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

86. Esperiopsis flagrum Lehnert, Stone and Heimler, 2006
Description. This sponge has a flagelliform or cylindrical
growth form; similar to Asbestopluma ramosa and
Euchelipluma elongata (differentiation requires careful
examination). Occasionally it is bifurcated. A central
long thin axis tapers near the tip and is covered with
many thin processes. Processes are 3–5 mm in length,
elastic but somewhat stiff. The central axis is up to 54 cm
in length with a diameter of 4 mm at the base and 2.5
mm at the tip. This cylindrical axis is compressible, elastic
but resilient. Color in life is beige to creamy white.
Skeletal structure. SEM images of spicules are shown
in Appendix IV. No special ectosome is developed. The
central axis consists of interwoven polyspicular tracts of
styles with many microscleres in between. The lateral
processes are supported by single polyspicular tracts
running into them. The outermost layer of the processes
and the longitudinal axis consists of densely arranged
microscleres. Megascleres are fusiform styles (980–1320
× 20–28 µm). Microscleres are large palmate isochelae
(98–112 µm), small palmate isochelae (28–43 µm),
large sigmas (37–48 µm), and small sigmas (17–20 µm).
Zoogeographic distribution. Locally common. In
Alaska – central Aleutian Islands. Elsewhere – not reported.
Habitat. Occurs at depths between about 700 and
1389 m. Appears to bury with root-like processes in soft
unconsolidated sediments.
Remarks. The lower portion of the stalk is often fouled
with hydroids. The species occurs within the same depth
range as Asbestopluma ramosa, but occurs in soft-sediment
habitats rather than attaching to hard rock. It does not
co-occur with Euchelipluma elongata.
103
Photos. 1) Mid-section of a specimen collected at a
depth of 954 m in the central Aleutian Islands. Grid
marks are 1 cm 2 . 2) Same specimen as in photo 1 in situ.