Schuchertinia
Schuchertinia is a collection of species with diverse morphological and ecological characteristics. These species have been put together in the same genus because of their genetic similarity, but a morphological definition for Schuchertinia is still lacking. Only one species occurs in Norway.
Identification
There are no morphological characteristics that separate Schuchertinia from other genera in the family, in particular Hydractinia. However, in Norwegian waters Schuchertinia is the only genus in which medusoids are produced, instead of hydromedusae or sporosacs.
Look-alikes
Biology, ecology and behavior
Colonies of Schuchertinia occur on both live and inanimate substrates, including snail shells inhabited by the snail or by a hermit crab, barnacles, bryozoans, and rocks.
Taxonomy
Before 2010 the species of Schuchertinia were included in the genera Hydractinia and Stylactis. The boundaries of Schuchertinia are still not resolved and will likely change in the future.
References
Miglietta MP, McNally L & Cunningham CW (2010). Evolution of calcium-carbonate skeletons in the Hydractiniidae.
Schuchert P (2008). The European athecate hydroids and their medusae (Hydrozoa, Cnidaria): Filifera Part 3. Revue suisse de Zoologie 115(2):221–302.