Find the fish

In late April, I photographed this fish resting between two Ochre Sea Stars.  I'm not sure what type of fish it is, but it was fun to see how well it matched the colors and patterns of the sea stars.

 

Here's a close-up of the head:

 

If you can identify the fish, let me know!

 

Take five

Dwarf Brittle Star (Amphipholis squamata), found in the low intertidal zone on Bodega Head on 28 April 2013 and photographed under a microscope.  It was ~15 mm across.

 

 

 

 

 

I could have stopped with that series of five images, but I was fascinated when I caught a brief glimpse of the underside of the brittle star.  Here's a close-up (below).  The mouth is the dark cavity in the very center of the disk.  But what's perhaps most interesting in this particular image is the white scale with a single pore to the left of the mouth.

 

That modified scale is the madreporite (or sieve plate).  Water is pulled in through the madreporite and enters the water vascular system which powers the tubefeet.  In sea stars, the madreporite is on the aboral surface (opposite the mouth) — for an example, see the salmon-colored spot on the Ochre Sea Star in the photo below. 

 

But in brittle stars, the madreporite is on the underside, adjacent to the mouth.  It's not often as visible as it is here, so this is a nice illustration of one of the differences between a brittle star and a sea star.

Here's another view with the madreporite in a slightly different position.  Can you find it?

 

The madreporite is in the lower right corner (remember it's about halfway between the mouth and the outer edge of the disk).  [If the brittle star was a clock, the madreporite is located between the arm that points to 3 o'clock and the arm that points to 6 o'clock.]

Although this brittle star was small, it revealed a significant lesson!

Tigers on the sand

When I left Massachusetts, I had been casually working on photographing all of the tiger beetle species in New England.  It was a great side project, especially because tiger beetles are attractive, fun to watch, and live in habitats that are interesting to explore.  I've had my eyes open for them since moving to California, but haven't encountered too many yet.

Last fall Eric spotted an iridescent green species along the Mendocino coast, but I wasn't there at that time, and was sad to have missed it.  This past weekend we looked again and were lucky to find a few individuals.

This was an open sand area along a coastal bluff.  The sand was very coarse, as you'll be able to see in the pictures.

 

The beetles were a dazzling bright green with cream-colored markings on their elytra (wing covers).  They were ~12 mm long.

 

The shape of the middle marking — the one that looks like a musical note — is very important for identification.  In fact, this beetle had me fooled at first before the shape of this marking clinched the identification as a Western Tiger Beetle (Cicindela oregona).

Note that the middle marking makes a very clear 90° turn — starting from the margin, it runs perpendicular towards the center line and then drops straight down towards the tail end.  In a very similar species (Dispirited Tiger Beetle, Cicindela depressula), there wouldn't be such a clear 90° turn; instead it would be a more gradual, sinuous wave.

What had me fooled initially was the overall color.  I had seen Western Tiger Beetles before (on Bodega Head and in Oregon), but both times they were dark brown rather than iridescent green!

Here's another individual from the Mendocino coast.  The wing markings are slightly different, but you can still see the strong angle in the middle marking.

 

You might be wondering why they're called tiger beetles.  These are very active predators.  They use their long legs to sprint after smaller insect prey.  And they have very long, serrated mandibles to capture them.

 

Modified from A Field Guide to the Tiger Beetles of the United States and Canada (Pearson, Knisley, and Kazilek 2006)

I didn't get great photos of their mandibles this past weekend, but if you look closely you might be able to make them out in the photos below.  In the first photo the beetle is holding its mandibles open, while in the second photo they're being held closed and so the tips are crossed.

 

 

If you're curious, I posted a photo of a Western Tiger Beetle from Bodega Head last September.  Now I'm wondering about what drives the color variation in this species, i.e., why are some of them brown and others green?

Impressionism in the sea

 

We had to finish a little field work along the Mendocino coast today.  The water was incredibly clear.  I couldn't resist this image looking down into a deep channel, with kelp along the shore, purple urchins below, and the blues, greens, and silvers of the ocean.  It reminded me of a Monet or a Childe Hassam painting.

Big spout, little spout

Calm ocean conditions during the past couple of days have made for excellent whale watching from shore.  At this time of year, it's common to see Gray Whale cow-calf pairs.

Here's the large spout of an adult:

 

It was followed immediately by the much smaller spout of a calf:

 

Gray Whale spouts are often described as heart-shaped or V-shaped.  The next image is a good example of a V-shaped spout.

 

This mother and calf swam steadily northward.  Although they've made it from Baja to Bodega Bay, they still have quite a journey left before they reach Alaska!

 

(Mother on the left, calf on the right)

P.S. The bluffs on the southern end of Bodega Head are excellent for whale watching.  To help spot whales and answer visitor questions, volunteer docents from the Stewards of the Coast and Redwoods are stationed there on weekends through about mid-May (look for them near the outer State Parks parking lot).

Mystery barbs

 

Northern Rough-winged Swallow (Stelgidopteryx serripennis) 

When I first started working at the Bodega Marine Lab in 2005, I noticed this species nesting in an open pipe in the wall of a small outbuilding.  Amazingly, I think I've seen these swallows using the same pipe every year since!  I'm not sure if it's the same pair, or if it's been several generations of swallows.  (Some swallows have been known to live for 8-11 years, but a shorter lifespan is more typical.)

Note the brown coloration above, white below, and gray/brown wash across the breast and down the sides.

 

Although I've been familiar with this species for many years, I realized tonight that I didn't really know exactly why it was called a "rough-winged" swallow, so I did some research.

The outermost primary (wing feather) is unusual — there are stiffened barbs along the leading edge that make the margin of the wing file-like (the barbs are recurved in males).  Both the genus and species name refer to this character — "Stelgidopteryx" means "scraper wing" and "serripennis" means "saw wing."  According to The Birds of North America account, "The possible adaptive significance of this feature remains a mystery."  (Although it goes on to mention that one possibility may be sound production during courtship or territoriality.)

I wondered if you could see the barbs, so checked a few photos that showed the leading edge of the wing.  The swallow is preening and scratching in the images below.

 

 

I couldn't see the barbs, but it was interesting to learn about them and to look for them.

I hope these beautiful swallows continue to nest locally for many more years to come!

 

Ruler worm?

Okay, I don't know the identity of this worm yet, but it's too interesting not to post a picture, and perhaps someone out there can help with the identification.  Eric and I have seen a few of them recently in the low intertidal zone on Bodega Head.

 

This worm is fairly small, ~4 cm long and only a few millimeters wide.  You can see the metallic silver coloration and the very regular black striping (reminiscent of a ruler!).  Note that both the anterior (head) and posterior (tail) ends are patterned slightly differently than the middle section.

Here are two close-ups of the head end:

 

 

If you have any thoughts about the identification, or just want to join in on praising this worm, feel free to submit a comment!

P.S.  You could also suggest a possible common name for the worm.  Ruler Worm? (for the tick marks)  Piano Worm? (for the resemblance to black-and-white keys)