Fin in the fog

  

A couple of weeks ago, Eric looked up from the surf zone to see this animal swimming by.

I was surprised how close to shore it was.  Here's a photo with the fin in the distance and the surf zone (next to the beach) in the foreground:

 

 

It surfaced a few more times, so we had some better views, but I didn't have my camera ready and it was a bit foggy and distant, so here's my best shot for the record.  Did you guess its identity?

 

 

 

A Harbor Porpoise (Phocoena phocoena) near Drakes Beach on 17 August 2024.

 

I don't spend a lot of time at Drakes Beach, so I'm not sure how often porpoises are seen near the surf zone in that area.  Is it common?  If you have observations to share, please do!

 

P.S.  This sighting reminded me of an older post showing porpoises in Drakes Bay, but in this case they were photographed looking down from above the Chimney Rock Lifeboat Station — see "Breathe" on 26 November 2014.

 

Little wonder

  

Camouflage week continues!

You might recall that back on 14 July 2024, I introduced this amazing nudibranch, Corambe pacifica.  I also mentioned that I needed to get a better photo.  Well, here you go!  And, lucky us...Eric was also able to record some beautiful video clips.

Things to look for: 

- how well the color and patterning of the nudibranch match the bryozoan in the background

- two rhinophores (sense organs) near the leading edge (viewed from above, they look like a pair of white spots)

- a small notch along the back edge of the nudibranch

- when viewed up close, sometimes you can catch a glimpse of the branched gills inside the notch (more about the gills in a future post!)

Here's the video clip (below).  [If you can't see the video player in the e-mail message, just click on the title of the post above to go directly to the NHBH web page.]

Stay tuned for more about Corambe pacifica.

And thanks to Eric for the great video!

Like sand, like spider?

  

Here's another great example of camouflage with beach sand.  Eric photographed this jumping spider, Terralona californica, on 21 August 2024.

It's a little bit easier to see than the isopod, but it's still impressive to see how well the colors of the spider match the colors of the sand:

 

 

Although they are small and can be overlooked, we often see Terralona running along the high tide line on the beach, and sometimes catching small flies.  Here's the same spider from the front, showing its large eyes:

 

 

 

Thanks for the great photos, Eric!

 

The hidden one

  

Alright, this is a little bit of a test.  Scan the image above — can you spot the isopod (an oval-shaped crustacean with a segmented body)?  Look carefully, it's a tough one! 

Okay, here's another view, a little bit more zoomed in (below).  Can you find it now?  (Hint: Look for something that doesn't look quite like sand grains.)

 

 

And now even closer — I'm sure you'll see it now!

 

 

And, because this isopod is so cool, here's a slightly different view:

 

 

Meet Tecticeps convexus!  Amazing to see how well its coloration matches the surrounding sand — black, orange, gray, white, and even pale blue!

 

It is so well camouflaged that it might still be hard to see, so here's another image without the sand.  [Note the two dark eyes and the short antennae on the head, and the large pale spots in the center and on the last segment.  You can use those features to locate the isopod in the photos above.]

 

 

 

We're so lucky that Suzanne looked down to see this isopod on the beach!  

 

Eric and I have been interested in finding this species for many years, but it probably lives mostly in the subtidal zone (so a little out of reach for biologists who spend most of their time in the intertidal zone).

 

One more extreme close-up so you can really appreciate the colors and patterns:

 

 

 

With many thanks to Suzanne for noticing Tecticeps and bringing it to our attention, and to Eric for the fantastic photos of this seldom seen species.

 

Looming large

  

Getting ready for some low tide work this morning, couldn't help taking a photo of the super blue moon!  Photographed from Cotati on 20 August 2024.

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!