Species sort-of of the Week week #5 OR On the benefits of a tautonomical diet

I'm sure you've heard the conspiracy theory that sea slugs are involved in a major trans-species arms smuggling operation. Well, your humble narrator has done some investigative journalism for which she is completely unqualified and can tell you, the rumors are true. That's why I'm cheating today, starting a Species species of the Week week with a nudibranch that's not even close to a tautonym (2).  Here is the culprit:

Blue Dragon

Glaucus atlanticus(1)

Figure 1. Glaucus atlanticus - the Blue Dragon (nudibranch).  Holy Daenerys Targaryen, Batman! Am I right?! This thing is crazy, and if your heart doesn't explode just a little bit when you see this and contemplate that you share the earth with this creature, well ... I can only sputter my disbelief.  Credit where credit is due.

Ok, so it looks cool, fine. But why does it deserve the [ahem, rather distinguished] honor of being a Species species of the Week week (weak?) when it's not even a tautonym (but see (2))?!  Well, there was a passage in the Wikipedia entry:

G. atlanticus preys on other, larger pelagic organisms: the dangerously venomous Portuguese Man o' War Physalia physalis; the by-the-wind-sailor Velella velella; the blue button Porpita porpita; and the violet snail, Janthina janthina. Occasionally, individual Glaucus become cannibals given the opportunity. 

Did you catch that? Almost every major prey item for this nudibranch is a tautonym (and Physalia physalis is just obnoxiously close - what a jerk)! Now I'm not saying that the diet of this slug is explained by the possession of a highly sophisticated taste - if I do say so myself - in grammar.  For one, though I admittedly haven't done the research to back this up, I feel like it's safe to assume the emergence of slug's diet predates the naming of these prey species. But still...what are the odds? Really, I'd love to know what the odds are if anyone is patient enough to figure that out. 

In the next few tautonym posts (3), I'll cover a few of the double-named prey of the Blue Dragon - except definitely not that tease Physalia physalis.

But now back to the arms smuggling operation...

So, of course I'm all fixated on the improbability of an almost exclusively tautonomical diet, when I am reminded that what's even cooler, at least to most people, is that this diet is also the slug's defense.  When the slug consumes jellies, it also eats the stinging cells (Figure 2).  The slug then puts these cnidocytes into its own flesh (the cerata, specifically, which are the long finger-like projections that make this slug look so flamboyant). Anything that tries to attack the slug gets stung.

Figure 2. This is why it hurts, y'all. I know, my eyes just glaze over too when I see diagrams in the pastel color palette of academic textbooks (haven't they figured that out yet?). But this really is one of the better diagrams of how Cnidocytes work - terrifying.

So the slug has basically stolen poisoned harpoons from the jellies and incorporated them into it's own body so it becomes super-invulnerable. This, of course, reeks of Hollywood script possibilities (whoops, it appears I've been scooped. SPOILER ALERT: it doesn't end well for the invulnerable trans-species defense idea). Here is a National Geographic clip demonstrating the awesomeness of the Blue Dragon (4). There is, of course, a word for this process of stealing cnidocytes and deploying them against your enemies: Bioterrorism.  No, well maybe, but the real word is Kleptocnidae.

Next up: Goodyear Mollusks.

References and miscellany (5):

(1) Pokemon disambiguation found here, in French.

(2) G. atlanticus was, however, the first (of only two) species named in the genus Glaucus, so according to my theory of tautonyms, it could have theoretically been Glaucus glaucus. And, frankly, if I'm going to editorialize here, atlanticus is a misleading species name (though hardly the only one) as the distribution of this species is not restricted to only the Atlantic ocean.

(3) Read: Until I get bored

(4) Editorial aside: Why does everyone now have these narrators that are so over the top for nature videos?! THis guy sounds so incredulous and has the dumbest comments.  This is why I like David Attenborough and Marty Stouffer. They get it: nature sells itself and doesn't need a monster truck voice-over to make it exciting. That's another soapbox for another day though.

(5) Does Blogger have a reference management software?  Rearranging these is getting rul old.

Coming in off the mud OR Terrestrial Radulas

There is a certain euphoria to be felt when your foot hits the first piece of truly solid ground coming in off the mud. Traversing the mud for hours at a time is a freaking slog, sure, but what's more surprising about it is how a short time on a mudflat subsumes every other walking experience you've ever had. You don't think, "Walking in the mud is hard!" but, "Walking is hard!" because mud is the only walking your body remembers at that exhausted, oxygen-starved, moment. In that incalculably small instant your foot gains leverage on something hard, the world suddenly becomes a different place: the curtain lifts and true enlightenment as to the ease with which walking can actually be accomplished is achieved. This temporarily endows you with a giddy sense of unlimited power and endless possibility. I suppose I get a little high off it. 

I worked what was hopefully my last tide of the season yesterday. So, to celebrate my return to a mostly terrestrial lifestyle for the next 6 months, I'ma post some short videos of land-based gastropods I took this summer during short visits to terra firma.  

Video 1: Slugga vs. Mushroom

My remarkable niece came out for her first PNW visit this summer (and I guess her parents came with her too...) and we went on a walkabout in the Anacortes Community Forest Lands (1).  I spotted this slug (2). As my friend Brad just pointed out, you never really see slugs doing anything, mostly they just slug along.  So seeing this one chow down on a mushroom was sweet.  I had Attenborough dreams in my head, as I was recording this, of getting a long clip and speeding it up, time-lapse style.  Oh well, this is what you get, you can fill in the gaps in your head.  Maggie is/was in a "What does the cow say?" phase, so we stepped up the challenge.  I'm still not clear on what a slug does say, but they probably say it veeeeery slooooowly (thank you very much folks! come back tomorrow, completely different show!).

Video 2: Snail vs. Lettuce

The video narrates itself (witness my mad iMovie skillz - stock soundtrack and everything!).  The snails are translucent (!!!) and so freaking fast (!!!), relatively speaking of course (3). Unfortunately, the beating heart of the snail doesn't show up on the video, but I could see it when I got close. When I have the chance I love to garden so I am not particularly attached to these buggers beyond nerd-fascination, but - **Note: I didn't actually eat any of the snails, at least knowingly or intentionally. I gave up eating mollusks (actually all sea creatures) for Lent years ago and have been clean since.

References and miscellany:

(1) ACFL is by far one of the most awesome things about Anaco.  Huge tracts of lands owned by the city just for cruising around.

(2) I sure don't know what kind of slug it is.  2 Points if you can ID it for me.
(3) Previous Attenborough aspirations notwithstanding, this video is also in real-time.

Location, Location, Location!

How great is Washington State?! Srsly. Pretty, pretty great.

This was originally posted by Mother Nature Network.


First the good news:

Fig. 1.  Way to go Washington, so redelicious! Kind of phoning it in Wyoming,
don't you think?  Did you really even have to try to win that one?

Then the better news:

Fig. 2.  Dang, Washington, you invaded! Also, Michiganders!
Get with it and EAT THE CARP!

HA! It turns out I live in the best place in the country to study invasive snails! Ima go do that, right now, or maybe just wait til Monday when the tide is better.

Species species of the Week week #4 OR Hiphopopotamus

Hippopus hippopus

(The Horse's Hoof Clam OR 

The Strawberry Clam OR 

The Bear Paw Clam)

Figure 1. What a wacky looking clam!!
Photo Credit: Mehmet Atatur

Figure 2.  Yup, wacky from this angle too!

Right, so the radness of the shell alone (Figs 1 & 2) is pretty much enough coolness for this tautonym to stand on, but there is so much more to Hippopus hippopus (Disambiguation: Did you mean "Hiphopopotamus"?) that makes it cool. And for that we need to see a picture of it in situ, up close:

Figure 3. Open live H. hippopus, looking even wackier

Go closer...

Figure 4.  Siphon and wacky mantle tissue.
Photo Credit: Artesub.com

Closer still...

Figure 5. Extreme Close-up. Reflective proteins in mantle tissue of Tridacna
Micrograph Credit: Griffiths et al. 1992

Too close, a little too close!

Figure 6. Dinoflagellates (non-algae algae) of the genus Symbiodinium.
They live in giant clam flesh!

There!  Living right in the mantle tissues of these Giant Clams are dinoflagellates (1),  phytoplankton of the genus Symbiodinium.  The genus name kind of says it all.  These  wiggly bulbous photophiles have a symbiotic relationship with the clams whereby they use sunlight to produce carbohydrates, which the clam then eats, and in return, they get a stable habitat in which to live and drink up the sun.  Free-living dinoflagellates, like all plankton, are at the mercy of the tides and currents and can get forced down to a depth beyond which they can obtain sufficient light to photosynthesize (= bitty dinoflagellates, wasting away).  By paying a bit of rent in the form of sugar to the clam, symbiotic dinoflagellates are assured that they will not be sucked into the deep.

Ok, so that's cool enough, but not unique.  This is roughly the same symbiosis as corals and our own local Anthopleura anemones (see really, really ... really cool research at Western on climate change and symbiosis).  

But!  What I learned just this week at a talk by Alison Sweeney (2) was that not only do the clams have algae all up in their skin, but they apparently also modify their own mantle tissue feed more dinoflagellates, and thereby get more sugar.  They're farmers! The iridescence you see in the mantle (Figure 4) is generated by iridocytes, cells with organized proteins all stacked up (Figure 5).  What are the iridocytes for?  There are a number of ideas that have been considered, including protecting the dinoflagellates from exposure to too much sun, which can cause chemical stress on both dinos and clams.  

However, modelling and experiments done by Dr. Sweeney and friends indicate that proteins in iridocytes forward scatter wavelengths of light that are useful in photosynthesis, deeper into the clam than it would otherwise go.  This is good news for the dinoflagellates and the clam (more light -> more photosynthesis for more dinoflagellates -> more candy for the clams!).  However, the iridocytes backscatter  the other wavelengths (like green), so we see green iridescence. So, it's possible that the clam uses iridocytes to improve their dinoflagellate husbandry.

Dang, clam, you pretty and smart!

References and miscellany:

(1) Pedantic note about pronunciation of this word: Neigh on a decade ago, it was STRONGLY emphasized to me by Greg Teegarden who learned it from his Academic forefathers/mothers that "Dinoflagellates" is pronounced "DEE-no" NOT "DYE-no".  The former is derived from Greek meaning "rotation", referring to the transverse flagellum that causes these guys to spin, while the latter signifies the Greek word "deinos", meaning "terrible" - like Dinosaur = "terrible lizard".   It seems to me that these are spinning, but not terrible, flagellates.  

(2) Most official website I could find for Dr. Sweeney, this is from Duke where she did her Ph.D. Currently at UCSB Institute for Collaborative Biotechnologies, headed to Penn Physics this fall. She has also done lots of work on coloring and iridesence and optic stuff in cephalopods. 

Species species of the Week week #2 OR Emily's FAVORITE Tautonym

Gemma gemma

(The Amethyst Gem Clam)

As it's at least supposed to be a molluscan marine blog it seemed worthy to start (1) with a redundant local marine mollusk.  Unfortunately, it turns out that very few, if any, tautonomical invertebrates are native to the Pacific Northwest (2).  So why not a non-native? It turns out this one is also my very, very favorite tautonym.

Figure 1. Peterson (of field guide fame) refers to G. gemma as, "a handsome ... clam, easily overlooked because of its small size".  Just so, sir.  Just so.

Photo Credit: Fisheries and Oceans Canada. Melissa Wong.

In addition to being the name of my wireless network, Gemma gemma (3) is the diminutive Amethyst Gem clam (Disambiguation).  These tiny bivalves are native to the east and Gulf coasts of North America, from Nova Scotia to Texas. They were introduced along the west coast of the US around 1960, but have only recently become very abundant in San Francisco Bay - but hey, what hasn't these days?! Am I right, folks?! (<---- NOTE: That was an excellent/horrible invasive species joke.  Insert rim shot here ... plz.)  

But seriously...

Ted Grosholz (UC Davis) tried to figure out why the gem clam population didn't really take off until decades after it was actually introduced (4).  It looks like the gem clam populations used to be held in check by competition (Figure 2) with native clams of the genus Nutricola (which I'm pretty sure are referred to as "Nut" clams).  

Figure 2. Schematic depicting San Francisco Bay pre-Green Crab Invasion (5).  Native Nutricola spp. (Pink, Yellow, and White individuals) originally kept non-native Gemma gemma (Green individual) at low abundances by eating up all of the food (phytoplankton represented by dinoflagellates, chain-forming and pennate diatoms and coccolithophores) leaving only scraps for poor G. gemma. 

Gem clams were kept at such low abundances that they were not, apparently, worthy of much notice or concern.  That is, until the arrival of the [non-whimsically named] European green crab, Carcinus maenas, which came to SF bay as a stow-away in the late 1980's.  The invasive crab, embracing the gastronomic culture of its host country, prefers to eat the biggest thing is can get its little green claws on, which in SF bay is the native Nutricola spp. The tiny gem clams get overlooked - lucky Gemma gemma devils!  That means no more selfish native clams hogging all the delicious phytoplankton (Figure 3)! Time for tiny gem clams to make tiny gem babies! 

Figure 3. My, how the tables have turned!  Schematic representing San Francisco Bay post-Green crab invasion.  Crabs (lower left) preferentially consume native Nutricola spp. (lonely yellow individual), freeing up more food for non-native gem clams (prolific green individuals) to make gem babies! 

Cool, huh?!  In many cases like this one, non-native species are present at low abundances for years after they are introduced, leading people to be all like, "ohhhhhhh....whateverrrr...it's no big deallll...I mean, who cares about some dumb clam anyway..."  And then something changes.  Maybe the non-native population develops a key adaptation that enables it to make more babies than before, or something else in the environment frees up resources (*cough, cough* I'm looking at you C. maenas), and the population of the non-native explodes and messes things up for EVERYONE.  And people are all like, "whaaa!? But how could we have known!?"  And I'm all like, "because it happens every time!"  Well, not every time, but surprisingly often. 


So called "lag times" are a pretty common property of biological invasions, and one extremely good reason that, notwithstanding any aesthetic arguments(6) for the moral equivalence of human and non-human invasions, all introductions of non-native species deserve to be treated with caution. 

References and miscellany:
(1) Yes "start" more than a month later, this is the first second species species of the week week. I did warn the one of you that reads this that these would be irregular and unlikley to actually appear on a weekly basis.
(2) I'm tempted do some arm waving here about how this probably has something to do with the idea that the tautonym species are so-named because they were the first of the genus to be described, and most of the marine genera in the PNW were first described in Europe or the east coast of North America.  But that arm waving will only appear in small print in the foot notes.
(3) On the pronunciation of Gemma gemma: "gemma" comes from Latin for "jewel". I assume it SHOULD be a hard G if you're being true to Latin pronunciation, but I have only ever heard it pronounced with a soft G, presumably in honor of the common name - which also pretty much comes from Latin for "jewel" but has since been bastardized.
(4) Grosholz, E., (2005) PNAS. 102(4): 1088. 
(5) If you have to look this game up, and don't have age as an excuse, your childhood was misspent.
(6) Drew Christie is a great Seattle animator and illustrator whose work I actually really like, but this piece got under my skin (really really far under my skin), for making a tenuous aesthetic (but it's cute!) and moral (humans are invasive too, who are we to point the finger?!) argument that manipulates feelings about a legitimate conservation issue.