The blue catfish is legendary for its tremendous size. Only two sturgeon species and the alligator gar are capable of reaching sizes larger than the blue catfish. That is some rare company. Blues can top the scales at over 100; several sources even mention a 300-pound blue caught in the 1800’s. By comparison, a giant channel catfish may reach 30 pounds.
But what if the catfish is small? How can you tell a blue catfish from a channel catfish?
Keith “Catfish” Sutton, author of Pro Tactics: Catfish and three other books on catfishing wrote, “It is often very difficult to distinguish blue cats and channel cats. When I was state fishing records coordinator for Arkansas, we often had people bring in large catfish that might have been either channels or blues…hoping they were channel cats larger than the current record.”
Well, blue catfish are”blue-ish” in color, right? Mr. Sutton says, “Coloration is never a good way to judge species because it is so variable.”
Pflieger’s book, Fishes of Missouri describes blue catfish as “never having dark spots.”
But some channel cats may not have spots.
Fishes of Missouri also mentions an anal fin (lower fin, just forward of tail) that is straight edged “like a barber’s comb.” But I recently returned from a lengthy viewing session of several large catfish at an aquarium in a mega fishing store and none of the fins inspired grooming the few remaining hairs on my head.
“In the end (pun intended?),” Mr. Sutton wrote, “There’s only one sure way to tell…the anal fin rays.” The channel catfish has 24-29 rays in this fin; a blue catfish is 30 or more.
I love catching all kinds of fish and knowing what I’ve caught. However, because of its sheer potential for massive size, the blue might be loved slightly more… that is, if I was sure it was a true blue.
“Catfish, how do I love thee?”
“Let me count the rays.”