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

33. Stylocordyla borealis eous Koltun, 1966
Description. Thin stalk terminates in a globular or
oval body with a smooth surface. Stalk is to 9 cm; body
to approximately 2 cm 3 . Color in life is golden brown.
Skeletal structure. Skeleton of the stalk is a tight mass
of parallel spicules running into the body and radiating
to the sides in tracts. Smaller oxeas form a palisade at
the surface of the body. Microxeas form a tangential
crust at the surface. Oxeas are exclusively centrotylote,
sometimes with blunt ends. Oxeas occur in a wide
size-range, possibly in three categories: 790–2460 ×
10–37 µm, 400–700 × 10–12 µm, and microxeas 70–110 ×
2–3 µm.
Zoogeographic distribution. Locally abundant in
the North Pacific Ocean. In Alaska – central Aleutian
Islands and Bering Sea (Pribilof Canyon). Elsewhere –
Sea of Okhotsk.
Habitat. In Alaska – attached to pebbles and emergent
epifauna at depths between 125 and 307 m and generally
in low-relief (i.e., flat-bottomed) habitats (central
Aleutian Islands). Sponges with very similar morphology
have been observed in the Aleutian Islands at depths
near 1100 m, but we would need to collect a specimen
to confirm conspecificity. Elsewhere – reported at a
depth of 200 m.
Remarks. Stylocordyla borealis eous can be distinguished
from the similar Rhizaxinella clavata by its thinner stalk
and smooth oval body. Also, S. borealis eous has exclusively
centrolyte oxeas while R. clavata has tylostyles and
subtylostyles.
Photos. 1) Specimen collected at a depth of 127 m
in the central Aleutian Islands. Grid marks are 1 cm 2 .
2) Same specimen as in photo 1 (indicated by the white
arrow) in situ. 3) Specimen collected at a depth of 208
m in Pribilof Canyon, Bering Sea. Specimen is attached
to an unknown hexactinellid sponge.
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