So I'm now a Shark? and other questions.

So I was checking out the barbarian class because the totems interested me. I picked the shark totem because the idea of a little goblin leaping from enemy to enemy biting their shins amused me (Plus I could use a goblin shark image as a player icon, Attachment 24600.)
I started looking through all the feats you could acquire and the 8th level 'animal rage' feat (Page 58 of the manual).

Now my confusion crops up here
Attachment 24598

Specifically the part stating: "You choose the specific type of animal you turn into
within the broader category (such as a lion or snow leopard for
cat). This has no effect on your animal form’s size or statistics."

So should I use my own stats, or do I use the stats of this big boy?
Attachment 24599

Furthermore, does this mean I am beached whenever I rage?
To sum up the question, what do I gain specifically from going Jaws when I get mad?

Thanks x
... wait can I even breathe!?

Welcome to the forums. There's a lot more information in that feat that is important in understanding how it works.

"When you rage you transform into a Medium form of your totem animal..."
Your gear is absorbed but still functions.
Ignore ACP and speed reductions.
Gain low-light vision.
Can't do cast spells, speak or carry out manipulate actions that require your hands.
Gain the listed abilities of the chosen animal. For a shark this is swim speed of 35 ft. and scent.
“This has no effect on your animal forms size or statistics.” So, no, you can’t transform into a gigantic megalodon.

You still keep a lot of your abilities (within the detailed restrictions). You can still walk, breath, etc..

Wait I can still walk? Ha! I'm a shark with legs. I imagine it's either one of Attachment 24602
So by "medium form" you mean like a were shark? not that I become a medium sized creature.

And by listed abilities I only get the swim speed and scent I don't get the attack of a shark creature from the bestiary, or really anything from the bestiary?

Logically you can’t change into a shark unless there is water around for you to swim in. And once you are a shark i’m not seeing legs there.