Unique way fish identify their species

[TP123]

I figured this would be an interesting article for this community.

http://www.nytimes.com/2010/03/02/science/02obfish.html?ref=science

Now for all difficult species IDs, we'll require a photograph with a UV filter in addition to the usual color photo.

[skibum9884]

Very interesting. Thanks for this. I always wondered how they could tell.

The question that still bothers me is how they can identify their own species (i.e. - how does a particular damsel know it is a damsel and not a chromis!). Obviously they've never seen themselves in a mirror, and even if they could, probably could not understand they are seeing a reflection.

I'm assuming this must be ingrained in some way, as it is seen in other animals as well.