Corvian

Rashnan: Yes, we are called Corvians. Many thousands of your years ago we used to live on the shore above. Our life was without worry, there was plenty of food, and space for us to live. We even started to explore the heavens above, but then a comet passed by us, and changed the ecology of the planet. Food was becoming scarce, the animals were starting to die. Our scientist tried many things to compensate for what happened, but then we looked to the sea. It was the only solution. We started to build the city under the sea, then the experiments began to change us. So we are as you see us now.

The Corvians are an amphibian race of people. Their existence on the world came about, due to many years of sub-space travel. Their appearance was that of a humanoid. Due to a passing comet that changed the balance of the planet's eco system, They had to resort to genetic science to become adaptable to the sea.