Orange Icing Sponge
September 14, 2008 Leave a comment
This is the excurrent opening of an Orange Icing Sponge. This sponge grows on hard corrals and protect it from bioerosion from boring sponges.
This sponge also modifies the growth of the coral causing it to bend as it grows, so these species are really symbiotic, albeit at a very slow pace.
There were a lot of these on this particular dive site, more than I usually see.
Sponges are filter feeders, drawing in water through their wall and exhaling it through one or more excurrent openings.
In fact sponges are multi-cellular organisms, when you are looking at a sponge you are in fact looking at a collective of fairly independent individual cells.