A guide to the deep-water sponges of - NMFS Scientific Publications ...

52 Professional Paper NMFS 12
36. Suberites excellens (Thiele, 1898)
Description. This massively lobate sponge has irregularly
cylindrical lobes. Surface is smooth to the unaided
eye but microscopically hispid. Circular oscula are near
tips of lobes and slightly elevated above the surface.
Consistency is firm but elastic. Height is to 14 cm. Color
in life is yellowish brown.
Skeletal structure. Skeletal architecture is more or
less confused in the interior but becomes radial towards
the surface. The surface consists of a palisade of smaller
tylostyles. There are thick tylostrongyles with round
tyles at one end and only slightly tapering at the other
(640–1890 × 17–46 µm), somewhat thinner and flexuous
tylostrongyles (1140–2100 × 17–26 µm), and small
tylostyles forming the palisade at the surface (175–520
× 8–12 µm).
Zoogeographic distribution. Rare. In Alaska – Bering
Sea (Zhemchug Canyon) and eastern Gulf of Alaska.
Elsewhere – Holotype described from Sagami Bay, Japan;
also recorded along Korean Coast (Sim and Kim,
1988).
Habitat. In Alaska – attached to boulders and cobbles
at depths between 390 and 601 m. Elsewhere – no information
available.
Remarks. This was previously known as Rhizaxinella
excellens Thiele, 1898. It typically harbors an abundant
and diverse complement of ophiuroid associates.
Photos. 1) Fragments of specimen with ophiuroid
associates collected at a depth of 390 m in Zhemchug
Canyon, Bering Sea. 2) Close-up view of oscula atop
the lobes.