Cardinal fish with a fake eye
(Cheilodipterus quinquelineatus)
Colours of the Reef
Red Sea butterfly fish
(Chaetodon paucifasciatus)

 
“In front of the biological station at Hurghada I (dived) the first time in a coral reef. It was a Garden Eden beneath the waves. I was almost drunken from watching the colourful fishes, which flit over the green-blue coral gardens”
Hans W. Fricke, Berichte aus dem Riff (1976)

 
Light – Water - Colours
Water filters the colours of sunlight by degrees. Red light is no longer visible at 10 metres depth. However, yellow is still visible down to 20 metres. In greater depth everything is immersed into deep blue. All other colours vanish. Only in shallow areas flooded by light, the colours of the reef are shown to advantage. Above all they are one thing: luxurious optical messages.
The Royal Anglefish Pygoplites diacanthus

 

Colour pattern: An adult Emperor Anglefish		 Colour pattern
Angle and butterfly fishes exhibit exceptionally conspicuous colour pattern. They want to show: this is my territory! They defend it against competitors such as rivals of their species or other fishes.
Juvenile angle fishes have a trick not to be driven out of their parents territory: they exhibit a different colour pattern. By this way they show that they do not compete for food. Until they change their eating habits adult angle fishes tolerate the young ones.

 
Fake eyes
Fake eyes are particularly characteristic for coral reef dwelling fishes. Usually these fake eyes are located at the back or close to the tail fin. The eyes of the fish are camouflaged by a dark bar or stripe in order to:
- Deception and confusion of predators. The fish deceives a fake head in order to escape in the opposite direction
- Distraction of attacks. Attacks of predators and rivals are distracted to the fakes eyes to prevent an injury of the eyes.
- Signals for ritual fights. Butterflyfishes can change the size and colour of the fake eyes. If necessary they can signal submissiveness in ritual fights to calm the rival down.
Fake eye: Buttefly fish Chelmon rostratus

The poisonouse Lionfish Pterois radiata		 Watch out! Danger!
Conspicuous colours are signals for danger. Nudibranchs and firefishes deter enemies, because after a bad experience the conspicuous colour pattern are kept in mind. This play of colours calls for imitation by non-toxic animals.

 

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© Marc Kochzius