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

82. Euchelipluma elongata Lehnert, Stone and Heimler, 2006
Description. This sponge is flagelliform or whip-like
and occasionally bifurcated. The species is similar to
Asbestopluma ramosa and Esperiopsis flagrum (differentiation
requires careful examination). Rigid long, thin
stalk is covered with thin, relatively short processes.
It is basally attached in soft substrates with a rigid
root-like system. Length is to at least 35 cm, but few
specimens attain this size. Color in life is light yellow
to creamy white.
Skeletal structure. SEM images of spicules are shown
in Appendix IV. The ectosome consists of densely
arranged isochelas, underlain by parallel oriented
fusiform styles with blunt ends and smaller tylostyles.
Single tylostyles are placed perpendicular to the orientation
of the styles and tylostyles. The choanosome
is dominated by ascending polyspicular tracts of styles,
tylostyles, and isochelae. Megascleres are blunt-ended
fusiform styles (1310–1510 × 40–55 µm). Tylostyles
(620–660 × 9–13 µm) often have the tyle subterminal
and occasionally polytylote. Microscleres are isochelae
(80–95 µm), placochelae (70–88 µm), and sigmas
(9–25 µm).
Zoogeographic distribution. Locally abundant. In
Alaska – central Aleutian Islands. Elsewhere – not
reported.
Habitat. Attached with a root-like system in unconsolidated
sediments at depths between 1525 and about
2200 m. Fairly abundant in some areas, reaching densities
near 15 individuals per m 2 .
Remarks. There are only four known species of Euchelipluma
worldwide. E. elongata is by far the largest species
in the genus. This species does not appear to harbor
the ophiuroid associates that are so common with the
whip-like pennatulacean corals present in the same
depth range. It may occasionally be preyed upon by the
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sea star Hippasteria. It does not co-occur with Esperiopsis
flagrum but does overlap in depth range with Asbestopluma
ramosa. Unlike A. ramosa, however, it anchors in
soft-sediment rather than attaching to hard substrate.
Photos. 1) Specimen collected at a depth of 2161 m
in the central Aleutian Islands. Grid marks are 1 cm 2 .
2) Same specimen as in photo 1 in situ (foreground).