Ostrich-Plume Hydroid (Aglaophenia spp.)

Description: Although it looks like a plant, this group of feathery structures is an animal in the hydroid family. Ostrich-plume hydroids are typically shades of yellow, orange, or red, but can also be black. They have polyps growing on one side of their plumes.

Habitat: This species ranges from Alaska to Central America. They grow in clumps attached to rocks and boulders in low intertidal and subtidal zones. At Haystack Rock they are most often found near the Needles.

Diet: Hydroids are predators that feed on animals like zooplankton and even fish.

Tide Pool Tidbits:

• These colonial organisms reproduce sexually with the females holding on to the eggs until fertilization. The larvae are then released and settle somewhere new.

• Ostrich-plume hydroid colonies can grow to be 15 cm long! 

• Hydroid lifespans can range from a few weeks to a year long.

Reference: Walla Walla University