While on vacation last week, I took the kids for a bike ride on the shinning sea bike path in Falmouth. I figured we'd hit the W.H.O.I. aquarium and check out some sea life. While on the upper deck there was a whoi employee answering questions from the kids. I asked "How long does it take for the stipers to change color?", he didn't know but the fish biologist was due back anytime. So we checked out the spider crabs, lobsters, mullet, herring, mackerel..... A great place to checkout what the bait looks like underwater. After a time Dave (didn't get his last name) the fish biologist shows up. I pose my question to him. The answer suprised me, just a few hours. :eek: He stated that they often go to a darker color at night. He has noticed that many of the fish display different colorings at night, one day he came in to turn on the lights and the scup were striped. I was curious because I saw blondes and black and white stipers in the same area at the same time when I was fishing the flats, but that's another story.
Great post. I've always wondered it myself. Now it begs the question...how come the dark ocean fish stay dark on the flats of Monomoy early in the season? Does this mean they've just come up out of the ocean? Or maybe they're just hanging out in deeper water at night?
08-13-2002, 09:52 AM
Guys, I'm in the middle of reading Alan Caolo's book Sightfishing for Striped Bass . He addresses this issue and also claims that color change occurs as quickly as two hours. If a fish is spotted coming across a flat and it's still fairly dark in color, it's most likely a fairly recent arrival from a channel or other deep water and Alan theorizes that these fish are choice targets because they might be less selective. After being on the flat for a few hours, they might already be keyed in on a very specific prey and ignore any offerings that are not imitating that particular food source. It's nice to know that a striper's time on a flat can be estimated by something as simple as color!
BTW, I think that Caolo's book is excellent. Just this one piece of info is almost worth the purchase price, but it's loaded with other tidbits.
Another point Dave brought up was that some flounder can really change color almost to the point of looking like the texture of a gravel/sand bottom. He went on to say that in an experiment a flounder was placed on a checkerboard and came very close to duplicating the pattern. I originally assumed that when fish change color it is because they have eyeballed the surroundings and make some effort to change. Is that what's really happening? When I asked Dave about the flounders ability to blend into the bottom when it was looking up he said they (scientists) had the same question. Sound like they've got a handle on the chemical compounds and physiology of the color change but not the trigger. Perhaps there is more at work here than the optic nerve.
When I got my answer of just a few hours, that was really all I was looking for but I have a new appreciation of the complexity of the biomass we call the ocean.
08-13-2002, 01:41 PM
It gets even more impressive with squid - those guys can alter color in real-time. Its a bit like the technology the "Predator" used to become invisible. There is some sort of network of photosensitive cells in the skin which react to their suroundings and generate signals which cause a color change on the opposite side - pretty clever stuff!
Ahh, the "Predator" I'm thinking 15wt.:hehe: