Metridium farcimen ( Brandt, 1835 )

Fautin, D. G., 2012, Taxonomy and distribution of sea anemones (Cnidaria: Actiniaria and Corallimorpharia) from deep water of the northeastern Pacific, Zootaxa 3375, pp. 1-80 : 41-42

Metridium farcimen ( Brandt, 1835)

( Figures 32–33, Appendix 14)

Synonyms: see Fautin and Hand (2000)

Diagnosis. Specimens to 1 m long in life (Fautin et al. 1989); preserved specimens greatly contracted (100 mm or less in length). Column smooth, white to pale salmon or brown. Margin typically contracted, partially or completely hiding oral disc ( Figure 32). Oral disc with lobes thickened with mesoglea. Oral disc covered in hundreds of tentacles; marginal tentacles shorter than discal tentacles. Pedal disc typically attached to rock or shell. For a detailed description of M. farcimen , see Fautin et al. (1989).

Cnidae. Spirocysts, basitrichs, microbasic p -mastigophores, microbasic amastigophores.

Distribution. Metridium farcimen was described by Brandt (1835) from Kamchatka, Russia. Specimens have since been collected throughout the North Pacific Ocean and we extend the range of the species from subtidal waters to 2,740 m, north to the Bering Sea and within the North Pacific from Mexico to Russia ( Figure 33).

Taxonomic remarks. Fautin et al. (1989) described as a new species Metridium giganteum Fautin, Bucklin, and Hand, 1989 , distinguishing it from the two other species found along the northeastern Pacific coast, M. senile

( Linnaeus, 1761) and M. exile Hand, 1956 . However, Fautin and Hand (2000) found several names that had previously been applied to this species: its valid name is M. farcimen ( Brandt, 1835) .

Its great size and lobed oral disc make large specimens of Metridium farcimen among the most distinctive species of sea anemone in the North Pacific. However, small specimens of M. farcimen have been confused with and misidentified as M. senile in publication, and because of their similarities, it is not possible to determine which were the subject of some publications ( Fautin & Hand 2000). Specimens of M. farcimen can grow much larger than specimens of M. senile , which reach a maximum length of only 100 mm (Fautin et al. 1989). The oral disc of M. farcimen is divided into distinct stiffened lobes whereas the oral disc of M. senile is flaccid and the lobes are less distinct.

Material examined. See Appendix 14.