Coloration of the bulbs is bright orange.
All radial canals are similar in width; the largest bulb carries 1-3 tentacles, depending on the maturity of the specimen.
Is found in the Barents Sea, Bering Sea and Sea of Okhotsk
Is a very widely spread boreal species.
Hydroid - Hybocodon prolifer Agassiz.
Umbrella asymmetrical due to a greater development of one of the sides. Radial canals are different in length; the longest originates from the bulb with the tentacle, the shortest is the one opposite from it. All canals are of the same width. The outer surface of the umbrella carries 5 rows of nematocysts. Ocelli absent. Coloration of the bulbs is bright orange.
Reproduction can take place in one of 2 ways: the budding of small jellyfish from the base of the tentacle, or the development of actinulae on the manubrium. The budding jellyfish, without separating from the parent organism, can produce a new generation.
Height up to 4 mm, width up to 3 mm.