Like granite

  

Fingered Limpets (Lottia digitalis), Eroded Periwinkles (Littorina keenae), and a few acorn barnacles (Chthamalus dalli) on Bodega Head granite, photographed 9 July 2022.

Keen on crevices

  

At the end of our field work yesterday (4 April 2021), Eric snapped a couple of quick photos of these dense Eroded Periwinkle (Littorina keenae) clusters along rock crevices.  

This high intertidal species has been noticeably abundant during the last few years and the snails were packed into narrow crevices (likely gravitating towards cooler and/or moister sites).

 

 

Your Highness

 

Eroded Periwinkle, or Flat-bottomed Periwinkle (Littorina keenae)

Highest on the shore

She waves from a rocky throne

Queen of the splash zone

 

Keen on keenae

Not too long ago, Eric wondered why I hadn't posted more pictures of local snails.  I think he was surprised because it was one of the first groups I started studying when I moved to California.  To be honest, I'm not sure what the answer is.  Many of them are small, so perhaps hard to photograph.  But since his observation is true, I'll be trying to share some more snail photographs.

 

These are Eroded Periwinkles (Littorina keenae) in a narrow crevice in the splash zone (the highest level of the rocky intertidal zone).  They live higher than any other marine gastropod.  They can be out of the water for such long periods of time that some people might consider them semi-terrestrial.

They're called Eroded Periwinkles because their shell erodes as they age.

 

This is a helpful characteristic when you're trying to identify them, but if you only look at larger, older individuals, you miss out on the wonderful variation and patterning of the juveniles:

 

As you can see, some are pale, others are dark (mahogany brown?), and they have variable amounts of white.  It's amazing how well these combinations match the surrounding rocks.

Below are two more examples of the pale and dark forms:

 

 

Although they blend in well, once you know what to look for, I'm guessing you'll find some Eroded Periwinkles in splash zone crevices during your visits to the coast.