I caught this little guy 2 weeks ago and he was literally the size of a tadpole and at first I thought it WAS a tadpole. Just a little under 1/2" long at the time. He's about 5/8" long now, is eating well and adjusting well in the tank. Don't think it's a Madtom but either a yellow bullhead or channel cat. Jet black with a snow white belly and lower barbels.
Never thought that a catfish could be as adorably cute as they are when tiny!