David Hall / A Giant rock scallop (Crassadoma gigantea) encrusted with and surrounded by several other invertebrates, including White anemones (Metridium sp.), White mushroom ascidians (Distaplia sp.), Red soft co...
Dimitris Poursanidis / Abandonded fishing gear in seagrass meadow, with red sea squirt (Halocynthia papillosa), Samaria National Park, Chania, Crete, Greece
Alex Mustard / Yellow tube sponge (Aplysina fistularis) on coral reef, diver exploring in background. Black Rock Drop Off, East End, Grand Cayman, Cayman Islands, British West Indies. Model released.
Alex Mustard / Portrait of a Giant frogfish (Antennarius commersoni) on a large Yellow elephant ear sponge (Ianthella basta). Bitung, North Sulawesi, Indonesia. Lembeh Strait, Molucca Sea.
Alex Mustard / Nudibranch (Nembrotha cristata) climbing on a Tunicate (Polycarpa aurata) at night. This species of seaslug feeds on seasquirts. A tiny cyclopoid copepod swimming past. Yillet Yecil, Yillet Islands, M...
Alex Mustard / Yellow tube sponges (Aplysina fistularis) growing on a Caribbean coral reef. Cayman Brac, Cayman Islands. Caribbean Sea.
Constantinos Petrinos / Chromodorid nudibranch (Chromodoris annae) on Sea Squirt (Polycarpa aurata) Lembeh Strait, North Sulawesi, Indonesia.
Olga Kamenskaya / Diver with Baikal sponges (Lubomirskia baicalensis). Lake Baikal, Russia, March 2007. Model released.
Alex Mustard / Portrait of Blacktip grouper (Epinephelus fasciatus) resting in Barrel sponge (Xestospongia testudinaria) Mabul Island, Sabah, Borneo, Malaysia. Sulawesi Sea.
Franco Banfi / Nudibranch (Cratena peregrina) on a sponge, Ist Island, Croatia, Adriatic Sea, Mediterranean.
Alex Mustard / A long exposure renders Bar jacks (Carangoides ruber) as ghostly trails as they swim around a sponge, on a coral reef, at night. East End, Grand Cayman, Cayman Islands. Overall winner of GDT competiti...
Franco Banfi / Scuba diver and yellow sponges (Aplysina cavernicola) on Brioni Steamship wreck, Vis Island, Croatia, Adriatic Sea, Mediterranean. Model released.
Sue Daly,Sue Daly / Reef wall with sponge and bryozoan growth, Poor Knights Islands, New Zealand, January
Franco Banfi / Tube sponge (Axinella cannabina), Vervece rock, Punta Campanella Marine Protected area, Costa Amalfitana / Amalfi coast, Italy, Tyrrhenian Sea, Mediterranean. October
Pascal Kobeh / Giant sponge (Xestospongia sp.) releasing its gametes, Indonesia, Sea of Flores
Pascal Kobeh / Giant sponge (Xestospongia sp.) releasing its gametes with a diver in the background, Indonesia, Sea of
Pascal Kobeh / Barrel sponges (Xestospongia sp., probably Xestospongia testudinaria) with feather stars / crinoids, Indonesia, Sea of Flores
Pascal Kobeh / Barrel sponges (Xestospongia testudinaria) with soft corals (Dendronephthya sp.) and divers in the background, Indonesia, Sea of Flores
Pascal Kobeh / Barrel sponges (Xestospongia sp., probably Xestospongia testudinaria) with feather stars / crinoids and a school of Smith's damsels (Pomacentrus smithi) on the reef, Indonesia, Sea of Flores
Alex Mustard / Barrel sponges (Xestospongia testudinaria) grow in shallow water, surrounded by hydroids (Aglaophenia cupressina), in shallow water beneath trees and sun burst. The Passage betweeb Waigeo Island and G...
Juergen Freund / Barrel sponge and Crinoids in coral reef, taken with fisheye lens. Indonesia.
Alex Mustard / A reef scene with an orange elephant ear sponge (Ianthella basta) and red sea whip (Ellisella sp) with schooling silversides fish above. Pelee Island, Misool, Raja Ampat, West Papua, Indonesia. Ceram...
Alex Mustard / Giant barrel sponge (Xestospongia testudinaria) releases a large cloud of gametes as it spawns on a coral reef, while a Threadfin hawkfish (Cirrhitichthys aprinus) looks on. Daram Islands, Misool, Raj...
Alex Mustard / Giant barrel sponge (Xestospongia muta) releases a smokey cloud of gametes as it spawns, watched by two white grunts (Haemulon plumieri). Jardines de la Reina, Gardens of the Queen National Park, Cuba...
Alex Mustard / Portrait of an Atlantic goliath grouper (Epinephelus itajara) on a coral reef, with orange clustered sponges (Agelas sp.). Jardines de la Reina, Gardens of the Queen National Park, Cuba. Caribbean Sea...