English: Additional File 2 Red fluorescent fish. MPG video clip showing fluorescent fish under "normal" viewing conditions versus conditions emphasizing red fluorescence. Sequence 1a: Redeye goby (Bryaninops natans) (field at ca. 17 m depth, using, natural daytime illumination, no filter). Sequence 1b: Several groups of Bryaninops natans showing red fluorescence (in the field at 25–18 m depth, using Canon PowerShot G7 and Sony HD HDR-CX6EK under natural daytime illumination through red filter, post-processed to highlight reds). Sequence 1c: Bryaninops natans individual under changing viewing conditions (laboratory with blue illumination, moving red filter, using Canon PowerShot G7). Sequence 2a: Pseudocheilinus evanidus in its natural environment (field at 25 m, using Canon PowerShot G7, natural daytime illumination, no filter). Sequence 2b: Pseudocheilinus evanidus showing red fluorescence (field at 25 m, using Canon PowerShot G7 and Sony HD HDR-CX6EK, natural daytime illumination, red filter, post-processed to highlight reds). Sequence 3a: Ctenogobiops maculosus at the entrance of its burrow (field at 17 m, using Sony HD HDR-CX6EK, natural daytime illumination, no filter). Sequence 3b: Ctenogobiops maculosus showing red fluorescent eyes (field at 17 m, natural daytime illumination, red filter, post-processed to highlight reds). Sequence 4a: Ctenogobiops tangaroai under broad spectrum light (laboratory, using Sony HD HDR-CX6EK, white light form halogen source, no filter). Sequence 4b: Ctenogobiops tangaroai highlighting red fluorescence under blue light (laboratory, using Sony HD HDR-CX6EK, white light form halogen source filter through scuba-blue filter, recording through red filter, not post-processed). Sequence 5: Eviota pellucida ( C. tangaroai in background) highlighting red fluorescence under blue light (laboratory, white light form halogen source filter through scuba-blue filter, recording through red filter, not post-processed). Sequence 6a: Enneapterygius abeli showing crypsis in large part of spectrum (laboratory, using Canon PowerShot G7, cold light source, no filter). Sequence 6b: Enneapterygius abeli showing red fluorescence (laboratory, using Canon PowerShot G7, blue light source, red filter, no post-processing). Sequence 7a: Corythoichthys schultzi showing cryptic colouration (field at ca. 20 m depth, using Sony HD HDR-CX6EK, natural daytime illumination, no filter). Sequence 7b: Corythoichthys schultzi showing red fluorescence (field at ca. 20 m depth,, natural daytime illumination, red filter, post-processed to emphasize red fluorescence).