Friday Fluff #2: For When Enough is Enough

Thing the First: Blue Tide hits Washington Coasts

What a freaking mess! Someone should do something about this! Photo: Tiffany Boothe, Seaside Aquarium

This is old news now, but I was resisting putting it on the blog for a long time. Really strong westerly winds have pushed literal heaps of everyone's favorite blue tautonomical cnidarian onto coastal beaches in Washington and Oregon over the last month. Is it called a "blue tide"? I don't know. Should it be? Maybe, "blue tide" is kind of redundant. In any case, yes, Velella velella has become a victim of its own ingenious dispersal ability (1), and create just endless fields of rotting blue mesoglea (2). The most stunning statistic coming out of this whole ordeal is that only 50% of science journalists know how to capitalize latin names. Editorial Fails include: USA Today, The Weather Channel, KOMO news (local, and having the opposite problem as the others). CNN did get it right, but then lost points for referring to "something fishy going on in Washington" which is as original as it is semantically correct - not at all. Anyway, there's a lot of cool pictures. This isn't really something anyone is concerned about, they aren't a huge health hazard, or an endangered species, and this isn't some major environmental catastrophe. This happens from time to time to these guys, and could happen more frequently as climate change alters the frequency of certain weather patterns.

Thing the Second: Pretty Subtidal Seattle OR Pretty (Subtitle: Seattle)

If you think it's beautiful above the waterline in Seattle this time of year (and you're right, it's ridiculous), check out this video my very talented friend Eliza Heery made celebrating our green waters! Eliza does what she calls Urban Marine Ecology, exploring how marine ecosystems function so closely to an extremely dense urban environment.

Thing the Third: Foaming with rage and bruised all over the chest

Just some old crummy boat...wait it looks familiar! Photo: Richard Rodriguez, Bitter End Blog

The most faithful molluscophiles among you will remember my reference to John Steinbeck's (and Ed Ricketts', cough cough) description of the infuriating intractability of the the Sally Lightfoot Crab (Grapsus grapsus, naturally). The vignette was from the Log from the Sea of Cortez, detailing a whimsical collecting trip the likes of which will never occur again. Some have tried, like really tried, down to the brand of beer, which was evidently a crucial aspect of the trip. But I suspect we won't get narrative like Steinbeck out of it(3). Anyway, the point is that the boat Steinbeck and Ricketts took, the Western Flyer, is still in existence, sort of, in Port Townsend, WA. It's sunk more than once, and certainly has some tragedy in its history, but the new owner hopes to restore it and potentially return it to Monterey - hopefully not as a restaurant...A book about the post-Steinbeck/Ricketts history of the Western Flyer recently came out - in time for father's day, score.

Happy weekend!

References and Miscellany:

1. If you don't recall the mechanics of the By-the-wind sailor, might I recommend this resource?
2. Word of the Day! There, go impress your friends and family and don't say I never gave you nothin'!
3. However, evidently there is currently a museum exhibit resulting from the repeat journey (inscrutably) at the AZ museum of natural history

Don't read this if you don't want nightmares about things that will never happen to you

You know what totally gives me the willies? Two words:

Transmissible cancer

Yikes. Yes, that is cancer that can be "contagious". This is different from oncoviruses, which are viruses that cause cancer (like some strains of HPV). But this is where a cancerous cells touching uninfected individuals can cause them to "catch" the cancer as well. Until recently, only three types were known (Spoiler alert/you can breath a sigh of relief: NONE in humans):

• Facial tumors in tasmanian devils (DFTD), which are transmitted when these guys chomp each other in the face squabbling over food, mates, territory, and who's more swole.
• Canine transmissible venereal tumor (yes, that is what it sounds like), which was recently sequenced. 
• And [sort of] a sarcoma in Syrian hamsters, too(1).

I have spared you pictures of any of the above, but feel free to do a Google image search - NO! DO NOT DO A GOOGLE IMAGE SEARCH!

Line at the Mya arenaria clinic. Soft shell clams waiting for a blood/hemolymph draw to test for cancer, photo from Metzger via Cell Press. It really looks like proper science what with the lab diaper and flasks, beakers, and bunsen burner in the background.

Well, welcome to the club, Steamer! I agree that name is really inappropriately adorable for a leukemia, but it has been so dubbed because it infects soft-shell, or "steamer" clams (Mya arenaria). This leukemia have been observed for over 40 years, and causes death in the majority of individuals who become infected, but the cause of the leukemia was unknown until recently. The natural question here is: "Leukemia? Do clams even have blood?" And the answer is sort of - they have hemolymph, which is a fluid that carries oxygen (and other junx) around the tissues of the clam's open circulatory system.

Graphical abstract from Metzger et al. 2015 Cell. One of the key findings in this paper is that the tumors all had the same genetic signature in infected clams, suggesting that they all came from a single source, even though the clam populations examined were found hundreds of miles apart. 

What/Who is Steamer? And how do I keep it the *bleep* away from me? Never fear! You won't have to give up your chowdah. Steamer is a "jumping gene", a retrotransposable element(2) that can get copied into the DNA of a host organism. If you can't imagine why mishmashing DNA could be problematic, everything you need to know on the topic can be found here. All kidding aside, let me be completely clear about this - this retrotransposon WILL NOT infect humans. But soft shell clams are indeed at risk. The most recent research shows that Steamer can travel hundreds of miles in the ocean and infect clams via these jumping genes. So, this is unusual because a virus is not spreading the disease but the tumor cells (hemocytes) themselves are spreading the disease. Hence: transmissible cancer.

It's certainly consoling that this newest discovery in the realm of terrifying things nature can kill you with is so distant from us in the tree of life that it's not a direct threat to us (lovers of clam chowder likely disagree, however. Disagreement noted.). Nonetheless, this is the first time a transmissible cancer has been discovered in an animal other than a mammal, which opens the possibility that there are many more of these out there infecting many more types of animals than we suspected. 

Now try to sleep at night...

References and Miscellany:

1. It seems like this isn't a "naturally-occurring" transmissible cancer, in that the cancer was initially chemically induced, and then transmitted from one individual to another by injecting them with cells from the original tumor. So this isn't really quite the same thing, nonetheless, I'm including it here, because you will see it referenced in Wikipedia, and I wouldn't want you to think I didn't do my research. Also, be warned, the article I linked is pretty clinical.

2. Cripes, I am having a hard time finding relatable resources on retrotransposons! Try this? Entry level online resources describing this genetic process is absolutely a growth market. You could make a billion bucks if you made one decent you tube video on this topic. You're welcome.

Friday Fluff: For when enough is enough.

It's after 4 on Friday, and I just spent a few hours trying to teach myself sql. Soooo ... brain. Because. But three easy pieces did cross into my field of view recently, and so:

1. Even extinct cone snails get all the attention!

Cone snails get a disproportionate amount of attention, mostly, I suppose because they are so diverse. Admittedly, they have some cool ecology, but nonetheless, those of us who don't work on them (or maybe just me) are sometimes a bit jealous of all the hubbub about a single group. So it was unsurprising when I saw this post from the Smithsonian blog about how entrancing even extinct cone snails are. A researcher from San Jose State University used UV light to show the color patterns on fossilized cone snail shells. Some of the pigmentation was no longer visible to the naked eye, but using this technique, this guy identified more than 10 new species! I feel like there should be some comment here about inspiration coming from the strangest places - like raves and velvet posters. Here's the original paper, with more cool photos.

Figure 2 reproduced from Hendricks 2015 PLoSOne demonstrating
how UV light can be used to reveal historic coloration of fossil cone snail shells

2. Between a rock and a limpet radula

Well, Rah rah radula indeed! In fact, we had better hail the radula or it will come for us, and we will not come out on top. Engineers at the University of Portsmouth (also in Science Daily) have proclaimed that limpet teeth are made of the strongest naturally-occurring material known to man. Here, "strongest" refers to highest tensile strength and has nothing to do with towing a 767. For those of you who still think terrestrial systems have anything to offer ("But, but, what about spiders?") it turns out these fangs have toppled spider silk as the champion of natural material strength. 

No, this picture does need to be this big. If the last post on attack snails wasn't enough to give you nightmares, this should be. Image from the University of Portsmouth. 

All of that from this:

Patella vulgata, the common limpet. Just think about how
strong teeth would be from an UNcommon limpet.
Image from Wikimedia Commons.

3. Beauty abounds thanks to El Nino!

California faces drought unprecedented in recorded history and John Steinbeck wishes he were alive to document it. But Californians have something positive to look forward to - population booms of this beautiful slug, Okenia rosacea, which benefits from warmer temperatures. The Hopkins rose nudibranch is being spotted much further north than is usual. More from Science Daily and the primary literature.

Image by Jerry Kirkhart from Los Osos, CA via Wikimedia Commons

Have you seen it on your beach? Send me pictures!

Dangerous hormonal snails OR Vacuum tube of death

So, here's a question: 

Why is this fish so dumb?

Good God, man! It's a giant snail vacuum mouth of death, coming at you very, very slowly - just move! All you have to do is ... anything! Nope. OK, you did nothing. 

What looks like a case of natural selection weeding out those fish without any common sense or athletic ability is evidently a case of chemical warfare. This species of snail, Conus tulipa, belongs to a group of predatory snails(1) that uses neurotoxins to immobilize and then overtake prey. The problem is, most of them use a poison dart like this:

Clearly that's not what's going on with C. tulipa. It's just a giant, obvious, excruciatingly slow, net-mouth coming right at the slimy little bug-eyed fish face - and that video is sped up! Because we are busy people who don't have time to watch this sort of slow-motion train wreck at its true glacial speed. 

But, OK, it's not hard to imagine that instead of darting them with a neurotoxin, they are releasing it in the water nearby before they "spring the trap". And that's what people thought for a while. A recent paper(2) shows that the fish aren't the victims of a toxin, but  a hormone. Fish are sent into hypoglycemic shock as C. tulipa releases an insulin into the surrounding water. This, according to WebMD, is likely to cause confusion, dizziness, sweaty skin, and "feeling shaky" in the fish. No, I'm kidding. Fish can't sweat. This is what it does to fish:

You just witnessed actual science! So the idea is the insulin makes fish susceptible to the snails' otherwise unambitious attack strategy. One of the other cool things is that, because there are many different forms of insulin, snails had to evolve an insulin that would work on fish! 

If snails have taught me nothing, it's that there's more than one way to skin a fish. And that it's totally fine to be lazy as long as you have a sweet chemical arsenal.

References and Miscellany:

(1) Don't you dare act shocked that there is such a thing as predatory snails! Did you not read the very first thing I ever published on this blog?! Pay attention, people.
(2) Actually, as of the writing of this post, it's not even published - just a preview still.

New baby orca J-50 spouts rainbows across Puget Sound! OR Acronymous B.I.G.[G.]

In Seattle, orca births are celebrated on the front page of the paper! Go ahead, make your jokes about what yokels we must be, we know better.

Yay baby J-50!

You gotta be kidding me! Photo by Ken Balcom of Center for Whale Research

J-50 is Slick's (J-16) sixth calf, but two of her calves haven't survived, including the calf I announced a few years ago, J-48. 

It's difficult not to get excited about an absurdly cute baby apex-predator, but it's been a rocky month for this pod. They just lost one of the best hopes for the growth of the pod. J-32, AKA Rhapsody, washed up dead on the shore near Courtenay, in British Columbia. A necropsy indicated she was underfed, and had an aborted, nearly full-term, fetus in her uterus. The thought is that she was unable to expel the fetus which ultimately resulted in an infection that killed her. Of the [now] 78 whales in the Southern Resident Killer Whale (SRKW) population, only about a dozen are reproductively viable(1) - you don't need to understand population viability analyses to understand why that doesn't sound good.

J-50 is a hopeful sign, maybe the nice round number will be good luck, but this whale faces an uphill climb. Something like 35-45% of SRKWs die within the first year of life. The three pods that comprise this population J, K, and L, are culturally (in terms of diet and dialect) and genetically distinct from other groups of orcas worldwide, even those they live right next to. J pod is known as the "urban orcas", and spend more time than the other pods closer to dense human populations. These whales have astonishingly high levels of toxins, such as PCBs, in their blubber, concentrations which can be as much as twice the level at which seals are known to experience immunotoxic effects. Orcas accumulate PCBs and other toxins from the food they eat over the course of their lives (Figure 1). PCBs are fat-soluble and get passed on to calves in their mom's fatty milk, so females end up with lower PCBs than males (Figures 1 & 2), but first-born calves get the highest dose. 

Figure 1. Yay, boring graphs! Bear with me here: The concentration of PCBs increases in male killer whale blubber as they age. But females start offloading PCBs on calves when they reach sexual maturity. Then whey they stop reproducing they start accumulating again. Reproduced from Ross et al. Mar. Poll. Bull. 2000

Figure 2. Transient killer whales eat marine mammals, higher up the food chain than the salmon that make up most of the residents' diet. That means they get an even higher dose of PCBs. Reproduced from Ross et al. Mar. Poll. Bull. 2000

The resident whales' diet protects them from PCBs relative to transient killer whales (which find seals and sea lions very tasty - biomagnification if you want to sound snooty at your next cocktail party). Ironically, the fish-based resident diet is also a reason they are imperiled. Super classy predators that they are, they really would rather eat Chinook salmon than anything else. Humans are good at copying nature and pretending we invented it, so we decided we also like Chinook...and electricity. We built a lot of dams and et a lot of salmon, so....good luck, orcas!

As a result, in spite of the fact there are at least 50,000 Orcinus orca in the world(2), the SRKW were listed under the Endangered Species Act 10 years ago. There was an awful hubbub about this(3), because globally, the species is no where near in danger. So why should we have to stop eating salmon!? SRKW are listed as a DPS (discrete population segment(4)), meaning they are culturally and genetically distinct enough to be considered a separate population, worthy of their own conservation plan. In spite of added protection, the population of SRKW is now the lowest it's been in 30 years. The 10 year milestone prompted NOAA to put together a report on status of the recovery efforts, and acknowledge that there is clearly ongoing need to improve conservation management efforts.

One major change that conservationists want to make is to dramatically expand the area that is considered "critical habitat" for SRKW, since it has been discovered that, like geese and wealthy retirees, SRKW (at least K and L pods) are snowbirds, and travel as far south as Point Reyes to find food during the winter (Figure 3).

Figure 3. By tracking two whales (K25/Scoter and L88/Wave Walker), researchers found out that K and L pods also get tired of Seattle winter weather. They spend nearly all of their time between January and June time foraging along the outer coast, almost to SF...hipsters. Map by Curt Bradley, Center for Biological Diversity

Given the hell this could raise with fisheries management along the 700 miles of additional coastline being considered, it's pretty unsurprising that this proposal is meeting some resistance. I will undoubtedly be keeping my eyes on this  one.

References and Miscellany
(1) - Female orcas, like elephants and some primates, often live well beyond their reproductive years. How does survival after menopause get selected for? Here's a possibility, and here's a more accessible explanation.
(2) - No one really can come up with a good number for the global population of orcas. Here is one of the better reviews of the data available. 
(3) - The Orca Conservation Network has a great timeline of news coverage of the ESA listing status of SRKW here including efforts to repatriate Lolita, who was captured from L pod in 1970.
(4) - You want more acronyms? I can go all day long!

Tonight at 11: Sea Star Wasting Disease Culprit Caught Red Handed! OR Tune in next week to find out!

Ok, so, unless you've been living under a rock in the marine world for the past 24 h, you'll no doubt have been informed that the mystery of sea star wasting disease (SSWD) has apparently been solved (1). Srsly, it's already in the Wikipedia entry for Sea Star Wasting Disease, get with the program. For those of you who would like a reminder of what SSWD is and why we care: as you wish(2).

This is why we care, because I almost stepped in a gross pile of sea star.
December 3, 2013, Shilshole marina. Evasterias troschelii(?)

Are we all caught up now?

Good because it turns out that it might not be as simple as we would want. This weekend, I spent a few days at a conference, and while in the past I have complained of SCAD, this year, I've really been enjoying the conferences I've been to (more to follow?). I saw a talk this weekend presenting additional data that will soon be published complicating the story. 

But first, let's see where we are: 

The Hewson et al. paper that is receiving so much attention this week appears in an early edition of PNAS, showing a bunch of evidence that this densovirus(3) is associated with the collection of symptoms known as SSWD, e.g., melting, wayward errant arms, complete disintegration of the body within 24 hours of first showing symptoms(4).

Here is some of the evidence the authors are presenting:

1. Researchers took infected individuals, mashed them up, then filtered the diseased mash through a filter with extremely small holes, designed to only allow particles as small as viruses to go through.  Then they took the virus slurry and heated some of it to very high temperatures, which should cause the DNA in the viruses to break apart.  Then they injected some asymptomatic sea stars with the heat-shocked virus slurry (which was subsequently cooled), and some with virus slurry that hadn't been heated. Stars that got the unheated slurry got sick, stars that got the heat-shocked slurry did not. 

• What this means: This shows pretty clearly that a virus, one that is susceptible to heat damage, causes SSWD.

2. Researchers took tissue samples from infected and uninfected stars (total of 28 stars) and looked for whatever virus DNA they could find. Then, after characterizing as many of the viruses as they could, the looked at whether any of the individual viruses was more common in infected stars than uninfected ones. The densovirus they currently attribute to SSWD appeared in 7 of 15 symptomatic stars, but only 2 of 13 asymptomatic ones.

• What this means: A single densovirus was more associated with the symptoms of SSWD in this sample of seastars. 

3. Having a guess about the thing doing the stuff allowed researchers to follow up with a bunch of experiments looking at the amount of the virus (viral load) present in symptomatic versus asymptomatic individuals. They measured viral load in a bunch of  stars collected from the field, and found that, generally, the stars that already look messed up have more of the densovirus in them, BUT asymptomatic stars also contain virus.

• What this means: Having more virus means a star is more likely to be showing symptoms of SSWD. However, the fact that stars that look just fine also have a non-trivial viral load is a bit tricky to interpret. It could be that they are incubating the virus and haven't started to show symptoms, it could be that they are resistant and the virus doesn't cause disease progression in that individual. It could also be that something else causes SSWD that makes stars more vulnerable to this densovirus (5).  

Ok, there's a bunch of other fun data in the paper as well, which makes excellent leisure reading. I suspect no disease of non-commercial marine invertebrates has ever received this much attention. 

Now to the caveat that started this post:

It's a lesson in ecology that as soon as you think you have a story, the next thing you do almost always blows your theory to bits.

Ben Miner gave a talk this weekend at the Western Society of Naturalists Annual Meeting in Tacoma (one of about 40 on SSWD), and showed new data that will soon be published that thicken the plot. Similar to the data shown in the PNAS paper (which he also co-authored), Ben took samples from stars and had them measured for viral load.  However, rather than calling them symptomatic/asymptomatic at the time of sampling, he watched each star for several weeks after the sampling. This way, any infections that were incubating would not be erroneously called "asymptomatic". It turns out when you look at the sea stars this way, the densovirus load is quite a bit LOWER in individuals that ultimately end up with SSWD. 

Well, shoot. Was the previous association of viral load with symptoms just a fluke? Is there another possible explanation? Too soon to tell! 

Science isn't a romance novel that ends all tidily with the one person cozily ensconced (in the PG version) in the other person's arms (trying to avoid being heteronormative here). Science is like one of those radio serial cliffhangers, where you have to "TUNE IN NEXT WEEK to find out how our heroes get themselves out of this jam!" The joy of science is that it is iterative, and this paper represents a substantial advancement of the knowledge on this disease which has been stymying scientists for nearly two years now. We can only wait with baited breath until the next installment!

References and Miscellany:

(1) Actually if you've been living under a rock in the marine world, you might have SSWD, check with your Dr.  (*Editorial Note: J/K, people don't get SSWD, our arms don't walk away like that)

(2) Christmas present to Emily?

(3) This virus is in the Parvoviridae family - which also includes canine parvovirus, to bring it back to something some of us might be able to use as a reference point)

(4) You know, things that generally suck when they happen to you.

(5) But, for the love of God, not radiation from Fukushima-Daichi. If anyone puts this forward as a serious suggestion, I have nothing left to say to you.

Yellow-Bellied Snails OR MORE SNAIL MAIL!!!

Ground Control to Major Emily.

Yeah, Ground Control. Go ahead.

Uhhh, you still doing science out there, Major Emily? 

Sorta, Ground Control. It's complicated.  

...


Well here's some snail mail. New arrivals from Georgia (Fig.1)!

Figure 1. I do declare! Southern snails! We share a love of sitting on the porch drinking mint juleps.

These snails just completed an amazing transcontinental voyage (and, boy, are their arms tired! Just kidding, they don't have arms). Like other molluscan mavens of aviation described on this blog, these guys know how to travel in style - which is to say in a plastic bag, in a cooler, in a box. These are Atlantic Oyster drills from Savannah, Georgia, which are being temporarily re-homed in quarantine in Washington State(1) while they await their opportunity to teach Science amazing things about assessing risk in new situations.

You might recall the Christmas-that-Emily-Ruined Special(2), well it turns out this is the snail I was actually talking about. When I collected this species from the invasive population here in Washington (Fig. 2), those snails stopped eating and hid when they smelled chemical cues from their injured friends - they didn't even need to smell the crab that was eating those friends. They just knew that something was wrong and beat it out of there. It turns out this response is common among invasive snails here, but not seen in native snails(3).

Figure 2. The author, ca. 2009, collecting invasive Urosalpinx cinerea from Long Island, Willapa Bay, WA.

So the question becomes, are these snail species better than our local native snail species at becoming invasive because they listen to their friends when their friends are in danger? That is, do the snails back at home, in Georgia and Massachusetts, also run for their lives when they hear their friends calling for help?  Or, did the pioneer Atlantic Oyster Drills, who left their cozy homes almost 100 years ago on a railroad car headed west to an unknown destiny, in search of a land of endless undespoiled mud to roam, act basically the same as our local native snail species, and natural selection has changed the behavior of the population.  It's possible that the snails that were, quite literally, dumped from the railroad car on arrival, were all basically clueless about the predators in Washington, but some of the snails in that group did run and hide when they heard their friends calling for help when the native predators did attack - and that those snails were the only ones that survived out of the initial emigrees. They were the only ones who could reproduce, and now we have a population where that is the default response.  

Was the invasion caused by snails that listened to their scared friends, or did it result from the invasion that we now have snails that heed the warnings of other snails?

Yellow-Bellied Snails: Invasion Drivers or Survivors?

Since no one back in the early 1900's thought to do the same experiments I have done on the source populations for our invasive snails, and because the logic of time travel makes my head hurt, I'm going to do what is called substituting space for time. If we assume that there has been relatively little change in the Georgian and Massacusettsian (?) snails in the last 100 years(4), we can compare modern east coast snails (in skinny jeans, on their iPhones) to the invasive west coast population. We would predict not only that the Washington population would be more passive-aggressive, but also that they would respond similarly to the east coast snails if running away from cries of help is an invasion driver, or they would respond differently if running away was a trait that was only helpful in the new Washingtonian waters.

Ergo the snails from Georgia, now to keep my fingers crossed that the Masshole snails will make an appearance.  

Fig. 3. Snails from native and non native populations could demonstrate a variety of hypothesized responses that may or may not be related to their native culture and geographic origin.

References and Miscellany:
(1). Don't worry folks, I've got a permit and a lot of bleach and I know how to use 'em.
(2). Specifically Act II, Scene 1.
(3). More on that at some point - it's not really ready for showtime.
(4). This really only applies to the assumption that the selection for response to injured conspecifics hasn't changed, of course there have been other changes. If there have been, for instance, predators that have invaded on the east coast (cough cough, european green crab, I'm looking at you) east coast snails might also have evolved a strong response to injured conspecifics by the same mechanism of the snails that are invasive here. Actually, now that I think about it, that's one good reason to compare snails from both Massachusetts (where the Green Crab has invaded) AND Georgia (where the green crab has not invaded)