A guide to the deep-water sponges of - NMFS Scientific Publications ...
A guide to the deep-water sponges of - NMFS Scientific Publications ...
A guide to the deep-water sponges of - NMFS Scientific Publications ...
- No tags were found...
Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
10. Heterochone calyx calyx Schulze, 1886<br />
Description. This sponge is polymorphic and similar<br />
<strong>to</strong> Aphrocallistes vastus, with which it is <strong>of</strong>ten confused.<br />
Sponge is cup or funnel shaped, and is up <strong>to</strong> at least 30<br />
cm in height and 40 cm in diameter. It forms bowls or<br />
plates in areas <strong>of</strong> low current. Lateral walls are <strong>of</strong>ten with<br />
hollow finger-shaped processes. Color is bright gold or<br />
pale yellow in <strong>the</strong> Aleutian Islands and Bering Sea. It<br />
displays two typical color morphs in <strong>the</strong> Gulf <strong>of</strong> Alaska<br />
– white and golden yellow.<br />
Skeletal structure. It has a rigid skele<strong>to</strong>n <strong>of</strong> fused<br />
hexactinal spicules with a poorly delineated honeycomb<br />
pattern <strong>of</strong> 1 mm wide channels passing vertically<br />
through <strong>the</strong> walls. Several types <strong>of</strong> loose megascleres<br />
include pinular hexactins on inner and outer surfaces,<br />
with thorned pinulus (48–150 µm long), tangential rays<br />
spined at <strong>the</strong> tips (100–302 µm long), and proximal ray<br />
(69–1265 µm long); scopules on both surfaces (242–630<br />
µm long); spined hexactins (80–204 µm/ray); uncinates<br />
(500–1540 × 14–54 µm); rough centrotylote diactins<br />
(308–786 µm/ray) are apparently absent in some specimens.<br />
Microscleres are discohexactins and discohexasters<br />
(44–100 µm in diameter) with 1–4 secondaries and<br />
terminal discs; oxyhexactins and oxyhexasters (53–100<br />
µm in diameter).<br />
Zoogeographic distribution. North Pacific Ocean; locally<br />
common and abundant in some areas. In Alaska –<br />
Bering Sea <strong>to</strong> Sou<strong>the</strong>ast Alaska. Elsewhere – Japan, Kuril<br />
Islands, Sea <strong>of</strong> Okhotsk, British Columbia <strong>to</strong> Panama.<br />
Habitat. Aleutian Islands – attached <strong>to</strong> bedrock,<br />
cobbles, and pebbles, usually in low-relief habitats, at<br />
depths between 112 <strong>to</strong> 740 m. Bering Sea – attached <strong>to</strong><br />
pebbles and hexactinellid skele<strong>to</strong>ns at depths between<br />
375 and 522 m. Gulf <strong>of</strong> Alaska – on <strong>the</strong> continental shelf<br />
23<br />
and upper slope at depths between 70 and at least 259<br />
m. Observed in <strong>the</strong> glacial fjords <strong>of</strong> Sou<strong>the</strong>ast Alaska<br />
growing on bedrock at depths as shallow as 21 m. Elsewhere<br />
– reported at depths between 23 and 1103 m.<br />
Remarks. This is one <strong>of</strong> <strong>the</strong> most ecologically important<br />
<strong>sponges</strong> in Alaska. Juvenile golden king crabs<br />
(Lithodes aequispina) use <strong>the</strong> spongocoel as refuge habitat<br />
in <strong>the</strong> Aleutian Islands (S<strong>to</strong>ne, 2006). Due <strong>to</strong> its rigid<br />
skele<strong>to</strong>n, this species is an important structural component<br />
<strong>of</strong> <strong>the</strong> sponge reefs reported along <strong>the</strong> Pacific<br />
coast <strong>of</strong> Canada (Conway et al., 1991, 2005; Krautter et<br />
al., 2001) and recently in sou<strong>the</strong>rn Sou<strong>the</strong>ast Alaska.<br />
We have not been able <strong>to</strong> confirm <strong>the</strong> presence <strong>of</strong> <strong>the</strong><br />
o<strong>the</strong>r subspecies (H. calyx schulzei) in Alaskan <strong>water</strong>s.<br />
This species may be preyed upon by <strong>the</strong> sea star Henricia<br />
longispina in <strong>the</strong> eastern Gulf <strong>of</strong> Alaska. Heterochone calyx<br />
calyx can be distinguished from <strong>the</strong> very similar Aphrocallistes<br />
vastus by <strong>the</strong> presence <strong>of</strong> pinular hexactins on <strong>the</strong><br />
inner (atrial) surface and by <strong>the</strong> lack <strong>of</strong> robust oxyhexasters<br />
with primary rays subsumed in a swollen centrum.<br />
Pho<strong>to</strong>s. 1) Specimen collected at a depth <strong>of</strong> 172<br />
m in <strong>the</strong> central Aleutian Islands. A small stalked demosponge<br />
grows from inside <strong>the</strong> specimen. Grid marks<br />
are 1 cm 2 . 2) Specimen collected at a depth <strong>of</strong> 520 m<br />
in Zhemchug Canyon, Bering Sea. Grid marks are 1<br />
cm 2 . 3) Specimen at a depth <strong>of</strong> 180 m with a juvenile<br />
rosethorn rockfish (Sebastes helvomaculatus) and juvenile<br />
brown box crab (Lopholithodes foraminatus) in <strong>the</strong> eastern<br />
Gulf <strong>of</strong> Alaska. 4) Specimen at a depth <strong>of</strong> 181 m in<br />
<strong>the</strong> eastern Gulf <strong>of</strong> Alaska. 5) Specimen at a depth <strong>of</strong><br />
190 m with a sharpchin rockfish (Sebastes zacentrus) and<br />
squat lobsters (Munida quadrispina) in <strong>the</strong> eastern Gulf<br />
<strong>of</strong> Alaska. Pho<strong>to</strong> by J. Lincoln Freese (AFSC).