From Halopedia, the Halo wiki
Glowfish are a species of fish native to the human Outer Colony of Gao. These florescent fish thrive in the underground waters of the planet's vast caverns, such as the Montero Cave System. They are likely a source of food for other cave creatures like frilled salamanders and saurios.
List of appearances
- Halo: Last Light (First mentioned)
- Halo: Last Light, page 124