strange fish in the pond

Hi Everyone!

My husband and I bought a home last August with a 14 x 14 pond in the back yard.

This morning I noticed a fishtail sticking out of a fallen over waterlily pot. I knew it wasn't one of the goldfish we put in, because the tail was black.
I checked back a few more time during the the day, but the fish never moved, so I figured that I was dealing with a nocturnal critter.
Being the intrepid biologist that I am, I went back after dark with my dive lamp to observe our mystery fish. My suspicions were correct and the fish was out and about. It is about 6 inches long, bass shaped without visible stripes and with a rounded but slightly forked tail. I wasn't able to get a close look at his dorsal fins because I could mostly only see him from above.
Any idea what species I might be dealing with here? We live in Maryland.

If he was purposefully added to the pond he must be at least 6 years old as the previous owners (who lived here for 5 years) indicated that all the fish they ever put in the pond were goldfish that got eaten by a heron.

Cheers!

Sepioteuthis

Plecostamous? They are nocturnal and have a forked tail.

Originally Posted by DrDave

Plecostamous? They are nocturnal and have a forked tail.

Thanks for the response!

No, I have a pleco in my aquarium and this definitely isn't one of those.
I teased it out of it's 'house' during the day yesterday and it looks like a bottomdwelling sunfish. It has a black spot on it's gill cover, and the right shape dorsal fin. It looks a lot like a mud sunfish (Acantharchus pomotis), but those don't have forked tails.

I'm think I might try to catch it with a net so I can take a picture of it.

Got another look at it today and it doesn't have a forked tail. It looks that way when in rest but when swimming it's clearly straight. I'm going to call in a mud sunfish until I hear otherwise!