The Biran are sapient aquatic organisms native to the a moon of the planet Bira V (all human exonyms; the Birans do not have a spoken language of their own to provide usable loanwords.) Their psychology is, in the broadest terms, similar to humans; both species work to advance individual and societal goals, form social relations with each other dependent on robust theories of mind, are capable of altruism, and value their individual continuity of existence highly.

The native environment of the Biran is analogous to the coldwater reefs of Earth. They communicate with bioluminescence. The Biran are exceedingly prolific spawners but do not begin to develop sentience until passing through a pelagic larval form which allows wide dispersal. When young adult-form Birans are found by mature adults after arriving in the reef, they are taken into the shoal and nurtured from that point. This mechanism allows genetic diversity to be maintained without adult Birans leaving their native reef environment (at considerable risk of predation) since they are unlikely to be very closely related to their neighbors. Like most higher life on their homeworld, they are tetraploid (having four sets of chromosomes). Their genetic material is not DNA but is broadly similar, with a different phosphate ester backbone and different nucleic acids.

Biran who reach adulthood live a very long time, typically over five hundred years in a safe, civilized context. They cannot survive at depths of less than 500m of water approximately and are challenged by depths less than 700m. Their preferred temperature range is -2 to 12C and they require salt water, though they are relatively hardy with respect to salinity and higher temperatures, beginning to perish from overheating only in the 40s C. Biran are approximately 50 cm long, 20cm wide and 30 cm high, and do not have sexes. (I.e. the species has only one kind of gamete, which needs to find another gamete from a different Biran to begin growing into the tetraploid organism.)

The Biran are tool-users but their manipulative appendages are cruder than those of humans. They regard the fingered hands of human mechanics and engineers with respect bordering on awe. The same, however, can be said of humans considering the Biran affinity for chemistry. They are masters of materials, organic and biochemistry. The have a great degree of conscious control over their biochemistry and specialized secretory glands, thought to have evolved to produce neurotoxins and antibiotics tailored to prey species, parasites or would-be predators in their ecological niche.

An old species whose historical records speak to thirty thousand years of agricultural civilization and symbolic record-keeping, the Biran were relative latecomers to spaceflight who might have settled the galaxy before humans invented the blackpowder rocket if they had not such difficulty developing their cosmology, being unable to safely reach the ocean surface of their world to glimpse the sky until they had developed reliable pressure vessel technology and the ability to create bulk gases for buoyancy. But once they reached the surface, they realized the value of its abundant solar energy to their industries, then dependent on scarce geothermal resources. Combustion, a relatively little-known laboratory phenomenon to the Biran at the time, was also quickly appreciated in practice and investigated. In the end, not two centuries passed between the first Biran eyes beholding the starry night sky of its homeworld and their first visit to another world. Discovery of the wormhole network followed, and with their advanced chemical technology being readily applicable to environmental engineering, they had success at colonization.

As spacefairers, the Biran's need for a (heavy) aqueous environment at high pressure is partially offset by their small size, tolerance of confined environments (a Biran feels very safe snug in a nook barely larger than its body, resting in a reef), long lifespan, and ability to survive extreme accelerations.