Bathydorus laniger Kahn, Geller, Reiswig et Smith, 2013

Bathydorus laniger Kahn, Geller, Reiswig et Smith, 2013 View in CoL

Fig. 9 View Fig ; Suppl. Tab. 8.

MATERIAL. IORAS 5/2/2046. RV ‘Akademik Mstislav Keldysh’ – 22, sta. 2295, HOV ‘Mir-1’, Pacific side of the Bering Island, 54 °57.65′ N 165°42.8′ E, 5975 m GoogleMaps .

DESCRIPTION. BODY. The specimen was observed from the submersible as a conical sponge attached to a stone (unfortunately a photo of the live specimen was not taken before a sampling. Several flat wall fragments about 1–3 mm thick were collected.

REMARKS. Due to the presence of the specific dermal and atrial spicules with rare short spines, generally stauractins, the similarity of microscleres, hypodermal pentactins, the identification of the new specimen is doubtless Bathydorus laniger . The external shape of the holotype colony was a simple flat disc (unusual for Hexactinellida) however this new specimen has the usual conical shape. The disc-like body of the holotype could be a result of destruction of the specimen to fragments during its life, or an early developing stage of growing of the base-bottom before the walls, or simply the result of life on the muddy silt. The observed differences are not sufficient, but they accomplish the primary description. Hypodermal pentactins may be rarely rough. Stauractins are dominating spicules of dermal and atrial surface but corresponding diactins, tauactins and pentactins may be rarely found. So-called hypoatrial hexactins, spicules which have rays equal to stauractins, are situated at both surfaces, they are not as common, as stauractins. A new type of microscleres — small oxyhexasters with numerous spiny secondary rays ( 6–8 in number) may be considered as a single specific variation between the type and newly collected specimen. ‘Weltner’s bodies’ are irregularly distributed on the dermal surface of this specimen.

DISTRIBUTION. N Pacific: off California coast and Pacific side of the Bering Island , at 3950–5975 m depth.