Rays

Rays are a common class of passive organisms which inhabit both The Crater and Sector Zero.

The Rays of Subnautica are inspired by Earth's rays both in name and in appearance.

Subnautica
Rabbit Ray: Rabbit Rays are the smallest of all Ray species and are the first rays encountered by the player, they get their name from distinct orange ear-like structure which resembles Earth's Rabbits

Jellyray: The Jellyray is a large ray species that possesses translucent skin and a bioluminescent body

GhostRay: The GhostRay primarily inhabits biomes like the Lost River, like the Jellyray it too possesses a transparent body which reveals its internal organs.

Crimson Ray: The Crimson Rays are the largest Ray species of 4546B, they can be found in high temperature environments like the Lava Lakes.

Subnautica: Below Zero
Only one ray species exists in Sector Zero, that ray species being the Arctic Ray, a strange ray species with multiple large fins and a resistance to cold environments.

Trivia

 * It is speculated that a common ancestor of all Ray species on 4546B, The Alpha Ray once existed but has now gone extinct.