Fish ID?

[Munsterdrool]

Hello, everyone We just purchased some Chromis(sp?) last night from Petco. Well, there was another odd..fish in with them, same blue/green color, only he's slightly flatter and has a more spiny dorsal fin. Pictures below!

 

[treylane]

so cute!

Anyway, it's a juvenile damsel, Pomacentrus or similar species (see the same body shape?)

He'll likely be much larger (most get ~4") and much more territorial than the chromis as he grows up, you should consider returning him to the store, especially if you have a small tank. They make very interesting pets, but there are a lot of tradeoffs to keeping them.

Many of these guys change their colors/patterns significantly as they grow up, but to take a stab, maybe a Amblyglyphidodon batunai ?
http://www.fishbase.org/Photos/ThumbnailsSummary.php?ID=54180

 

[Munsterdrool]

Oh, that's awesome, thanks! Yeah, at night he has brown tiger stripes.. to say I was fascinated was a huge understatement. lol. Though, him reaching adult-hood is very unlikely within our tank. Due to the dwarf lionfish (whom we're getting rid of) and the angler (not sure if he's staying or going back to the petstore, atm).

 

[Khemul]

I suspect they are Amblyglyphidodon curacao (Staghorn Damsel), but Amblyglyphidodon batunai and Amblyglyphidodon flavilatus look similar also. Under lighting they don't entirely match any of them, but when the lights go out they look a lot like a Staghorn damsel. They usually get labeled as "Green Chromis".

There is also a yellow version of the fish, Amblyglyphidodon aureus (Golden Damsel). Which gets labeled as "Yellow Chromis" often.

They seem to be rather peaceful, especially for damsels, but I haven't seen them as full grown adults (outside of a petstore at least, but everything looks calm and peaceful in a petstore). When young they swim together (not really a school, just swim in the same area), even the different species, and there is very little in the way of fighting.