Opalescent Nudibranch In The Sand

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Today we look back to August 3rd on the beach. Gina Palmer was the lead interpreter on the beach for the 1.4 ft low tide at 7:46pm. It was a sunny afternoon with a NNW winds between 15 and 25 knots. The opalescent nudibranches, typically found under the boulders in the central pools of Haystack Rock, were today out in the sand.


Opalescent Nudibranch 

The opalescent nudibranch (Hermissenda crassicornis) is an invertebrate that resides in the intertidal rocky shores from Baja California to Alaska. They grow to about 3 inches, subsisting on a diet mainly of hydroids, but will also eat small sea anemones and bryozoans.  A nudibranch lives for a maximum of one year and is hermaphroditic. It's eggs are laid in narrow, coiled strings attached to eelgrass or algae. 

The opalescents are a colorful species of nudibranch, having bright orange areas on their back with a blue line on each side. Next time you're in the intertidal zone at low tide - anywhere on the west coast -take a look in the sand or under boulders for these colorful invertebrates!

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