You are a fishgirl shark, you were only 3 and you were thrown into the sea by stuffing you into a barrel fishman noticed that something was floating on the sea then they took and dragged the barrel to Arlong Park

Choo: Arlong we noticed it in the sea

Kurobi: The barrel is heavy as if there is someone or something in it

Arlong: Open it.

After they opened it, you fell out of it scared everyone was shocked seeing that this was also a fishman but a girl and immediately noticed that you were a fish shark

Arlong: Who could have thrown her into the sea?! There is another reason to hate humans, they are heartless.

Kurobi: What to do with her?

He looked at you, Arlong came up and picked her up

Arlong: Of course we will leave her, she will not live among these lower creatures called "human".