One Gender Race: There are a few of these, most of them having got that way via their evolutionary process never having figured out sex, or natural hermaphroditism, or merely looking this way because of extreme sexual dimorphism; but also some exceptions – digisapiences, for example, have neither sex nor gender by default, although some of them adopt one. Many bioshells are manufactured in only one sex, usually neuter, and some clades – usually the made-to-an-ideal kind, likewise, without said usually.
But there are occasional weird exceptions. The shan kari, for example, are recovering from an approximation of this state (very slowly, because it did quite the psychological number on them, too), the anti-self-replication code in their robots having, through generalization, led to something of a Gendercide. Oops.
Gendercide: Happened, incompletely (two-thirds of the female population killed), to the shan kari, when their learning robots generalized their anti-self-replication police-code to things that weren’t robots, and therefore concluded that it was necessary to wipe out the female of the species due to their built-in factories for making more of themselves.
Today, the Shan Kari Confederacy is known for its skewed sex ratio, its extensive use of forced-growth cloning, and its extreme hostility towards robotic technology and digital sophonts.
Starfish Aliens: Most of them. Digisapiences, of course, have no bodies at all. The galari are sophont crystal-virus hybrids with inbuilt techlepathy and mechanical psychokinesis. The codramaju are pseudo-fungoids which can merge, exchange, and separate bodies and minds at will. The kaeth are vaguely draconic pseudosaurians with a metal-rich biology. The hydrogen-breathing sssc!haaaouú are fragile collections of membranes that dwell in the upper layers of gas giants. The myneni are crystal-based carbohydrosilicate amoeboids with built-in chemosynthetic talents. The mezuar are a network of collectively sophont purplish-blue trees. (Yes, as sessile as that implies, although the selyéva are green-blue plantimals – non-sessile photosynthetics – who probably most closely resemble walking broccoli.) The esseli have engineered themselves into brains with manipulating tentacles and customized personal auxiliary organs, and don’t even remember what they used to look like. (And the link!n-Rechesh are heading that way.) The qucequql are ammonia-metabolising octopi from a world of nitrogenous oceans. The múrast would be simple multiheaded snakes, except that they breathe methane, live in oceans of hydrocarbons, and their primary body structures are constructed of ice. The ulakha are metal-plated, fast-moving lizardoids who think Venerian conditions are just about right for a planet. The linobir resemble furless, leathery-skinned, hexapedal, hermaphrodite bears. The shan kari resemble larger versions of Terran mustelids fairly closely, actually, except they prefer to breathe warm methane. The mirilasté are legged-serpents with skin we would recognize as essentially plastic, who breathe the most astonishingly noxious fluorine-hydrocarbon soup. The ktelaki are furry arachnids with trilateral symmetry and multi-branched legs. The seb!nt!at are star-dwelling creatures of plasma and electromagnetic force. The celsesh are quadrilaterally-symmetric with a fused-barrel body plan, and sensory organs on stalks in lieu of a head. The embatil are worm/tentacle creatures whose life cycle begins with individuals, but which merge into single creatures as they mature – while transforming a ganglionic into a collegiate intelligence. The tennoa are chlorine-breathing radial-crabs blessed/cursed with obligate utilitarianism…
And that’s all before we get to uplifts, neogens, and exotic neomorphic bioshells.