Scientific classification |
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| No rank : | Bilateral symmetrical |
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| International scientific name |
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Ciona savignyi ( Herdman , 1882) |
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Content
Ciona savignyi - solitary ascidium with a bottle-shaped or vase-shaped body up to 15 cm in length. Typically, the body expands to the base, which is constantly attached to a solid surface. The outer surface of the body, or shell, is jelly-like transparent from whitish to cream-colored. Often through the transparent membrane visible muscle bands and internal organs. At the upper end is an oral siphon through which water enters. The hole closes with eight wings with yellow edges and orange-red spots. On the side next to the oral siphon is an atrial (cloacal) siphon, through which filtered water is thrown out. The atrial siphon closes with six yellow valves with red spots, similar to the valves of the oral siphon. 5 to 7 muscle bands stretch along the body membrane, [1] with the help of which siphons can be compressed in case of danger. [2] The species is very similar to Ciona intestinalis , but Ciona savignyi has white spots on the membrane that are absent in C. intestinalis . In addition, C. intestinalis does not have a reddish color on the oral siphon. [one]
The birthplace of Ciona savignyi is considered to be Japan, as well as, possibly, Alaska and British Columbia . However, in 1985, the species was seen in Long Beach in California, after which it spread along the coast of California. [1] In 1998, it was discovered already in Puget Sound and on the islands of San Juan ( Washington state).
This shell prefers docks, piles, yachts , bays and aquaculture facilities. It is believed to spread with ballast water. In the USA it is considered as an invasive species, [1] although the possible impact on the local ecosystem is unknown. [3]
Ciona savignyi feeds by filtering water. Water enters through an oral siphon and passes through the mucous network, which traps plankton . Periodically, mucus with plankton coagulates and is swallowed, and a new one is secreted in its place. Filtered water is thrown out through an atrial siphon. [2]
Like other shells, Ciona savignyi is a hermaphrodite . However, male and female gonads mature at different times, which prevents self-fertilization. Gametes are released into the sea, and after fertilization, tadpole larvae hatch from eggs. After a few days, the larvae attach to a solid surface and undergo metamorphosis, turning into young tunicates. [four]
Genome
The Ciona savignyi genome has been sequenced. The species has the greatest genetic diversity among known species. [five]
- ↑ 1 2 3 4 Fofonoff, PW; Ruiz, GM; Steves, B .; Carlton, JT Ciona savignyi (neopr.) . National Exotic Marine and Estuarine Species Information System (2003). Date of treatment June 19, 2013.
- ↑ 1 2 Ruppert, Edward E. Invertebrate Zoology, 7th edition / Edward E. Ruppert, Richard, S. Fox, Robert D. Barnes. - Cengage Learning, 2004. - P. 945. - ISBN 81-315-0104-3 .
- ↑ Ciona savignyi (neopr.) . University of Washington. Date of treatment June 20, 2013.
- ↑ Allen Pleus; Pam Meacham. Ciona savignyi (Solitary sea squirt) (neopr.) . Aquatic Invasive Species . Washington Department of Fish and Wildlife. Date of treatment June 20, 2013.
- ↑ Leffler, EM .; Bullaughey, K .; Matute, DR .; Meyer, WK .; Ségurel, L .; Venkat, A .; Andolfatto, P .; Przeworski, M. Revisiting an old riddle: what determines genetic diversity levels within species? (English) // PLoS Biol: journal. - 2012. - Vol. 10 , no. 9 . - P. e1001388 . - DOI : 10.1371 / journal.pbio.1001388 . - PMID 22984349 .
