General Description

Branched chains of beads (vesicles) varying in shape from round to oval depending on habitat. Beads appear spotted/bumpy (conceptacles). Several simple or branched stalks can arise from a simple disc-like holdfast. Tan to dark brown. Up to 30 cm long (thallus).

Biology

This alga can form large mats on rock platforms and is the only persistent intertidal canopy-forming algal species in Victoria. The canopy forms important habitat for intertidal invertebrates and other algae such as gastropods, crustaceans, delicate red algae. It is very slow growing and is easily broken by human trampling and wild storms which reduces its habitat quality. No animals are known to graze on Hormosira, possibly because it contains chemicals in its cells that are thought to taste bad. Colonies are thought to mainly reproduce vegetatively, though individuals can also reproduce by releasing sperm or eggs into the water during low tide which meet and grow into new individuals.

Habitat

Intertidal rocky reefs and shallow subtidal reefs, to depth of 1 m.

Reefs

Coastal shores

Distribution guide

New Zealand and southern Australia.

Species Group

Seaweeds and seagrasses › Brown algae

Depth

Shore (0-1 m)
Shallow (1-30 m)

Water Column

On or near sea floor

Max Size

30 cm

Diet

Photosynthetic - sunlight

Commercial Species

No

Global Dispersal

Recorded in Australia

Identify

• Seaweeds and seagrasses

Conservation Status

• DSE Advisory List : Not listed
• EPBC Act 1999 : Not listed
• IUCN Red List : Not listed