narcomedusa Solmundella bitentaculata

Solmundella bitentaculata is found in the Atlantic, Pacific, and Indian Oceans and the Mediterranean and is particularly common in the southern hemisphere; it has been found throughout Antarctica and in New Zealand, southern Australia and Chile [1,3,5]. Found at depths from the surface down to 1,100 meters, S. bitentaculata is usually found between 100 and 500 meters [1,3]. S. bitentaculata can be up to 7.2 centimeters wide and is higher than wide [1]. S. bitentaculata has thick apical jelly and the apex of the bell tends to be sharp-edged and keel-shaped, with the line of the keel between the two long tentacles [3,5].



Here's Solmundella bitentaculata taken from above, looking down at its central circular mouth, which opens to the aboral surface. Its two long tentacles issue from near the apex of its umbrella and are up to ten centimeters long [3].

S. bitentaculata swims with those two tentacles held in front of its umbrella, rather than trailing like most medusae.


Here's a line drawing of Solmundella bitentaculata to see all of its features [1]. In this drawing S. bitentaculata is not in its swimming posture because its two tentacles are trailing behind the umbrella rather than being held in front of the umbrella.

S. bitentaculata can have the hitchhiking hyperiid amphipod Hyperiella dilatata on its exumbrella [2]. One prey item of S. bitentaculata is the shelled pteropod Limacina (Limacina) helicina subspecies antarctica [2,4].

1: Guide to the Hydromedusae of the Southern Ocean and Adjacent Waters. David O'Sullivan. ANARE Research Notes 5 (Australian National Antarctic Research Expedition). Kingston, Tasmania, Australia : Australia Dept of Science and Technology, Antarctic Division, 1984; 2: Polar Biology 11(1):19-25, 1990; 3: Marine Invertebrates of Southern Australia Part I. SA Shepherd and IM Thomas, eds. Handbook of the Flora and Fauna of South Australia. South Australia: DJ Woolman, 1982; 4: Antarctic Journal of the United States 23(5):135-136, 1988; 5: Marine Fauna of New Zealand: Hydromedusae (Cnidaria: Hydrozoa). J Bouillon & TJ Barnett. NIWA Biodiversity Memoir 113, Wellington, NZ : National Institute of Water and Atmospheric Research, 1999

Text ©Peter Brueggeman. Photograph ©Luke Hunt & M Dale Stokes. Photographs may not be used in any form without the express written permission of Luke Hunt & M Dale Stokes.