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Sunday, July 27, 2014

Southern drifter?

I haven't started with a mystery close-up in a while, so here you go.  Can you guess what type of animal this is?


Here's another perspective (below).  This view is of the underside:


Any guesses yet?  I'll zoom out a bit more and show about half of the animal:


Okay, now here's the entire thing:


Did you guess jellyfish?  This is a Purple-striped Jelly (Chrysaora colorata, formerly Pelagia colorata).

According to the Light & Smith Manual (2007), this species "regularly washes ashore on the beaches of Southern California and is occasionally found as far north as San Francisco and Bodega Bay."

From a distance, when I saw a large jelly washing up on the beach, my first thought was that it was going to be a sea nettle (Chrysaora fuscescens).  Sea nettles are the most common of the large jellies in this area, but they are more brownish overall and lack the dramatic purple stripes of this species.

The bell of this Purple-striped Jelly was ~15-18 inches across.  I didn't have a ruler at the time, but here's a picture with my Xtratuf boot (size 6.5) for scale.


I'm wondering if this Purple-striped Jelly might have drifted north with some of the warm ocean water that we've been experiencing recently?

It looks like there's warm water to our south and offshore.  You can look at sea surface temperature maps at different web sites.  Here are two examples:



 
Have you seen Purple-striped Jellies in Bodega Bay before?  If so, I'd love to hear more about your observations.

Saturday, July 26, 2014

Phocoena phocoena

A few days ago, I was excited to see quite a few Harbor Porpoises (Phocoena phocoena) swimming not too far off of Bodega Head.  Yesterday I was disappointed to hear about this individual that washed up on the beach.  It wasn't alive, so if you're not comfortable viewing pictures of a dead porpoise, you'll want to skip this post.  

These situations have always generated mixed reactions for meI'd rather see the animals alive and well, but it's an opportunity to learn more about a species that we don't get to see up-close very often.

Here are views from above and from the side.  The porpoise was between 5-6 feet long, the maximum length for a Harbor Porpoise.



Whenever I talk about porpoises, the question often comes up about how to tell the difference between a porpoise and a dolphin.

There are a few characteristics that are generally useful (but not always, because of some exceptions) like a blunt snout, rather than a long, pointed snout:


And a short, triangular dorsal fin, rather than a taller, falcate dorsal fin:



But one of the best characteristics (although it's not a great one if you're watching a swimming animal!) is the shape of teeth.  Porpoises have flattened, spade-shaped teeth, while dolphins have sharper, conical teeth:


When ocean conditions are very calm, that's your best chance for seeing Harbor Porpoises.  They're small enough that they don't rise very far above the surface, and they don't generate much of a "blow" when they breathe.  So when the ocean is flat, use binoculars to watch for their small arching backs and triangular dorsal fins.  (I posted a few photos of them in Washington last spring.)

For more information about Harbor Porpoises, check out the OBIS-SEAMAP web page

Tuesday, July 22, 2014

The sound of raindrops...

...in July!

I was a little surprised to hear the sound of raindrops this morning.  I went outside to experience the passing shower, and looked up to see raindrops falling from the sky with the crescent moon in the background:


The sun was high enough that I thought there was a good chance for a rainbow.  I finally spotted a faint arch in the western sky:


The clouds were spectacular.  I couldn't choose just one photo, so here are a few:





Quite a morning for sky watching!

Monday, July 21, 2014

17.5

Today the seawater temperature off Bodega Head reached 17.5°C (63.5°F).  That's one of the warmest temperature readings I've seen since moving here 10 years ago!  It made me look out at the ocean and wonder where that warm water was coming from:


Even far offshore, at the NDBC Bodega Bay buoy, the seawater temperature passed 61°F today.

Sunday, July 20, 2014

Peanuts with chocolate chips

For years I've been trying to photograph this intriguing peanut worm, Themiste pyroides:


I've discussed peanut worms on the blog before (see post from 31 January 2013), but I haven't shown this species yet.

Remember that peanut worm tentacles are located at the tip of a long "introvert" that can be withdrawn, or rolled in on itself.  Here's a series of pictures illustrating that process (below).  Watch the tentacles disappear!
 

Themiste pyroides has wonderful golden tentacles, a purple "neck", and fascinating hooked brown spines — see close-up below.  You'll laugh, but the shape of the spines reminds us of tiny chocolate chips!


Because peanut worms live in crevices, you often only get to see their tentacles.  Look closely for clusters of golden tentacles extending from low intertidal zone crevices along rocky shores, and you may be rewarded with a sighting of Themiste pyroides!

P.S.  In this species, the tentacles are used for suspension feedinggathering small food particles from the water.

Friday, July 18, 2014

Summer sailors

I haven't been able to get out in the field as much recently, so pardon me if I've been missing this event (and please tell me if I have!).

Today I came across some very large By-the-wind Sailors (Velella velella) washing ashore on the beach.


Most of these individuals were 7-8 cm (~3 inches) across at the base of the float see next photo.  [With the mantle extended (the dark blue portion), they measured 10 cm (~4 inches) across.]


Although I submitted a 3-part series about Velella in March, I'm posting these pictures now because it's somewhat unusual to see Velella during the summer...and because I haven't seen Velella this large on Bodega Head in a long time (I think it's been years!).

The local ocean water is extremely warm right now — 62°F (16.7°C).  Perhaps there's a different water mass nearby that's brought a population of Velella near shore at an unusual time of year?

It'll be interesting to see if anything else unusual shows up with this warm ocean water.

P.S.  For more information about Velella velella, see previous posts: December surprise (2012) and Below the water line (2014).

Wednesday, July 16, 2014

Slant of light and shades of gray



Early evening light, photographed from Bodega Head, 16 July 2014