Listed below are the many races of the Arcadia universe.
Homo-Sapiens, otherwise known as humans, are a sentient & sapient race of creatures who overall have a great way with tools and technology. Far more spread out than other races over their time and with high populations the human race seems to effect everywhere it goes in some way.
Commonly seen as curious and experimental creatures, whether good or bad, but also produce very varied magnitudes of individuals from their countless cultures across the many planets.
Adapting slightly differently to each environment they encounter this race makes many sub-species of itself, as seen below.
The humans of this system most likely spawn from the original humans, the Terrans even more so, as this is their home system with the home planet of Earth.
The Venusian people are a sub-species of human who live on the planet Venus. They mainly live in an area of the atmosphere 45-50 km high. At 50-60 km there is an Earth surface-like atmosphere that was originally colonised with floating cities. However after many centuries the cities floated down and now rest just below that level. Surviving humans have lungs which filter out the unwanted gases with more phlegm and a gas to balance in their ears for the cities would usually tilt and fluids got caught.
Other than these main differences the Venusians have paler skin to get more sunlight, thicker skin for warmth and more alkaline sweat for protection from the acidic rain. (This last detail being made by genetic modification)
The Terran sub-species of human is the one that currently lives on Earth.
The A'ris uter are an alien race who live in dense atmospheres on terrestrial planets or in the middling bands of gas giants.
Although they are split into four castes (and a young stage beforehand) there are several defined aspects of these creatures. The main one being the construct of a balloon-like organ filled with air sacs of hydrogen to float. The next main feature is the tentacles they use to interact with their environment. The third feature is the lack of any orifice on their body, as instead of ingesting any solids and breaking them down (like humans do) they instead diffuse all nutrients from the air around themselves and excrete in the same way.