Aplidium punctum is a colonial ascidian forming capitate colonies reaching 6 cm in height.
Up to forty zooids are embedded in a common test forming a flat-topped lobe arising from a stalk.
The base of the
colony is often encrusted with sand. The test is transluscent and the general colour of the colony is
pale orange. Each zooid has a six-lobed oral siphon and a red spot at the upper-end of the endostyle.
Colonies of orange flake-ascidians often live aggregated, forming bunches attached to rocks
from low water level to 25 meters deep.
It is found in the North-East Atlantic and the English Channel.
Phylum Chordata, subphylum Tunicata, class Ascidiacea, order Aplousobranchia, family Polyclinidae, Aplidium punctum (Giard, 1873).
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.
Endostyle: Groove through which food particles are moved up to the oesophagus.
Photograph: © Wilfried Bay-Nouailhat. Published with author's kind permission.
Aplidium punctum, Iles Glénan, South-Brittany, West of France. Depth 12 meters.
Text: Anne Bay-Nouailhat © 2005-2008.
Translation: Anne Bay-Nouailhat © 2007-2008.