- Kingdom: Animalia
- Phylum: Arthropoda
- Subphylum: Chelicerata
- Class: Pycnogonida
- Order: Pantopoda
- Family: Nymphonidae
- Scientific name: Nymphon gracile
- Norwegian: -
N. gracile is together with N. brevirostre the two most common species in Norway. The most obvious difference between the two is the shape of the proboscis, the "trunk" at the front of its head. The proboscis of N. gracile is rather elongated, while N. brevirostre has a short and stout proboscis. Both species have four pair of legs. The smooth and cylindrical body of N. gracile may reach a length of 4mm. In general it is difficult to identify sea spiders from pictures alone.
It thrives on hard, rocky substrate on current exposed locations.
It is well known from European parts of the Atlantic Ocean.