With a pearly luster

  

A quick shot of a fun sea squirt, Cnemidocarpa finmarkiensis.  One description says this species has a "pearly luster," which seemed right to me.  

Photograph from the South Jetty in Bodega Harbor on 24 July 2024.  Good spotting, Eric!

Bound together

 

 

Yellow social tunicate (Perophora annectens) photographed in the low intertidal zone on 29 May 2021.  Although it's hard to tell, all of these zooids (each yellow blob) is connected via a stolon or runner that extends across the substrate.  The smallest zooids in this photo are new buds that arise from the stolon. 

A clam, a sea squirt, and a snail

Well, I didn't get a chance to take any photos today, so I browsed through photos from the last month or so (from various locations) and picked a few that caught my eye.  I hope they brighten your day!

 

Juvenile Pacific Razor Clam (Siliqua patula)

 

A golden colonial tunicate (sea squirt), Pycnoclavella stanleyi 

 

Red Turban Snail (Pomaulax gibberosus) with coralline algae

P.S.  What did the clam say when the sea squirt and the snail walked into the bar?  "Sorry, I'm just about to close up for the night."  :)

Dense little clubs

 

Pycnoclavella is one of my favorite tunicates (sea squirts).  This photo gives you a feel for how it grows in dense colonies.  (But remember, each one is only a few millimeters high!)

I first introduced this species ~6 years ago, so for more information, see the post called "The tiny tunicate, Pycnoclavella" on 17 February 2012.

P.S.   I think Pycnoclavella means "dense little clubs."  It's an appropriate name!

 

Beach finds

Longer story, but we haven't been able to walk the beach lately.  But we went for a quick walk on Salmon Creek Beach after work tonight.  There were some interesting invertebrates washed up, perhaps due to the large waves during the storms this weekend?

I only took a few photos for the record.  I'll show three different animals.  Do you want to guess what they are?  I showed all three on the blog last year, so if you've been reading for a while, you might have seen them before.  If you're new to the blog, you'll be at a disadvantage, but you can still play along.  Don't worry if they're unfamiliar — these are pelagic animals not often seen onshore!

There were hundreds of Animal A:

 

Around 50 of Animal B:

 

And only a few of Animal C:

 

And the answers are:

Animal A = the swimming bell of a siphonophore, Diphyes dispar

Animal B = a small pyrosome ("fire body"), probably Pyrosoma atlanticum

Animal C = a salp, possibly Salpa fusiformis 

 

I mentioned that I posted about all of these animals in 2014.  If you'd like to review those entries (or read them for the first time), here are the links:

• From the south on 26 October 2014 (siphonophore)

• "Fire bodies" on 8 December 2014 (pyrosome)

• March Madness on 31 March 2014 (salp)

Note that some of these animals may be associated with warmer ocean water.  The water temperature is still an astounding 14.5°C (58°F) — unusually warm for this time of year.

March Madness

Over the last few years, I've come to realize that March (and April) are good months to look for interesting pelagic invertebrates washing ashore on local beaches.  I'm guessing it has to do with the beginning of upwelling season, strong winds, and big waves.

So although some people call this time "March Madness" for other reasons, I've also come to know it by that name.  Partly because the intense weather during this month can feel somewhat "mad."  And partly because I'm "mad" about these fascinating animals that we don't get to see very often.

For example, if you look back at the blog during previous Marches and Aprils, we've documented a hyperiid amphipod living in a salp, sea angels, siphonophores, and salps.

A few days ago we came upon another species of salp.  It didn't look like much at first — mostly clear and elongate, with a large orange/reddish spot at one end.  This individual was ~5 cm long.

 

 

However, when we brought it in to identify it under the microscope, it was a different story!  Many of its organs were visible through the transparent body wall.  (Note that because the salp had washed up on the beach, there are scattered sand grains in the background.)

 

To make this easier, here's a diagram with some of the organs labeled: 

 

Modified from The Biology of Pelagic Tunicates (Bone 1998)

A salp has a similar body plan to its close relative the sea squirt (an ascidian), except that the salp's incurrent and excurrent siphons are on opposite ends of the body.  Water enters at one end and passes through a mucous net that is produced by an organ called the endostyle.  The mucous net is suspended between the endostyle and the gill bar and traps fine particles of food.  Periodically the food-laden net is rolled up and moved into the stomach to be digested.  The muscle bands contract to force water through the net and the excurrent stream of water also moves the salp via jet propulsion.

And now I'll go back and identify these same organs in the picture I showed above: 

 

 

Below is an even closer view of the heart and a portion of the gill bar and endostyle.  The tubular heart is intriguing because it periodically reverses its direction of pumping which drives the clear blood through the circulatory system in the opposite direction! 

 

I think this is Salpa fusiformis.  Although this species is known to occur along the West Coast, this is the first time I've documented it washing ashore in the Bodega Bay area.

For more general information about salps, you can review the post from 29 March 2013.

And here's a photo of March Madness weather when we found these salps:

 

Wide mouth and ribbon-like muscles

Sometimes when you discover gelatinous bits washed up on the beach, it's hard to tell what animals they came from.  But other times, if you take a closer look at those mysterious bits of transparent "jelly," you might find structures that provide more clues.

Here are a few photos of a gelatinous animal we found washed up on Salmon Creek Beach on 23 March 2013.  It was roughly cylindrical and ~3 cm long. 

 

Under the microscope the dramatic ribbon-like muscle bands encircling the animal were quite prominent.

In the photo above, note the wide mouth near the top of the photo (see close-up below).

 

And the small reddish spot at the bottom of the "V" below the mouth.  I'm not 100% certain, but I think this is the brain/eye of this animal (again, see close-up in next image).

 

At the posterior or tail end, there was a pointed projection and a pale mass which is probably the gut.  Here are two slightly different views.

 

 

This is a type of pelagic tunicate called a salp.  Salps are much more common offshore.  They don't often wash up on beaches unless there are strong onshore winds.

Many of them are very strong swimmers, hence the well developed muscle bands.  The large slit-like mouth is the equivalent of a siphon.  It takes in water which, after passing through the body, is released out the back end.  This water current is used for jet propulsion, gas exchange, and feeding.  As the water flows through the barrel-shaped body, food is captured in sheets of mucous and ingested.

I don't have a lot of experience identifying local salps, but I think this could be Iasis zonaria.  I'll be sending out the photos for confirmation.

If you are having trouble envisioning the animal with all of these parts, here's a basic illustration with labels:

 

Modified from The Biology of Pelagic Tunicates (Bone 1998)

 

Reproduction in salps is somewhat complicated.  They alternate between a solitary form and an aggregate (or chain) form, and one form produces the other.  The solitary form reproduces asexually and releases a long chain of aggregates.  The aggregate form reproduces sexually; each aggregate form produces one (or a few) solitary individuals.

Earlier in March we found a solitary individual that was producing a chain.  I'm not sure if this is the same species as the one pictured above.  It's possible, but either way, it's still worth showing you what a salp chain looks like.  I hope you can make out that there are lots of tiny individuals all lined up next to each other.  If this salp hadn't washed up on the beach, eventually the chain would have been released and would have been free swimming in the ocean.

 

This seems to be a good time of year to find gelatinous animals on local beaches.  I'll feature a few more during the next few days.