Language & Naming
Seresans are magical creature and can speak to other intelligent creatures telepathically. They also have a written language and a sign language. These languages are known as "Serin" respectively.
Most Seresans have one name. They give themselves their own name when they reach maturity in a traditional coming of age ceremony called Alabresa (which means "The New Coming" in Serin sign language). Part of the coming of age ceremony also involves a battle against a captured Gleana, a monster of the deep that, while it does not prey on Seresans, is opportunistic and will kill and eat one if given the chance. The group of young adults must face this creature and live to complete the ceremony. Those that do close the ceremony out feasting on it's flesh and naming themselves.
Magic & Technology
Seresans themselves evolved through water magic attached to Ambrivans and are themselves magical. They have the innate ability to control water to a degree. They do not have technology tho... They do know of technology as they see the Ambrivans use it and some speak with the Ambrivans at length.
Organized Religion & Sports
Coming from Ambrivans, they have kept true to Horreliea, the God of the Warring Seas. They view themselves as a warrior race as well, like Horrelea in many ways. Seresan do not participate in sports. Their environment is not conducive to organize fun with groups of other Seresans. Small games of catch, hide-and-seek, tag, and similar games are playing by nursery-goers and young adults.
Laws & Social Norms
Seresans are more-or-less archaic in their ways. They have a governing circle of elders who is led by the oldest female Seresan. Males who are actively nurturing the youth (and the youth) are directly below the council. Those protecting the pod are last with the best warriors looked at with reverence. The goal of Seresan society is to protect the pod as a whole with no Seresan left behind. And everyone in a pod, no matter their age or specific duties, can fight.
Seresans never turn their backs on each other when in small groups, foraging/hunting parties, and in the nursery. This is for protection purposes as it allows them to see 360 degrees of their environment. They rely on each other to survive, so a Seresan who turns their back on anyone in a small group situation is showing mistrust of them and putting others lives at risk. This is something they can be, and most likely will be, shunned for.
Risks of the Sea & Other Seresans/Pods
Kraken, giant squids, sea serpents, gleana, dragons from above (fishing for food), and other see and air monsters. Pods are usually on the move because staying in one place for too long creates a location for predators to hunt them.
Other Seresans can also be a risk. A council unwilling to merge may very well want to exterminate rival pods to keep down on resource competition. While intentionally splitting off from a pod is unusual, it has happened. There are 4 known pods to date and their leaders keep to their own waters on Ambaran in loose treaties with each other (Lerex Pod (largest of the 4), North Forest Pod, Northeastern Mountain Pod, and the Southern Waters Pod).
Seresans & Other Species
Seresans evolved from Ambrivans who wanted to swim more than walk. They collectively used water and nature magic to fuse their legs. At first, this could be undone. But after a while, they developed more water-based traits and just stayed in the water. Now they are exclusive to the water. Ambrivans are not good swimmers but the Seresans coax them into the water anyways. In the shallows, they can play and interact peacefully and so do on the shorelines frequently with Ambrivans of small villages...
Horrelea, God of the Warring Seas
Horrelea is fearsome creature with the lower body of a sea serpent and the upper body of a winged Ambrivan. He swims fast, his blue and green body blending into the see, his blond hair obscuring him further. He pledges himself to the crashing waves and cares little for the lives of those who venture out into the lakes and seas of Ambaran. Like all gods, he glows lightly.