Wednesday, February 29, 2012

Four brooders in one

In the picture below there are four different invertebrates (in four different phyla) that brood their young.  This might be tricky, but can you find all four species?



(1) Proliferating Anemone (Epiactis prolifera).  Phylum Cnidaria.  Orange with white stripes (although color in this species is highly variable).  At least 8 young are being brooded by this adult.  Fertilized embryos are moved from the mouth across the oral disc and then down to a depression at the base of the column.  The mother broods the juveniles for about 3 months and then they depart to live independently.

(2) Six-armed Seastar (Leptasterias sp.).  Phylum Echinodermata.  Small pink seastar.  This individual was only about 1 cm across, but maximum size for this species is about 5 cm.  Females brood clusters of eggs under their bodies for about 6 weeks and then the tiny juvenile seastars crawl away from the mother.  (See more photos below.)

(3) Spirorbid tube worm.  Phylum Annelida.  Small white coiled tubes (see post on 6 February 2012).  Fertilized embryos are retained and brooded either along the abdomen, in a brood chamber, or within the operculum.  Planktonic larvae are released into the water, but settle after a very short time.

(4) Tube snail (Petaloconchus montereyensis).  Phylum Mollusca.  Purple-orange tube on the upper left side of the photo.  This is a vermetid gastropod that builds calcareous worm-like tubes and lives cemented to the rock.  Eggs are brooded within capsules inside the tube, juveniles complete their development within the capsules and then emerge from the tube as small snails and attach to a nearby rock.


Six-armed Seastar with eggs.  Their main brooding season is winter and spring.


Six-armed Seastar adult with many tiny juveniles in the lower right corner.  How many can you find?


Different eyes might find different individuals, but I found at least 15 juveniles.

The first photo was taken at The Great Tidepool in Pacific Grove, but all four species are also found on Bodega Head.  The second and third photos were taken on Bodega Head.

Tuesday, February 28, 2012

The rabbit and the barnacle

Can you guess what these two species have in common?

Black-tailed Jackrabbit (Lepus californicus).  Found in both grassland/shrubland and dune habitats.  Their numbers seem relatively low on Bodega Head right now.



Pelagic Gooseneck Barnacle (Lepas anatifera).  After strong winds in spring, found washed in on beaches attached to various floating objects, e.g., wood, seaweed, and plastic (even toy dinosaurs!).



Here are a few close-ups taken under a microscope.  Notice the long fan-like cirri (legs) expanded for feeding, the long peduncles (stalks), and the delicate shell plates.


And I can't resist including a couple of photos of the cyprids, the stage between the early larval form (nauplius) and the sessile adult form.  They are small (but relatively large for barnacle cyprids), blue, and teardrop shaped.  The cyprids attach to an object head first, and then metamorphose into juvenile barnacles.


So what do a rabbit and a barnacle have in common?  Both of these species have very similar latin names Lepus and Lepas (both basically pronounced Leap'-us).

Happy Leap Year! 
 

Monday, February 27, 2012

Heads or tails?

This exquisitely patterned worm was exploring the surface of the tidal flats in Bodega Harbor on 20 February 2012.  I don't know what species it is, but I'm hoping someone out there does.

I think it was about 10 cm long, and only a few millimeters wide, with a striking green and gold color pattern. (Click on the photos to enlarge.)


The head was very small and it looks like there were at least two eyes and a few tentacles or appendages held out to the side.


Sometimes the worm would start to go down a hole (was it searching for prey?).



After reviewing the photos, I noticed that the tail end of the worm had a bright shiny gold spot.  I started wondering if this might be a way to lure potential predators to the tail rather than the head of the worm, perhaps allowing the worm to escape?


If anyone knows what species this is, I'd love to hear more about it!

Sunday, February 26, 2012

Whimbrel

Whimbrel (Numenius phaeopus)Numenius means "new moon", apparently after the crescent-shaped bill.  

A beautiful curlew, relatively common on Bodega Head rocky shores in winter (although not in large numbers); may also be seen on sandy beaches and tidal flats.  Often feeding with other shorebirds, such as Black Oystercatchers, Surfbirds, and Black Turnstones.


After rain, they sometimes feed in upland sites along the bluffs or in the grassland.



This one caught a porcelain crab (Petrolisthes sp.).  Look closely for the crab near the tip of the bill.  There aren't many other birds that could reach a porcelain crab deep within the mussel bed!


Saturday, February 25, 2012

Probing for prey

Sanderlings (Calidris alba) are one of the more familiar shorebirds on outer coast sandy beaches.  They spend the winter here, and then fly to the high-Arctic tundra to nest during the summer.  You'll encounter them running along the edges of the waves, then following the receding water out and probing very rapidly in the sand.



Can you identify the type of prey captured by this Sanderling?



It's a mole crab, or sand crab (Emerita analoga).  Mole crabs are active burrowers in the swash zone.  They have smooth, rounded bodies (up to ~35 mm long) and specialized appendages for rapid digging.  Instead of claws (mole crabs are filter feeders), the terminal segment of the first leg formally called a dactylopodite is a large, oval, paddle-like appendage.  

Their eyes are on long stalks that are sometimes visible above the sand, even when the rest of the crab is below the surface.  Check out the eyes and the digging paddles in the photos below.  (These images were taken at Asilomar Beach in Pacific Grove, but the same species is found on Salmon Creek Beach and Doran Beach).


Friday, February 24, 2012

Sea otters in Pacific Grove

Pictures from Pacific Grove, California, on 24 February 2012.  Several sea otter mother/pup pairs were visible from the shoreline.  Here are a few scenes: a mother carrying a pup on her chest, a mother/pup feeding, a pair floating in a wave.


[Although sea otters used to be more common at Bodega Head (before the mid-1800s), I've only heard of two sightings of individuals during the last 10 years.]

Thursday, February 23, 2012

Green eyes and green tentacles

A few photos from the tidal flats in Bodega Harbor (20 February 2012).

 
View from Doran Beach looking towards the town of Bodega Bay.  Mount Roscoe is in center background.


Can you find the animals in the picture below?



There's a small fish (~4 cm long) camouflaged against the sand (probably a sculpin).  Here's a closer view.  Look at those eyes!



There are also a couple of phoronids (Phoronopsis harmeri, formerly P. viridis) above the fish.  Phoronids are worm-like animals in their own phylum.  There are only 14 species in the world, so we're fortunate to have 2 species on Bodega Head!  

Here are two more photos that show phoronids with their lophophores (crown of tentacles) expanded.  The largest lophophore is ~5 mm across.  These U-shaped, spiraled feeding structures are very distinctive.  If you want to find phoronids, look closely for the small green lophophores in shallow pools on the tidal flats.



P.S.  The other species of phoronid on Bodega Head (Phoronis vancouverensis) is shown in the post from 27 November 2011.  It has white lophophores and is found on outer coast rocky shores.

Wednesday, February 22, 2012

Type locality: Russian Bodegas...or, History in a clam shell

Is anybody else still amazed by the wonders of the Internet?  Today I was thinking that it would be fun to post some information about species that include "bodega" in their scientific names.  One example is a clam called the Bodega Tellin (Tellina bodegensis).  Here is a photo of it from Salmon Creek Beach taken on 21 February 2012, and a scan of another specimen.  Note the elongate shape and the narrow concentric striations.

 
I wanted to check on the origin of the name.  Where did "bodegensis" come from?

Through a book, I found that the Bodega Tellin was described by R.B. Hinds in 1845 in a report called The Zoology of the Voyage of H.M.S. Sulphur, Under the Command of Sir Edward Belcher, R.N., C.B., F.R.G.S., etc. During the Years 1836–1842.

I searched the Internet for the title of this report and was amazed to find a full electronic version.  It was easy to locate the description of Tellina bodegensis along with the plate containing an illustration (see below).  


 Tellina bodegensis is in the upper left corner.


It was very interesting to read the location for the collection (perhaps the type locality) listed as "Russian Bodegas".  The Russians didn't leave the Bodega Bay/Fort Ross area until 1841, and it's thought that they had a small settlement on the southern end of Bodega Head (near Campbell Cove).  It seems as though Richard Brinsley Hinds named the Bodega Tellin after collecting it at a depth of 7 fathoms (42 feet) on a sandy bottom near Bodega Head. [The name Bodega began to be associated with this area in 1775 when charted by the Spanish naval officer Bodega y Quadra.]

Fascinating to think about Hinds viewing Salmon Creek Beach or other nearby sites and describing a local clam for the very first time!

Salmon Creek Beach in the fog on 21 February 2012.

Tuesday, February 21, 2012

White-tailed Kite

White-tailed Kites (Elanus leucurus) may be seen in open grasslands and shrublands on the Bodega Head peninsula.  The best places to look for them are probably the grasslands across from Westside Park and the field and dunes near the Bodega Bay Community Center (between the Bodega Dunes and Highway 1).

I've been struggling to capture good (= sharp) images of this species.  They seem shy around people (at least me), so it's hard to get close to them.  And of course there's the challenge of the "Blowdega Bay" wind, with both bird and camera moving a lot.  Although I hope to take better photos in the future, I can't help posting a few photos of this handsome raptor.

Note the strongly hooked bill, black shoulders, white tail, and yellow feet.  You may be able to catch a hint of red in the eyes.

While watching this kite, I was struck by how similar the facial pattern is to another local species.  In this case, "local" may be stretching it a bit, as Laysan Albatross (Phoebastria immutabilis) are most often found near Bodega Canyon and Cordell Bank, about 20 miles offshore.  Here's a photo from 28 August 2011.  Check out the similarities of the pale face and dark feathering in front of the eye.


(There will be more posts about offshore species in the future!)

Monday, February 20, 2012

Overwintering Monarchs

Bodega Bay is close to the northernmost site for overwintering Monarch butterflies on the West Coast (it looks like Rockport, CA, in Mendocino County is the limit).  Sites to the south (e.g., Santa Cruz and Pacific Grove) support much higher numbers, but up to 5000 overwintering Monarchs have been counted in recent years in Bodega Bay.  

In California, Monarchs roost primarily in eucalyptus, Monterey Cypress, and Monterey Pines.  I don't know a lot about the local timing, but it sounds like they arrive at the overwintering sites in mid-late fall and remain until about mid-March.  

On warm, sunny days in winter on Bodega Head, an occasional Monarch may be seen gliding by.  On 18 February 2012, it was very windy, but fairly mild (~51°F or higher in the sun), so I decided to see if I could find more butterflies in wind-protected areas of the Bodega Dunes campground.

There was a minimum of 25 individuals basking high in the trees — beautiful orange against the greens of the trees and the blue sky.


Above, note the center butterfly is a male, with expanded oval black spots in the middle of the inner vein of the hindwing.

Soon these Monarchs will be on their way inland and north!