Barrel sponge

Barrel sponge: Underwater reef landscape with a barrel sponge (Xestospongia testudinaria). — Dunia Kecil, Wajil Batan, Rajat Empat, Indonesia, Nikon Coolpix 5400, Fischaugen-Vorsatz, March 15, 2005. Nikon E5400, 1/57 s, F/5.2, 24 mm, ISO 50, Tuesday, March 15, 2005 16:05:07