Legality of Selling Live Fish in California?

I have a major overpopulation of Catfish in a pond at my house in SoCal and was thinking of ways to "get rid of them". Someone offered to buy them for their fish tank. I wanted to try to sell more and was curious if it is legal to sell live fish like this and if i have to do something special. I wanted to try and advertise them in the Penny Savor which is kind of like a newspaper for selling things. Is this legal?