Trichydra pudica

Wright, 1858

Description
Umbrella bell-shaped or hemispherical with thickened apical process [Trichydra pudica ]; exumbrella without nematocyst clusters; jelly fairly thick; velum fairly broad. The four radial canals often with exceedingly fine branches, which may anastomose; ring canal ? solid.
Manubrium large, about 2/3 of length bell cavity, four-sided; mouth with four slightly wavy lips.
Each of the four interradial, cushion-like gonads almost completely covers an interradial manubrium wall.
Thirty to forty (or more) solid marginal tentacles with large basal swellings and small basal bulbs; ocelli absent.

Size
Umbrella 2-4 mm wide.

Colour
Manubrium and bases of marginal tentacles brown.

Ecology and depth range
Neritic; both the Pacific and North Sea reports are from the period April-June.

Distribution in the North Sea
Probably only a rare visitor, carried into the English Channel and southern North Sea by water from the cyclonic swirl south of Ireland; also in the northernmost North Sea (Russell, 1953a; Fraser, 1972; as Pochella polynema).

World distribution
E North Atlantic Ocean; Pacific coast of Canada.

Remark
The medusa Pochella polynema Hartlaub, 1917 [Pochella polynema ] appeared to originate from the hydroid Trichydra pudica Wright, 1858 (Edwards, 1973a).

[After Russell, 1953a; Russell, 1978b; Kramp, 1959]