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

54 Professional Paper NMFS 12
38. Suberites sp.
Description. This “mobile” sponge lives as an irregularly
globular encrustation on empty gastropod shells.
Frequently lives in symbiosis with hermit crabs including
Pagurus dalli. Surface is smooth to the unaided eye
but microscopically hispid due to dense spicule brushes
that leave open numerous small pores (50–100 µm diameter).
Irregular short tracts in the choanosome form
a vague reticulation. Diameter is at least 10 cm. Color in
life is red, orange, or tan; pale yellow in ethanol.
Skeletal structure. Viewed under high magnification,
the spicules are relatively dense without particular orientation.
There are tylostyles to tylostrongyles (123–350
× 7–12 µm).
Zoogeographic distribution. Locally abundant. In
Alaska – Bering Sea to Southeast Alaska.
Habitat. In Alaska – typically encrusts gastropod shells
at depths between 20 and 165 m.
Remarks. This species is indistinguishable from Suberites
domuncula that is common to the Mediterranean Sea
and Atlantic Ocean along the west coast of North Africa.
However, we doubt conspecificity based on the disjunct
zoogeography and leave the species assignment for this
specimen as undecided. The species complex is in desperate
need of taxonomic revision. There are probably
several sibling species that live in symbiosis with hermit
crabs (more than a dozen species reported worldwide).
S. domuncula contains suberitine, a neurotoxin that can
cause fatal hemolytic hemorrhaging in some animals
including some reef fish. However, the hawksbill turtle
(Eretmochelys imbricata) does prey upon it in tropical waters
(Meylan, 1988). No studies have been conducted
on Alaskan specimens.
Photo. 1) Specimen collected at a depth of 84 m in
the central Aleutian Islands. This is the ventral side of
the sponge showing the cavity in which a hermit crab
Pagurus dalli (completely retracted) is living. Grid marks
are 1 cm 2 .