hydroid text index | photo index
Phylum Cnidaria > Class Hydrozoa
Fern hydroid
Sertularella sp.*
Family Sertulariidae
updated Mar 13

Where seen? This elegant colony of tiny animals is sometimes seen on our Northern shores, but often overlooked as it resembles a plant. It grows on boulders and coral rubble. It is also often seen by divers on our Southern shores.

Features: Each 'frond' 10-15cm long with regularly spaced branches that form a large elegant fern-like shape. Usually bright orange, but sometimes covered with encrusting organisms. This hydroid is eaten by the Cuthona nudibranch (Cuthona sibogae).

Beting Bronok, Jun 03

Cuthona nudibranch
Beting Bronok, Aug 06

Tiny polyps of the hydroid.
Beting Bronok, Jun 10

Beting Bronok, May 11

East Coast, Jun 06

East Coast, Jun 09

*Species are difficult to positively identify without close examination.
On this website, the animals are grouped by external features for convenience of display.

Fern hydroids on Singapore shores

Photos of Fern hydroids for free download from wildsingapore flickr

Distribution in Singapore on this wildsingapore flickr map


  • Gosliner, Terrence M., David W. Behrens and Gary C. Williams. 1996. Coral Reef Animals of the Indo-Pacific: Animal life from Africa to Hawaii exclusive of the vertebrates Sea Challengers. 314pp.
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