It's a carcaradon carcharias.

Day 27.1

Quint: Y'all know me. Know how I earn a livin'. I'll catch this bird for you, but it ain't gonna be easy. Bad fish. Not like going down the pond chasin' bluegills and tommycods. This shark, swallow you whole. Little shakin', little tenderizin', an' down you go. And we gotta do it quick, that'll bring back your tourists, put all your businesses on a payin' basis. But it's not gonna be pleasant. I value my neck a lot more than three thousand bucks, chief. I'll find him for three, but I'll catch him, and kill him, for ten. But you've gotta make up your minds. If you want to stay alive, then ante up. If you want to play it cheap, be on welfare the whole winter. I don't want no volunteers, I don't want no mates, there's just too many captains on this island. Ten thousand dollars for me by myself. For that you get the head, the tail, the whole damn thing.

Brody: We want it alive Quint. Something that we can use for tourism.
Quint: [to Brody] See what I do, Chief, is I trick 'em to the surface. And I jab at 'em. I'm not gonna haul 'em up like a lot of catfish. But, for another five thousand...
Hooper: We need it in a bag, a big plastic bag, so everyone can see it.
Quint: A bag? Aye, I can use a bag.  Ziploc or just a twist tie?

Brody: Twist tie will be fine. Easier I think to keep it fed and the water changed.
Quint:  It’ll be a mess in there after a day or so, do ye have a tank?
Hooper: It’s on backorder. For now a bag will have to do.

Quint:  Aye, it’ll do, what is the worse that could happen, ‘eh Chief?