Amphipods

Below are a few examples of amphipods living on Oregon’s exposed shores. The photos are from northern Oregon unless noted. These are the easy-to-spot amphipods I’ve seen and photographed on the beaches and around the tidepools; they’re the ones you can find with a light touch without turning rocks or creating disturbances. Organization-wise, I loosely follow Lamb and Hanby (2005). If I use common names, they’re my choice. Experts cover these examples and many more in the books, field guides, and identification resources listed at the bottom of the page.

Let’s explore the amphipods!


Megalorchestia californiana, California beach hopper
When these good-sized beach hoppers are out in numbers, say around dawn, they’ll grab your attention.

A beach hopper on bare sand.
Beach hoppers bring cuteness and personality
Closeup on the head and antennae of a beach hopper (on the sand).
Those antennae
Somewhat blurry image of a beach hopper retreating from the photographer.
If you get too close, California beach hoppers won’t hesitate to hurry away

California beach hoppers are social creatures. Here’s a five-second fight sequence (Central Oregon shore).

Two beach hoppers fighting near a burrow entrance.
6:05:44 am
Two beach hoppers fighting near a burrow entrance. They've flipped each other upside down!
6:05:45
Two beach hoppers fighting near a burrow entrance.
6:05:48
Two beach hoppers fighting near a burrow entrance seem to be done. They've separated.
6:05 :49 | It’s over. Who won?

California beach hopper lives revolve around their shelter and drift seaweed. Burrows are easy to recognize once you’ve seen a few. Spying a pair of antennae in a burrow opening is a beach treat you’ll remember.

The hind end of a beach hopper digging a burrow in the sand.
Excavating at sunrise
A mound of sand around a beach hopper burrow entrance.
The spoil gives a volcano-like look to the burrow opening
A beach hopper burrow entrance on smooth wind-blown sand.
A stiff wind can blow away the spoil
Four beach hopper burrows and two beach hoppers nearby on the sand.
Fresh burrows for all!
Three occupied beach hopper burrows and a lone beach hopper out on the sand.
No vacancy

Beach hopper workings disturb the sand in and around drifted seaweed—all the better on beaches fronting dunes. Look for workings around drying masses pushed up into the high intertidal.

Beach hopper workings in the sand.
Drying Macrocystis is a beach hopper feast
Beach hopper workings around an unidentified seaweed mass.
Whatever it is, the beach hoppers like it
Workings around the bulb end of a bull kelp stipe.
Bull kelp is a favorite
Workings almost bury drying Postelsia
Postelsia reduced to a remnant by beach hoppers
***


References

Gotshall, D. W. 2005. Guide to Marine Invertebrates, Alaska to Baja California 2nd Edition (Revised). Shoreline Press.

Harbo, R. M. 2011. Whelks to Whales: Coastal Marine Life of the Pacific Northwest. 2nd ed. Harbour Publishing Co.

Jensen, G. C. 1995. Pacific Coast Crabs and Shrimps. Sea Challengers, Monterey.

Kozloff, E. N. 1993. Seashore Life of the Northern Pacific Coast. 3rd ed. University of Washington Press.

Lamb, A. and B. P. Hanby. 2005. Marine Life of the Pacific Northwest. Harbour Publishing.

Sept. J. D. 2019. The New Beachcomber’s Guide to the Pacific Northwest. Harbour Publishing.


Online Resources

Biodiversity of the Central Coast’s Crustaceans page has excellent information on several Pacific Northwest amphipods. Accessed August, 2023.

Friends of Netarts Bay WEBS  Crustaceans page has excellent information on several Pacific Northwest amphipods. Accessed August 28, 2023.

It’s worth scrolling down to amphipods in Common Sea Life of Southeastern Alaska: A field guide by Aaron Baldwin & Paul Norwood. Accessed August 28, 2023.


Species Accounts

Cowles, D. (2008). Megalorchestia californiana Brandt, 1851. Invertebrates of the Salish Sea. Rosario Beach Marine Laboratory. Accessed August 28, 2023.


This page was published August 28, 2023