Pascal Kobeh / Honeycomb moray (Gymnothorax favagineus) in a crack of the reef covered with soft corals (Dendronephthya ) with Ring-tailed cardinalfish (Ostorhinchus aureus), coast of Dhofar and Hallaniyat islands,...

Pascal Kobeh / Black spotted moray (Gymnothorax isingteena) near its hole in a crack of the reef with Short-tooth / Goldbelly cardinalfish (Ostorhinchus apogonoides) and Five-lined cardinalfish (Cheilodipterus quin...

Claudio Contreras / Redstriped Cardinalfish (Apogon margaritophorus), Batasan Island, Danajon Bank, Central Visayas, Philippines, April

Claudio Contreras / Split-banded Cardinalfish (Apogon compressus) juvenile, Bilang Bilangang Island, Danajon Bank, Central Visayas, Philippines, April

Claudio Contreras / Manylined Cardinalfish (Apogon multilineatus), Pandanon Island, Danajon Bank, Central Visayas, Philippines, April

Tony Wu / Copperstriped cardinalfish (Ostorhinchus holotaenia) male releasing newly hatched fry from mouth whilst swimming, Kagoshima Prefecture, Japan, Pacific Ocean.

Jacob Guy / Close up of Reef octopus's (Octopus briareus) eyes as it watches a shoal of Cardinalfish (Ostorhinchus sp.), Indonesia, Pacific Ocean.

David Fleetham / Plain cardinalfish (Ostorhinchus apogonoides) male, incubating its eggs in mouth, Philippines, Pacific Ocean.

Joel Sartore / Photo Ark / Ring-tailed cardinalfish (Ostorhinchus aureus) close up of head looking around and breathing, Sharjah Aquarium. Captive.

Henley Spiers / Male Ringtailed cardinalfish (Ostorhinchus aureus) rotating eggs that he is brooding in his mouth, Zamboanguita, Negros Oriental, Philippines

Frederique Olivier / Yellow cardinalfish (Ostorhinchus flavus) swimming over Fire coral (Millepora) head, Worldfish Research Station, Nusatupe Lagoon, Solomon Islands.

Frederique Olivier / Yellow cardinalfish (Ostorhinchus flavus) swimming over a large coral bommie (Acropora), Nusatupe Lagoon, Solomon Islands.