Black Sea Rod
Plexaura homomalla
California Golden Gorgonian
Muricea californica
About
The golden bushes standing under the kelp canopy off southern California and the Channel Islands. On a good reef they grow thickly enough to look like an underwater orchard.
Also known as: golden gorgonian, California gorgonian, gorgonian, sea fan
- Length
- 1 m
- Depth
- 12–40 m
How to tell it apart
A stiff brown bush covered in golden-yellow polyps in a southern California kelp reef. The red gorgonian growing alongside is bright red-orange in the skeleton itself, not just the polyps.
Appearance
A stiff branching colony up to about a metre tall, branching in a rough plane. The skeleton is dull brown, but the polyps are golden yellow and stand out in dense rows, so a feeding colony glows gold under a torch and looks drab brown when the polyps are closed.
Habitat
Rocky reefs from southern California to Baja California, typically between about 12 and 40 m and down to 65 m. It grows under and beyond the kelp forest, on rock with moderate to strong water movement.
Behaviour
The colony orients across the prevailing current so the filter-feeding polyps meet as much passing water as possible. It carries no symbiotic algae and feeds around the clock whenever there is flow.
Diet
Plankton and drifting detritus captured by the golden polyps.
Breeding
Separate sexes, spawning into the water column in summer. Larvae settle on bare rock, and recruitment is slow and patchy.
Conservation
Not formally assessed. The main damage is mechanical, from lost fishing gear, anchors and divers, and the slow growth rate means a broken colony takes decades to replace.
Did you know?
It grows roughly a centimetre a year, so the metre-tall colonies on the Channel Islands reefs were already standing when scuba diving arrived in California.
Log it in Into the Blue
Describe what you saw and we name it, then keep every species you find in your Oceandex.
