Coloration of reef organisms
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  hot buttons for colours section of Biology of Caribbean Coral Reefs website
This section deals with the function of colours. Topics of HOW COLOURS ARE CREATED and HOW COLOURS ARE PERCEIVED can be accessed via the icon.

Function of colours

  Functions of colours and colour patterns in reef animals fall into 2 broad categories of SOCIAL and DEFENSE, one topic of the latter, mimicry, being considered here. Most or all of these topics have been mentioned elsewhere in the BCCR but, by its nature, this section on FUNCTION OF COLOURS pulls them together in broad summary. A third category of UV PROTECTION is also included in its own, short section. CLICK ON a topic to learn about it.

Function of colours: defense: mimicry


Mimicry is when an animal's shape and colour resemble something else in order to attract its prey, hide from its prey, hide from its predators, or to benefit in copy-cat fashion by appearing to be another animal entirely. Fishes such as frogfishes that use lures to attract their prey are employing mimicry, and colours as well as form and behaviour are involved.

This section deals with fishing lures & camouflage mimicry, while other sections deal with EYESPOT MIMICRY, AGGRESSIVE MIMICRY, and BATESIAN & MULLERIAN MIMICRY.


Function of colours: defense: mimicry: fishing lures & camouflage mimicry

seahorse dive leader for Biology of Caribbean Coral Reefs website photograph of some reef fishes taken from a video

"There are only a few examples of mimicry in Caribbean coral-reef animals, so let's start with this lionfish in the Red Sea so you can see what might be fish-mimicking lures on its you think that prey fishes might investigate these as possible food, and then be eaten by the lionfish?...I wonder if there are any copy-cats of poisonous fishes; that is, a fish which is palatable, but which has evolved colour and behaviour patterns to mimic those of an unpalatable fish? That would be cool, don't you think?" - Red Sea, Grand Cayman Island 2008

NOTE Pterois sp.


photograph of a lionfish's head showing fish-mimicking lure, taken from a videoA few fishes, mostly frogfishes and anglerfishes, have evolved a lure that sits at the end of a rod, actually the modified first spine of the dorsal fin, that is twitched in a life-like manner
to attract the attention of possible prey fishes. When a prey fish investigates what may seem to be something to eat, it is sucked in by sudden expansion of the frogfish's jaws.
photograph of a frogfish Antennarius multiocellatus courtesy Anne Dupont, Florida

Is this a fish-mimicking lure on
the head of a lionfish Pterois the Red Sea? 0.5X

Longlure frogfish Antennarius
1X Photo of frogfish courtesy Anne
Dupont, FL.


photograph of sargasso nudibranch Scyllaea pelagica courtesy Anne Dupont, Florida
The sargasso nudibranch is another example of mimicry where not only matching colours are employed, but also modifications to body shape and behaviour. These shell-less snails mimic the environment in which they live presumably to hide from photograph of sargasso nudibranch courtesy Anne Dupont, Floridapredators; however, when disturbed, they can also escape in a side-to-side thrashing form of swimming. Photos courtesy Anne Dupont, Florida.

Are the bright blue spots on some
specimens mimicking sun-sparkle
in the shallow surface waves?

Sargasso nudibranch Scyllaea
on sargassum weed 3X


Another mimic of sargassum weed is the sargassumfish Histrio histrio that ambushes prey fishes from disguised locations among floating weeds. Apart from its mimicking camouflage, it appears to have no other defenses.

NOTE lit. "actor" L.photograps of a sargassumfish eating a small perch taken from a video

Sargassumfish orienting
towards, then attacking
and gulping down, a small
perch 1X. The sargassum-
fish will attack and eat prey
fishes equal to and even
larger than themselves


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