Botryllus schlosseri   (Pallas,  1766) (Sea Squirt)
Organism information awaits expert curation
Class: Ascidiacea

Image copyrights: Keith Hiscock

Colony of Botryllus schlosseri on rock.

Size: Zooids 1-2 mm long; Colonies 75-100 mm.

Color: Living colonies purple brown in color.

Colonies investing sheets or fleshy lobes. Test very thin and soft. Zooids arranged in circular to elongate, often crowded systems. Common cloacal openings circular to elongate. Terminal ampullae of test vessels conspicuous, crowded in between the systems and in the border of the colony.

Branchial aperture terminal with a smooth border. Atrial aperture small, upper border produced into a large pointed atrial lip. 12 branchial tentacles. Branchial sac with 9-12 rows of stigmata. 20-24 stigmata per row. Stomach short, spherical or barrel shaped with 11 folds. Caecum ā€˜Lā€™-shaped with a knob like tip. Gastrointestinal connective present. Anus opens between the sixth and seventh row of stigmata. Gonads one on each side of the body, consisting of a 7-9 testis follicles and two or three large ova.

Hermaphroditic; eggs shed and fertilized in the water.

Synonym (s)
Alcyonium borlasii Turton, 1807
Alcyonium schlosseri Pallas, 1766
Aplidium verrucosum Dalyell, 1839
Botryllus aurolineatus Giard, 1872
Botryllus badium Alder & Hancock, 1912
Botryllus badius Alder & Hancock, 1912
Botryllus bivittatus Milne-Edwards, 1841
Botryllus calendula Giard, 1872
Botryllus calyculatus Alder & Hancock, 1907
Botryllus castaneus Alder & Hancock, 1848
Botryllus gemmeus Savigny, 1816
Botryllus gouldii Verrill, 1871
Botryllus marionis Giard, 1872
Botryllus miniatus Alder & Hancock, 1912
Botryllus minutus Savigny, 1816
Botryllus morio Giard, 1872
Botryllus polycyclus Savigny, 1816
Botryllus pruinosus Giard, 1872
Botryllus rubens Alder & Hancock, 1848
Botryllus rubigo Giard, 1872
Botryllus smaragdus Milne-Edwards, 1841
Botryllus stellatus Gaertner, 1774
Botryllus violaceus Milne-Edwards, 1841
Botryllus violatinctus Hartmeyer, 1909
Botryllus virescens Alder & Hancock, 1848
Polycyclus renieri Salfi, 1931

Common Name (s)
• Golden Star Tunicate (English)
• Star Squirt (English)
Economic Importance and Threats

Habitat:  Rocky, Coastal
Trophic Level:  Consumer
Prey:  Plankton


• Tamil Nadu, Keezha Vaipar INDIA
• Tamil Nadu, Tuticorin INDIA
• Kerala, Vizhinjam Harbour INDIA
• Tamil Nadu, Vellapatti INDIA
• Tamil Nadu, Mandapam INDIA
• Kerala, Vizhinjam INDIA
• Tamil Nadu, Tiruchendur INDIA
• Tamil Nadu, Kayalpattinam INDIA
• Tamil Nadu, Tuticorin Harbour INDIA
• Tamil Nadu, Vembar INDIA
• Tamil Nadu, Mandapam INDIA
• Tamil Nadu, Chennai INDIA
• Tamil Nadu, Kalpakkam INDIA (Record: 1987-1988)

Literature Source(s)
  • Meenakshi, VK and Senthamarai, S (2006) First report on two species of ascidians to represent the genus Botryllus Gaertner, 1774 from Indian waters Journal of the Marine Biological Association of India The Marine Biological Association of India, Cochin 48(1) 100-102 Available at - NIO, Goa
  • Society for the Management of European Biodiversity Data (2009) World Register of Marine Species (WoRMS) Available at -
  • MarLIN: Marine life information network Biology and sensitivity key information sub-programme [on-line] Available at -
  • Sealifebase Available at -
  • Meenakshi, VK; Renganathan, TK; Senthamarai, S and Jeyalakshmi, J (2003) Marine biodiversity - Taxonomy of Indian Ascidians Technical report Available at - Biodiversity Informatics Group, NIO, Goa
  • Sasikumar, N; Rajagopal, S and Nair, KVK (1989) Seasonal and vertical distribution of macrofoulants in Kalpakkam coastal waters Indian Journal of Marine Sciences Scientific Publishers 18(4) 270-275 Available at - NIO, Goa

Page last updated on:2011-06-30

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