The Jelzap is one of the few natural aquatic predators on the planet Tallon IV, like the Aqua Reaper. It is said to be Tallon's aquatic apex predator. 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.
The Jelzap is immune to attack until Samus approaches, whereupon it separates its two halves and reveals its vulnerable core. To destroy the creature, Samus must fire a missile or charged beam at it, as an uncharged shot only makes it close itself. It is possible to kill a Jelzap when it is closed, but only within a second after it has closed itself. At this time, the Jelzap drags her toward it with magnetic force. This can present an unexpected challenge when navigating the underwater regions of Tallon IV, especially without the Gravity Suit.
"Morphology: Jelzap. Aquatic predator made of electrically bound skeletal halves. The Jelzap's brain is located in the upper half of its body, while the heart and digestive tract occupy the lower half. Linked only by electrical impulses, the two halves somehow function effectively enough to launch the Jelzap to the top of Tallon IV's aquatic food chain."