- Kingdom: Animalia
- Phylum: Cnidaria
- Class: Anthozoa
- Subclass: Hexacorallia
- Order: Actiniaria
- Suborder: Protantheae
- Family: Gonactiniidae
- Scientific name: Protanthea simplex
- Norwegian: korallnellik
This is a small anemone, the column is only 1-2 cm. The 200 tentacles cannot be retracted into the column. The color is white or pale yellow. There are 24 vertical rows of gonads, often visible through the cylinder wall.
The sealoch anemone is most frequent deeper than 40 meters, but in the fjords and at other sheltered locations it may occur as shallow as 10 meters.
It is known from the coasts of Scotland and Scandinavia, as far north as Troms.