Phelliactis spp.

Sanamyan, N. P., Sanamyan, K. E., Bocharova, E. S., Morozov, T. B. & Galkin, S. V., 2023, Sea anemones (Actiniaria, Corallimorpharia and Zoantharia) from the Western Bering Sea (Northwest Pacific), Invertebrate Zoology 20 (1), pp. 27-56 : 44

Phelliactis spp.

Fig. 4H, I .

MATERIAL. LV-75-22, 55.5134ºN 167.3270ºE, depth 3599 m, one specimen photographed.

LV-82-6, 55.6826°N 167.1075ºE – 55.6825°N 167.1075ºE, depth 3397– 3393 m, sample 3, one specimen collected; LV-82-10, 55.3188°N 167. 2907ºE, depth 2605 m, one specimen photographed.

REMARKS. Two species of Phelliactis have been recorded from the Vulcanologov Massif and Komandorsky Basin in the southwest of the Bering Sea. The specimens are large with a beige-brownish cylindrical column with longitudinal rows of tubercles (mesogloeal thickenings) and very wide oral disc (about 20 cm in diameter). The tentacles are on the margin of the oral disc, more than 100 in number. Two specimens photographed on the northern slope of the Vulcanologov Massif in 2016 (3599 m, not collected) and on the small high to the west of the Komandor Graben in 2018 (3397– 3393 m, collect- ed), most probably belong to one species. They have a similarly looking high column, large circular oral disc and long thin tentacles with weak thickenings at the base on the aboral side; the recorded depth is also similar ( Fig. 4H ). The specimen, photographed on the southern slope of the Vulcanologov Massif (2605 m), differs in very strong aboral thickenings on the tentacles, red undulating oral disc and lower and wider column ( Fig. 4 I ).

aff. Hormathiidae sp.1

Fig. 4 J .

MATERIAL. LV-75-18, 55.4343°N 167. 2673ºE, depth 1389 m, one specimen photographed; LV-75-21, 55.4818°N 167.2573ºE – 55.4772°N 167.2514ºE, depth 2841– 2732 m, four specimens

photographed.

REMARKS. Five specimens of the small species were photographically documented on the sides of large stones on the northern slope of the Vulcanologov Massif at 1389–2841 m (not collected). The specimens have low column, wider at the base (up to 4 cm in diameter), covered by cuticle. Oral disc and tentacles are pale-rose. The oral disc is wide (up to 3 cm in diameter), with oral cone at its center. The tentacles are thin, its length is up to the diameter of the oral disc, without mesogloeal thickenings, up to 50 may be counted in photographs.

aff. Hormathiidae sp.2

Fig. 4K .

MATERIAL. LV-75-18, 55.4336°N 167. 2673ºE, depth 1349 m, one specimen photographed.

REMARKS. White sea anemone was photographed on the northern slope of the Piip Volcano at the depth of 1349 m in 2016 in community of glass sponge Farrea spp. (see Rybakova et al., 2020). The tentacles are hexamerously arranged in six cycles: 6+6+12+24+48+96= up to 192 (120 tentacles are visible in the photograph). The length of the inner tentacles can be as large as the diameter of the oral disc. Brownish radial dashed lines from the base of the tentacles to the mouth extend on the oral disc above the endocoels.

Figures

Fig. 4. A — Halcampidae sp. from the northern slope of the Piip Volcano; B — Halcampidae sp. from the Komandor Graben; C — cf. Halcampoides sp.; D — Amphianthus sp. from the northern slope of the Piip Volcano; E — Amphianthus sp. from the southern slope of the Piip Volcano; F — Paracalliactis cf. involvens; G — Hormathia sp.; H — Phelliactis sp. from the northern slope of the Piip Volcano; I — Phelliactis sp. from the southern slope of the Piip Volcano; J — aff. Hormathiidae sp. 1; K — aff. Hormathiidae sp. 2; L — Sagartiogeton californicus. Рис. 4. A — Halcampidae sp. на северном склоне вулкана Пийпа; B — Halcampidae sp. в грабене Командор; C — cf. Halcampoides sp.; D — Amphianthus sp. на северном склоне вулкана Пийпа; E — Amphianthus sp. на южном склоне вулкана Пийпа; F — Paracalliactis cf. involvens; G — Hormathia sp.; H — Phelliactis sp. на северном склоне вулкана Пийпа; I — Phelliactis sp. на южном склоне вулкана Пийпа; J — aff. Hormathiidae sp. 1; K — aff. Hormathiidae sp. 2; L — Sagartiogeton californicus.