Branching Tube Sponge
Pseudoceratina crassa

f8 @ 1/60s, ASA 64, Ektachrome 64 slide film, Nikonos II w 15mm, Oceanic 2000 flash, Ikelite slave flash

Branching Tube Sponge (yellow variation). This sponge is common throughout the Caribbean. The exterior color is variable, often exhibiting different shades of yellow, purple, orange and olive-green. It is often found on reef walls.
Salt River Canyon, St. Croix, U.S. Virgin Islands