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

34 Professional Paper NMFS 12
20. Bathydorus sp., description by Reiswig and Stone, in preparation
Description. Very small flattened ovoid sponge attaches
to a cobble. External surface is smooth and covered
by a lattice of mainly stauractin dermalia; about one-half
of the surface is profusely spined by long diactins and
sports a veil of raised pentactins. An osculum and atrial
cavity could not be distinguished. Consistency is soft and
delicate. The specimen is 11 by 8 by 2 mm. It is transparent
and colorless.
Skeletal structure. Skeleton is composed entirely
of loose spicules, but parts of the fused basidictyonal
skeleton remain attached. Megascleres are hypodermal
pentactins (0.26–1.4 mm long tangential rays; 0.47–1.55
mm long proximal rays); thick prostal diactins (3.2–16.8
mm long); thin diactins (0.96–6.82 mm long); dermal
stauractins and diactins (81–381 mm ray length). Microscleres
consist only of hemioxyhexasters (112–181
mm in diameter) and oxyhexactins (124–204 mm in
diameter).
Zoogeographic distribution. Rare. In Alaska – central
Aleutian Islands. Elsewhere – small incompletely
identifiable Bathydorus spp. have been reported worldwide.
Habitat. In Alaska – occurs on cobble but probably
also on boulders and bedrock; collected from 494 m but
may have a broad depth range. Elsewhere – small Bathydorus
spp. are reported from depths of 446 to 1625 m.
Photo. 1) Whole specimen collected at a depth of 494
m in the central Aleutian Islands.