Well it depends on what kind of Catfish you have. If you just went out and caught a catfish from a lake then it is not considered Kosher until a rabbi. It must have been raised without hormones and slaughtered quickly. Within three days of the slaughter you must de-vein it, salt it, and rinse it three times in fresh flowing water to remove the blood. Which you are forbidden to eat. Also the Catfish must have both fins and scales or else its a non-kosher fish. Conversely if you decided to buy it from a store, if it has a U or a K in a circle, are from two of the largest Kosher organizations in America The Union of Orthodox Jewish Congregations of America and The Committee for the Furtherance of Torah Observations respectively.