Bio-Barrier

Bio-Barriers are creatures found primarily on Zebes and SR-388. There are various types of Bio-Barriers, each of them discussed below.

Zebes Bio-Barrier
These creatures live in Brinstar on Zebes. They are impervious to all weapons, but can be eaten by Bomb Bugs. To get past them, Samus must attach the Bugs to herself and then take them to the Bio-Barrier in Morph Ball Mode.

SR-388 Bio-Barrier L1
These Bio-Barriers, found on SR-388, can be destroyed by three Missiles to the core. In the games they have so far been found only on the BSL Space Station, primarily in Sector 2.

SR-388 Bio-Barrier L2
These Bio-Barriers originated from SR-388 and were studied on the BSL Space Station. They can bre destroyed by one Super Missile and are found mostly in Sector 3.

SR-388 Bio-Barrier L3
The most powerful Bio-Barrier, this subspecies originated from SR-388. They ar enormous and can only be destroyed by Power Bombs. They are found in remote sections of the Main Deck on the BSL Space Station in Metroid Fusion.

Bio-Doors
Hailing from various worlds, Bio-Doors are living doors found primarily on SR-388 and Zebes. They are easily recognizable by their single eye, and block the entrance to the boss room. The Zebes variation is destroyed in one hit and cannot shoot plasma, whilst the SR-388 subspecies takes 3 Missiles or one Super Missile to destroy and can shoot plasma from its eye. They are amphibious.