A Nord hunter called Briring, who lived in the Skyrim Mission of Ebonheart, in Morrowind, mentioned two very dangerous species of slaughterfish. Namely, the blind slaughterfish, and the electric slaughterfish. I hope we'll see some of them.

This would also be a good reason to add in the King Mudcrab as a boss fight.

This would make being an Argonian even better...

But, if they added an actual reason to explore underwater, along with underwater combat...they would be giving Argonians a meaningful racial advantage. We can't have that, since all the races are supposed to function the same, and be only cosmetic.

That'd be good... a real reason to use waterbreathing, apart from during Blindsighted...

Yeah, I've said it a few times now, there should be more to do underwater. It would make the Argonians racial ability, water breathing potions, spells and enchantments more useful.

It is to vast not to have more lore and explorable areas intergrated in the storyline or future DLC.