Description
Hydrallmania falcatabelongs to Sertulariidae family. The slender main stem with featherlike branches are characteristic for this species. These branches are helically placed on the stem. The polyps are placed on the feather-like side branches, in groups of 2 to 5 individuals. They stand nicely in line on the top side of the side-branch. Very conspicuous is equal distances between all branches and side-branches.

Size
The average length is 250 mm.

Colour
Light brown.

Habitat
The base of the main stem is always firmly attached to hard substrata.

Distribution
In the most western part of the Oosterschelde, in areas with strong currents.