Tuesday, February 28, 2017

Red Turban


A wonderful Red Turban Snail (Pomaulax gibberosus), photographed in the rocky intertidal zone in northern Sonoma County on 25 February 2017.  This juvenile snail was only ~1 cm across.  (Adults can reach diameters of over 5 cm.)  Look for the distinctive nodules along the body whorl (photo above) and the spiral cords visible on the base of the shell (photo below).

Unlike many snails in this region, Red Turban Snails have a calcareous operculum ("trap-door").  And note that the operculum is very smooth:


P.S.  For a view of a different species with a calcareous operculum, review the Pheasant Snail post from 20 December 2015.

Monday, February 27, 2017

Banded tentacles


A beautiful feather duster worm, Parasabella media, in a rocky shore tidepool.  The tentacles (called radioles) are used to capture suspended food particles from the water and in respiration.  Photographed in northern Sonoma County on 24 February 2017.

Sunday, February 26, 2017

The original sequins

Lepidozona, a genus of chitons, means "scaly girdle."  When you see these chitons up close, you understand where the name comes from.

In chitons, the girdle is the "rim" surrounding the eight shell plates.  

Here are three different species of chitons, all in the genus Lepidozona.  There's a lot to appreciate about each one, but remember to look closely at the texture and markings on the plates and especially at the beautiful scales on the girdle!  [Click on the images for larger versions.]

 Lepidozona cooperi
and a close-up:




 
Lepidozona (Tripoplax) regularis
and a close-up:



Lepidozona radians
and a close-up:


I hope you can see that these scales and the patterns they create are rather "fancy."  I was thinking that they reminded of something, and then I realized what it wassequins!

These chitons were ~2-3 cm long and were found on rocks in the intertidal zoneAll photos were taken in northern Sonoma County on 25 February 2017.

Saturday, February 25, 2017

Amazing


We were fortunate to spend a few minutes watching an octopus in a tidepool this afternoon.  

It performed some "cephalopod magic" dramatically changing texture and color.

This is the same octopus, but check out the pointy protuberances everywhere:
 



And yes, pictured below is the same octopus, but here it has turned itself into a rock, matching the colors and patterns of its surroundings, including patches of coralline algae:



And I couldn't resist including one detail picture.  For orientation, the eye of the octopus is in the lower right (the black horizontal slit):


Amazing.

Thursday, February 23, 2017

Tubes and slippers on the beach

I've heard from several people that pyrosomes have been washing ashore on beaches — in Monterey and Bodega Bay, California and in Seaside, Oregon.  We saw some pyrosomes ourselves last night (22 February 2017) on Salmon Creek Beach:


We estimated there were over 1,000 pyrosomes washed up along about a 1-km stretch of beach.

Below is a closer view.  You might recall that pyrosomes are a type of pelagic tunicate, related to sea squirts.  [For an introduction to pyrosomes, review the "Fire bodies" post from 8 December 2014.]




We encountered a variety of sizes (most of them were on the larger end of this size range):



I've received a few questions about how to tell pyrosomes from Corolla spectabilis pseudoconchs.  So for anyone who's been puzzling over either one, here's a side-by-side comparison.  Note the overall shape (oval vs. elongate) and color (clear and transparent vs. pinkish and opaque) and structural differences (slipper-shaped vs. tubular).


And if you haven't seen it yet, there's an introduction to Corolla on the "Gelatinous thimble" post on 11 August 2012.

Wednesday, February 22, 2017

Blurry clouds



Some amazing clouds were visible in the late afternoon and early evening today.

I know the white clouds in the photo above appear to be out of focus, but that's really how they looked!  I'm not sure I've seen clouds like that before.  They were actually blurred!

Here's the sky about 5 minutes later (looking west from Bodega Head):



And a close-up of those blurred white clouds about 10 minutes after the first picture was taken:



I'd love to learn more about what causes those blurry clouds.  Does it have to do with temperature?  If you know what was going on, let me know!

Tuesday, February 21, 2017

"Soft belly"


Here's a quick introduction to the Furry Crab (Hapalogaster cavicauda).  [The best part is the video at the end!]

This species reaches its northern range limit at Cape Mendocino.  We haven't encountered it very often in northern California, but we photographed two individuals on 12 February 2017.

In all of these photos, look for the short, dense setae (hair-like bristles) covering the carapace and claws that give this crab its common name.  In the photo above, note the very broad abdomen curled under the body.  Although you can't tell from these pictures, the abdomen on Furry Crabs is very soft.  It's quite noticeable when you hold these crabs.  Fun fact: Their scientific name "Hapalogaster" — means "soft belly."

Here's a good view of the dense setae on the claws:



Here's a juvenile (and a slightly better view of the abdomen, curled under the body between the last pair of walking legs):



Eric put together a great video clip of Hapalogaster.  Watch for a few different things views of the dense setae; a close-up of the eyes; and some bryozoan "friends" living on one of its claws!  [If you can't see the video below, click on the title of this post to go to the web page.]


 

Monday, February 20, 2017

Off the top

A few wave images from 20 February 2017.  Swell heights were ~12 feet.  Winds were from the south at ~15-20 knots, creating good conditions for spindrift blowing back off the tops of the waves.  [Click on the images for larger versions.]






Sunday, February 19, 2017

Foamy photos

A few foamy photos from yesterday (18 February 2017).  It was windy enough that large pieces of foam were becoming airborne:



Can you find the "foam elephant" in the photo below?  :) 



As you can probably tell, many of these pieces were much larger than snowflakes:



Sometimes the foam was lifted high into the sky who knows how far it traveled? 


P.S.  One of the dangers of trying to take pictures of flying foam is that sometimes your camera (or your face) is in the direct line of flight!  It's a funny experience because it's a bit scary to realize that a large flying object is headed towards you, but then you remember it's just foam, and you feel a gentle but noticeable "thwap"and then the clump of bubbles breaks apart upon contact.

Saturday, February 18, 2017

Northwest winds


If felt like spring today, with strong 20-25 knot northwest winds.

I'm guessing the swell was ~12-14 feet when I took this picture ~mid-day today (18 February 2017).

Thursday, February 16, 2017

Pelagic Red Crab zoea!

Okay, here we go the answer to last night's mystery photo.  As a reminder, here's the image:


We received several correct guesses.  This is the zoea (free-swimming larval stage) of a Pelagic Red Crab (Pleuroncodes planipes)!  The photo below shows the entire zoea:


We haven't been able to find many pictures of Pelagic Red Crab larvae, so we thought it would be fun to share a few.  Eric also recorded some video (see below)!

Here's the basic sequence of events:

After finding live Pelagic Red Crabs on 24 January 2017, I was measuring them and counting the number of males and females.  I discovered that several of the females were carrying eggs.  Similar to lobsters, they brood their eggs attached to the underside of the abdomen (see below):


We wondered if the embryos would develop in Northern California waters.  Based on a previous study that found they did well at 12°C, it seemed like they should develop and hatch in ~22 days.

Right on schedule, the embryos hatched today (after a minimum of 22 days)!  This is what we saw when we came into the lab this morning — an adult female surrounded by hundreds of larvae, each ~2 mm long:


And here's a close-up of some of the larvae in the jar:


Carl Boyd described the larval stages of Pelagic Red Crabs in 1960.  This drawing shows the first zoea:
Modified from Boyd, C.M.  1960.  The larval stages of Pleuroncodes planipes Stimpson (Crustacea, Decapoda, Galatheidae).  Biological Bulletin 118: 17-30.


And here's a close-up of a zoea in a similar position (shown in dorsal view, from above):


As mentioned, Eric took advantage of a rare opportunity to film some live Pelagic Red Crab larvae.  You'll see the very active newly-hatched zoeae zipping around.  (Among the swimming sequences and close-ups, watch for the rapidly beating heart.)  Note: If you receive this via e-mail and can't see the video file below, click on the title of the post above to go directly to the web site.


 
I can't help showing a couple more pictures — two extreme close-ups.  Check out the beautiful telson (last abdominal segment or "tail")...


...and the wonderful second antenna (the outermost antenna, adjacent to the eye):

 

We feel very fortunate to have observed and photographed these fascinating larvae.  We hope you enjoy them, too!

Wednesday, February 15, 2017

Guess who?

Time for a close-up mystery photo!  

Do you have ideas about what type of organism this is?  

[I'll reveal the answer tomorrow night.]


Tuesday, February 14, 2017

Sunrise in the western sky


The moon in the western sky at sunrise, as seen from Cotati on 14 February 2017.

Monday, February 13, 2017

Pink roses


Although there were more Hopkins' Rose (Okenia rosacea) nudibranchs around in 2015 and 2016, there are still some individuals present in the Bodega Bay area.  This one was photographed on 12 February 2017, when we spotted 8 others during a survey in the rocky intertidal zone.

For some background information about these nudibranchs, review the post from 3 January 2015.

                  ♥     
Happy Valentine's Day!  
    ♥    ♥    ♥        ♥    ♥   

Sunday, February 12, 2017

Scarlet fire


About two years ago, I shared a post about the Scarlet Sea Cucumber, Lissothuria nutriens (see post on 22 January 2015).  At that time, I noted this species was rare in Bodega Bay, but we also wondered if this southern sea cucumber might increase in abundance if sea water temperatures became warmer.  It appears that has happened!

The Scarlet Sea Cucumber reaches its northern range limit in Bodega Bay.  There are some records from Duxbury Reef in Bolinas, but so far we haven't been able to find any records from further north.  (This would be a good time to look for them in northern California!)

Remember that this is a small sea cucumber.  Here's a picture from the rocky intertidal zone with some fingertips for scale.  It shows several Scarlet Sea Cucumbers on the rock look for three reddish blobs in the center of the picture:


When the cucumbers are out of water, their tentacles are retracted.  And note that they cover their bodies with bits of debris.  (Recognizing this "covering" behavior is helpful when searching for these sea cucumbers — it differentiates them from red sponges and sea squirts.)

Here's another example, this time a close-up of a single Scarlet Sea Cucumber:


Because this species has been rare in our area, we wanted to be certain about the identification.  So Eric double-checked the ossicles (the calcareous plates inside the body wall, tube feet, and tentacles that help identify different species of sea cucumbers).

Below is a diagram illustrating the different types of ossicles found in Scarlet Sea Cucumbers:

Ossicles of Lissothuria nutriens.  (A) Curved supporting plate from tube foot, (B) end plate from tube foot, (C) smaller, hourglass-shaped bodies from dorsal body wall.  Modified from Deichmann, E. (1941).  The Holothuroidea collected by the Velero III during the years 1932 to 1938. Part I. Dendrochirota.  Allan Hancock Pacif. Exped. 8: 61-194.


For comparison, here are a few of the ossicles from one of the local specimens.  You can see that the shapes match the drawings above, confirming the identification:


If you get lucky and spot a Scarlet Sea Cucumber in a tidepool, along with the red oblong body you might see the tentacles extended.  Interestingly, the tentacles vary in color from fiery orange to scarlet red:


These sea cucumbers feed by catching organic material on their tentacles and then moving it to their mouth in the center of the tentacles.  Eric filmed some of this behavior under a microscope in the lab, and he made a wonderful video clip so that you can see the tentacles in action.  (Also watch for the shiny ossicles embedded in the tentacles and tube feet.)




We have counted quite a few Scarlet Sea Cucumbers in the low intertidal zone while conducting surveys this past week.  We're also wondering if the warm ocean temperatures during the last couple of years might have allowed this species to move even further north, beyond Bodega Bay.  We'd be very interested in any Scarlet Sea Cucumber observations in northern California, so let us know if you spot one!
 

Saturday, February 11, 2017

Solar-powered

Air temperatures in Bodega Bay reached ~56°F (~13°C) this afternoon.  After a week of rain, it seemed like a lot of insects were taking advantage of the sun today:


Red Admiral (Vanessa atalanta)



Monarch Butterfly (Danaus plexippus)



Variegated Meadowhawk (Sympetrum corruptum)




Unidentified fly (Let me know if you recognize it!)


ADDENDUM (12 February 2017): One of the suggestions I received about the fly in this post was that it could be a hover fly.  I did a quick image search, and noticed a similar-looking hover fly here.  I don't think it's the same species (based on the abdominal patterning), but it's very close, and I think it's likely the fly in the picture above is in the same family (Syrphidae).

Then I skimmed some information about syrphid flies, and learned that sometimes they eat aphids.  In the field I had noticed that these flies were spending a lot of time around the tips of the Monterey Cypress.  I wondered about what they were doing there (i.e., what was attracting them to those sites).  Well, I went back and reviewed my photos and it looks like there might be tiny aphids on the cypress tips!  Check it outand note the arrow pointing to one of the possible aphids: