Aglaophenia Lamouroux 1812

How to Distinguish from Similar Species: There are several species of Aglaophenia, which need more systematic work. Cladocarpus has gonophores which are on slender branches instead of within corbulae. The genus Aglaophenia has hydroids with sessile nematophores, hydrothecae with toothed margins, and gonophores enclosed in basketlike corbulae made of overlapping leaf-like structures.

Rocky subtidal habitats, especially where exposed to current.

Geographical Range: British Columbia, Canada to San Diego, CA.

Aglaophenia sp is a large benthic, colonial hydroid with a distinctive pinnate growth form. Its polyps have a hydrotheca into which they can withdraw. The perisarc margins on the hydrotheca are toothed and the hydrotheca is deeper than wide and attached directly to the main hydroid stalk. The hydrotheca has no operculum. The gonophores are within corbulae, which occur in series on some branches of the hydroid and can readily be seen without magnification. Plumes may be up to 15 cm long.

Biology/Natural History: This hydroid retains the medusae within the corbulae. Corbulae containing male and female gonophores look slightly different. The medusae, which are highly modified, release eggs and sperm. The planula larva settles to the bottom, crawls for awhile, and grows into a new hydroid. Caprellid "skeleton shrimp" and pycnogonids can often be found climbing on hydroids such as this species.

Aglaophenia is a genus of hydrozoans in the family Aglaopheniidae.