(O.F. Müller, 1776)
Description
Umbrella tall thimble-shaped with small conical apical projection [A.digitale-habitus]; jelly thin; subumbrellar muscles strong; velum broad and well-developed. Eight straight radial canals an ring canal narrow.
Gastric peduncle slender, almost as long as bell cavity; manubrium small; mouth with four simple lips.
Gonads long, sausage-shaped, suspended from radial canals near base of peduncle [A.digitale-gonads ].
A single row of 80 or more solid smooth marginal tentacles, all alike. Eight free club-shaped marginal statocysts, each situated midway between adjacent radial canals on inner side of ring canal.
Young specimens: A.digitale-young-habitus
Size
Umbrella10-40 mm high and about half as wide as high.
Colour
Pink of varying degrees.
Ecology and depth range
Holopelagic; epi- to bathypelagic. Vertical distribution extensive, though rare in the uppermost surface layers and very deep water; in the southernmost area of distribution on the northern hemisphere, it occurs only in the intermediate and deep strata.
Distribution in the North Sea
North Sea, Skagerrak.
World distribution
W South Atlantic; North Atlantic; Arctic; Indo-Pacific.
Remark
Polyp stage absent.
[After Russell, 1953a; Russell, 1981a; Kramp, 1959; Bouillon, 1999]