As a general rule, for land animals at least, bright flashy colors are a warning sign that either:
A: “Hey, I’m poisonous!”
For example Coral snakes, Bees and wasps, poison arrow frogs, the bright red hourglass on a black widow spider, etc…
Or B: “Hey, I taste really nasty!”
Ladybugs, Monarch butterflys, fire newts, (I’m taking my Boy Scout Guide’s word for it, I haven’t actually tasted a ladybug recently and have no plans to do so).
But underwater, especially in warm climates, the fish are a riot of colors. Now here’s my point, clown fish, parrot fish, striped darters, all brightly colored, all big, slow, STOOPID, harmless and tasty!
Anybody who’s ever gone snorkeling around Catalina island will tell you about Garabaldi fish. They’re like great big traffic-cone orange loaves of bread that stupidly bumble up to you while your spear fishing.
So, whats the advantage in bieng big, slow, stupid, tasty, harmless and brightly colored?
Just strikes me as an engraved invitation to a passing barracuda.
Coloration in animals (both land and aquatic) is more complex than the two examples you gave. For example, butterflys are not brightly colored because they are tasty, but because the coloration helps them blend in with the flowers they feed on. Camoflage.
Bright colors are also used in mating displays. Certain animals are attracted by members of the opposite sex displaying the brightest colors. Think of peacocks as an extreme case. (Or, ask any redhead. )
Other cases… With some species of birds both the male and the female sit on the eggs. In others, only the female does. In the second case, the male is usually brightly colored (cardinals and blue jays, for example). The male, being highly visible, leads predators away from the nest. Other birds are dull colored; again for camoflage.
As for the fish, any of the above can apply. Have you ever seen a coral reef? Coral, sponges and the like can be brightly colored; brightly colored fish can blend in with the reef better. In some species the males are brightly colored; probably for mating displays.
Finally, remember that color fades out fast underwater. Thirty feet down just about everything looks blue unless you are very close.
“You can’t run away forever; but there’s nothing wrong with getting a good head start.” — Jim Steinman
For one thing, many brightly colored fishes live in, on, and around coral reefs. Since reefs are brightly colored, they actually tend to blend in more than you would expect.
Next time, take a look at the benthic fishes that live in the sands and grassbeds just off the reefs (flatfishes, goatfishes, tilefishes, and many smaller fishes such as gobis and blennies, to name just a few). Most are pale or drab. And the pelagic fishes that spend most of their time in the water column, even above and around reefs, are usually silvery to blend in with sunlit clear waters.
Parrot fishes are not particulary tasty. They are full of uric acid (yuk–even to a predator).
There are many other defense mechanisms, such as schooling. Take a look next time at all the snappers and grunts forming large schools of mixed species and genera. Safety in numbers, you know.
Many brightly colored species are small and can dart into crevices.
Many species spawn millions of larvae, most of which will be eaten, yet the species survives because of this ecological strategy (known as being ‘r-selected’).
And yes, many bright colors are used for courtship and mating. In many species, including wrasses and parrotfish, only “supermales” are bright. Females are actually quite drab. Fishes have some of the most developed color vision in the animal world.
Don’t even get me started on why soft, bright, and sessile sponges don’t get eaten!
Granted, the benifit of bright colors from a mating standpoint is the message “Hey baby! I’m right here!! Hello?!”.
But where’s the advantage in a strategy of…
Hatch (hurry, hurry!!), eat, grow (hurry, hurry!!), attract mate (Now baby! Now!! Hurry!)lay eggs (hurry!!), get gobbled up by a nurse shark (or whatever)?
Over a strategy of camoflage, lurk, survive, live to mate more than the one season?
There may seem to be an advantage of one over the other, but that’s human prejudice showing. Nature doesn’t care what would be “best” or “most efficient”; it has no judgemental capabilites at all. If the hurry-fish survives long enough to produce young, the species will continue, and there will be more hurry-fish next year. As long as the species continues, we should call its reproductive “strategy” a success.
Of course I don’t fit in; I’m part of a better puzzle.
Well, this strategy is actually the case for many insects (except for the nurse shark). Hatch, mate, and die. A particular species may use any of the strategies already mentioned (crypsis, warning colors, behavioral patterns, etc…) just to make it from ‘hatch’ to ‘die.’
As far as fishes go, most spawn more than once over a lifetime. They do not just mate and die. Of course there are exceptions (salmon comes to mind). I’ll stick with reef fishes because that’s what I know more about.
Ecologically speaking, it really doesn’t matter to the species if adults get eaten here and there by predators. Let’s say there are 20 adult angelfish that live around a certain reef. Barracuda, moray eels, and sharks eat 16. As long as there is a male and female to spawn another million larvae, those 16 don’t matter at all.
Remember, as much as it is hard to grasp sometimes (being humans) what happens to indivduals really doesn’t matter in the animal kingdom as long as the replacement rate for the species is stable or positive.
And different species have different strategies. Certainly, hide and lurk is one strategy, but bright, slow, and nasty may get another fish through many spawning events as well. And remember, being bright on the reef is often a blending strategy, as Tanstaafl and I have already pointed out.
There’s another survival strategy which I haven’t seen mentioned here:
Look like something poisonous, venomous, nasty-tasting, or just generally vicious. If that means being brightly colored, large, and slow-moving, be those things. You benefit from the reputation of whatever it is you look like without the bother of growing your own venom glands (or whatever).
Actually on that subject Torq, I was thinking about those flies that look like bees…
I can’t escape the feeling they are the insect world’s equivilent to the geeky little brother of the school bully. They get no respect, nobody talks to 'em, but nobody will mess with 'em either just in case.
Don’t forget that fish likely see in a different way than people do. I saw somewhere that goldfish can easily distingush the color blue from a background, but does not recognize some other colors nearly as well.
Regarding insects, and possibly fish, many of the “colors” we see could just be a by-product of the pigments that also have a wavelength meant to be seen in the ultraviolet spectrum.
So all those bright colors might just be so much camouflage to a predator. Except for the blue ones, of course. They’re obviously suicidal.
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