SR388

SR388 is a planet that was visited by Samus Aran during Metroid II: Return of Samus and the very beginning of Metroid Fusion (the rest of the game takes place on the Biologic Space Laboratories research station, which orbited the planet at the time of the game).

Geography
The barren surface of SR388 is notable for its rough, rocky and dry terrain. Gamma radiation constantly pounds the planet, making it difficult for any species to inhabit the surface. Underneath SR388's surface is a vast maze of tunnels and rivers of lava and acid. Since the planet was once inhabited by the Chozo, it is safe to assume that the species created much of the underground complex.

Species

 * X Parasites. The X Parasites were sent to the planet to overrun the Chozo by a currently unknown source. To keep the parasite in check, the Chozo created the Metroid. At the beginning of Metroid Fusion, Samus Aran is attacked by an X-Parasite that takes control of her Power Suit, setting up the events of the game.


 * Metroids. The Metroids were originally engineered by the Chozo in order to keep the X-Parasite threat in check. The effectivity of the Metroids' parasite regulation can be observed as the X Parasites are never seen during the entirety of Metroid II: Return of Samus (although many believe the lack of X parasite to be a continuity mistake). As Metroids grow, they turn into stronger forms of metroid, such as the Alpha Metroids and the Gamma Metroids. Some people say that the radiation on SR388 caused the Metroids to evolve, but Nintendo has stated that this is not the case, however it is shown this is a way they asexually reproduce. No one knowing the true reason of the Metroid's origin, it was decided that the species to be too much of a threat to galactic peace, and Samus was sent out on a journey to eradicate all of the Metroids. The sole survivor, a young larva, was taken by Samus to the Ceres Space Colony, where it was kidnapped by Ridley and eventually killed at the end of Super Metroid.

Metroid Fusion
The events of Metroid Fusion take place mainly on the BSL research station orbiting the planet. At the end of the game, Samus evacuates the X-Parasite overrun station and crashes the complex into the planet. Both the station and the planet are destroyed.