In the Galaxy, sapient species include Surface-dwelling species, Aquatics and Post-Biologicals.

Surface-dwelling (air-breathing) species include:

The Uralians who are Utahraptor-like sapient creatures with feathers. They invented SafeGuard, a treatment used on interior-dwelling planets (like the caves of Luna) to keep the air and water from seeping away over time. They all have names with 4-6 letters that have no vowels. They include:

Ptsgbw, Tfns, Clmntr, Lnbršr, Dnhns, Frdjkn, Lzyrnl, Rjnspn, Wndwls, Vldšng, Jnysf, Srvrd, Lncn (the Uralian Speaker), Mrnpk and Jrčtr (the Galactic Government Representatives.)

Uralia was a planet with two continents; the Urans lived on one and the Lians on the other.

The star in the Uralian system is expanding, and the Uralians have moved to more remote, safer parts of their system and to other planets throughout the Galaxy. Their original planet is presently actually inside of the expanded star.

A new planet was purchased (with the approval of the Galactic Court) about two and a half years before the first story. The settlers who had moved there were killed by their Leader.

Lunars are human descendants of refugees that fled Earth about 60 years before the first story in the series. They have Earth names like:

Wan Li, Juan Hidalgo, Johann Schneider, Lt. Malcolm Forbes, Dr. Madison Forbes, their three children Maddy, Connor, and Melissa, Dr. Levine, Tim and Alana, Yaeyeia's Aide Kevin, Dr. Lorie Russo, Dr. Tan, Kitty (who is a sentient, not a sapient).

The Gilgot are the Galactic traders. They are sapient crocodilians and generally are called only by the names of their duties: front-door guard, etc. The exception is the very revered senior Ambassador Heresh. They are probably the second-best warriors in the Galaxy after the Ratihinaconaxemuwezo.

Oeyiah is a planet of sapient plants. Yaeyeia is rubber plant-like while Woh is bush-like. The tree species on Oeyiah do not leave their home planet - it would be too difficult. They communicate with non Oeyians using sensors that translate their sounds (which are beyond human hearing) and chemistry into words. There are humanoids on Oeyiah, but they are not sapient.

The Xx are sapient slime mold. They manufacture most things in the Galaxy. They communicate by changing color, spelling out words.

The Polarans are spherical, sapient creatures. They are very good dancers. They wear pressure suits (without them, they would expand like balloons in the Lunar air pressure.)

The Delitrians are sapient humanoids, about 10-foot tall, have a deep, strong voice, and are very dignified. Their religion forbids dancing. They wear protective suits because the air chemistry on Luna is corrosive to them - without them, they would melt.

The Ratihinaconaxemuwezo are sapient, rigidly hierarchical, take offense easily, declare war easily. To avoid unnecessary wars, members of the high-caste rarely attend events where they likely would feel almost ANY interactions to be insulting. They are very good warriors. They are mining Uralia2 for a compound to stabilize the atmospheric chemistry on their home planet.

Post-biological species include the Setow, who are pure thought spirits that float around making contacts between physical species when necessary. The Akher are also pure thought spirits which are very private and do not want any interactions with modern physical species.

Aquatic species are hugely important in the Galaxy - they are actually the most common of sapient species. They are rarely physically present in the stories because, unfortunately, they cannot travel away from their home planets - it is just too uncomfortable for them to be trapped in a small "aquarium" of their home planet water. Because water chemistry is so different on each Aquatic planet, there is no one water chemistry that can support multiple species. And the weight of water makes it impossible for even a small "aquarium" to be supported by the floors used by Surface-species. All meetings would have to be held outside on the solid ground.

Aquatic species include:

The jellyfish-like sapient Feyar, who invented the quantum communication system used by all species. They are the Leaders of the Galactic Government. They have no genders.

The sapient humanoid-ish Kalad who produce a very pricey wine.

The Qrad who have traditionally been isolationist and were not members of the Galactic Government. They are sapient trilobites (similar to a horseshoe crab.)

There are also the fish-like Wrvsh and 15 other Aquatic sapient species.