Georgette Douwma / Translucent coral goby (Bryaninops erythrops) in Seapen (Virgularia gustaviana). Komodo National Park, Indonesia. Indo-West Pacific.

Fred Olivier / Watchman goby (Cryptocentrus cinctus) and alpheid shrimp mutualism, the goby keeps watch while the shrimps dig and clean a shared burrow in the sand, Uepi Island, Solomon Islands.

Alex Mustard / Large whip goby (Bryaninops amplus) with a parasitic copepod (with two trailing egg ribbons) perched on Red whip coral. Whale Rock. Fiabacet Islands, Misool, Raja Ampat, West Papua, Indonesia. Ceram S...

Nick Upton / Common prawns (Palaemon serratus) and a Rock goby (Gobius paganellus) feeding on a dead Montagu's crab (Xantho hydrophilus) in a rockpool, Cornwall, England, UK, September.

Nick Upton / Rock goby (Gobius paganellus) stealing food from a scavenging Common prawn (Palaemon serratus) in a rockpool, Cornwall, England, UK, September.

Alex Mustard / Glasseye snapper (Heteropriacanthus cruentatus) head portrait with a cleaning Goby (Gobiosoma genie) East End, Grand Cayman, Cayman Islands, British West Indies, Caribbean Sea.

David Fleetham / Fire Dartfish / Fire Goby (Nemateleotris magnifica) against colourful coral. Fiji's outer reef.

Todd Mintz / Sharknose cleaner goby (Gobiosoma evelynae) pair sheltering in hard coral, Netherlands Island, Dutch Antillies, Caribbean

Brandon Cole / Four-foot long Goliath Grouper (Epinephelus itajara) being cleaned by cleaner gobies. Florida Keys National Marine Sanctuary, USA, Atlantic Ocean, July.

Jurgen Freund / Two Twinspot / Crabeye gobies (Signigobius biocellatus) West New Britain, Papua New Guinea.

Jurgen Freund / Two whip coral gobies (Bryaninops yongei) on a black coral sea whip. Lembeh Strait, North Sulawesi, Indonesia.

David Fleetham / Goby (Eviota sp) and juvenile porcelain crab (Pteroeides sp), on a Seapen. Komodo National Park, Indonesia.

Georgette Douwma / Loki whip goby (Bryaninopss loki) on Sea pen (Virgularia gustaviana). Komodo National Park, Indonesia

Wild Wonders of Europe / Banfi / Red mouthed goby (Gobius cruentatus) on seabed, Larvotto Marine Reserve, Monaco, Mediterranean Sea, July 2009

Jurgen Freund / Crab eyed goby (Signigobius biocellatus) Indo-pacific

Georgette Douwma / Maiden gobies (Valenciennea puellaris) "kissing", Red Sea, Egypt

Claudio Contreras / Goby (Elacatinus sp.) on Lesser Starlet Coral (Siderastrea radians), Banco Chinchorro Biosphere Reserve, Caribbean region, Mexico, May

Alex Mustard / Portrait of a rock goby (Gobius paganellus). Swanage, Dorset, England, United Kingdom. English Channel. North East Atlantic

Alex Mustard / Pink eye goby (Bryaninops natans) perches on hard coral (Acropora sp.). Gubal Island, Egypt. Strait Of Gubal, Red Sea.

Alex Mustard / Pink eye goby (Bryaninops natans) hovers over a coral. This fish seems to have its ovipositor extended and may have been laying eggs. Laamu Atoll, Maldives. Indian Ocean

Alex Mustard / Close up photo of a Cleaning goby (Elacatinus genie) on a coral reef. Jardines de la Reina, Gardens of the Queen National Park, Cuba. Caribbean Sea.

Sirachai Arunrugstitchai / Wire coral goby (Bryaninops yongei) resting on its host Wire coral (Cirrhipathes), Lembeh Strait, North Sulawesi, Indonesia.

Georgette Douwma / Wide-barred shrimp goby fish (Amblyeleotris latifasciata). Lembeh Strait, North Sulawesi, Indonesia.

Nick Upton / Juvenile Edible crab (Cancer pagurus) among Common mussels (Mytilus edulis) in a rock pool with a Rock goby (Gobius paganellus) in the background, Gower Peninsula, Glamorgan, Wales, UK, August.

Nick Upton / Rock gobies (Gobius paganellus) and a juvenile Shore crab (Carcinus maenas) scavenging amongst Common Mussel shells (Mytilus edulis) in a rock pool, Gower Peninsula, Glamorgan, Wales, UK, August.

Claudio Contreras / Goby (Elacatinus sp.) on sponge, Guanahacabibes Peninsula National Park, Pinar del Rio Province, western Cuba.

Claudio Contreras / Goby (Elacatinus sp.) on coral, Guanahacabibes Peninsula National Park, Pinar del Rio Province, western Cuba.

Georgette Douwma / Translucent coral goby (Bryaninops erythrops) resting on Bubble coral (Plerogyra sinuosa). Derawan Islands, East Kalimantan, Indonesia.

Georgette Douwma / Translucent coral goby (Bryaninops erythrops) with parasite under gill, resting on Starfish (Asteroidea). Derawan Islands, East Kalimantan, Indonesia.

Magnus Lundgren / Whip gobies (Bryaninops yongei) sitting on coral whip at night. Triton Bay area, West Papua, Indonesia. Magnus

David Fleetham / Pair of Yellownose shrimp gobies (Stonogobiops xanthorhinica) with Randalls blind snapping shrimp (Alpheus randalli) excavating their den. Fiji.

David Fleetham / Red-banded prawn-goby (Amblyeleotris fasciata) sharing burrow with Shrimp (Alpheus bellulus) Yap, Micronesia.

Alex Mustard / Lemon coral goby (Gobiodon citrinus) shelters in the branches of a coral (Acropora sp.). Gubal Island, Egypt. Strait Of Gubal, Red Sea.

Nick Upton / Rock goby (Gobius paganellus) in a rock pool, Rhossili, The Gower Peninsula, UK, August.

Georgette Douwma / Translucent coral goby (Bryaninops erythrops) in Seapen (Virgularia gustaviana). Komodo National Park, Indonesia. Indo-West Pacific.

Georgette Douwma / Bluestreak goby (Valenciennea strigata). Triton Bay, West Papua, Indonesia.

Georgette Douwma / Canary wrasse (Halichoeres chrysus) following a pair of feeding Maiden gobies (Valenciennea puellaris). The gobies take gulps of sand and filter this through their gills. The wrasse picks of any escap...

Alex Mustard / Cleaning goby (Elacatinus genie) hovering in mid-water. East End, Grand Cayman, Cayman Islands, British West Indies. Caribbean Sea.

Alex Mustard / Lemon coral goby (Gobiodon citrinus) shelters in the branches of a coral (Acropora sp.). Gubal Island, Egypt. Strait Of Gubal, Red Sea.

Alex Mustard / Pair of pygmy lemon gobies (Lubricogobius exiguus) make their home in an old heart urchin (Maretia sp.) test. Dauin, Dauin Marine Protected Area, Dumaguete, Negros, Philippines. Bohol Sea, tropical we...

Alex Mustard / Pygmy lemon gobies ( Lubricogobius exiguus) guarding their home in a glass bottle (backlit with a torch). Anilao, Batangas marine protected area, Luzon, Philippines. Verde Island Passages, Tropical We...

Alex Mustard / RF - Pygmy lemon gobies (Lubricogobius exiguus) make their home in an old heart urchin (Maretia sp.) Dauin, Philippines.

Alex Mustard / RF - A pair of pygmy lemon gobies (yellow pygmy goby: Lubricogobius exiguus) make their home in an old heart urchin (sea mouse: Maretia sp.) test. Dauin, Philippines.

Alex Mustard / RF - Shorthead fangblenny (Petroscrites breviceps) living in a discarded tin-can, with a pair of pygmy lemon gobies (Lubricogobius exiguus). Dauin, Philippines.

Fred Olivier / Watchman goby (Cryptocentrus cinctus) and alpheid shrimp mutualism, the goby keeps watch while the shrimps dig and clean a shared burrow in the sand, Uepi Island, Solomon Islands.

Fred Olivier / Watchman goby (Cryptocentrus cinctus) and alpheid shrimp mutualism, the goby keeps watch while the shrimps dig and clean a shared burrow in the sand, Uepi Island, Solomon Islands.

Fred Olivier / Banded prawn goby (Cryptocentrus cinctus) and alpheid shrimp mutualism, the goby keeps watch while the shrimps dig and clean their burrow in the sand, Uepi Island, Solomon Islands.

Nick Upton / Young Edible crab (Cancer pagurus) and a Rock goby (Gobius paganellus) side by side in a rock pool, looking towards the camera, The Gower, Wales, UK, August.