Sanamyan N.P.1, Sanamyan K.E.1*, Lundsten L.2 2015. Two new deepwater sea anemones (Cnidaria: Anthozoa: Actiniaria) Sicyonis heliodiscus sp.n. (Actinostolidae) and Hormathia pacifica sp.n. (Hormathiidae) from Pacific // Invertebrate Zoology. Vol.12. No.2: 131–149 [in English].

1 Kamchatka Branch of Pacific Geographical Institute, Far-Eastern Branch of the Russian Academy of Sciences, Partizanskaya 6, Petropavlovsk-Kamchatsky, 683000, Russia. E-mail:

* corresponding author

2 Monterey Bay Aquarium Research Institute, 7700 Sandholdt Road, Moss Landing, CA 95039, USA. E-mail:

ABSTRACT: Sicyonis heliodiscus sp.n. and Hormathia pacifica sp.n. are described from the Taney Seamounts, NE Pacific. The species belonging to these two genera are known mainly from N Atlantic and Antarctic locations, and only a few species were recorded from the Pacific. Sicyonis heliodiscus sp.n. is a large species which has unusual exterior with short column hidden in live specimens under the wide oral disk and short marginal tentacles directed downward. It is a rare species, which have been observed only a few occasions during more than 25 years of research by the Monterey Bay Aquarium Research Institute. In contrast, Hormathia pacifica sp.n. is common at the Taney Seamounts. It has a common appearance for the genus and can be distinguished from other Hormathia species by a combination of features including the morphology of the body and cnidom.

doi: 10.15298/invertzool.12.2.02

KEY WORDS: Sea anemone, Actiniaria, North Pacific, Taney Seamounts, abyssal, Actinostolidae, Hormathiidae.

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