Flashlight Bad for Livestock?

ralphie16

In Memoriam
I have a brittle star that hides with the lights on so I only get to see him at night. Last night I used a flashlight to see him and he got real annoyed by it so I wont use that again. But what also happened was my puffer came over and blew up.

So it looks like my guys do not like to be woken up with a flashlight. Go figure ;-)

So some of you have mentioned using a red filter? Can you guys please explain why this would work? Is it the color they can't see? I know plants can't see the color green so is it the same thing with fish and inverts?
 
Red is the first colour to disappear in water so the fish and invters have evolved not to be able to see it, a bit like animals that live in constant darkness have evolved without eyes because they don't need them... I think!!!
 
You can probably red light from a hunting place I assume. They gave us some when I was in boot camp and all it is is a plastic lense that goes over the light to turn it red. You might be able to find it at a military surplus store no clue. Walyworld might have it just look around for it and you can prob find something in your area. And it's not that they live in constant darkness it's that they have less use for red light as blue light is what penetrates the water the best so that's what they see the most. It's pretty much like being colorblind to red I suppose.
 
ya i'm pretty sure its what chris said. But its not that the other light is bad for the fish, otherwise everyone w/metal halides would have dead fish ;) But its more just the fact that they were surprised and didnt like it. And the stars are probably just nocturnal or something anyways, so thats why he went away from the flashlight, along with the other lights.
 
I have a red flashlight (Walmart camping department) and my shrimp react to it. So I'm not sure how invisible it is to them. I'm sure it's not as glaring as a bright white light, but dont' expect to sneak up on your tank at night.
 
I guess another option could be those blue moon led lights? never used them but with those on for a while livestock would probably get used to it and provide some viewing light for you.
 
Jakaru that's not what i said!! It's a bit like an animal that lives in constant darkness not needing eyes, there isn't a lot (if any) red colour in water so they don't need to be able to see it so the body doesn't bother developing the bits and bobs (can't remember all the inn’s and out's at the moment!!) to see red just like an animal not needing eyes so they don't waste the energy developing them!!
 
Ah your right I misread your post sorry 'bout that lol. You are right. If you don't need it you probably wont evolve to have it.
 
i'd say you are both right. Theres some sort of freshwater fish (cant remember the name...i havent paid attention to freshwater for a few years) but i'm thinking its something like a cave fish?? i cant remember..but it lives in caves so it evolved to either not have eyes, or its completely blind, again, cant remember which.

But like jakaru said...those blue led moonlights that are really low light work too. The fish can see that color, yes, but its really dull, so they'd get used to it.
 
I got my flashlight at walmart in the camping supply department. It came with a red and blue lens with a carrying case.
 
I dont think it's that they don't see red because there's red fish in the ocean. I think it's more because the light disperses faster. Kinda like the moon lights. It's more to just dim the light then to make it a color fish can't see. I think they use a similiar color lens in the army when they need to read maps and such and night. I think it's just cause a white light uses all the colors on a spectrum and therefore the light doesn't disperse as easily and is easier to see. My fish don't usually mind my white light but if it's a suttle red light they still see it it's just not as blinding. Sit in a dark room for a few hours and then place a flashlight infront of your face adm turn in on. I bet the red light won't hurt as much.. haha.
 
my fish are just used to it. I quit using the red cap a long time ago. I move slow and usually don't put the light directly on what I'm looking at.
 
<a href=showthread.php?s=&postid=8139035#post8139035 target=_blank>Originally posted</a> by MrsDorothy
I got my flashlight at walmart in the camping supply department. It came with a red and blue lens with a carrying case.

I got the same one, it works very well, and its something for this hobby that was inexpensive. :lol:
 
Dusting off the old high school physics memories.

Red light has the longest wavelength and gets dispersed more easily in water. Blue has one of the shortest, so it penetrates deeper. That's why moonlights in aquariums are blue, since 10m down thats the only light that will penetrate, even though the light source is white at the surface.

Why red light for night? In humans, our eyes slowly adjust to darkness by chemically making our eyes more sensitive to light. That's why your "night vision" gets better a few minutes after lights out. Since red light is the longest wavelength, it is the least harsh to eyes adjusted to darkness. I think the assumption is that it works the same for fish.
 
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