Bladerunner?

  

A nice view of a small, but fancy nudibranch — Diaphoreolis lagunae (formerly Cuthona lagunae) on a blade of surfgrass (Phyllospadix sp.).  This individual was ~10 mm long.  Photographed on 22 June 2024.

Green on green

  

Sculpin resting among blades of surfgrass (Phyllospadix sp.).  

Thanks for the great photo, Eric!

In the zones

  

This morning (24 April 2023) we were finishing some surveys at a site with lots of wave splash.  In this case that means the intertidal zonation is clearly demarcated and the zones extend very high on the rocks.  

For example, on the left, the brownish coloration is made up of seaweeds (primarily Pyropia and Pelvetiopsis), the dark blue areas are California Mussels (Mytilus californianus), and below that is a band of surfgrass (Phyllospadix scouleri) and coralline algae (some of it is bleached, likely by warm or desiccating conditions, so it's paler than usual).

In this view there was also a nice flock of Surfbirds (Calidris virgata) foraging in the zone above the mussels.

An iridescent neighbor

  

This snail can be quite common in the rocky intertidal zone, but it's small enough (only ~4 mm long) that you might not notice it.  Meet Lirularia succincta!  Photographed 4 July 2022.

3 for 3,000

Whew, well it's hard to believe, but this is post #3000!  (3000 posts over 10.5 years.)  So here's a little video clip to mark the occasion.

This is an older video (from 2018), but I've wanted to share it for a while.  It shows a River Otter family (a mother and three pups) on a morning outing — waking up from a nap, using a communal latrine, sliding down some Feather Boa kelp into the water, swimming along the shoreline together.  And it includes audio!  I've written about otter calls before — the pups use a high-pitched bird-like chirp to keep in touch with the rest of the family.

On this day I was working quietly in the low intertidal zone when I noticed this otter family swimming by.  They swam past me, climbed up onto the seaweed-covered rocks, and curled up for a nap!  I didn't want to disturb them, so I kept working and watched for activity out of the corner of my eye.  Eventually they woke up and that's when this video clip starts. 

I didn't know the otters were going to make their way back towards where I was working.  You'll see that eventually they notice me.  One of the pups makes sure the others know about me, too, and then they continue along the shoreline.

I hope you enjoy this little window into the life of River Otters.  Thanks so much for checking into the Natural History of Bodega Head blog.  Knowing you're out there inspires me to keep learning and to keep sharing.  Who knows how far beyond #3000 we'll go!

 

 

P.S.  Many thanks to Eric for helping to edit this video, and for participating in so many NHBH blog posts!

Fishing in the surfgrass

We were on our way out to do some early morning field work today (11 July 2021) in a rocky boulder field when I heard a high-pitched whistle.  It didn't register immediately, but when my mind starting ticking through possible options, I realized it was probably a young River Otter (Lontra canadensis).  So I looked around for a bit and finally spotted where the sound might be coming from.  Can you find the face of the adult otter in the photo below?

 

 

She's peeking out from around the seaweed-covered rock, in the middle of the photo, just right of center.  It's only her face, but you can see her eyes, nose, and whiskers.  

 

I stood very still and then watched as the adult entered the water and was followed by two young otters.  I don't often shoot video, but the point-and-shoot camera I had has that option, so I decided to give it a try.

 

It was so much fun watching the otters hunt for prey among the surfgrass (Phyllospadix sp.) and seaweeds.  They were so fluid and so fast!  They disappeared under the surfgrass blades, but their movements were still visible at the surface.  Then they would dive and reappear from below some kelp fronds.  So cool!  Here are a couple of short video clips:

 

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

And one more photo, of the mom (on the right) and one of the young ones (on the left), both feeding on fish:

 

 

Expert craftsmanship

I was sitting in my office, the phone rang, and I heard Eric say, "You have to come see this."  So off I went to where Eric was looking through a microscope.  This was my first view:

 

Huh?  What is going on?  I knew these animals had been collected from an intertidal area with surfgrass, but they looked like caddisflies from streams! 

Maddy had spotted these tiny crustaceans walking around in the most beautiful, perfectly cylindrical tubes.  For scale, this tube was only ~5 mm long and ~1 mm in diameter. 

Below are two more views.  You can see the wonderful antennae, bright orange with clear tips.  I eventually figured out that these are tube-dwelling amphipods. 

 

 

The amphipods would sometimes start to emerge from the tube, revealing a little more of their elongated bodies, but they never left the tubes completely.  The amphipods could reverse direction and emerge from the opposite end of their tube, and Eric noticed that they could attach the tube to an object (like a seagrass blade) with a strand of silk.

 

I was fascinated by the expertly crafted tubes.  What were they made of?  (Could it be material from surfgrass roots?)  How did the amphipods make the tubes?  The stripes on the tubes seemed so regular that it didn't seem like they were unprocessed bits of debris stuck together, but could they have been "woven" by the amphipod?  And what happens when the amphipods need to molt to grow?  How do males and females mate?  

Here's a close-up of one of the tubes:

 

It's been a little bit of a windy road trying to identify which species of amphipod this is.  Spending some time with the Light & Smith Manual, I wondered if they could be a species of Cerapus.  However, I found a newer document online that makes it seem like there has been some taxonomic confusion in this group and they now might be considered an undescribed species of Notopoma.  I'll need to consult with some experts, and we are eager to figure out more about the identity and biology of these amphipods, so stay tuned.  

All these years looking at intertidal marine invertebrates, and I had no idea there were these amazing little tube-dwelling amphipods wandering around in surfgrass beds.  I suppose that shouldn't be surprising, but it's so awesome when you realize that there's an endless amount to discover in our own backyards!

This amphipod is brought to you thanks to Maddy's sharp eyes and to Eric's skill with the microscope camera.  I'm so thankful to have been introduced to such a cool critter!

Always greener?

 

During a break in field work today (12 April 2019), I looked across to the other side of a surge channel in the rocky intertidal zone and I was impressed with how green the Surfgrass (Phyllospadix scouleri) looked.

Field of bubbles

This afternoon I was looking into a tidepool and was intrigued by all of the bubbles attached to the surfgrass (Phyllospadix sp.).  I decided to try to get a picture from an underwater perspective.  Here's the first shot:

 

That was pretty fun, so I decided to try another from a little further away to show the extent of this "field of bubbles."  [I was kneeling next to the tidepool, holding an underwater camera below the surface, so I couldn't quite see what was in the frame.]

 

Wow!  It worked pretty well...and there was a bonus!  A nice Surfgrass Limpet (Lottia paleacea) was in the center of the photo near the top.  This limpet is remarkably well adapted for life on a surfgrass blade.  [For an introduction to the limpet, see the post from 7 June 2012.]

I kept taking pictures from different positions, and I ended up with one more image of the surfgrass blades, the bubbles, and the limpet:

 

I'll definitely keep trying to capture this beautiful underwater scene in other surfgrass meadows!

Blade runner

I first wrote about Surfgrass Limpets (Lottia paleacea) several years ago (yikes, almost 5½ years ago now!) — see the post called "Chemical camouflage" on 7 June 2012.

Tonight I took a couple of pictures of this limpet that made me curious:

 

Remember that Surfgrass Limpets only live on surfgrass (Phyllospadix spp.) blades, which are very narrow (depending on the species of surfgrass, only ~0.5-4 mm across).

Generally when I see a Surfgrass Limpet, it's a single individual on a blade.  This is the first time I recall finding two limpets next to each other.  So then I wondered — can Surfgrass Limpets turn around on the blade?  Or, do they only move back and forth?  If there are two limpets on one blade, do they compete for food?

Here's the next photo:

 

I noticed at least one individual that looked different from the others — it was smaller and much paler, appearing pale green, at least when looking down on a cluster of surfgrass blades.

Many of the Surfgrass Limpets we see are brown, and they're often ~10 mm long.  This individual was only ~4 mm long (note millimeter marks on the ruler above).  Is this a juvenile Surfgrass Limpet?  If so, how old is it?  What time of year do the adults spawn?  When do the larvae settle out of the plankton?  Is the pale coloration a variation, or is it more typical of juveniles, or is it a signal of new shell growth?

Lots of questions for which I don't have answers, but it's always fun to wonder, especially when you look at a familiar species from a different perspective!

Green!

 

Surfgrass (Phyllospadix scouleri) photographed along the outer coast in January 2012.  

P.S. For more information about surfgrass, check out the post called "Seeds in your socks" from 9 April 2014.

P.P.S.  Many of you know that I'm from New England and, well...once a Boston sports fan, always a Boston sports fan.  With apologies to Matt, I couldn't help posting something green tonight to celebrate the nice win by the Boston Celtics.  Way to go, Green Men!

Seeds in your socks

In late March, we noticed this object washed up on Salmon Creek Beach:

 

In took a few seconds for us to realize it was a sock! 

The sock was absolutely covered with marine life.  Here's a closer view (below).  It's easy to see that the dominant animals are hydroids (golden in color) and bryozoans (white and encrusting).  

When we were scanning to see what else was there, we were amazed to see a very high number of surfgrass seeds (Phyllospadix sp.).  Surfgrass is a flowering plant found in the low intertidal zone along outer coast rocky shores.  Almost all of the black structures on the sock are either entire or broken surfgrass seeds.  We counted at least 30 seeds on this sock!  

 

If you haven't seen a surfgrass seed before, you're in for a treat.  The following is a view under high magnification.  I didn't record the size at the time, but I'm guessing this seed was ~5 mm across.

 

Note the long barbs on either side with well-developed bristles.  These structures function to hook the seed on something like coralline algae, where the surfgrass seedling can then start to grow by putting down roots and sending up green shoots. 

This process was first illustrated by Robert Gibbs in 1902 (his research took place in Bodega Bay):

 

Modified from Gibbs, R.E. 1902. Phyllospadix as a Beach-Builder.  American Naturalist 36: 101-109.

Here's an example of what this looks like in the field (although it's better for the algae and the surfgrass if they don't wash up on the beach!).

 

I don't know if you noticed, but several of the surfgrass seeds on the sock had started to produce shoots!  In the picture below, look for the seed lying flat at the bottom of the image.  The green shoots are emerging from that seed.

 

Sadly, because this sock and seedling were washed up on the beach, this plant won't survive.  But here's what a nice bed of adult surfgrass plants looks like:

 

I'm sure many of you have experienced walking through grasslands during the summer and finding many grass seeds stuck in your socks...but until now, have you ever considered finding surfgrass seeds in a sock?  ;)

P.S.  If you're missing a sock, let me know.

Chemical camouflage

 

View from the southern end of Bodega Head, with Bodega Rock offshore and Tomales Point in the far background.  Note the bright green surfgrass (Phyllospadix scouleri) in the foreground.

 

The Surfgrass Limpet (Lottia paleacea) (= Notoacmaea paleacea) is one of the smallest of the West Coast limpets.  They are tall and narrow, up to 10 mm long and about 3 mm wide (no wider than a surfgrass blade).  

Surfgrass Limpets only live on these slender seagrass blades.  They feed on the plant's outer tissue — look for the grazing scars in the photo below (paler section to the right of the limpet).

 

Surfgrass Limpets appear to be chemically defended against predation by seastars.  Debby Carlton studied this relationship on Bodega Head.  Three small gastropods are common in surfgrass beds — Surfgrass Limpet, Chink Snail (Lacuna marmorata), and Carinated Dove Snail (see yesterday's post).

The two snails react strongly to Six-armed Seastars (Leptasterias sp.).  When contacted by a seastar, the Chink Snail waves its tentacles, twists its shell, and drops off the surfgrass blade, all defensive behaviors to avoid the seastar's grasp.  The Carinated Dove Snail flees, but may also bite the seastar.  In contrast, the Surfgrass Limpet clamps down and remains motionless.  Sometimes the seastar even crawls over the limpet and continues on, without capturing it.

Debby proposed that this was an example of chemical camouflage.  She found evidence that the same chemicals (flavonoids) were present in both the surfgrass tissues and in the limpet's shell.  It's possible the non-visual seastar predator does not detect this likeable limpet because it smells like surfgrass!