- Kingdom: Animalia
- Phylum: Chordata
- Subphylum: Vertebrata
- Superclass: Gnathostomata
- Class: Actinopterygii
- Order: Perciformes
- Family: Pholidae
- Scientific name: Pholis gunnellus
- Norwegian: tangsprell
A unique feature of the butterfish is the 9-15 dark brown spots framed by white circles, just beneath the dorsal fin. The slender, eel-like body may reach a length of 25 cm. The color is light brown. The butterfish is the only member of the Pholidae family in Norwegian waters.
It is usually seen among algae in the subtidal zone (rarely deeper than 30 meters)
It can be found on both sides of the North Atlantic Ocean. In the east it is distributed from the Kanin Peninsula to France.