Squeem

The Squeem are an aquatic hive-minded species. They are notable as the first sapient spacefaring race to encounter Humans and the first of two to conquer them, before the Qax.

Anatomy and Physiology
Squeem are never described in detail, but they are apparently small fish-like aliens, about the size of goldfish. They are biochemically similar to Earth life, although they have slightly different mineral requirements. Because of their group-minded nature, they are generally found in large groups.

Diet
Squeem are apparently carnivorous, since one Squeem forcibly used as a symbiote by a Human began to eat the man from the inside out.

Group Mind
The Squeem share a group mind of unclear nature, described as telepathic, which links them over interstellar distances. This group mind appears to unite the entire species, with each Squeem little more than a neuron within the greater whole. The group mind does not take much notice of a single Squeem's death, but killing large numbers of Squeem all at once can cause the entire species great distress.

History
The Squeem evolved on a mostly aquatic world, which was taken over by an unknown alien race early in their history. These aliens used the Squeem as slaves until they managed to rise up and enslave their conquerors, but they suffered lasting psychological scars from their enslavement. Following this, the Squeem traveled the galaxy and scavenged Xeelee technology, eventually building up a trade empire.

In the late 4000s AD, the Squeem encountered humanity and established a trade relationship. However, the Squeem soon turned on mankind in a devastating surprise attack. They fired virus-laden asteroids at major cities on Earth, forcing the surrender of Human governments - they are said to have used this same strategy on other species. The Squeem then became humanity's colonial overlords, ruling over the entirety of Human space. The Squeem occupation was brutal and tyrannical. The Squeem extracted all of Earth's remaining hydrocarbons to sell, and also used Humans themselves as slave labor, shipping millions off to unknown regions of the galaxy.

In response to a rebel attack on Lake Superior that killed all the Squeem living there, the Squeem responded by freezing all the water on Earth and leaving it that way for a full year before ending the effect. The surviving Humans were too traumatized to work properly, so the Squeem cooperated with Human leaders to engineer a virus that would erase nearly all Humans' memories of the event. The oceans were forever left almost bare of life, even after the Squeem tried to restock them.

After over forty years, Humans finally managed to overthrow and expel the Squeem. Humans retained a genocidal hatred of Squeem even after ending the occupation, and at some point Humans attacked the Squeem homeworld. Not long before the Qax invasion, Humans found a colony of Squeem on Saturn's moon Rhea and decided to destroy the entire moon with a dark energy black hole rather than let them live.

Under the Interim Coalition of Governance, Humans enslaved the Squeem, using them as symbiotes to enable telepathy. The Squeem were thoroughly "broken" both individually and as a collective, although some still managed to resist and harm their hosts.