Hang on & let me look back for the details as one way to distinguish a Channel or a Blue. Sometimes "their" hybrids will throw you for a loop. I caught a Channel one time in Lake Limestone, that the head actually reminded me of a Yellow (flat & looked like the back side of a square point shovel). But forked tail & other such criteria past the head, said it was a Channel.
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OK, here is one such item from TP&W in my archives-
Channel Catfish
A Body with dark spots (spots may be absent in large adults)
B Outer margin of anal fin rounded, and anal fin with 24 to 29 rays
Blue Catfish
A Body without dark spots
B Outer margin of anal fin straight, and anal fin with 30 to 36 rays
Further info might be found here:
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http://www.tpwd.state.tx.us/publications/pwdpubs/catfish_diagrams.phtml>
I noticed the anal fin curved up towards the front, but actually the curve they seem to speak of, is the outer end of the rays.
Also, I have noticed Blues have a sharper forked tail, while Channels have a blunter one. But that may not always be the case. As to records, I wonder where a Hybrid would fit in, as to a classification.
And spots are usually on the younger & smaller ones, compared to larger ones.