Friday, October 17, 2014

Searching for Ciona (see-o-na)

Ciona intestinalis; note the two "siphons" that the animal uses for filter feeding.
Ciona intestinalis is probably never going to be the star of its own Nat Geo special.  Charismatic it is not; nor is it megafauna.  But this small tunicate (or sea squirt) is a major player in the Gulf of Maine, and believe it or not is our kissing cousin.

Both my marine bio and my friend Beth Richard's developmental bio labs are interested in Ciona.  Tunicates (which include the sea squirts as well as colonial tunicates) are urochordates -- somewhat similar to the chordates (the group we belong to, along with birds, reptiles, fish, and other mammals).  Chordates have several features in common because we all evolved from a common ancestor.  Some of the characteristics we have in common are a notochord during development (a rod-like structure akin to our backbone); a nerve chord; pharygeal slits (in tunicates, these are used for filter feeding; in humans, these have evolved to become part of our faces and other parts of our anatomy); and a post-anal tail (we've lost ours, but still have a "tailbone").

The similarity of tunicates -- which really look pretty blobby compared to us -- is most apparent in its larval form. Beth searches out tunicates so her students can observe the eggs, sperm, and if they're lucky, fertilized eggs and the larval "tadpole" form.  I've only seen this form once, by chance, and let out a whoop that probably confirmed my students' suspicion that I'm a bit nuts.  So I was more than happy to go out collecting with Beth, in exchange for getting to spend some time checking out the eggs, sperm, and maybe larvae.

How do you collect Ciona?  Well, they grow all over docks, so we headed out looking for a likely spot.  First it was off to Dolphin Marina, where we had a lot of luck finding colonial tunicates -- mostly invasive species that smother whatever their larvae land on.  It's hard not to feel bad for that kelp!

Then we hit a lobsterman's dock, where we had terrific luck.  Beth scooped up a "hunk of junk" as I like to call it, and we'd hit the jackpot.  Take a look at all the amazing organisms attached to the side of docks next time you head to the shore -- you might find some Ciona, and you can impress your friends by telling them the blobs are just your kissin' cousin!

Beth, sneaking up on tunicates.
Searching, or napping?  You be the judge.
A "hunk of junk".
Colonial tunicates of several species.  Poor kelp.
More of the blob.
Ciona intestinalis.
The side of the dock at Dolphin Marina.  Interesting hydroids, mussels, anemones, and tunicates.
A wonderland!

Thursday, October 9, 2014

Mudflat Moon Snail Mania

No lab is anticipated more than the mudflats lab I lead each fall.  For some, the anticipation is tinged with dread, as they envision themselves dirty and cold and wet, pulling up unrecognizable worms.  For others, it's all an adventure to be enjoyed.  For me, it's the best lab of the season -- one where we always encounter new habitats and organisms.  This is when my appreciation of a student increases exponentially when I see her kneeling in the mud, quietly picking through the algae looking for organisms.  When we are children again, turning over rocks and digging up thick muck.  Squealing with delight over our finds.  And yes, getting dirty.  For some people, really dirty.  You can't explore a mudflat without falling over once in a while.

I give two excellent prizes for this lab:  One for the muddiest person,  one for the person who finds the coolest thing.  This year we had two candidates for muddiest person, but making the choice for coolest find will be tough -- in that we found more moon snails than we've ever found, and many other amazing things -- rock gunnels, tiny sipunculids (peanut worms!), nemertians (ferocious wrom predators), crabs the color of shells, etc. etc.  It'll be a tough decision . . . .

I could go with the obvious choice, moon snails.  They are my favorite.  But there were so many of them -- exponentially more than any other trip -- that is seems difficult to say they are particularly rare this year.  How many did we find?  This many:

I love hearing a student say "What's this?  OH MY GOSH IT'S HUGE!"

Steve Dudgeon came along and shared his considerable knowledge.

Passing one around to amaze ourselves.

This is an odd place to find two -- count 'em two -- moon snails.  Rocks?  Odd.

Brave student!

Look at that foot!

A little one!

Our cup runneth over.

She's thinking "What the . . . ?"

This is more commonly where I find them!

Sarah Kingston found this hard-shell clam with a drill hole from a moon snail!

Well, after all those moon snails, everything else might just be icing on the cake.  But really, all this stuff is amazing in and of itself.  Take a look:

Green crabs in the most beautiful shell hash colors.  What camouflage!

Loads of Mercenaria!  Quahogs or hard shell clams.

I do love a rock gunnel!

Two is even better!

Whoa!  Lady Asian shorecrab.

Peanut worms.  A big one and a baby.  Don't you dare say "ew".

Annie's not freaked out.  Why should you be?
All this bounty wasn't easily won.  We got a little stuck in the mud.  That's half the fun.

Boot stuck?  Pull it out with your hands!

Oh, I hate it when they fall.  I know what it's like.

This is why the mudflats are poorly studied.

Using a bucket for help.  Smart.

Oh, this is a serious case of mud.  Annie's in the running for a prize!
I have to thank my wonderful students letting me drag them along on my adventures.  They think I'm doing it for them!  Ha.  Seriously, they pay me for this?

Monday, October 6, 2014

What could possibly be better than this?

Yesterday, I dragged Damon to Freeport to do a little shopping.  It couldn't be helped.  There is a wedding to attend later this month, and even an Ocean Lover wants her guy to look sharp.  So we dragged the dog along, found a parking spot in the garage under the Bean outlet (lest Dory get too hot), and fought our way through the leaf-peeping shoppers to the fitting rooms.  It all worked out just fine, as Damon found two really nice pairs of LL's pants that cost a grand total of $3.76 (yes, you read that right).  What could be better than that?

Well, maybe a waterfront lunch at Piney Point.  What could be better than that?

An exploration of the dinghies next to the restaurant.  What could be better than that?

Going barefoot -- in October.  What could be better than that?

How about a big, wide, flat beach.  What could be better than that?

A dog-friendly beach?  Is this what the big deal is all about?  Nope, it gets even better.

Everything was just a prelude to a nerd's paradise: BABY MOON SNAILS. Nothing could be better than that.  Nothing.

I've written about big mamma moon snails.  They're rather extraordinary.  But never have I seen babies, and yesterday I saw not a few -- I saw hundreds.  Old Orchard Beach was rotten with them.  And they're so stinkin' cute!  With their little con-trails they leave behind, and their tiny feet bulldozing through the soft sand, and their exquisite little shells.  I mean really, what's a girl to do?

Ain't life grand?

Wednesday, October 1, 2014

Stalking Snails with Sarah

Sarah and her snails.
There's nothing better than getting paid to be at the coast.  Last week Sarah Kingston's Marine Molecular Ecology class asked for an assist in finding two types of intertidal snails -- Littorina obtusata (the smooth periwinkle), and Littorina saxatilis (the rough periwinkle).  So off to Giant Steps I went with them, back in my boots.

Intertidal snails clockwise from top left:  Littorina littorea, Nucella lapillus, Littorina obtusata, Littorina saxatilis.  Common names, respectively:  common periwinkle, dogwhelk, smooth periwinkle, rough perwinkle.

There are actually three Littorine species in Maine's rocky intertidal -- the third one being Littorina littorea, the common periwinkle.  Luckily, they have different habitats and morphologies, so telling them apart is relatively easy.

Littorina littorea is ubiquitous in the rocky intertidal, and is found from the Fucus zone down to the bottom of the intertidal zone, including in tidepools.  The common periwinkle is an invasive species that is thought to have arrived on the ballast stones of European trading vessels early in the colonial period.  These ravenous grazers feed on seaweeds, and probably have a huge effect on the rocky intertidal zone.  Interestingly, they have clear preferences for certain seaweeds, so they have changed the species composition of the habitat quite a bit.  You can identify these by their size -- they become large, perhaps an inch across, although they start as small snails so you can be confused if not careful.  The spire of their shell is pointy, and do not exhibit clear sutures between the "layers" of this whirled part of the shell.

Littorina saxatilis (the rough perwinkle) is probably my favorite intertidal snail.  It can be the hardest to find, since it is very small, and is found high above the intertidal, in the splash zone.  These are only common where there are crashing waves -- so exposed headlands are a common place to find them.  These little guys can go many days without being wet, and have almost lung-like organs.  They feed on the black Calothrix (the slick blue-green algae you can find at the top of the intertidal zone).

Hundreds of rough periwinkles hiding in a crack at Pemaquid Point.

"Halos" of Calothrix algae around the cracks where rough perwinkles hide.  They come out of the cracks when it's wet and cool to feed, then return to the cracks when it's dry and hot (to get some relief from the heat).
Littorina obtusata (the smooth periwinkle) is the jewel of the intertidal.  Relying exclusively on knotted wrack (Ascophyllum nodosum) for habitat and food, this snail  mimics the colors of this beautiful algae -- yellow, orange, green, brown, and even red.  They can be tough to find because they are so well camouflaged.

Typical habitat of the smooth periwinkle.
Our mission was to find about 40 individuals of both rough and smooth periwinkles, so Sarah's class can study their genetics.  The first place we looked was in the knotted wrack, and it wasn't long before the first "I found one!" was heard.  Once people got the search image in their heads, we found our quota pretty quickly.  Then it was on to the exposed rocks at the southern end of Giant Steps (where we were very careful).  We had a great look around, then got to work looking in the crevices at the top of the intertidal zone.  Thousands of tiny rough periwinkles were hiding there, so we quickly hauled in our snails.  Not a bad way to spend a Friday afternoon, and I didn't even have to go to the probability lecture that the students sat through after our intertidal adventure!

Found one!
Maybe I got a bit distracted by the anemones in the tidepools at Giant Steps . . . .
A box full of snails.
Aha!  They thought they could hide from me.  No way.
These are dogwhelks -- predatory snails also found in the intertidal zone.  They're eating these barnacles.
Hunting for rough periwinkles.
Checking out our haul.
A photo for Facebook?