Hartlaub, 1894
Description
Umbrella hemispherical with thick apical jelly, much thinner at sides [E.maculata-habitus]. Velum moderately broad, ca 1/4 bell radius. Stomach short, without gastric peduncle; mouth cross-shaped, with four wide unfolded lips with narrow rims. The four radial canals and ring canal all narrow.
Gonads linear, leaving proximal third of radial canal free while distally not quite reaching ring canal [E.maculata-medusa].
Marginal tentacles usually 16-20 [E.maculata-2], occasionally up to 30, with large elongate conical bases [E.maculata-margin]. 1-3 rudimentary marginal bulbs between adjacent marginal tentacles. One spiral lateral cirrus each side of each marginal tentacle base; with rudimentary marginal bulbs. Eight closed marginal vesicles with normally 5-6, at most 10, concretions.
Size
Diameter of bell up to ca 13 mm, height up to ca 10 mm.
Colour
Marginal tentacle bases and gonads bright reddish-brown; one large black spot on each interradius of the stomach (pigmentation may become lost in preserved specimens).
Ecology
Reproductive season: medusa recorded off southern England mainly in August, and in southern North Sea 'usually late summer and autumn' (Russell, 1953a, 1970a). BMNH specimens from Southend, 25 June, and Hirtshals, N Denmark, 29 July.
Depth range
— Medusa in coastal plankton.
— Hydroid material from NW Spain referred to this species reported by Ramil (1988) on an anomuran crab (Porcellana platycheles), an ascidian, the brown alga Himanthalia elongata and another unspecified alga, and on several species of thecate hydroid; in subtidal region, 4-15 m depth.
Distribution in the North Sea
— Medusa known from the southern North Sea, W Baltic Sea and the English Channel, having been reported from off Roscoff, St Vaast, Sheerness, Dover, Southend, Helgoland, Belgium, Jutland, in the Kattegat and near the Elbe estuary (Russell, 1953a, Russell, 1970a; Kramp, 1961; Teissier, 1965).
— Hydroid reported from Helgoland, Netherlands, Belgium, Iberian Peninsula, Mediterranean Sea (after Ramil, 1988).
World distribution
Russell did not report the species from Plymouth, tending to support the impression of this extraordinarily limited distribution. Medusa apparently reported outside European waters only twice, off SW India (Vannucci and Santhakumari, 1972) and Argentina (Goy, 1979).
[After Cornelius, 1995a]