Candlefish

Candlefish is a consumable item obtainable from fishing.

Fishing
Candlefish can be obtained by fishing. In order to catch Candlefish, the player's hauling level has to be at least 65. Candlefish have a weight of 200.

They grant 3010 xp for the Hauling skill when caught.

Other methods
Candlefish can also be obtained by opening a Fish Case.

Usage
Candlefish is a consumable item, and can be consumed at any time by holding the use button while holding it. Candlefish offer minimal hunger and saturation but heals the player by health if consumed.

Gnawer
Candlefish can be fed to a gnawer. Feeding one to a gnawer will heal health to the player and do  damage to the gnawer.