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

18 Professional Paper NMFS 12
6. Farrea sp. nov. Reiswig and Stone, in preparation
Description. Erect bush of small-caliber (8-mm diameter),
relatively long, branching tubes increasing in
size (of the entire specimen, not the tube elements) by
terminal growth of the constituent tubes; attached to
hard substrate at a small original base. Surface of the
mass consists of the terminal tube apertures as oscula,
but both inner and outer surfaces of individual tube
elements are smooth. Consistency is stiff and brittle
due to fusion of the thin primary skeleton. Size of the
original specimen from which the fragments were collected
was not recorded, but it must have been at least
10 cm tall. Color in life is white; preserved fragments
are light brown.
Skeletal structure. The primary framework is a fused
farreoid lattice of hexactins forming a network of rectangular
meshes with longitudinal sides 269–720 µm
long and lateral sides 534–778 µm long; it is continuous
throughout the specimen. Loose megascleres include
dermal and atrial pentactins, often with knobs as rudiments
of the sixth distal rays (159–361 µm tangential
ray length, 206–452 µm proximal ray length); pileate
clavules without shaft thorns (333–490 µm length);
moderate-size uncinates (1.02–2.98 mm length). Microscleres
include oxyhexasters and hemioxyhexasters
(62–117 µm in diameter); oxyhexactins (83–130 µm
in diameter); discohexasters and hemidiscohexasters
(48–76 µm in diameter); discohexactins (58–98 µm in
diameter).
Zoogeographic distribution. In Alaska – a rare species,
known only from a few locations in southern
Amchitka Pass and near Bobrof Island in the central
Aleutian Islands. Elsewhere – not reported.
Habitat. In Alaska – attached to small boulders,
cobbles, and pebbles at depths between 529 and 905 m.
Remarks. Our Aleutian specimen was compared with
the four other species of Farrea that lack anchorate
clavules. It differs from each of them in its microsclere
complement. Its description as a new species of Farrea
is now in progress.
Photos. 1) Preserved (frozen then dried) fragments of
a specimen collected at 887 m in the central Aleutian
Islands. 2) The same specimen as in photo 1 (indicated
by the white arrow) in situ. The separation between the
red laser marks is 10 cm.