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  Topic: old article of mine, ontogenetic color change in fishes< Next Oldest | Next Newest >  
sir_toejam



Posts: 846
Joined: April 2005

(Permalink) Posted: May 18 2006,09:41   

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What do the adults see?


indeed.  not just the adults, what about predators?

colors that look like bright blue spots to us, might look black to a predator, or neutral gray.

think leopard spots, tiger stripes, etc.

I tend to lean towards more simple explanations of camouflage these days to explain OCC; but it's VERY hard to gather evidence to attempt to refute this to begin with.

example:

how would you gather conclusive evidence to refute the idea that a leopard's spots help to camouflage it from its prey (or potential predators - yes, lions will kill leopards, for that matter)?

you'd have to know something about the way the common prey animals process their surrounding visually, and maybe even paint a few leopard's spots out to see if it has a direct effect.

not easy.

John Endler has been doing a lot of excellent work on this question lately in fish.  I've half thought about getting another degree and apply to his lab.

money is always the issue, tho.  It's really hard to get money to study this kind of thing, interesting tho it might be to some.

as to reef fish changing color...

many fish can radically alter their coloration on short time scales.

if you ever get the chance, try doing a night dive and a day dive in the same area and you will see great differences in not only the species assemblage, but also the colors of many of the individuals that are present at both times.

parrotfish, for example, can look like a totally different species when they are "sleeping".  

diet can also have an effect on fish color.  in reefs that are shifting away from live coral and more towards dead coral with algae (common in the tropics these days), this will result in some shifts in diet which can affect color.

note that these issues are entirely different than OCC, just to be clear.

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I brought my 6mm wetsuit and hood.


lol.

a full 6 mm?  that would be a bit toasty.

I often wear a full 3 mm suit in the tropics if I'm doing a lot of diving.  around 30 feet plus, the water ain't THAT warm.  Even at 80 f, your body is still losing heat pretty fast without a suit on.

I did some snorkelling off the keys last year (near key West and a bit south of Largo); is that where you were?

  
  14 replies since Mar. 06 2006,18:25 < Next Oldest | Next Newest >  

    


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