Phylum: Cnidaria

Class: Hydrozoa

Order: Anthoathecata

Suborder: Filifera

Family: Eudendriidae

Scientific name: Eudendrium rameum

 

Norwegian: trehydroide

(Ingdalen - The Trondheim fjord / 2.21.2004 / 40 meters)

Distribution: This cosmopolitan can be found anywhere along the Norwegian coast. It grows on hard substrate on depths between 5 and 100 meters. As in the picture below, amphipods are often found feeding on these hydroids.

Characteristics: The colonies can grow to a height of 25 cm. They are heavily branched. The main stem is brown and significantly thicker then the branches. The branch diameter decreases evenly with the distance from the stem. The hydranths are colored pink and have 20-24 tentacles. It may be confused with E. ramosum. The branches of the E. ramosum are tending more upwards, giving the colony a more slender and upright profile.

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