Orange and pink

 

Sunset from Bodega Head, 14 November 2012

The oranges and pinks in the sunset photo reminded me of this nudibranch crawling on coralline algae photographed the day before (13 November 2012).

 

This is a Spotted Triopha (Triopha maculata).  Note the dark brown background color, bright orange projections on the head and back, and bright orange gills (ruffled structure about 2/3 of the way back from the head).

This nudibranch was ~3 cm long.  Smaller individuals may appear dominantly orange and larger individuals are often yellow, but all of them show the spots.  Interestingly, Morris, Abbott and Haderlie (1980) note that the color pattern resembles orange/brown kelp blades with white bryozoan colonies.  (Spotted Triophas are often found on kelp and they eat bryozoans.)

I don't have a photo of kelp with bryozoans, but I do have one of kelp with white spirorbid tube worms (next photo).  To my eye, the nudibranch spots also resemble these coiled worm tubes!

 

Here's a different individual, this one was discovered at Duxbury Reef in Bolinas in November 2007.  (The image below is posed; we placed the nudibranch in an empty mussel shell filled with seawater for the photo.)

Lilliputian

Dune lichens photographed during a light rain on 8 November 2012:

 

 

 

P.S.  There are lots of books on lichens, but I've always enjoyed the title, Forests of Lilliput: The Realm of Mosses and Lichens (by John Bland).

Twinkle, twinkle, little stauro

 

Today, Eric's sharp eyes found one of the most intriguing intertidal inhabitants of Bodega Head.  This is a little-known marine animal called a stauromedusa.  They're cnidarians, related to jellyfish, sea anemones, and hydroids.  Most of them are very small (a few centimeters tall) and cryptic (blending in with algae or seagrass), so they aren't encountered often.  [The one in these photographs is ~1 cm tall and is attached to coralline algae.  It was found in a wave-exposed surge channel.]

Several features stand out.  Note the long, flexible, contractile stalk.  Stauromedusae often stay in place, but they can also let go and move around.  Here are two views of the stalk when extended and pulled in (below). 

 

Opposite the disc is a large bell-shaped calyx.  To make it easier, review this illustration and then search for the features in the images.

 

Illustration modified from the following:  Larson and Fautin, 1989.  Stauromedusae of the genus Manania (= Thaumatoscyphus) (Cnidaria, Scyphozoa) in the northeast Pacific, including descriptions of new species Manania gwilliami and Manania handi.  Canadian Journal of Zoology 67: 1543-1549.

The calyx has eight clusters of short tentacles surrounding the mouth.  The tentacles contain cells with nematocysts (tiny harpoons) for capturing prey such as copepods and amphipods.

In between the tentacle clusters are small anchors.  The anchors are useful for reattaching (if the disc becomes detached) and may aid in securing food.

 

The white and brown zigzag markings running between the stalk and the tentacles are reproductive structures or gonads.

 

We believe this is Manania gwilliami.  It was first described in 1989 and named after G.F. Gwilliam — an early graduate student of Cadet Hand (the first director of the Bodega Marine Laboratory) and one of the first people to study stauromedusae in the eastern Pacific.

Manania gwilliami occurs along the Pacific Coast from British Columbia to Baja California (records from Oregon and Washington are apparently lacking, but it's likely that the species is found there).  It prefers surf-swept rocky outer coasts.

When I first learned about stauromedusae they were thought to be most closely related to jellyfish (visualize a tiny, upside-down jellyfish on a stalk).  But recent molecular studies have suggested that they belong in their own class, Staurozoa (Collins and Daly 2005).

We've been wanting to find a local stauromedusa for a long time.  What luck to find our first one on Bodega Head on a beautiful November afternoon!

 

You can learn more about stauromedusae at the Encyclopedia of Life web pages.

Anemones & friends

Just back from a meeting in Monterey, CA, but we were able to take a quick field trip to the Big Sur coast this afternoon before heading north.

This shallow tidepool offered an especially nice view of Giant Green Anemones (Anthopleura xanthogrammica), Purple Sea Urchins (Strongylocentrotus purpuratus) of various sizes, and a few species of pink coralline algae.  There's also a tiny bit of bright orange sponge (below the large anemone).  And if you look closely, the small dark holes scattered around the urchins belong to a colonial tubeworm (Dodecaceria sp.).

Kite flying

In Febuary, I mentioned that I struggle with getting good pictures of kites.  Because there have been a few on Bodega Head this fall, I've made several more attempts during the past couple of months.  I still haven't come up with a photograph that I'm happy with, but thought I'd share a few more, just because kites are irresistible and I love watching them fly.

Below is an adult White-tailed Kite (Elanus leucurus) perched on a Douglas-fir.

 

In the photo above, note the all white breast of the adult.  In contrast, juveniles often have a tawny or rust-colored "necklace" across the breast (see below).

 

When hunting, kites hover in place, searching the ground below for small mammals (next image).

 

Once committed to a dive, they hold their wings at a very steep angle and almost seem to flutter towards the ground.  It's very different from the high speed stoop of a falcon.  The vertical drop of a White-tailed Kite somehow has a very graceful and delicate quality (although I don't think you'd feel the same way if you were the prey!).

 

Click here to review the earlier post about White-tailed Kites.

Zigzags and blotches

 

Lined Chiton (Tonicella lineata) with coralline algae.  Photographed near Mendocino, CA, 28 October 2012

While the eye-catching zigzag markings are distinctive in this species, the dark maroon blotches are variable.  I don't recall reading anything about why some individuals have blotches and others don't.  Any ideas?

Pigments and pens

 

I was excited to find quite a few squid egg capsules washed ashore on Bodega Head this afternoon.  Although it's not a good situation for the squid (they need to stay submerged to survive), it was an opportunity to look for tiny developing squid inside the egg capsules.   

The photo above shows a late stage squid embryo.  Its external yolk sac (the teardrop-shaped structure above the eyes) is relatively small.  The embryo also has functioning chromatophores — the red, yellow, and brown spots scattered across the head and mantle.  (The mantle is the hood-like structure used in jet propulsion.)

There were squid embryos in various stages, some more developed than others.  Compare the next two images and guess which is younger.  Hint: the younger embryos have larger yolk sacs.

 

 

Answer: The first photograph shows younger embryos. 

As I was searching the egg capsules, a newly hatched squid larva (formally called a paralarva at this stage) swam by!  It was very small (only a few millimeters long) and very active.  I didn't have much time, but here are a couple of shots.

 

Note the arms (with tiny suckers!) in front of the eyes.

 

Squid chromatophores expand and contract via muscles stimulated by nerve signals sent from the brain. Seeing the chromatophores pulsing reminded me of a video circulated this past summer.  

The clip shows squid chromatophores responding to music being played on an iPod (the iPod was connected to squid skin with an electrode).  Its pretty amazing — check out "Insane in the Chromatophores"! 

Along with the egg capsules, there were also several squid pens on the beach (although slightly damaged, see a scan of one below).  Squid pens are basically internal shells (squids are molluscs like snails and clams).  They're long and slender, often transparent, flexible (made of chitin), and sometimes described as feather-shaped.  The pen supports the squid's mantle and serves as a muscle attachment site.

 

If you're interested in looking for squid eggs, try searching the wrack line at Doran Beach or Dillon Beach.

P.S.  I'm not 100% certain of the species of squid illustrated here, but it might be a Market Squid (Doryteuthis (formerly Loligo) opalescens).