Zanclea costata

Gegenbaur, 1857

Umbrella bell-shaped; jelly moderately thick, sometimes thicker in the apical region and near margin; velum fairly broad [Zanclea costata ]. Four straight radial canals and ring canal of moderate breadth; central sections of radial canals with linear thickenings. Exumbrellar nematocysts in meridional oval or club-shaped patches immediately above marginal bulbs or elongated meridional tracks towards apex.
[Z.costata-medusa ] Manubrium cylindrical, not reaching beyond umbrella margin and without tentacles. Mouth circular, simple, with nematocysts along margin.
Gonads interradial, leaving mouth end free. Species may occur with two opposite or four perradial hollow marginal tentacles, species immediately identifiable by the abaxial stalked cnidophores on the tentacles, stalks filiform.
Cnidophores oval in shape, 0.02-0.03 mm in length, each containing 2-5 nematocysts. Marginal tentacular bases elongate.
Young medusa: Z.costata-young-habitus

Umbrella up to 3 mm high and wide.

[Z.costata-habitus ] Manubrium pale yellow, radial canals and ring canal pink; marginal tentacle bulbs reddish or orange.

Ecology and depth range
In British waters recorded from the plankton in May to September.

Distribution in the North Sea
Northern and southern North Sea, Skagerrak, W English Channel.

World distribution
North Atlantic Ocean including Mediterranean Sea; Red Sea, Pacific Ocean.

[After Russell, 1953a; Russell, 1977a; Kramp, 1959]