I recently took a trip to Santa Catalina Island and while I was beach combing I found multiple rough cockle shells at random locations and at random growth stages. Now, I know that a population of rough cockles there is unlikely, and when I was snorkeling around the area I didn’t find any live cockles, just more dead shells. I would normally blame this on people buying/bringing shells that they proceed to leave here, but they were too scattered and at way too different life stages for me to think that’d be the case. Anyone know if that’s just what happened and I’ve overcomplicated it, or if it’s something else?
None of these are rough cockles. The first two are western strawberry cockles. The last three are pretty worn so it’s hard to say, but likely Nuttall’s cockles. All are native. I’ll add IDs when I get back on desktop.
From what I’m seeing, rough cockle is one of several top suggestions. If a top suggestion isn’t labelled as “seen nearby”, it’s probably not the correct. Best to stick with the “pretty sure” suggestions. If there’s no such suggestions, go with what you know: cockle, bivalve, etc.