Caulophacus (Caulophacus) hyperboreus Koltun, 1967

Caulophacus (Caulophacus) hyperboreus Koltun, 1967 View in CoL

Figs 16–18 View Fig View Fig View Fig ; Suppl. Tab. 12.

MATERIAL. IORAS 5/2/2084; IORAS 5/2/ 2153; 2154; 2161.1; 2228.1; 2229; 2231; 2232; 2233; 2234 : RV ‘ Akademik Mstislav Keldysh’ – 22, sta. 2309, trawl, N off the Bering Island , 55°13.24– 12.02′ N 167°29.07 –26.7′ E, 3957–3978 m . IORAS 5/2/2150; 2158; 2177; 2178; 2182; 2183; 2183.1; 2217 : RV ‘ Akademik Mstislav Keldysh’ – 22, sta. 2316, trawl, N off the Bering Island , 55°36.08– 35.00′ N 167°23.04 –24.46′ E, 4200–4294 m . IORAS 5 /2/3811; 3811.2–3811.9; 3820, 3821 : RV ‘ Akademik M.A. Lavrentyev’ – 75, sta. 22 , ROV ‘ Comanche’, 55°30′36.1″ N 167°19′27.1″ E, 3879– 3578 m GoogleMaps .

DESCRIPTION. BODY. The specimens had mushroom-like bodies or fragments often attached to a peduncle branching into many separate bodies. It is not obvious if they represent a single specimen with stolonial branching or multiple organisms of same species that settled on the peduncle of one colony. The specimen sizes ranged from those with the disc 3 mm in diameter and 1 mm in thickness with peduncle 1 mm in diameter to the biggest ones 55 mm in diameter, 3–4 mm in thickness and the peduncle about 5 mm in diameter. But some of them reach even larger sizes — a single lamellate fragment of the discoidal body 90x 70 mm and 4–6 mm in thickness was found.

REMARKS.Thespecieswasoriginallydescribed as a subspecies: Caulophacus schulzei hyperboreus Koltun, 1967 . Both species from the North Pacific, C. (Caulophacus) schulzei and C. (Caulophacus) elegans , are completely different from the subspecies described by Koltun (1967).

Among the newly found specimens of Caulophacus hyperboreus many had pinular pentactins among both dermal and atrial hexactins sometimes in large amounts. As it is seen from the Suppl. Tab. 12, it can be assumed that spicule combination and their sizes are very similar between investigated specimens and dissimilarities are considered as an inerspecific variation. Unlike specimens described by Koltun, some specimens from the new series from the Bering Sea have dermal and atrial pinular pentactins with their rudimentary ray directed inside the body, in some specimens they are even more numerous then corresponding hexactins (for instance, IORAS 5/2/2229; 2232 and some other specimens). Meantime, the other spicules correspond in shape and size to typical representatives and these specimens are undoubtedly belonging to the same species.

DISTRIBUTION. Bering and Okhotsk Seas,

3400–4294 m depth.