Halocynthia papillosa is a solitary ascidian which is generally 10 cm high but
may reach 20 cm. The body is ovoïd, the red test is cartilaginous, rough with a granulous surface.
The siphons are distant: the oral siphon is terminal and the atrial siphon is half-way down the body.
Rigid bristles, used as sensitive elements, surround the siphons. The red sea-squirt can contract and
close its siphons when disturbed.
It lives attached to rocks, overhangs or among Posidonia, avoiding luminous areas, between 2 and 100
meters deep. It is a Mediterranean species that may live in the surrounded Atlantic Ocean, particularly
along the Portuguese coasts.
(source : European Register of Marine Species)
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.
Halocynthia papillosa
Red sea-squirt.
Halocynthia papillosa
Close view.
Top photograph :
© Wilfried Bay-Nouailhat. Published with author's kind permission :
Halocynthia papillosa,
Illes Medes, Costa Brava, East of Spain. Depth 15 meters.
Bottom photographs : © Wilfried Bay-Nouailhat. Published with author's kind permission :
Halocynthia papillosa, Red sea-squirt.. Illes Medes, Costa Brava, East Spain. Depth 18 meters.
© Wilfried Bay-Nouailhat. Published with author's kind permission :
Halocynthia papillosa, Close view.. Illes Medes, Costa Brava, East Spain. Depth 18 meters.
Text : Anne Bay-Nouailhat © 2005-2020.
Translation : Anne Bay-Nouailhat © 2007-2020.
