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

49. Artemisina amlia Lehnert, Stone and Heimler, 2006
Description. This sponge is stalked with a subhemispherical
or conical body. The stalk widens gradually
from 4 to 25 mm over a distance of approximately 9 cm
and is not sharply separated from the body. The consistency
is soft, elastic, and easily torn. There are wart-like,
slightly elevated oscula on the dorsal surface of the
sponge only that are circular and 2 mm in diameter. Diameter
of conical body is to 20 cm; total height to 15 cm
or more. Color in life is light orange to golden brown. In
ethanol the body has a whitish, translucent ectosome on
top with a yellowish, fibrous choanosome underneath.
Skeletal structure. SEM images of spicules are shown
in Appendix IV. The ectosome of the conical body is
composed of a mesh-work of polyspicular tracts (55–175
µm in diameter) of small styles with a mesh-size of 350–
750 µm. This large mesh is subdivided by a finer net of
strands of spongin-embedded isochelae. This finer net
has a mesh-size of 45–90 µm; single, translucent strands
are 15–25 µm in diameter. The ectosome of the stalk
is thinner and consists of a dense, unispicular layer of
tangentially arranged, parallel-oriented thick styles. In
the choanosome of the stalk, ascending polyspicular
tracts of thick styles are connected by paucispicular
tracts and single spicules, comparable to the choanosome
of the conical body. There are large, smooth styles
(400–520 × 20–25 µm), small styles (330–550 × 10 µm)
with acanthose heads and often with one prominent
dent, isochelae (10–13 µm), and toxa (110–170 µm).
Zoogeographic distribution. Locally common. In
Alaska – central Aleutian Islands. Elsewhere – not
reported.
Habitat. Attached to bedrock, boulders, cobbles, and
pebbles at depths between 97 and 253 m. Associated
with the demosponge Mycale carlilei.
Photos. 1) Specimen collected at a depth of 119 m
in the central Aleutian Islands. Grid marks are 1 cm 2 .
2) Same specimen as in photo 1 in situ showing dorsal
surface with elevated oscula.
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