Shrimp Vision

theshrimp_123 · Post by **theshrimp_123** » Sun Jul 30, 2006 10:38 pm

Hey guys,

How do shrimp see? I was watching them one night with a flashlight and it bothered them. When I switched to a red filter, they seemed to be unaffected. When I use a blue filter, it bothers them. Also, ghost shrimp eyes are reflective whereas amano eyes aren't. Does this mean they see better? And also, can they see colors and images the way we see them? How good is their vision, and is there a difference between species?

Thanks,
Chris

Baby_Girl · Post by **Baby_Girl** » Mon Jul 31, 2006 7:20 am

The colors that they see has to do with the types of pigments and different cones (color-receptor cells) in their eyes. I'm sure that some animals have more of one color cone and less of others, for whatever adaptive reason. Many aquatic nocturnal animals do not see red (this color is the most absorbed by water, hence usually less of it exists underwater) and I have heard blue is usually not visible either (moon lights are colored blue), but this may not apply to all species, especially invertebrates. Astronomers use a red filter over their flashlights, to prevent "ruining" their night vision (temporary) when they look at books and guides.

The reflective layer (at least in mammals) is to help them catch any available light. By reflecting it back, it essentially allows them to use availble light twice. In Australia, we would go spotlighting for nocturnal mammals by looking for their eye-shine, and sometimes I would see the chilly blue glow of 6 eyes from a single large wolf spider! It may just be that amanos are more diurnal and ghosts are more nocturnal in activity, so they don't need the reflective layer.

But I'm not an expert in shrimp anatomy, so maybe it's just the way their eyes are formed/function/etc. And not having owned amanos myself, I don't have any experience with that and could be totally wrong

Hope that helps! That was your friendly lesson of the day on vision

ShrimpFan · Post by **ShrimpFan** » Mon Jul 31, 2006 9:14 am

Try shining the light on the amanos again. I've done this and mine have reflective eyes you can see if you angle the flashlight correctly. It might be easier to see the ghosts' eyes because they have bigger ones. Also, my amanos seem to dislike the light more than my ghost does, so they move away and make it harder to see them.

I should mention something interesting about shrimp and light that I've observed, actually. One time I was bothering my shrimp with a flashlight at night, and I had some very young cherries in the tank (1-3 days old). They all crawled over to where I was shining the light and started moving towards it. My boyfriend thought it was the cutest thing

. So, very young cherries seem to like light rather than shy away from it like the adults do...

theshrimp_123 · Post by **theshrimp_123** » Mon Jul 31, 2006 10:53 am

I tried again with a ghost, an amano, a cherry, and a wood shrimp. All but the ghost's eyes kinda absorbed the light and seemed matte black. When the ghost shrimp were tried, they appeared silver and shiny, with a black spot in the middle.