(Romanes, 1876)
Description
Umbrella only slightly flatter than a hemisphere [Eutonina indicans ], jelly rather thick. Velum narrow, ca 1/10 bell radius.
Stomach short, situated on broad and elongate conical gastric peduncle reaching only a little beyond umbrella. Mouth with four folded lips [E.indicans-habitus ].
Radial canals four, extending along gastric peduncle; they and ring canal narrow. No lateral cirri. Eight closed adradial marginal vesicles each with ca 12 concretions.
Young specimens: E.indicans-juvenile.
Size
Diameter of umbrella when fully grown ca 25-35 mm; gonads starting 1.25-3.5 mm from base of peduncle in Atlantic specimens (Russell, 1953a); distal end 1.0-1.5 mm from margin.
Colour
Stomach, gonads and marginal tentacle bases bright sepia, with dark pigment on tentacle bases and along dorsal surfaces of grooves in roof of stomach.
Ecology
Medusa recorded from May-September around the British Isles (Russell, 1953a).
Depth range
Coastal plankton; the species may be taken at the surface during daylight. Since the medusa can live for more than 100 days, it might be found far from shallow waters.
Distribution around the British Isles
Medusa reported from several localities in (Russell, 1953a; Howe, 1959; J. H. Fraser, 1972), regularly Clyde though hydroid not located (C. Edwards, 1968, and in Russell, 1970a), and Fair Isle (McMillan, 1986).
Distribution in the North Sea
Northern North Sea off NE and SE Scotland and Northumberland; southern and eastern North Sea; Skagerrak and Kattegat, extends into the Baltic Sea at least to the Sound of Fehmarn, near Kiel Bay.
World distribution
NE Atlantic Ocean from the southern North Sea, north to Iceland and mid-Norway (Kramp, 1961, and other sources); also recorded from Alaska and the Pacific coast of Canada (Arai and Brinckmann-Voss, 1980, many records) and California (Rees, 1978), and from the Kurile Islands, Kamtchatka and Japan (Kramp, 1961; Naumov, 1969; Arai and Brinckmann-Voss, 1980). Also reported from India.
Remark
Hydroid only known from culture.
[After Cornelius, 1995a]