Are there any sea creatures in Avatar?
Being that James Cameron's ideas and influences were heavily influenced by earth sea creatures: James Cameron’s Love for Scuba Diving Shows in Avatar
“I just swept in every design influence in my life. I've always had this deep respect for nature and a lot of my youth was out in the woods hiking around. I was a total science geek. I spent over 2,500 hours underwater and I've seen things that are absolutely astonishing on the bottom of the ocean. It really is like an alien planet. I've always felt like that's something I've been able to do was live out a science-fiction fantasy adventure for real in my diving work. So yeah, there's a lot of stuff there. There's even a lot of stuff in the shallow ocean that's influenced things. The Banshee wings are based on the colourations of tropical fish, for example. We were a little concerned that these large creatures wouldn't scale with these incredibly vivid colour patterns, but we managed to make that work.” – James Cameron
And we are shown Jake falling in to what looks like a river, an ocean looking like scene when gathering the tribes and we are even shown Jake and Netiri swimming. There seems to be a lack of water dwelling creatures.
Seeming James Cameron's love of the ocean, there seems to be a very visible lacking presence of water dwelling creatures.
Was there anything in or out of universe that shows James Cameron having water dwelling creatures?
Answers can be plain and simple, either he did or didn't or even we are never shown will be accepted.