When we were in northern Sonoma County a few days ago, Eric called me over to see some high density clusters of limpets. The limpets were on the vertical sides of some channels.
The photo above is an overview of the setting, but here's a closer view where you can see 5-6 tight clusters of limpets on the walls:
And a slightly different perspective:
And here's an even closer view of one cluster (below). These are Fingered Limpets (Lottia digitalis). It's a common species in the rocky intertidal zone in this area. Although this limpet is known to form aggregations, I don't think we've ever seen such striking, numerous and dense clusters.
So why so many limpets in such dense clusters? We're not sure, but it could be related to high wave exposure (the limpets might be more vulnerable on the horizontal surfaces), or perhaps predation pressure (again, more vulnerable when horizontal). Another possibility is that this site has a lot of good food resources, so the limpets are doing exceptionally well, and therefore the clusters have even more limpets than usual. Perhaps you can think of some other options!
Should retain more water to prevent desiccation
ReplyDeleteHi, James!
ReplyDeleteYes, I thought about moisture, too. This seems to be a pretty wet place -- fairly low in the intertidal zone and splashy. However, it was our first time there, so I'm not totally sure about the conditions the limpets might experience in general. Perhaps it could be drier or hotter than it looked that day.
Jackie