Whelp, haven't been posting worthy critiques for a while, so I may as well start now, as it's the season of giving.
First off, I'm going to try and not repeat what's been said. But to be honest, with all the details you've given for this race, it doesn't show in your piece. It just looks like some linear basic sketch, with no thought of design. And when I say design, I don't mean swirlies and pretty dresses, I mean character design and concept. You're trying to achieve an aquatic type being, whom still retains human characteristics, yet the current piece doesn't signify this. It just looks like another one of the billions of blue furries you see at Deviant art. It's basically too simple for my tastes. Though, I tried to conform to the design, without changing too much, or straying from the originals, despite my wanting to:
The hair was just flat. I think either no hair(to fit swimming around) or more wild type hair would be better, much like mermaids dancing in the water, calling to the horny viking fools who hither to the sea(also a great way to attract their male counterparts, even though they can self reproduce...ahem, I'd still prefer the sex to self reproduction, however). Of course, the anatomy needed a lot of work, as it was just stiff like a board. Of course, my version isn't fairly true to actual human anatomy, but more so, towards a comic book type feel(seductive mermaid, is the best way to describe it).
However, if we humans were to live in the see, there would probably be several changes to our natural land walking anatomy. You say your beings don't have web feet or hands, and they predate our human species...come one now, millions of years, and evolution still hasn't given them any type of webbed appendages to better maneuver the great blue deep? Without them, they would be bumbling and stumbling down in the depths as a normal human would...and be easy meals for bigger predators. Their existence would be extinct before you could turn the next page in a history book.
Where both our designs suffer, is that they are wanting to be more humanly built, yet survival wouldn't allow our bodies to stay this way. Even if you look at Olympic swimmers, you notice their bodies are more adaptive towards their sport. Take Michael Phelps, for example: an American Olympic swimmer and Gold medalist, whose body is built slightly different than ours. He is tall, and thin as paper, yet if you were to stand behind him, you'd notice how broad and wide his shoulders are: this is an excellent swimmer's body, which allows for better aerodynamic(or hydrodynamic?) movement. I would think that your fictional creatures would be slightly built like this, and also have longer bodies than ours as well...
To be honest, all my edits and critiques are just preference. These are things I'd prefer, not necessarily have you change, as I'm more for the conceptual design, rather than fashionable(if that makes sense). And hopefully, this isn't coming off as some jerk whose hating your art, as that's not the case. I'm just not a fan of the furry look. Honestly though, give it a thought, and submit a sketch, as Helm mentioned, so we can see just what type of design it's really supposed to be.
