The Size of Your Bait

I’ve heard it told
That to catch a fish of size,
One must present a bait
That looks large in a fish’s eyes.
Nothing demur like a worm or a grub;
I’m talking large, like a tub.
Something which says to the fish
Stand back cause this is a large fish’s dish.
Oh I know what I need to achieve
And I need to present before the large fishes leave;
Yet try as I may,
I seem not to know what’s a fish’s parfait!
I can do large and that’s not the rub;
It’s what to put into this thing called a tub.
I’ve a thing or two to learn about fishes,
Maybe one day I’ll know what they consider delicious.