- Kingdom: Animalia
- Phylum: Bryozoa
- Class: Stenolaemata
- Order: Cyclostomatida
- Suborder: Tubuliporina
- Family: Tubuliporidae
- Scientific name: Idmidronea atlantica
- Norwegian: -
The Tubuliporidae family seems to be under constant revision. Several new members have been added the recent years. Genetic studies have to performed for certain identification. It usually impossible to identify them from pictures alone. It is likely however that the species on the pictures is the very common Idmidronea atlantica.
All members of the Tubuliporidae family build structures looking like small organ pipes. The zooid stretches out of a small opening at the end of a short tube, 1-2 mm long. I. atlantica forms very small, fan-shaped colonies. The branches have few, often symmetric divisions. The robustness of the branches depends often on local environment. More delicate branches are often seen on sheltered locations.
I. atlantica attaches to hard substrate like rocks and shells, as well as hydroids and algae.
There are registrations scattered around most Atlantic coasts of Europe. The observations are however somewhat uncertain, due to possible confusion with similar species.