|CNIDARIA : PROBOSCOIDA : Campanulariidae||SEA ANEMONES AND HYDROIDS|
Description: Obelia geniculata is readily distinguishable from other members of this genus by the structure of its stem. It forms a series of internodes that are zig-zag in their arrangement, and it is jointed at each bend. There are several annulations after each joint. Just below each joint the internodes are thickened on alternate sides, forming a 'shelf' for the support of ringed pedicels which in turn, support the hydrothecae. The hydrothecae are obconical in shape and have a smooth outer margin. The gonothecae are shaped like a grecian urn, and are also borne on ringed pedicels.
Habitat: This species normally grows on kelp fronds, especially on Laminaria hyperborea in conditions of moderate wave exposure.
Distribution: Widespread around the British Isles.
Key Identification Features:
Distribution Map from BioMar data for Ireland - Google Earth map: download this placemark (not got Google Earth installed?)
Distribution Map from NBN: Grid map (fast) : Interactive map (slow, requires login to view records) : National Biodiversity Network mapping facility, data for UK.
|Picton, B.E. & Morrow, C.C., 2010. [In] Encyclopedia of Marine Life of Britain and Ireland |
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