Fan of phoronids

 

 

A few phoronid photos for you!

 

 

 

 

 

 

Always nice to see Phoronis vancouverensis.  For more information about phoronids, see this post called, "Waking up with phoronids" from 17 July 2019.  It has several links with more photos and some introductory information about this group.

Green swirls

  

A beautiful phoronid, Phoronopsis harmeri, in Bodega Harbor on 5 February 2022.  For a little more info about phoronids, check out the post called "Ebb and flow" on 26 July 2017.

Swirls above the sand

 

Yesterday I was helping Maddy and Eric look for ribbon worms on the tidal flats in Bodega Harbor.  I know, I was supposed to be looking for ribbons worms (and I did find some!), but I always get distracted when there are phoronids around.  Crowns of tentacles (lophophores) of Phoronopsis harmeri, Bodega Harbor, 20 July 2020.  [You can click on the image for a larger version.]

Waking up with phoronids

 

I encountered some beautiful phoronids today.  Above is a close-up of Phoronis vancouverensis photographed on 17 July 2019.

And here's a group of individuals highlighting their graceful feeding tentacles:

 

I've written about phoronids before, but I can't help sharing photos of these wonderful invertebrates. 

For an introduction to (and more photos of) phoronids, you can review these previous posts:

"My, what a nice lophophore you have!" on 27 June 2013

 "Phoronids for the Fourth" on 4 July 2017

"Ebb and flow" on 26 July 2017

Out on the flats

Last September I posted about an interesting "sap-sucking sea slug" called Aplysiopsis enteromorphae.  The photographs accompanying that post were taken in the lab, but recently I encountered this species in the field, so here's a picture from the Bodega Harbor tidal flats:

 

This sea slug was ~20 mm long.  To learn more about this local species, check out the post called "One cell at a time" from 23 September 2017. 

P.S.  Related to last night's post, there are a couple of very small phoronids in the photo above (bottom center and top right).  I didn't notice them when I was trying to photograph Aplysiopsis traveling across the sand.  But when I was reviewing the photos, I saw these tiny phoronids emerging from the sand.  Fun!

A fan of phoronids

It's getting late, but here are a couple of quick photos of phoronids (Phoronopsis harmeri) from pools on the tidal flats in Bodega Harbor this week:

 

 

I've always been impressed by the elegant feeding tentacles (lophophores) of these fascinating animals.  For more information about phoronids, you can review the post called "Ebb and flow" on 26 July 2017.

P.S.  Hi, Amy!

Ebb and flow

Remember last night's mystery close-up?

 

Here's a zoomed out view:

 

If it looks familiar, I showed a similar animal, but a different species, earlier this month.

This is the phoronid Phoronopsis harmeri (formerly Phoronopsis viridis).  Note the long tentacles and the greenish coloration.  This species lives on the tidal flats in Bodega Harbor.  It's amazing to me that you can just park on the side of the road, walk out onto the mudflats, and find these beautiful animals in shallow pools.  (There are only 14 species of phoronids in the world!)

The close-up photo above highlights an interesting feature of phoronids.  Can you see the red color in some of the tentacles?  Phoronids pump blood (containing hemoglobin) into their tentacles to absorb oxygen from the water, then move the oxygenated blood down into their body below the surface of the mud.

Several years ago, Eric wrote an excellent description of blood circulation in phoronids, accompanied by a very helpful illustration.  I highly recommend reading his post called "Ebb and Flow."  

Then return to this post and check out some of my favorite phoronid images from 25 July 2017:

 

 

 

Perhaps I'll try to get some video of the blood flowing up and down in the tentacles.  Not sure whether my camera can capture that, but I think it's worth a try!

Phoronids for the Fourth

Eric and his summer students spotted these wonderful phoronids, Phoronis vancouverensis, at the Spud Point Marina docks yesterday (3 July 2017):

 

Remember that phoronids are known for their beautiful lophophores, the U-shaped crown of tentacles shown below:

 

 

While looking at these phoronids, we noticed some of the lophophores looked a little different — some had paired white spots in the center of the lophophore:

 

Here's a closer look (below).  Note that each of the white spots looks like a little bunch of grapes (clusters of smaller rounded blobs).  Do you have a guess about what they are?

 

The next image is the closest I could get with my camera at the time:

 

Each of the white clusters is a group of small developing embryos. Phoronis vancouverensis is a brooder!  The embryos will develop within the lophophore for about 2 weeks.  Then the tiny larvae will swim away, spending time in the plankton before returning to the benthos and undergoing metamorphosis into tiny juvenile phoronids.

I felt fortunate to be photographing phoronids on the Fourth of July!  :)

P.S.  For more information about phoronids, review the post from 27 June 2013.

Under the hood

A few days ago, Emily brought Eric a mystery critter from a plankton sample off Bodega Head:

 

Eric knew what it was, and called me to take a look because he knew this was one of my favorite types of larvae.  But there was a catch.

We recognized this as an actinotroch — the larval form of a phoronid.  (I've talked about adult phoronids a couple of times — see the post from 27 June 2013.)  However, it looked different than actinotrochs we'd seen before.

The tentacles were very long and slender, and it appeared to have more tentacles than we were used to.  When you have a chance to see a new species of phoronid, it's pretty exciting, because there are only about 14 species in the world!  So we embarked on a journey to identify this actinotroch.

Eric read that we had to look for several features.  To help you as we talk about them, here's a general illustration of actinotroch anatomy:

 

Modified from An Identification Guide to the Larval Marine Invertebrates of the Pacific Northwest (edited by Alan Shanks)

The number of tentacles is important.  In this case, we counted 26.  Next — the presence and shape of the secondary sense organ.  This was fun, because we'd never looked for one before.  And there it was!  

In the picture below, the arrow is showing the secondary sense organ — the pointed projection on the hood of the actinotroch.

 

Eric got an even better picture of it under high magnification (next image).  The actinotroch uses the ciliated sense organ to identify a good place to settle.

 

  

Another important characteristic is overall size.  Although small, this larva is relatively large for an actinotroch — about 1.2 mm long (next photo).

 

We could also see adult tentacles starting to form on this actinotroch.  Importantly, not all actinotrochs develop adult tentacles.  In the picture below, the adult tentacles are the small, stubby ones forming a fringe.

 

Given all of these characteristics, we think this is Phoronis architecta.  Phoronis architecta is common in southern California.  There are also records in Washington, but apparently not much is known about it north of Point Conception. 

Here are a couple of other really fun things about this amazing larva.  

The posterior end consists of a very active band of cilia (see below).  This is called a telotroch and the larva uses it for swimming (see video!).

 

Earlier I mentioned that the actinotroch has a hood and lots of tentacles.  Both are involved in feeding.  Strathmann and Bone studied this in 1997.  They discovered that the ciliated tentacles generate currents that draw food particles towards the tentacles. When a particle contacts a tentacle, the hood lifts and creates suction, drawing the food particle toward the mouth (which is under the hood).

If you watch this video clip, you can see particles being drawn towards the tentacles, the tentacles flicking, and the hood lifting (occasionally). 

Introducing Phoronis architecta!

phoronis architecta actinotroch from Jackie Sones on Vimeo.

P.S.  Information about feeding from Strathmann, R.R. and Q. Bone.  1997.  Ciliary feeding assisted by suction from the muscular oral hood of phoronid larvae.  Biological Bulletin 193: 153-162.

My, what a nice lophophore you have!

 

How many people get to start their day with a few nice images of phoronids?  You can count yourself among the lucky ones!

Phoronids are invertebrates related to bryozoans and are in their own phylum, Phoronida.  There are fewer than 20 described species in the world.  

These pictures were taken under a microscope on 27 June 2013.  The phoronids are Phoronis vancouverensis from the rocky outer coast.  

 

Phoronids feed with a crown-like structure called a lophophore.  Note the U-shaped indentation on one-side.  The tentacles are ciliated and actively draw water currents down through the lophophore to trap food particles.

 

For the record, we also noticed a few very small phoronids (see next image).  I'm not sure how old they are, but it's helpful to document when juveniles are present.  It might indicate the timing of larval settlement from the plankton.

 

P.S.  See the post from 27 November 2011 for a picture of Phoronis vancouverensis in the field.

P.P.S.  In February 2012, I shared images of Phoronopsis harmeri in Bodega Harbor and a little more general information about phoronids.

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.

Drakes Estero and phoronids

On 26 November 2011, we were fortunate enough to enjoy a wonderful sail in Velella (our 13.5 ft. Melonseed) in Drakes Estero (Point Reyes, CA).  Here's a photo of Eric and my mom -- Eric's excited because a breeze has finally come our way.  Behind the sailboat you can see the cliffs near the entrance to Barries Bay in the background.  The next photo shows a close up that I took from a kayak.  

While sailing and paddling in this area of Drakes Estero, we observed very dense beds of phoronids on the seafloor (the water was extremely clear!).  I couldn't take any photos of them at the time, but here's another photo that I took of some phoronids (different species) on Bodega Head.  Look for the delicate U-shaped rings of tentacles (lophophores)...and how dense groups of many individuals look "fuzzy".  This is how the bottom of Drakes Estero looked as we cruised by on the surface.