a closed species is an original species made by someone with specific traits . in this case, the species is called korali and they are humanoids born from coral. their traits are coral like horns, seaweed ponytail, coral on their tail, scales, webbed hands, etc. but closed species means you need to get a slot from the owner to be able to make your own oc with those traits!! a lot of closed species requires you to pay money for a slot, but for korali you dont (currently). theres also certain level of rarities in their traits, so if you get a common slot, you cannot use an ultra rare trait.

then theres open species, where you dont need to get a slot from the owner. anyone can make any oc they like! theres little to no restrictions with open species.