Description
The appearance looks like a bouquet of similar flowers, because they grow in groups close to each other. The stem of organ pipe hydroid is not branched. The mouth is at the top end of the stem and is encircled by a double ring of tentacles. In the spring you can observe white and pink clusters between the tentacles. These are the reproductive organs. After fertilisation, small larvae will hatch and start crawling down along the stem. At the base it attaches to the substrate and grow to become a hydroid.

Size
The height of the stem is maximum 150 mm. The tentacles have a maximum diameter of 15 mm.

Colour
The stem is yellow to brown, with pink to red polyps, encircled by transparent tentacles.

Habitat
Organ pipe hydroid likes a strong current and will attach to mud covered hard substrata.

Distribution
Only in the Oosterschelde.