English: Fluorescent eyes of marine fish. Many red fluorescent marine fishes have their fluorescence concentrated in or near the eyes, illustrated here by 25 species from 12 fish families. (a,b) (Gobiidae—Gobies): 1, Bryaninops natans; 2, Bryaninops loki; 3, Ctenogobiops feroculus; 4, Ctenogobiops maculosus; 5, Fusigobius melacron; 6, Eviota guttata; 7, Eviota zebrina; 8, Pleurosicya micheli; 9, Phyllogobius platycephalops; 10, Tomiyamichthys oni. (c) (Tripterygiidae—Triplefins): 11, Ucla xenogrammus; 12, Helcogramma striata; 13, Helcogramma steinitzi; 14, Enneapterygius pusillus; 15, Tripterygion delaisi. (d,e) (other families): 16, Lepadogaster candollei (Gobiesocidae—Clingfishes); 17, Synchiropus moyeri (Callionymidae—Dragonets); 18, Paracheilinus octotaenia (Labridae—Wrasses); 19, Corythoichthys schultzi (Syngnathidae—Pipefish); 20, Aulostomus chinensis (Aulostomidae—Trumpetfishes); 21, Bothus pantherinus (Bothidae—Lefteye Flounders); 22, Scorpaenopsis diabolus (Scorpaenidae—Scorpionfish); 23, Dactyloptena orientalis (Dactylopteridae—Flying Gurnards); 24, Paracirrhites forsteri (Cirrhitidae–Hawkfishes); 25, Upeneus tragula (Mullidae—Goatfishes). Photographs were taken in the following regions: Mediterranean Sea in Croatia (15) and Corsica (16), Red Sea in Egypt (1, 4, 8, 13, 14, 18, 22, 24) and Indo-Pacific in Indonesia (Sulawesi and Raja Ampat, remaining pictures). Photographs 13, 14 and 16 were taken indoors; all others were taken while scuba diving. All photographs were taken with various red-enhancing filters. An additional blue light source was used for pictures 13, 14 and 16 (laboratory), 20 and 21 (field). All other pictures show fluorescence under natural light at depths below −15 m.