I wonder how three similar and closely related surfperch can live together on homogenous sandy beaches. How do they subdivide theoutershores? One solution might be partitioning their food. To study this, I’m learning to identify what they eat; surf perch and their competitors.
This is one of the first surfperch food items I ever examined. I think it’s a worm. In December 2011 I wrote a little about this specimen in Prey on the Outer Shores. This specimen remains unidentified, so if somebody can tell me what it is, I would appreciate it.
Much of the surfperch prey is crustacean and I’ve found lots of smooth bay shrimp, Lissocrangon stylirostris and Pacific mole crabs, Emerita analoga, in the stomachs of surfperch.
Idotea, an isodpod, is a common food item. I should be able to identify this one by the shape of the telson, but so far I’m stumped. I’m hoping somebody will help me out.
I think these are crustacean eggs, an impressive gob. The Idotea provides scale.
Goose barnacles, Pollicipes polymerus.
Staghorn sculpin, Leptocottus armatus (left), and sand sole, Psettichthys melanostictus (right), both arrive on the beaches in summer, just before surfperch give birth to their babies. Are they predators on baby surf perch or competitors for crustaceans?
Speaking of competitors, here’s one you don’t see every day. An theoutershores reader sent me the following link: http://www.flickr.com/photos/cambriabird/8354888665/in/photostream
This footage was taken on an outgoing tide, mid-morning on January 6, 2013. I’ve never seen anything like this, but apparently some others have, particularly near where this occurred in San Luis Obispo County, California. It looks to me like these birds are dabbling for crustaceans in the surf. What do you think?