Much more than a warm, breathing pin-up
The Syreen are a race of bipedal hominids astonishingly similar to the Humans.1 There has been much speculation about the relationship between Humans and Syreen, including possible intervention on the part of the Arilou.
Physiologically and genetically, Syreen are Human: the only visible differences between the races are that Syreen skin tint is somewhat more bluish and their retinas reflect light like an Earth cat's. Additionally, the typical Syreen is more comfortable in a slightly warmer and more humid environment than the typical Human. According to some, Humans and Syreen have nearly identical diurnal cycles, exhibiting even further similarity between the two species. Other sources claim that the Human diurnal cycle differs greatly from that of the Syreen, which consists of twenty hours of wakefulness followed by ten hours of rest.2 By scanning Syra, the former variant can be confirmed.
Syreen are also more psychically active than humans, to such an extent that the captain of a Penetrator starship can make use of a psychic amplifier to coerce enemy crew. It is not known if Penetrator captains are chosen for exceptional psychic potential, or how common psychic potential is in the general Syreen population, although they do not evince casual telepathic powers that races such as the Pkunk or even the Zoq-Fot-Pik do. On Earth, stereotypes of the Syreen are rampant: "Space Amazons," "Space Gypsies," "warm, breathing pinups," and other sorts abound. Of course, the truth is more complex than such stereotypes would imply.
Syreen society, like Human society, developed from hunter-gatherer tribes. But unlike Humanity, the Syreen were unplagued by war or other great social upheaval, instead joining together until their whole world was a single, peaceful, agrarian super-community. Also unlike Humanity, Syreen society and Syreen military roles were dominated by the females of the species.
A little more than seventy-five years before the advent of the Ur-Quan Slave War, the Syreen suffered a terrible setback. Their homeworld, Syra (also known as Beta Copernicus I), was by all accounts a tropical eden. However, a Mycon Deep Child, mistaken by the Syreen for one of the many asteroids in their system, was implanted beneath the crust of the planet, creating a huge caldera in the vicinity. In weeks, the magma cooled off and solidified, everything returning to normal. However, soon after a year had passed, calderas began appearing all over the planet's surface, emitting vast quantities of poisonous gas and superheated steam, which raised the temperature of the planet by 75 degrees centigrade (well above the boiling point of water), ultimately destroying nearly all life on the planet. Apart from a few survivors on the planet, only the recently created Syreen Space Patrol, the vast majority of which were female, remained. During a period of a few years, they made preparations for an exodus, gathering survivors from the surface and outfitting the orbital facilities with makeshift, mostly sub-luminal drives, and created the Habitat fleet.
Everything that remained of the Syreen civilization was less than ten thousand people, among which only five hundred were males, living aboard improvised Habitats and the Penetrators of the Space Patrol. Voyaging through HyperSpace at an incredibly slow pace, they began looking for a new world.
As the War began, and with no homeworld to fall back to, the Syreen maneuvered into Human space to avoid VUX raiders. It is implied but not explicitly stated that Humanity's industrial base supported the Syreen fleet. The Humans and Syreen also participated in at least one crew exchange, confirming the viability of Human/Syreen crossbreeding and bolstering the Syreen's flagging population.3
After the defeat of the Chenjesu, the Mmrnmhrm, and finally Humanity, the Syreen were abandoned by the remainder of the Alliance and left to face the Ur-Quan alone. They surrendered, and in exchange the Ur-Quan searched their planetary database to find them a new homeworld. This homeworld, renamed Gaia, orbits the star Betelgeuse.
The Syreen are content to remain neutral at this point until The Captain proves to them that the destruction of Syra was in fact engineered by the Mycon using a Deep Child. After The Captain retrieves the Syreen Penetrator fleet from Epsilon Camelopardalis and helps the Syreen wreak their revenge upon the Mycon, the Syreen join with the New Alliance.
 Known individuals
 Gameplay notes
 Sources of information
Another alien race must reveal the nature of the Mycon Deep Children in order for the Syreen to recognize the significance of the Deep Child Egg Case Fragments. The only races that are able to provide this information are the Melnorme, the Druuge, the Arilou, and the Mycon themselves.
The Ur-Quan vault containing the Syreen fleet of starships can be found by searching the few stars that match the clues Talana provides—a red/orange star within 200 HyperSpace units of Betelgeuse and likely in Ur-Quan space. The Zoq-Fot-Pik can give the exact location.
 Notes and references
- 1From the 2007 IRC chat with Toys for Bob (robot is Fred Ford, PR3 is Paul Reiche III):
- 23:22 <@Meep-Eep> This one's from me: Given that the Syreen can convince individuals of each species to jump ship using their mental powers, the state in which the humans came back from a Syreen ship after the crew exchange mentioned in the SC1, and the monster growl in the sex scene, is what we see really the Syreen's true form?
- 23:24 <+PR3> The Syreen went through a bit of a transformation from SC1 to SC2. At first they were space succubi (how DO you spell that). In SC2 I felt compelled to give them a lot more 'reason' to act the way they do.
- 23:25 <+robot> About the Syreen: if you've met some of the human women I know, this would not be a very mysterious question.
- 23:25 <+PR3> However, the Syreen should ALWAYS be sexy and strong. The image of them in SC3 was spooky and unpleasant.
- 2The Syreen conversation in the PC version state that the diurnal cycles are nearly identical. The conversation in the 3DO version gives the 20 hour/10 hour diurnal cycle.
- 3Star Control Manual, pp. 28-29