Species 116 is the Borg designation for a highly advanced civilization from the Delta Quadrant. Their real name remains unknown. They were first encountered by Starfleet in 2374 when the starship Voyager came into contact with a member of the species, named Arturis.
The species had been nearly entirely assimilated by the Borg sometime before 2374. The sole encounter of Starfleet with the species was when Arturis had attempted a ploy to have the entire Voyager crew assimilated by the Borg using a ship disguised as a Starfleet vessel. The plan ultimately failed and Voyager escaped. Arturis remained behind by his own choice and was assimilated by the Borg.
At least one member of the species felt that Voyager was partially responsible for the near complete assimilation of their species, citing their interference in the Borg/Species 8472 war. Species 116 had a vested interest in the war, hoping Species 8472 would prevail and destroy the Borg, who had been slowly winning ground on Species 116. Voyagers aid of the Borg ended the war and had left Species 116 at the mercy of the Collective according to Arturis. (JB: "Just Between a Rock & a Hard Place")
It is also this species that developed the Quantum slipstream drive, on which the Starfleet version of the drive is based. When Seven of Nine had been re-assimilated and had been transformed into One of Many she stated that it had been this piece of technology that had allowed species 116 to avoid assimilation for as long as they had. The collective was also considering attempting to combine Borg transwarp drive with slipstream technology. One of Many considered the slipstream technology more elegant in use. (JB: "Just Between a Rock & a Hard Place")
As of 2379 the Collective had not implemented this idea. This was made apparent when the Starfleet vessel, the USS Millennium encountered a Borg Sphere, no mention was made of any apparent changes to their transwarp drive by the crew of the ship. (MLN: "Collective Comprehension")
The starship Voyager was the first Federation vessel to adapt the technology for their own use. Later it was further developed and implemented at a far more advanced scale on the experimental Starfleet vessel, the USS Millennium. (JB: "Just Between Past & Present")
Current status Edit
As of 2380 the ultimate fate of the species remains unknown. Arturis had stated that there had been more survivors but Starfleet has not encountered any further as of yet. However this does not mean the species is extinct, since Starfleet has simply never returned to their area of space they might simply not encounter any until they do.