From Wikitroid, the Metroid wiki
The
Jelzap is one of the few natural aquatic predators on the planet
Tallon IV, like the
Aqua Reaper. The fish is composed of two halves connected by a link of electrical impulses. The upper half houses the brain, and the other half has the digestive organs. The electromagnetic field it emits will briefly disable any visor that comes too close to it.