Thanians are an intelligent, aquatic species from a planet almost entirely covered by water.  The home star of the Thanians is an anomaly, as it burns primarily with green light, not overpowered by other wavelengths in the visible spectrum.  The reason for this is unknown, as nature does not normally produce green stars, and the thanian home-world lies in remote, relatively unexplored sector of the galaxy.

Physiology: Thanian physiology tends to be fairly variable, largely due to bio-modification technology.  What follows is a description of the most common traits.  A Thanian’s head resembles a cephalopod, with two large eyes facing forward for hunting.  Thanians tend to be blue-green in color.  Thanians typically have a torso that resembles a human torso, but with four arms instead of two.  Most Thanians do not have legs, but do have a tail, configured horizontally, like a whale’s.  Thanians breathe water through gills, like fish.  The gas-filled organ that Thanians use to control their depth is also capable of producing a wide variety of sounds, this is used both for communication and echolocation.  Thanians are omnivorous, but are biased toward eating meat.  Contact with the Empire of 1,000,000 Suns has introduced Thanians to bio-modification technology, which has produced a wide variety of forms, including land-adapted Thanians.  

Thanians are an egg-laying species, and the physical characteristics that distinguish male and female Thanians are not immediately obvious to casual human observers.  Thanians are similar to humans in proportions, with adults generally ranging from 1.5 to 2 meters in length, massing 50-100 kg.

Culture: Thanian society and culture had advanced to a state similar to that of the middle ages, before they were conquered by the Empire of 1,000,000 Suns.  Government was based on a feudal model, with fairly large, settled kingdoms divided into smaller fiefdoms.  There were also significant populations of nomadic Thanians.  Like the middle ages on Earth, religion tended to dominate Thanian politics, with the largest religion wielding substantial power over the dealings of many of the larger states.

The largest, most influential Thanian religion worships a huge creature, said to be sleeping in the deepest part of the ocean.  The trench where the creature is said to lie is so deep that the pressure is too high for Thanians, or even the most advanced submarines to descend.  The faithful say that one day the creature will awaken, and ascend to destroy the world.

Tech: Thanian technology was primitive compared to their culture, due to the fact that the native environment of Thanians is underwater.  Without fire, metal could not be smelted.  Even though some wood-bearing plants could be grown in the shallower areas, wood was rarely used as a building material, and the manufacture of paper was basically impossible.  Thanians also did not develop dyes, although the seaweed of their homeworld grew in a wide enough variety of colors for most purposes.  Most Thanian tech consisted of stone, seaweed fibers, and the scales, shells, and bones of the local fauna.  Bioluminescence also figures prominently in Thanian technology, as many deep-dwelling species produce some form of the phenomenon.

Thanian writing systems are typically achieved by tying knots in cords made of seaweed fiber, similar to the Incan system. Their arts include poetry, drama, and song, with the visual arts lagging behind due to technological limitations, although they do have some, mainly in the form of earthwork sculpture made from stacked earth and stone.

Thanian buildings are made primarily of stone.  The first Thanian buildings were communal nests to protect their eggs from predators.  These later had storehouses attached to them, and eventually developed into elaborate, underwater castles and temples.

Thanians tend not to wear clothing, but are biologically well adapted to a wide range of temperatures.  Their blood contains a natural antifreeze agent.

Thanian warriors generally use two distinct weapons, a double-ended trident, and a net with weights attached around its perimeter.  The tridents are traditionally carved from the bones of large fish, although after contact with the outside world, metal and composite models became popular.