This pink encrusting sponge is common under rocks on lagoon reefs and pinnacles, and can also be found on the seaward reef. The photos below show two distinctly different growth forms that might be different species, but there seem to be enough intergradation between the two that we are keeping them together at this time. The two form look similar in structure to the two forms of Aplysilla sulfurea, but we have also seen something like the more prickly looking form called Dendrilla cactos. At this point we are leaving it as unidentified. The sponge is preyed upon by several chromodorid nudibranchs, including the Verconia simplex in the first four photos below.
The pink Verconia cf romeri seems to prefer the more prickly form of the sponge.
More Verconia simplex on the prickly form of the sponge.
This Thorunna australis was in the vicinity of the sponge but not obviously eating it.
Created 1 June 2019