Clavelina lepadiformis is a colonial ascidian living in groups of 3 to 3OO zooids. They
are elongated, cylindrical and up to 2 cm tall. The test is smooth and completely transparent so that the
branchial sac is clearly visible. The endostyle, the dorsal axis, the margin of the oral and atrial siphons
as well as the upper part of the pharynx are underlined by a thin white or yellowish line. The zooids are
joined together
by a short basal stolon that cling on rocks, seaweeds or piles.
It is found from surface to 50 m deep in the Atlantic Ocean, the North Sea, the English Channel and
in the Mediterranean Sea.
(source : European Register of Marine Species)
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.
Endostyle : Groove through which food particles are moved up to the oesophagus.
Stolon : Root-like element binding together the individuals of a colony.
Clavelina lepadiformis
Close view
Clavelina lepadiformis
Detail of the siphons
Top photograph :
© Wilfried Bay-Nouailhat. Published with author's kind permission :
Clavelina lepadiformis,
Illes Medes, Costa Brava, East of Spain. Depth 7 meters.
Bottom photographs : © Wilfried Bay-Nouailhat. Published with author's kind permission :
Clavelina lepadiformis, Close view. Ria d'Etel, South Brittany, West of France. Depth 8 meters.
© Wilfried Bay-Nouailhat. Published with author's kind permission :
Clavelina lepadiformis, Detail of the siphons. Illes Medes, Costa Brava, East Spain. Depth 12 meters.
Text : Anne Bay-Nouailhat © 2005-2020.
Translation : Anne Bay-Nouailhat © 2007-2020.
