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Monday, April 24, 2017

Crossed cups around the Pacific Rim

Okay, remember the mystery photo from last night?  Here's a reminder, with a slightly different view:



I'll zoom out a bit so you can see a little more.  And yes, for those of you who were wondering, the sand grains on the tentacles are a clue:


Any guesses yet?  When we first found this animal, we didn't know what it was.  We had to step through various options and rule out different groups.

Did you notice that the skin adjacent to the tentacles looks shiny?  Here's an extreme close-up so that you can see what I'm referring to:


Those shiny pieces are ossiclestiny calcified plates.  To help identify this organism, we looked at a few of the ossicles under high magnification (400x):


Do you have a guess yet?  Think about a soft-bodied animal with a cluster of branched tentacles at one end and microscopic ossicles embedded in the body wall. 

It'll probably help if I tell you that although this animal doesn't have them, most of this animal's relatives have tube feet. 

Here's another look at those digitate (finger-like) tentacles:


Yes!  It's a sea cucumber!  We hadn't seen this species before.  It's a Sand Sea Cucumber (Paracaudina chilensis).  Amazingly, it's distribution includes the entire Pacific Rim (coastal South America, Central America, North America, China, Japan, Australia, and New Zealand).

As you might guess from the common name, and the pictures, this sea cucumber burrows in the sand.  It ingests large volumes of sand to capture organic material from the sand grains for food (hence the "sticky fingers").

This is what the entire sea cucumber looks like (photo below note there was debris sticking to the cucumber, but that's likely a result of being in the drift line).  We found it washed up on the beach, and puzzled over it for a while.  With my hand lens I could see the tentacles — that helped because the tentacles didn't look right for a peanut worm or a sea anemone.  

Note the very long posterior end.  This sea cucumber lives upside down in the sand (up to 50 cm deep) — tentacles down, and posterior end up near the surface.



The shape of the ossicles helped clinch the identification as Paracaudina chilensis.  Many of them are beautiful three-dimensional "crossed cups."  Compare the ossicle images above with this published figure from a specimen in Australia:

Modified from O'Loughlin, P.M., S. Barmos, and D. VandenSpiegel. 2011. The paracaudinid sea cucumbers of Australia and New Zealand (Echinodermata: Holothuroidea: Molpadida: Caudinidae). Memoirs of Museum Victoria 68: 37-65.
 

P.S.  Are you wondering about the extra credit (i.e., the source of the brilliant red coloration in the tentacles)?  Paracaudina chilensis has hemoglobin-filled blood cells (in the body cavity and in the tentacles)!  The hemoglobin is likely an adaptation to living buried down in a low-oxygen environment.
 

Sunday, April 23, 2017

Like little jesters' caps?

A close-up mystery photo, taken with a microscope.  Do you have any ideas about what type of organism this is?


I'll reveal the answer to this mystery tomorrow night.

P.S.  Extra credit if you can guess why the structures are red!

Saturday, April 22, 2017

Resting on the beach


A beautiful Harbor Seal (Phoca vitulina) pup, 22 April 2017

Remember the mother/pup photos from several years ago?  You can review that post from 14 May 2013 here.

Today and every day


Celebrating Earth Day and science, today and every day!
 

Thursday, April 20, 2017

Bearded


Bearded Clover (Trifolium barbigerum), Bodega Head, 19 April 2017

P.S.  Check out the interesting color patterns on this clover's leaflets (on the left-hand side of the photo).  I'm intrigued by the markings, so I did a quick search into what's known about the patterning.  It sounds like they're formally called "anthocyanin leaf markings" and they're known to be linked to certain genes.

Wednesday, April 19, 2017

Pinpoint


Pinpoint Clover (Trifolium gracilentum), Bodega Head, 19 April 2017
 

Tuesday, April 18, 2017

Which is which

There was a bit of fog on the coast today.  I didn't get a chance to take a picture, but here's a foggy one from late March 2013:


Although the boundaries in this picture are pretty distinct, today was one of those days when it is hard to tell which is whichwhere the ocean ends and the fog begins.
 

Monday, April 17, 2017

Spot-on

I was sorting through some pictures from last spring when I encountered this one:


I said to myself, "Huh...do Two-spotted Keyhole Limpets (Fissurellidea bimaculata, formerly Megatebennus bimaculatus) eat sponges?"  It certainly looks like the limpet (relatively small, dark brown shell surrounded by a bright yellow mantle) had been eating the green sponge (Halichondria sp.).  

So I read the species account in Intertidal Invertebrates of California which said this:

"This species often occurs on compound ascidians where the color pattern provides good camouflage.  In the laboratory, Megatebennus has been observed feeding on compound ascidians, and sponge spicules have been found in the gut of specimens collected in the field."


And then I laughed, because the next photo I found was this one:


The Two-spotted Keyhole Limpet above is in the centerwith a dark brownish shell (barely visible) surrounded by a pale yellow mantle.  It's flanked by several compound ascidians, and you can see how well camouflaged it is.

The description in the species account by Don Abbott and Gene Haderlie was spot-on!

Sunday, April 16, 2017

Migrating north


A distant shot in the rain, but I don't think I've posted a photo of a Greater Yellowlegs (Tringa melanoleuca) before.  In our area, Greater Yellowlegs are less common at the coastI don't encounter them often in Bodega Bay.  

In the spring, Greater Yellowlegs are migrating north.  According to The Birds of North America, they'll nest in muskeg habitats in central Canada and southern Alaska.  

This photo was taken along Valley Ford Road in Petaluma on 16 April 2017.

Saturday, April 15, 2017

Sometimes...

...it makes your day just to sit and watch:




River Otter (Lontra canadensis), 15 April 2017

Friday, April 14, 2017

Blue strand

A significant stranding of By-the-wind Sailors (Velella velella) on Salmon Creek Beach tonight (14 April 2017).  It was blue as far as you could see:



Most of the Velella were ~2-3 cm long, but there were a variety of sizes:



A small flotilla viewed from above:


Northwest winds were blowing at about 20 knots this afternoon, but they're predicted to calm down tonight.

Wednesday, April 12, 2017

Blue


I've been working on some photo organization, so here's one from the archivesan Acmon Blue (Plebejus acmon) photographed on Bodega Head on 15 March 2016.

Tuesday, April 11, 2017

Named after Chamisso


Camissonia strigulosa, photographed in the Bodega Dunes on 5 April 2017

The genus, Camissonia, is named after Adelbert von Chamisso — a German botanist who joined Otto von Kotzebue aboard the Rurik on a scientific voyage around the world in 1815-1816.  

Fun fact: When they visited California, Chamisso collected the California Poppy (Eschscholzia californica) and later named it after another scientist on the voyage, Johann Friedrich Eschscholtz.

The species name, strigulosa, is a reference to the short stiff hairs lying flat against the surface of the plant, some of which are visible on the reddish stem in the lower right corner of the picture (they look like a bit of white frosting).

I found several common names for this wildflower.  Which do you like better Strigose Suncup or Sandy-soil Suncup?

Monday, April 10, 2017

Soaking up some rays

Air temperatures reached ~58°F (~14.5°C) in Bodega Bay this afternoon, but the sun and calm wind conditions made it feel even warmer.

I happened upon a few insects basking in the sun:


Two-banded Skipper (Pyrgus ruralis)
(This is the first time I've seen this butterfly species in Bodega Bay.)




California Darner (Rhionaeschna californica

And a close-up from the side:





Cardinal Meadowhawk (Sympetrum illotum)


It looks like it might be cloudy for the next few days, but the sun might return at the end of the week, bringing more chances for insect sightings.
 

Sunday, April 9, 2017

At home in the sand


Beach Strawberry (Fragaria chiloensis)



Dark-eyed Gilia (Gilia millefoliata)


Both photographed in the Bodega Dunes, 5 April 2017
 

Friday, April 7, 2017

Spring break

  
14-foot west swell today, 7 April 2017

Thursday, April 6, 2017

A sea of purple


Dwarf Lupine (Lupinus bicolor), 5 April 2017

Wednesday, April 5, 2017

The Distributor

Remember the mystery fossil from last week (see "Long in the tooth" and "A closer look")?  Well, we think we might have figured it out!  It took some sleuthing, and some help from experts.

To review, here's the fossil as we found it on the beach:


Amazingly, we had trouble even identifying what type of organism this might be.  For example, suggestions ranged from a walrus tooth, to a rudist (an extinct bivalve), to a barnacle, to a plant.

When we looked under a microscope, we noticed channels on the outer wall:



These eroded channels seemed reminiscent of a barnacle.  For comparison, here's a close-up of a wall plate from a local barnacle, Balanus nubilus, that lives in the rocky intertidal zone:


You can see why some people thought this fossil might be a barnacle.  But we were confused because we couldn't see any sutures, or divisions between wall plates, which would help confirm the identification as a barnacle.  [Many barnacles have 4-6 wall plates that fit together in a circle to form the familiar shell that is shaped like a little volcano.]

We sent the photos to Bill Newman at Scripps, one of the world's foremost barnacle experts.  Bill suggested that we had discovered the basis (basal plate) of a fossil barnacle!  Since it was only the basis, that would explain why we didn't see individual wall plates.

Here's a local barnacle (see below).  Many (but not all) barnacle species have a calcareous basal plate where they are attached to a rock (or other surface).  The wall plates sit on top of that base.  Most of the time, the basal plate is flat.  But note that sometimes the basal plate is elongated upwards and forms a shallow cup.  The blue arrow is pointing to the division between the lower basal plate and the upper wall plates.


Now imagine if that basal plate could be elongated a lot more, forming a conical tube (like our fossil!).  It's an unusual shape for a barnacle, but it's typical of an extinct barnacle called Tamiosoma gregaria (formerly Balanus gregarius).



We found some older illustrations of Tamiosoma fossils, so here's a comparative view from abovethe fossil we found is on the right:



Left-hand illustration from Pilsbry, H. A. 1916. The sessile barnacles (Cirripedia) contained in the collections of the U.S. National Museum, including a monograph of the American species. Bulletin of the United States National Museum 93.


Tamiosoma has been found in fossil deposits from central California to Baja.  It's thought to have lived in shallow embayments between the early Miocene (16-23 million years ago) through the Pleistocene (2.6 million to 11,700 years ago).

Previous studies suggested that Tamiosoma's very elongate base might have been an adaptation to living in mud where sediment accumulated rapidly.  [Fun fact: Tamiosoma means "distributed body" and might refer to its unusual elongate form.]

Although we don't know what Tamiosoma looked like when alive, Eric thought it would be helpful to imagine how this amazing barnacle might have been positioned in the mud.  He scanned the fossil basis that we found, and then added wall plates (from a drawing of a Tamiosoma fossil) and cirri (feeding appendages).  The barnacles probably attached to small hard objects (e.g., a piece of shell) on the surface of the mudflat, and then continued to grow upward as sediment accumulated around them over time.  Sometimes multiple individuals were clustered together.  Check out Eric's excellent illustration:


P.S.  Many thanks to everyone who contributed to this story, especially Bill Newman, folks on the Fossil Forum, and Karen Whittlesey's thesis on this intriguing barnacle!

P.P.S.  The next question — where did the fossil we found come from?  Do you know of fossil deposits in the Bodega Bay area?

Tuesday, April 4, 2017

Snowy in the spring

A couple of quick shots of Snowy Plovers today (4 April 2017):





Sunday, April 2, 2017

From the northwest

There was a pretty good swell today in the late afternoon, it was about 12 feet at 16 seconds.



Impacts against the shore were impressive:


Saturday, April 1, 2017

A thorny identification

While conducting a survey on the beach yesterday (31 March 2017), we noticed a Turkey Vulture in the distance.  We could tell it was feeding on something, but couldn't tell what it was.



When we got closer, the vulture had flown off, so we went over to look at what had attracted the vulture's attention:


At first I thought it was an electric ray, but there were several characters that didn't seem right.  After doing some more research, I believe this is a Thornback Guitarfish (Platyrhinoidis triseriata)the first I've seen.

It's especially important to note that the caudal fin (at the tip of the tail) is relatively small; the two dorsal fins (on the right side of the photo) are about equal in size; and there are three rows of prominent spines running down its back and along the tail (sorry I don't have better pictures of those!). 

Thornback Guitarfish prefer shallow water and sandy or muddy bottoms.  They are known to occur as far north as Tomales Bay.  Have you seen them in Bodega Bay, or anywhere further north?

P.S.  To compare with a Pacific Electric Ray, review the post from 5 February 2014.
 

Friday, March 31, 2017

Leaning in

Whew!  It's been a windy week!  

That's not necessarily unusual at this time of year in Bodega Bay (sometimes known as "Blow-dega Bay").  

Yesterday northwest winds were blowing over 25 knots (30 mph) with higher gusts.



The wind was so strong that it made us wonder how far you could lean into it?  

Eric decided to give it a try:


I know it's hard to gauge the wind speed in this picture, but — Wow!   Although the wind only supported Eric at that angle for around 15 seconds, it was impressively strong wind, and I had trouble believing what I was seeing.



Okay, it was very windy, but it wasn't quite that windy.  We thought it would be funny to stage a photo like this.  Eric was actually leaning against a board that we later removed from the image using PhotoShop.  Did we fool anyone? 

Happy April Fools' Day!
 

Thursday, March 30, 2017

Gathering


Common Raven gathering nest material, 28 March 2017

Wednesday, March 29, 2017

A closer look

I received quite a few e-mails and comments about last night's mystery object (thank you!)...but as of tonight, it still remains a mystery. 

There are some ideas floating around, but none have been confirmed.  We're starting to lean towards an invertebrate, rather than a vertebrate.  And our strongest leaning is towards a fossil barnacle (at least as of 9 p.m. on 29 March 2017).  [Note: Although some aspects of this object look barnacle-like, others do not, so we're still looking for assistance with the identification.]

We're continuing to work on the identity of this object, so I thought I'd share a few more images, in case they're helpful.

A nice scan of two different sides:



I need to take a better picture of the wider, open end, but here's one view of the interior edge (looking down into the hollowed portion at the top of the first photo):



The photo above was taken under a microscope.  I was so intrigued by the patterning that I zoomed in even closer:


I'm not sure whether this helps with the identificationit might just be a pattern that developed while the object was being fossilized.

I'll provide updates if we learn more...