Shwu

The genus of shwu plants produce a molecule called shwu. It flows through the veins of their leaves, helping them regulate their intake of sunlight and water. Shwu is useful not only to the plants themselves, but also to animals. This unique molecule helps to develop and repair brain tissue. It increases intelligence, so animals on Shra can actually 'eat' themselves smart, without ingesting excessive amounts of protein. This gives them an important edge in the fight for survival.
Shwu is not actually eaten, because the digestive systems of the eaters would tear the molecules apart, nullifying their effect. Several species have developed a 'sniffer', a small second tongue that is anchored on their palate, to suck the moisture from shwu plant leaves. The sniffer filters out the shwu and transmits its directly to the brain. Anthropoids like humans and surre (see below), already intelligent, have not missed this chance. They have developed rudimentary sniffers too, inside their nose. These are not so adept in obtaining shwu plant sap, but their deft hands can do that work for them and produce a kind of shwu 'drink'. This is not swallowed and digested like normal beverages, but sniffed through a reed through the nose directly to the brain.
Shwu is not a drug because it is not addictive, though in some respects it acts like one. If animals with a high shwu anabolic rate suffer a drop in 'sniff', their intelligence will slowly degrade back to 'normal' levels. They will lose memories and 'unlearn' skills. Therefore all intelligent species fight fiercely to keep their supply of the stuff steady.
The use of shwu is not without risk. Some plants defend themselves against plunder with toxins. If ingested, these go directly to the brain and can cause serious physical and/or mental disorders. Some of these are temporary, others permanent. The best, most pure shwu comes from Agllid, the zhaw settlement in the Tawija Khogh.

Humans

Humans on Shra are invariably dark skinned, a defense against the fierce ultraviolet radiation from the sun. They are more adapted to temperature extremes than Earth humans. In winter, Shra people put on extra fat and grow body hair to insulate themselves; in summer this adaptation is reversed. During that season they sweat a lot, which is quite effective in the dry Shra air, though it requires them to drink a lot of water. While doing so, they perspire relatively little salt. The hairing and molting, though far less extreme than that of truly furred animals on Shra, has given rise to distinct winter and summer fashions. Humans on Shra, like all other sapients and and animals, have a circadian rhythm with cycles of 17.6 Earth-hours, matching the day-night cycle of the planet.

Surre

Surre are 'reptile men'. Their physiology is clearly based on humans though with many changes that put them closer to reptiles. That comparison is only partially correct. Surre have the same bone structure as humans, do not have tails, do not lay eggs but give birth to live young, etcetera. The most important difference is that they are poikilotherms, able to vary their body temperature and metabolism rate. This allows them to cope with the large temperature variations on Shra. Like reptiles, surre and physically and mentally more active in warmth and sluggish in cold. Naturally, they prefer summer over winter, though Shra's murderous high summer heat forces even them to seek shelter at peak temperatures.
Another difference is in their skin. Surre do not sweat to loose excess heat. Their skin is thin but tough and scaly, yellowish in color, like that of reptiles. Likewise, they shed old skin and replace it with a new layer many times over, especially when young. Surre can reclaim some of the moisture from the urine in their bladders.

Zhaw

Zhwaw are not spread all over Shra like humans and surre, but concentrated in a single clan, housed in the Agllid fortress in the Tawija Khogh. They are very secretive and reclusive, seldom appearing outdoors. Through the limited contacts that exist, others have learned a few things about them. They are not anthropomorphic at all, but look somewhat like Earth aardvarks, though with a thick coat of reddish fur. Their snouts are even longer than those of aardvarks, very dexterous and serve as hands as well as noses. Zhaw are reputed to be very intelligent, because of their shwu-rich aghana-diet, which is unequaled in Shra.

Nnniyh

These creatures are lizards: reptiles with scaly skin, four legs somewhat to the side of the body, moving from side to side. Humans often mockingly compare surre to them, yet the two species have not much in common, except the reptileness and being poikilotherms. Nnniyh are predators, who lie in wait and pounce on unsuspecting prey. They can vary their skin color and patterns even better than chameleons. They have shwu sniffers and drink themselves smart, then use their intelligence to lay the most cunning ambushes. Nnniyh are solitary creatures, meeting with other members of the species only to mate. Babies are no larger than one foot in length. Throughout their lives they keep growing in size. Some elders reach lengths of several meters and weigh up to two tons. They have the strength, shrewdness and experience to take on the mightiest of preys, including other sapient species.

Ravens

Ravens are birds that are well adapted to the temperature extremes of Shra. They scavenge food everywhere and get most of their water from it. They are also keen on spotting shwu and making use of that too. Humans and surre often work together with ravens, offering food, water and shelter in return for aerial knowledge of the surroundings and messenger services. Ravens cannot speak like the anthropoids, though use a language of their own called Ahkrar that mimics their speech. Equally smart humans and surre can understand that yet their vocal chords are unable to make them speak Ahkrar. Ravens are opportunistic and work with whomever can get them food, water and safety. For example, they have been known to both lead humans in surre into predator ambushes and to warn against them. Shra ravens live longer than their Earth counterparts, up to 30 - 40 years.

Sand cats

Sand cats on Shra resemble those on Earth in many respects. They are even hardier, able to cope with more extreme temperatures, though they shield themselves from the worst in burrows. Shra sand cats have sniffers, use them to gain shwu and use their intelligence and acute senses to track prey and evade larger predators. They are extremely stealthy, so much that some people believe they are ghosts rather than physical animals. There are rumors that some people are in communication with them and use them as spies or even assassins. This has never been proven, but the myths abound.
There are two categories of sand cats, desert cats and oasis cats. The former roam the wilderness of Shra, using their wits and other talents to eke out a living among the rocks and sands. The latter prowl oases, hunting small prey. Humans and surre appreciate them because they hunt rodents and birds that are after the seeds and crops that the humanoid races grow, just ordinary cats. However the oases cats are not pets. They are not bound to a household, do not seek shelter and do not rely on gifts of food. They do occasionally steal food but there is a belief that punishing sand cats or even killing them will bring down disaster on the head of anyone who attempts that.

Zuway

Zuway resemble fire ants, but are a more advanced race. They harvest shwu and use it to create a distinct caste of 'directors', next to queens, drones, workers and warriors. The directors are considered to be semi-sapient. They orchestrate the endeavors of the colony. Zuway use their mandibles and several types of acid to dissolve rock and dig tunnels deep down to reach water. They carry the water up to plants at the surface, which they also keep free of weeds and use the acids to scare away herbivores. Their plantations supply them with food, which they carry back down to their vast underground cities. Sapients and animals alike prey on them and covet the underground supplies, but the ants' defenses and sheer depth of the tunnels defies most attacks.

Racism

There is much animosity between humans and surre. The former claim that they are the original master race, superior the 'degenerated' surre. The latter state that they are an improvement over the 'failed attempt' of the gods to create a race that would be suitable to Shra. Humans often classify surre as slow and stupid; surre consider humans hyperactive and smelly.