(O.F. Müller, 1776)
Description
Body pear shaped in sagittal plane, laterally compressed in the tentacular plane; large oral lobes comprise one third of the body height. Sub-tentacular comb rows extend in the oral extend in the oral direction into the auricles; subsagittal comb rows much longer and extend into the free outer ends of the oral lobes. Internally the meridional gastrovascular canals anastomose and send loops into lobes and auricles. Tentacle reduced in length, without sheaths, situated at each side of elongated mouth; accessory tentacles present along the edge of the mouth.
Colour
The adult has a milky appearance, the extension of the subsagittal comb-rows into the oral lobes may be black in its outer part.
Juveniles
The early larva may be distinguished from the young stages of the Genus Pleurobrachia by the V-shape of the comb-rows in pairs close to each other at the aboral end and more distant orally. The tentacle of the larva is inserted in the body as in the Genus Bolinopsis while in the Genera Pleurobrachia and Mertensia the basis of the monofilamentous tentacle is on the surface of the body. During development the tentacle bulbs migrate orally, the oral lobes appear and with it the modifications of the gastrovascular system. It is extremely fragile, and only when caught and preserved with great care will identifiable fragments of the animal remain.
Size
Adult up to 150 mm high.
Depth range
No information available.
Distribution in the North Sea
All North Sea, including Skagerrak an Kattegatt; occasionally in the Baltic Sea.
World distribution
North Atlantic and the coastal waters of NW Europe.
[After Greve, 1975]