Micro Macro

  

During a beach walk yesterday (17 August 2024), Eric and I came across quite a few Giant Kelp (Macrocystis pyrifera) juveniles, including this very young individual (above) with a very small holdfast and one single blade. 

Most of these juvenile kelps were a little bit larger, but still early in their development.  Here's an example:

 

 

Below, two images show a closer view of the holdfast and the developing blades.  You can see the blades starting to split and the floats just starting to develop (as small swellings at the base of the blades):

 

 

 

 

 

I appreciated coming across these Giant Kelp juveniles and learning more about how they develop.

P.S.  I'm including one more photo just for fun.  The floats are little larger in this individual, and I hadn't noticed at the time, but you can see my reflection in the floats.  A self-portrait in kelp!

 

 

 

P.P.S.  Regarding the title of this post — In casual conversation, we sometimes shorten the scientific name of Giant Kelp, Macrocystis, to "Macro."  And because I am highlighting small individuals in this post, I thought it would be fun to play on those two names = Micro (small) Macro (Macrocystis).

The door to the moon?

  

The operculum, sometimes called a "trap door", to a Lewis's Moon Snail (Neverita lewisii).  This is the part attached to the snail's foot that seals the opening to the shell when the animal pulls in.  This operculum was 2¾ inches (7 cm) long.

Interestingly, the inside of the operculum was very reflective and looked quite silvery in the overcast light of the fog today (17 August 2024).

Untangling the diversity of ribbon worms

  

Such a nice mosaic of local ribbon worms!  [You can click on the image for a sharper version.]

Eric and Maddy (partnering with Christina and Svetlana) worked on a project documenting and discovering the diversity of nemerteans, commonly known as ribbon worms, in Bodega Bay.  Their results were recently published in ZooKeys and a story about their findings is now available in Bay Nature magazine.

For the Bay Nature article, click here.

For the ZooKeys article (scientific publication, with pdf version available), click here. 

Remarkably, their research found 11 ribbon worm species that are new to science!  Nice work, everyone, on documenting this understudied group and opening our eyes to the diversity around us.

Barrel bubble

  

Caroline spotted this intriguing gastropod in Tomales Bay on 7 August 2024.  It's a species we hadn't seen before, so Eric took some documentary photos and videos (see the wonderful video below!).

Although we need to confirm with experts, we think this is a barrel-bubble snail, Acteocina inculta.  This is generally described as a southern species, from either Monterey Bay or Morro Bay southward.  There are a couple of museum records for San Francisco, but it's possible this is the first record for Marin County — we'll need to do more research on museum records.

Acteocina inculta is a small head-shield slug (this individual's shell was a little over 3 mm long).  Note the head-shield in front of the shell — and that the back edge of the head-shield is split into two rounded lobes.

Eric captured some very nice video footage of this hard-to-find species, so here you go!  

[If you can't see the video player in the e-mail message, click on the title of post above to go directly to the NHBH website.]

With many thanks to Caroline for her sharp eyes and hard work!