In Trais Orbital Academy, there are currently seven main species.

Earthians? We know about Earthians.

Aqatans and Claraquians both live underwater, but only Claraquians can breathe air as well as water. Aqatans have to use a breathing apparatus for that. Of course, the Claraquians are short - they also all have dark blue hair and skin - but I would say it's a fair trade. After all, the Aqatans' skin is varying shades of green.

Tanekians. Well. Tanekians have what appears to be cat ears attached to their heads. No, they're not playing dress-up, it's how they are. And their skin? Tan, almost an Earthian tan, really. In fact, they'd be mistaken for Earthians much more often if it weren't for those ears.

Nexans, as a whole, aren't exactly known for their peace-loving ways. They... well, they're always plotting and counterplotting. But enough of that. Nexans' skin ranges from Earthian pink to red. Hair? Red to black. No more to be said, really.

Rocketelos. They can fly. They have wings and they can fly. They look like Earthians except they can fly.

What? You want to know what the seventh one is? All right then. It's the Maraxi. That's all I can tell you at this time.

Well, which one will you be?
Earthian
Aqatan
Claraquian
Tanekian
Nexan
Rocketelo
Maraxi