Edwards, 1983
Description
Umbrella bell-shaped, jelly at maturity rather thicker apically than laterally [Sarsia striata ].Velum broad. Exumbrella of young medusa with a few scattered nematocysts. Four radial canals, narrow in young medusae and with an umbilical canal, remain narrow and only at maturity each canal passes through the jelly to enter the middle of the upper side of the tentacle bulb. A small round apical knob may be present or absent. Subumbrellar pockets between the canals in apical and lateral view clearly marked with angular ridges. Interradial exumbrellar furrows well developed and deep, the perradial furrows very shallow.
Gonad continuous, surrounding most of the manubrium, leaving short basal portion and mouth portion free.
Manubrium reaches a length of about 4 times length bell cavity. Mouth region capacious, occupying about 1/4 of manubrium length.
The four marginal tentacles are hollow and several times longer than height of umbrella; tentacles densely armed with nematocysts in spirally arranged clusters and a terminal hollow globular mass. Tentacle bulbs each with an aboral ocellus.
Size
Upon release from the hydroid the umbrella is about 1.2 mm in diameter, mature medusae may reach a size of about 11 mm high and wide.
Colour
Apical chamber and tentacle bulbs scarlet; ocelli black.
Ecology and depth range
Medusae described from culture, reared from hydroids that were found at 15-20 m depth off Oban, Scotland. Active swimmers in the upper water layers, common in more open waters.
Distribution in the North Sea
Northern North Sea.
World distribution
E North Atlantic.
[After Edwards, 1983]