Identifying for a friend

[Clerk]

A friend of mine had one of these in his tank. I'm fairly sure its a bad idea for him to have it, but I am not sure what it is.

[steveh28]

It appears to be some sort of bluegill/sunfish. Not really compatible with tropical fish, and they are extremely aggressive. They are native to North America, and keeping them might go against state regulations where you live (Some states are more strict about keeping natives). They are a quite attractive fish.

[Clerk]

I was leaning towards bluegill, but didn't see the typical black spot.

[steveh28]

It didn't look quite right to me either, but it is closely related. Bluegill can also vary from location to location as well. It doesn't quite look like one I have caught around here, but it could be one from just about anywhere. Did your friend catch this and bring it home, or did a store have it for sale? Either way, hope he enjoys the fish.

[Clerk]

I'm fairly sure he picked it out of a comet tank. He is not quite as strict on the fish etiquette as I am, but nothing I can do.

[steveh28]

Yep, fairly sure it would be a bluegill then. It is quite common to get a few of those with a comet shipment

[pleco_breeder]

The fish in question is not a bluegill, but is in the same genus. The fish in the pic is Lepomis gibbosus, commonly known as pumpkinseed, kiver, or red eared sunfish. As mentioned, they are HIGHLY aggressive and capable of beating fish several times their size to death. Very nice fish for a specialist hobbyist, but I can't say I'd recommend them for anything other than a large species tank.

Larry Vires

[zippo]

AKA SHELL CRACKERS in the South, mean fish. And they get fairly large as far as pan fish go.