Alex Mustard / Spotlight goby (Gobiosoma louisae) looking out from inside a Yellow tube sponge (Aplysina fistularis), growing on a coral reef. Bloody Bay Wall, Little Cayman, Cayman Islands, British West Indies. Car...

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...

Alex Mustard / Common ghostgoby (Pleurosicya mossambica) with another fish in its mouth on soft coral (Dendronephthya sp.). Tulamben, Bali, Indonesia. Java Sea

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.

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

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

Brandon Cole / Goby {Gobiidae} on gorgonian sea fan, Indonesia.

Chris Newbert / Black-rayed Shrimpgoby (Stonogobiops nematodes) with Shrimp guarding burrow, 80 feet deep, Papua New Guinea

Fred Bavendam / Goby (Amblyeleotris sp) keeping watch while a Snapping Shrimp (Alpheus randalli) excavates their shared burrow, Bali, Indonesia

Jurgen Freund / Shortfin Lionfish (Dendrochirus brachypterus) and two Golden coral goby (Paragobiodon xanthosoma) using rubbish as their home, Sulawesi, Indonesia. November.

Jurgen Freund / Black banded damselfish (Amblypomacentrus breviceps) and Yellow clown goby (Gobiodon okinawae) hiding in a discarded bottle, Sulawesi, Indonesia. November.

Georgette Douwma / Brown-barred goby (Amblygobius phalaena). West Papua, Indonesia. Indo-West Pacific.

Georgette Douwma / Crab-eye goby / goby (Signigobius biocellatus). West Papua, Indonesia. Indo-West Pacific.

Georgette Douwma / Brown-barred goby (Amblygobius phalaena). Lembeh Strait, North Sulawesi, Indonesia.

Remi Masson / Great blue spotted mudskipper (Boleophthalmus pectinirostris) with mouth open in aggression, on mud at low tide. Kyushu Island, Japan. August.

Remi Masson / Great blue spotted mudskipper (Boleophthalmus pectinirostris) resting in mud at low tide. Kyushu Island, Japan. August.

Remi Masson / Great blue spotted mudskipper (Boleophthalmus pectinirostris) in aggressive pose, on mud at low tide. Kyushu Island, Japan. August.

Remi Masson / Great blue spotted mudskipper (Boleophthalmus pectinirostris) emerging from burrow in mud at low tide. Kyushu Island, Japan. August. August.

Remi Masson / Great blue spotted mudskipper (Boleophthalmus pectinirostris) with mouth open in aggressive pose, on mud at low tide. Kyushu Island, Japan. August.

Remi Masson / Great blue spotted mudskipper (Boleophthalmus pectinirostris), two males in territorial fight. On mud at low tide, Kyushu Island, Japan. August.

Remi Masson / Great blue spotted mudskipper (Boleophthalmus pectinirostris) resting on ud at low tide, surrounded by crabs. Kyushu Island, Japan. August.

Remi Masson / Great blue spotted mudskipper (Boleophthalmus pectinirostris) resting on mud. Kyushu Island, Japan. August.

Remi Masson / Great blue spotted mudskipper (Boleophthalmus pectinirostris) submerged with head above mud. Kyushu Island, Japan.

Remi Masson / Great blue spotted mudskipper (Boleophthalmus pectinirostris) next to burrow, in myd at low tide. Kyushu Island, Japan. August.

Remi Masson / Great blue spotted mudskipper (Boleophthalmus pectinirostris) emerging from burrow in mud. Kyushu Island, Japan. August.

Remi Masson / Great blue spotted mudskipper (Boleophthalmus pectinirostris) in burrow with another mudskipper above. Kyushu Island, Japan. August.

Remi Masson / Great blue spotted mudskipper (Boleophthalmus pectinirostris) resting on mud at low tide, portrait. Kyushu Island, Japan. August.

Remi Masson / Great blue spotted mudskipper (Boleophthalmus pectinirostris), two in territorial fight on mudflat. Kyushu Island, Japan. August.

Remi Masson / Great blue spotted mudskipper (Boleophthalmus pectinirostris), portrait. Kyushu Island, Japan.

Remi Masson / Great blue spotted mudskipper (Boleophthalmus pectinirostris), portrait. Kyushu Island, Japan.

Remi Masson / Great blue spotted mudskipper (Boleophthalmus pectinirostris), portrait. Kyushu Island, Japan.

Alex Mustard / Common ghostgoby (Pleurosicya mossambica) perches on an orange and white seafan (Euplexaura sp.), on a coral reef. Bitung, North Sulawesi, Indonesia. Lembeh Strait, Molucca Sea.

Alex Mustard / Pair of Common ghostgobies (Pleurosicya mossambica) spawning on a pink sponge. The male is the larger fish on the right. Bitung, North Sulawesi, Indonesia. Lembeh Strait, Molucca Sea.

Pedro Narra / West African mudskipper (Periophthalmus barbarus) Joao Vieira Poillo , Bijagos Archipellago. Guinea Bissau

Pedro Narra / West African Mudskipper (Periophthalmus barbarus) Joao Vieira Poillo , Bijagos Archipellago. Guinea Bissau

Pedro Narra / West African mMudskipper (Periophthalmus barbarus) portrait, Joao Vieira Poillo , Bijagos Archipellago. Guinea Bissau

Pedro Narra / West African mudskipper (Periophthalmus barbarus) Joao Vieira Poillo , Bijagos Archipellago. Guinea Bissau

Magnus Lundgren / Wild Wonders of China / Bluespotted mudskippers (Boleophthalmus pectinirostris) skipping along the beach, Hong Kong Wetland Park, Hong Kong, China.

Magnus Lundgren / Wild Wonders of China / Bluespotted mudskippers (Boleophthalmus pectinirostris) on mudflat, Hong Kong Wetland Park, Hong Kong, China.

Magnus Lundgren / Wild Wonders of China / Bluespotted mudskippers (Boleophthalmus pectinirostris) skipping along the beach, Hong Kong Wetland Park, Hong Kong, China.

Magnus Lundgren / Wild Wonders of China / Masked shrimpgoby (Amblyeleotris gymnocephala) and shrimp in Lembeh Strai, Sharp Island or Kiu Tsui Chau, Kiu Tsui Country Park, Hong Kong, China.

Magnus Lundgren / Wild Wonders of China / Masked shrimpgoby (Amblyeleotris gymnocephala) and shrimp in Lembeh Strai, Sharp Island or Kiu Tsui Chau, Kiu Tsui Country Park, Hong Kong, China.

Magnus Lundgren / Wild Wonders of China / Yellow prawn-goby (Cryptocentrus cinctus) Sharp Island or Kiu Tsui Chau, Kiu Tsui Country Park located at Port Shelter of Sai Kung, Hong Kong, China.

Magnus Lundgren / Wild Wonders of China / Yellow prawn-goby (Cryptocentrus cinctus) Sharp Island or Kiu Tsui Chau, Kiu Tsui Country Park located at Port Shelter of Sai Kung, Hong Kong, China.

Claudio Contreras / Redhead goby (Elacatinus punticulatus), Espiritu Santo National Park, Sea of Cortez (Gulf of California), Mexico, February

Claudio Contreras / Redhead Goby (Elacatinus punticulatus), Espiritu Santo National Park, Sea of Cortez (Gulf of California), Mexico, February

David Fleetham / Steinitz' prawn / shrimp goby (Amblyeleotris steinitzi) and Alpheid worker shrimp (Alpheus sp) side by side. Mutualism occurs between the two species, the blind shrimp maintaining the shared burro...