Diazona violacea Savigny, 1816

Football sea-squirt

Diazona violacea

Ria de Arosa, Spain, 32 meters, 2011, JS

Diazona violacea

Bay of Lannion, France, 28 meters, 2011, WBN

Diazona violacea

Ria de Arosa, Spain, 32 meters, 2011, JS

Diazona violacea

Illes Medes, Spain, 22 meters, 2011, WBN


Diazona violacea s a colonial ascidian forming massive colonies of up to 40 cm in diameter and 20 cm in height. Young colonies are rather ball-shaped, whereas older ones are slightly flattened. The zooids are joined in a common gelatinous cushion-shaped base. The branchial parts of the zooids (the upper parts) are distinct and emerge of 2 cm from the base. The test is more or less translucent, white or yellowish. A vertical line draws the endostyle of each zooid; the atrial and oral siphons are underlined by a white margin and six white spots ornate the upper part of the pharynx. Diazona zooids resemble clavelina ones but their bases are different: a thick basal mass for Diazona versus a thin basal stolon for Clavelina.
At the end of summer, after reproduction time, zooids atrophy and there's only the basal mass left. In spring-time, the colony buds again from this base.


Diazona violacea lives attached to rocks or stones covered by sand, in strong current-swept areas between 15 and 200 meters deep in the Atlantic Ocean, the English Channel and the Mediterranean Sea.

Image satellite: © Esri, DigitalGlobe, GeoEye, Earthstar Geographics, CNES/Airbus DS, USDA, USGS, AeroGRID, IGN, and the GIS User Community.

Données de distribution : Diazona violacea Savigny, 1816 in GBIF Secretariat (2019). GBIF Backbone Taxonomy. Checklist dataset accessed via on 2022-05-23.


Source : World Register of Marine Species

Biota (Superdomain)
Animalia (Kingdom)
Chordata (Phylum)
Tunicata (Subphylum)
Ascidiacea (Class)
Aplousobranchia (Order)
Diazonidae (Family)
Diazona (Genus)
Diazona violacea (Species)

Page glossary

Zooid : individual, single animal.

Test : or tunic: thick layer secreted by the mantel containing cellulose and protecting the animal.

Oral siphon : opening by which water is drawn in the ascidian.

Atrial siphon : opening through which water is expelled.


Text : Anne Bay-Nouailhat © 2007 - 2022.

Photos : © Javier Santiago, Wilfried Bay-Nouailhat. PPublished with their kind permission.
Websites and reference works : Consult bibliography

How to cite this page

Bay-Nouailhat A., January 2007, Description of Diazona violacea, [On line], consulted on 2022 May 23.


Photographie de Anne Bay-Nouailhat

Anne Bay-Nouailhat

Project manager in marine environment
Professional diver - Naturalist

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