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

96 Professional Paper NMFS 12
79. Cladorhiza corona Lehnert, Watling and Stone 2005
Description. Body consists of a long cylindrical stalk
with a basal plate and two sets of distal appendages:
the basal set radiating in a full circle more or less in
one plane, and the distal set forming a quarter circle
of triangular-shaped structures oriented in a plane
almost perpendicular to the basal appendages. Distal
appendages are shorter than the basal and terminate
in a spherical tyle. Root-like processes (common within
the genus) are absent and the sponge attaches directly
to hard substrate via the broadened basal plate. Consistency
is wiry and elastic, with an easily detachable
ectosomal membrane. Total length is to at least 33 cm.
Color in life is light yellow or creamy white.
Skeletal structure. SEM images of spicules are shown
in Appendix IV. The three distinct parts of the sponge
(basal plate, stalk with the basal appendages, and the
crown) differ considerably in spicule types and their
arrangement. The basal plate consists of fusiform
styles and shorter anisoxeas with slightly unequal ends,
packed in one plane parallel to the surface of the substrate.
The basal plate has no ectosomal membrane and
is devoid of microscleres. From the basal plate polyspicular
tracts of long fusiform styles run in thick bundles
through the center of the long cylindrical stalk, which
is covered by an ectosomal membrane, densely packed
with ancorate anisochelae. The basal appendages are
constructed in a similar manner as the stalk. The polyspicular
tracts of long fusiform styles reaching the crown
fan out in one plane, leaving little space between the
tracts. Single, thin (sub-) tylostyles are arranged more
or less perpendicular to the thick fusiform styles. The
ectosomal membrane of the crown is devoid of anisochelae
but rather contains flattened sigmancistras with
thin claw-like extensions at each end. These latter two
spicule types occur exclusively in the crown. Megascleres
include fusiform styles, almost anisoxeas (600–4260
× 10–65 µm), present in all parts except the ectosomal
membrane; (sub-) tylostyles (510–1650 × 8–20 µm)
present in the ectosomal membrane of the crown; and
thick, short anisoxeas with slightly unequal blunt ends
(140–660 × 38–43 µm) present in the basal plate. Microscleres
include anchorate anisochelae (30–42 µm),
present in the ectosomal membrane of the stalk and
the basal appendages; and flattened sigmancistras, each
end with a thin pointed “claw” (35–42 µm), present in
the ectosomal membrane of the crown.
Zoogeographic distribution. Locally common. In
Alaska – central Aleutian Islands. Elsewhere – not
reported.
Habitat. Occurs in small patches at depths between
726 and 2077 m on bedrock, fragmented bedrock,
mudstone, and cobbles, and at temperatures between
1.8 and 3.1°C.
Remarks. C. corona is carnivorous and feeds mainly
on calanoid copepods (Watling, 2007). Collected specimens
may have small crustaceans trapped in their outer
tissues.
Photos. 1) Specimen collected at a depth of 1720 m
in the central Aleutian Islands. Grid marks are 1 cm 2 .
2) Same specimen as in photo 1 in situ.