Barrel sponge
Fig. 26: Underwater reef landscape with a barrel sponge (Xestospongia testudinaria). — Dunia Kecil, Wajil Batan, Rajat Empat, Indonesia, Nikon Coolpix 5400, Fischaugen-Vorsatz, March 15, 2005 — EXIF: E5400; Δt=1/57 s; f=24 mm; f/5.2; ISO 50; 2005-03-15 16:05:07