Gary Bell/ Oceanwide / Scarlet Cleaner Shrimp (Lysmata amboinensis) cleaning mouth of Goldbelly Cardinalfish (Apogon apogonides), Tulamben, Bali, Indonesia

Georgette Douwma / Banggai cardinalfish (Pterapogon kauderni) with a Corkscrew or Long tentacle anemone (Macrodactyla doreensis). Lembeh Strait, North Sulawesi, Indonesia.

Martin Dohrn / Cardinal fish (Apogon sp) moments after it has mistakenly tried to eat an ostracod. The ostracod then releases glowing mucus that is so bright that it can be seen through the body of the fish. This gi...

Juergen Freund / Schooling Banggai cardinalfish (Pterapogon kauderni). Lembeh Strait, North Sulawesi, Indonesia

Juergen Freund / Schooling Banggai cardinalfish in anemone tentacles. (Pterapogon kaudemi). Lembeh Strait, North Sulawesi, Indonesia

Wild Wonders of Europe / Banfi / Cardinalfish (Apogon imberbis) Larvotto Marine Reserve, Monaco, Mediterranean Sea, July 2009

Georgette Douwma / Banggai cardinalfish {Pterapogon kauderni} sheltering amongst the spines of an Urchin, Lembeh Strait, North Sulawesi, Indonesia.

Chris Newbert / Yellow-striped Cardinalfish (Apogon cyanosoma) male with eggs in mouth, 40 feet deep, Solomon Islands

Fred Bavendam / Ring-tailed Cardinalfish (Apogon aureus) male protectively carrying a fertilized egg mass in his mouth while they incubate, Bali, Indonesia

Georgette Douwma / Kaleiscopic Banggai cardinalfish (Pterapogon kauderni). Lembeh Strait, North Sulawesi, Indonesia.

Tony Wu / Spotnape cardinalfish (Ostorhinchus notatus) pair, male taking cluster of fertilised eggs into mouth to brood. Shizuoka Prefecture, Honshu, Japan. June.

Tony Wu / Spotnape cardinalfish (Ostorhinchus notatus) pair, male taking cluster of fertilised eggs into mouth to brood. Shizuoka Prefecture, Honshu, Japan. June.