ORDER
Trachymedusa
FAMILY
Rhopalonematidae
TAXONOMY
Medusa digitale O. F. Müller, 1776, North Atlantic.
OTHER COMMON NAMES
French: Méduse doigtier.
PHYSICAL CHARACTERISTICS
Umbrella cylindrical, 0.39–1.5 in (10–40 mm) high, about twice high than wide, with a small conical projection; lateral mesogleal walls thin, subumbrellar muscles strong; peduncle slender, long, conical, almost as long as subumbrellar cavity; manubrium small; mouth with four simple lips; eight long, sausage-shaped gonads, arising from the radial canals near the apex of the subumbrella and hanging freely in subumbrellar cavity; 80 or more solid marginal tentacles with a core of single endodermal chordal cells; eight free statocysts.
DISTRIBUTION
Worldwide distribution in all oceans and entering the Mediterranean. (Specific distribution map not available.)
HABITAT
From surface down to considerable depths, 1,970 ft (600 m).
BEHAVIOR
Prolate medusae using the entire bell for jet propulsion; extremely active medusae.
FEEDING ECOLOGY AND DIET
Other small planktonic animals.
REPRODUCTIVE BIOLOGY
Dioecious, sex cells released in sea water, direct development.
CONSERVATION STATUS
Not listed by the IUCN.
SIGNIFICANCE TO HUMANS
None known.
