Just checked a Japanese dictionary:
ara 粗 - remaining bony parts (of a fish after filleting)
ara 𩺊 - saw-edged perch (a species of marine ray-finned fish)
They're both pronounced the same.
I'm guessing the yokozuna was asking for the ara fish, but Oohara misunderstood? Because that one panel had him asking like "isn't ara just the guts of the fish" or something.