If you're interested in using any of these photographs, please contact me. Send an e-mail to naturalhistoryphotos(at)gmail.com. Thanks!

Thursday, June 22, 2017

Silk Road to Enlightenment

On 20 June 2017, I posted some pictures of colorful strands of silk in a spider web.  I was so taken with the phenomenon that I went out to try again yesterday morning.

First, I'll show two photos with the spider.  Although it is hard to believe, these are the actual colors created by diffraction as the early morning light hit the spider web!

Next is a series of close-ups of the strands in the center of the web, some of which are shown in the photos above.  [You can click on the images for larger versions.]

In one photo I captured some of the strands directly adjacent to the spider.  Eric calls this image "The Silk Road."  The diversity of colors is amazing.

I can't help sharing one more series.  This morning I focused on one section of one particular thread.  Its appearance changed, likely depending on when I took the picture and the camera settings.  Remember, this entire series (below) is of the same thread (!).  There are so many colors in these pictures, that I started wonderingif you kept photographing spider webs, could you discover new shades of colors?

Spending time with these spiders and their silk strands has certainly been inspiring and enlightening for me!  :)

Wednesday, June 21, 2017

Happy Cephalopod Week!

We're in the middle of Cephalopod Week, and we didn't want to miss out!  So here's a short video clip highlighting a local Red Octopus (Octopus rubescens).  Students will observe this octopus as part of a summer course at the marine lab.  Eric had to clean its tank, so he took the opportunity to put together some nice footage.

Watch for curled tentacles; quick color changes (from dark to light and back again); a close-up of the skin featuring the amazing chromatophores expanding and contracting; and a wonderful view of the eye (from above) with silver and gold flecks.



P.S.  For more cephalopod videos, check out this Science Friday page.

Tuesday, June 20, 2017

Celebration of light

Tonight's post will start with some mystery close-ups.  More clues will be available as you progress through the images.  Can guess what this is?

A similar image, zoomed out a little farther:

Here's a similar pairing, but from a slightly different angle.  Notice that each long band is made up of many fine, colored stripes.  (Click on the images for larger and sharper versions.  These pictures are pretty mind-boggling!)

And now I'll zoom out a little farther.  Do you have a guess yet?  

Eric spotted this in our backyard this morning.  The photos were taken with my camera just before we left for work.

Are you ready?  The next photo will reveal the answer!

Yes!  This a spider web, one section of which was lit up in a very special way. 

Eric was brushing his teeth and looked out the window to see this spider web partly lit by the morning sun.  He rushed me out the back door to take a few pictures before we had to leave.  I struggled with the camera settings, and I didn't really know if any of the pictures had come out.  When I reviewed them later in the day, I was blown away to see the dazzling colors revealed in some of the close-ups.

To learn more about what produces the colors, I did a Web search, followed some threads, and found a few sites that describe optical effects in spider webs.  I'll admit that the physics behind this phenomenon are over my head.  However, it was interesting to note that some of the resulting colors are related to the structure of the sticky strands in parallel rows between the radial lines (or spokes) of the web.  These cylindrical silk threads are coated with adhesive droplets.  The droplets apparently act like miniature lenses!

I'll show one more picture, and will also explain one thing you might be wondering about.  I took these pictures with a relatively slow shutter speed.  The longer exposure time likely captured a small amount of web movement.  The wide bands of colored stripes are an artefact of the camera.  That is, the strands of silk are actually narrower than they appear in the photographs, but these images allow you to see the amazingly varied colors!

What a great way to celebrate the summer solstice — with an incredible light display!

With many thanks to both the spider and the sun...the orb-weaver and the orb!

Monday, June 19, 2017

Sunrise clouds

I've always enjoyed getting up at sunrise it feels like a very special time of day, when the world is just waking up.  This morning I stepped outside to a beautiful skysoft pink lighting up the undersides of the clouds on the eastern horizon.  Somehow it seemed like an appropriate color, given the heat of the last few days.  It was 103°F in Cotati yesterday!

All photographs taken on 19 June 2017.

Sunday, June 18, 2017

Tubercles and tube feet

Yesterday I took a few close-up photos of a Purple Sea Urchin test (or skeleton).

You can see the rounded and raised tubercles to which the urchin spines are attached:

Also noticeable are the podial pores, or the holes from which the tube feet emerge.  

Note that the pores are paired (two are placed side-by-side).  One tube foot emerges from each pair of pores:

To provide some context for these anatomical features of the skeleton, here are two images of live urchins (an adult and a juvenile), highlighting the urchin spines and the extensible tube feet:

Saturday, June 17, 2017

Sunrise moon

I looked up around sunrise this morning to see pale pink clouds below a Last Quarter moon:

A closer look (click on the image for a larger version):

Recently I've been reading a book about tides, so I've been thinking about the moon quite a bit.  How lucky are we to have such a nice moon orbiting the Earth!

Friday, June 16, 2017

Super star

Joe and Sam dropped by to say they had found something interesting in an aquarium at the marine lab.  I was a little surprised to look down and see one of the largest brittle stars I've ever seen!

We found a smaller Flat-spined Brittle Star (Ophiopteris papillosa) last year, but the size of this individual was notable.  The central disc alone was ~3 cm (~1 inch) across!

Here's a close-up of the disc:

 And a view of the flattened spines at the tip of one arm:

Amazingly, the largest specimens of this species have central discs up to 4.5 cm across!

Many thanks to Joe and Sam for sharing this impressive brittle star.

For a look at the smaller individual we photographed last year, along with a short video clip, see the post from 1 March 2017

Thursday, June 15, 2017

A little leather

We don't encounter juvenile Leather Stars (Dermasterias imbricata) that often, but here's a nice example.  This sea star was only ~4 cm (~1.5 inches) across.  It was photographed in Del Norte County on 26 May 2017.

Wednesday, June 14, 2017

Beauty and intrigue

A few miscellaneous images from our trip to Oregon in late May:

A purple encrusting bryozoan, Disporella separata

Peanut worm, Themiste pyroides, with coralline algae

The nudibranch Aeolidia loui (formerly Aeolidia papillosa

The beauty and intrigue of coastal marine invertebrates!

Tuesday, June 13, 2017


Here's a fun mystery close-up an extreme view taken through a microscope.  Can you guess what type of animal this might be?

I'll zoom out a bit more:

And now I'll show the entire animal, so be prepared for the answer below!  

First, a few more hints: This is a crustacean that can be found in the low rocky intertidal zone and subtidal areas, but it's relatively small and can be quite cryptic.  [In the photos above, the small, colorful patches are chromatophores which play a role in camouflage.] 

Hmmm.  On second thought, I've change my mind — here's one more close-up before I give the answer away.  (Although this photo will probably help a lot!)

Isn't that a spectacular tail?

Okay, now here's the entire animal:

Meet Spirontocaris prionota, commonly known as a Deep-blade Shrimp.  This is the first time we've encountered one on Bodega Head.  I was impressed with the details and colors when viewed under high magnification.

The "deep-blade" portion of the name refers to the distinctive rostrum the portion of the carapace that projects forward in front of and above the eyes.  It's extremely narrow (like a knife), and impressively serrated above (see first two photos).

To orient you to this shrimp's anatomy, the next image shows the same photo with a few labels:

Apparently, not much is known about the biology of this species.  Here's one more image a head-on view emphasizing how well camouflaged this shrimp would be among the rocks and sand.  And note some of the other intriguing features.  For example, what do they do with those small front appendages tipped with noticeable black spines?  Why do they have clusters of long setae (bristles) on their legs?

Sunday, June 11, 2017

June thunderstorm

Late in the day, I looked up to see dark clouds on the eastern horizon:

Not too long after, a very loud clap of thunder rolled across the sky.  The thunder lasted for about 25-30 minutes, so I recorded a few examples.  The recordings are best heard with headphones, if you have them.  Otherwise, you might need to turn up the volume of your speakers.  [If you can't see the audio files below, click on the title of the post above to go to the website.]

It started to rain...and then the storm decided to add some pea-sized hail:

The thunderstorm moved off to the south, and the sky started to clear, but this wonderful storm ended with a grand finale:

Photos and recordings are from Cotati on 11 June 2017.

Saturday, June 10, 2017


Close-up of the sea star, Henricia sp., displaying pentamerism (radial symmetry organized in five parts around a central axis).

Photographed in Del Norte County on 26 May 2017.

Friday, June 9, 2017

Spiny -- Part 2

Okay, here's the mystery photo from last night:

This is a noticeably spiny crab claw.  Next questionwhich species of crab is it from?

The photo below is another hint.  (And note the sandy habitat where this crab lives.)

The picture above shows a distinctive crab carapace, with dramatic spines.

This species might be more familiar to those of you living south of San Francisco.  It's a Spiny Mole Crab (Blepharipoda occidentalis).  I've written about them once before; you can review previous photos from Doran Beach and Salmon Creek Beach here.

Most people are probably more familiar with the more common Mole Crab (Emerita analoga).  In contrast to Emerita, Spiny Mole Crabs can grow to be much larger; they have dramatic spines; and as the mystery photo shows, they have claws.  They use the claws to scavenge and tear apart food.  The spines on the outer edges of the claws and the carapace probably help to deter predators (such as fish).

I don't have a digital photo of a Spiny Mole Crab, but you can find a nice picture of the entire crab here (by Zen Faulkes) and on this EOL page.

I'm writing about Spiny Mole Crabs again because we're interested in whether anyone has found them north of Salmon Creek Beach.  

Recently, we counted many more molts than usual, so it's possible Spiny Mole Crab numbers have increased in our area, which also means there is potential for them to be found even further north than previously documented.

Below are two more examples of Spiny Mole Crab carapaces (two different sizes).  Let us know if you see a Spiny Mole Crab carapace or claw on a beach near you!