The Carriaseius are equally at home in river water, and in the deep ocean. There are physical adaptations one must make in the long journey from the Abyssal Plains where its safe because few can reach one there, to the mid-ocean, to the surface, to the river, and back again in the twenty year cycle. This cycle can be considerably abbreviated, as short as one year, as Body skills modify the body, but in general its best to follow nature's normal path, and swim the Great Cycle four-to-six times before laying down to fertilize the next generation, and for the Great Sleep before the Lord of Waters wakes all who sleep in the Day when the Universe becomes Water.
The C have powerful talons, and poisons in their vaguely humanoid bodies. But, they also have mental control of water via telekinesis which makes them rulers of the world's oceans.
The Aistrye are fierce, unkind to themselves and others. They, unlike the C who are calm and kind, are full of pitiless drive and thundering courage. They live atop the tallest mountains, and launch themselves into the jet stream so that they can cross the ocean in hours. Their razor edged wings absorb sunlight, and their taloned feet chip rock into soil which can be swallowed, and crushed in a kind of gizzard. After this, it is respat out, and swallowed again by the second stomach, and then the third stomach finally gets most of the good from it, and it is disposed of.
They live in a fury of activity, finding it slovenly to sleep four hours a night, and weak to pause once an hour for breath. They can, in their giant expandable lungs, catch enough air to actively move as high as twenty miles above the surface. Their bodies are filled with hormones demanding activity, and right now. They live to be perhaps thirty before dying, usually from a burst heart as they attempt to prove they are not declining and rise high into the sky.
There is a name for this among them. Sunchasing. It is thought that they come from the stars, and want to return to them (this is not true. They have a cultural and biological fascination with extreme heights, and a need to prove themselves).
Some of them develop powers of the will (and with their formidable willpowers these are great in power indeed) which give them mental control over the wind.
The highest recorded flight is thirty miles.
They rarely go below four miles from sea level.
The Roaulia are huge, slow creatures which live for centuries. They give birth via eggs, but these eggs require great heat to soften the exterior and waken the child inside. That is, the typical Roaulia egg will not hatch unless its owner is buried in hot lava.
Now, one thing about lava is that when it cools, it becomes tufa. This curious rock is soft, and easily carved, but when exposed to the air it hardens. So, the infant, being woken from his perhaps decades long coma by the heat begins to peck at the shell as the heat inside drops. Sometimes, he makes it halfway and the temperature he has stored has gotten so low that he relapses into a coma. This is tragic because he is likely to die from various causes.
Usually, he cracks the shell after the lava turns into tufa, and carves his way to the surface. (All Roaulie have perfect directional senses. The very concept of 'getting lost' is meaningless to them. They can sense the shape of a gravity field.)
Once on the surface, he searches for heat which is usually a volcano, and begins to eat. His body is made of silicon and iron primarily along the general shape of a walrus. Mature Roaulie can reach fifty feet in length, and live for a millenia. They tend to move at a speed of 1/10th of a mile per hour, but their brainspeed is about half that of a human.
Naturally, they are a contemplative and logical race.
Once filled, the youngling (after several years) goes forth in search of a teacher. He seeks a mature Roaulie (the larger the better) who will instruct him in the ways of the world and in knowledges. This varies from basic items like what types of rocks to avoid to theories about the beginning of the universe. It also involves training in mental control by telekinesis of fire.
The teacher receives a couple benefits. One, he knows someone will teach his or her children even if he does not know who those children are. Two, failure to teach at least once a century is generally regarded as proof of social 'loserdom', and teaching brings respect from others (the Roaulie have little in the way of material things. Status is gained by physical size, exploration, brilliance of thought or talk, and of course, teaching). Three, the teacher gets a personal servant for the duration of the teaching.
The feeding of the Roaulie requires heat, and heated stone. Volcanoes are ideal. Happily for the Roaulie, they can survive short dips in hot lava, and their telekinesis can provoke volcanic eruptions. Unhappily for others such as the C, the Roaulie can live on the Abyssal Plain, and provoke volcanoes, and they do. And the high mountains of the A are also targets for volcanoes.
The R would say that the A spread like locust. "In the space of a century, they would go from a few mountains to all the mountains in the world." The R think that the C's on the Abyssal Plane are not yet intelligent, and don't matter. The first is true, but not the second.
The A have the capability to kill the R with their fierce talons, although its like wolves taking on an elephant. The C are sometimes able to drag an R away from a heat vent far enough that the R goes into a 'cold coma' before it trundles back.
The R on the ocean floor would say that they can't leave without taking some of the A's mountains, and without causing serious devastation on the way out to provide heat. They claim that for the R to leave would require dozens of volcanoes on the Abyssal Plain to heat the way, and this would be more damaging than what little they do each year.
The Mruudia are humanoid-ish lizards who are so susceptible to heat and radiation that they spend nearly all their time slathered in several inches of mud. They can dig very well, and swim quite well too either in shallow salt seas or in river waters with equal facility.
They are roaming tribes looking for hunting grounds. The C are a favored prey, especially as they make the transition from surface salt to river surface (which leads to mating). However, the M will climb mountains to rob nests of the A. They oppose the volcano-ization as they dislike heat. When they can, they spread mud and delta, and cause avalanches to degrade mountains.
They do not eat that often as they sleep much of the time. The others hunt them when they sleep (even the A have attempted to bomb their mud dams which they make in attempts to turn plains into swamps with the result that sleeping M who are breathing air suddenly choke on water, and sometimes are not able to transition before they wake).
The Mruudia feel they only seldom eat, but they must survive. And they greatly fear their sleep times which sometimes last for two to three weeks because they claim that many more of them are killed than they kill. "And we kill to eat. They kill for spite."
The Mruudia are carniverous with a very large mouthful of teeth. Most of them have telekinetic control of earth, mud, and rock. This last makes them very dangerous to the Roaulie, although the Roaulie can call fire, and the Mruudia do not enjoy fire at all. Full out wars between R and M tend to be very bloody. Both sides try to ambush the other side because they fear all out slugging matches with each other.