One of the bizarrest parasitic relationships you will ever see

My good colleague Janine Caira wrote a paper way back in 1997 about one of the strangest parasites ever recorded in an animal.  This paper has stuck with me ever since, I think because I saw the original photos when I visited the lab of one of the other co-authors George Benz, when he was with Tennessee Aquarium (he's now at Middle Tennessee State U.).  So, I thought I'd revive it for you guys; the story goes like this:

Janine and her co-author Nancy Kohler had received a report from a longliner of a really big foul-hooked shortfin mako caught near Montauk, NY.  (a shortfin is shown at right, from discovery.com, this one with plenty of parasitic copepods on the dorsal fin - it sucks to be a shark sometimes).  Now, Janine is the queen of tapeworm taxonomy in sharks and rays - believe it or not, there's lots of them - and had visited Montauk before to collect parasites during catch-and-kill shark tournaments held there.  To make the most of the unfortunate death of this mako, they raced across the sound from Connecticut to collect parasites from the beast.  It was a huge animal, nearly 900lbs, and during necropsy, as they say in the paper, they "were astonished to find two anguilliform fish in the lumen of the heart".  Thats right, eels; this shark had two eels living in the chambers of the heart!  These particular eels, called pugnose eels or Simonchelys parasitica, have been recorded before burrowing into the flesh of halibut and other large North Atlantic fishes (hence their species name), but never completely internal and certainly not in the lumen of the heart, so this was a truly remarkable find. 

Janine and her colleagues were unable to determine the path of entry, but they showed good evidence that the eels were alive in the heart prior to the shark being killed and put in the fridge, because their guts were full of blood and there were pathologic changes to the heart.  Their conclusion?  That this was a facultatively parasitic relationship.  In other words, the eels didn't need to be living in the sharks heart (that would be obligate parasitism), rather they took advantage of an opportunity to get a meal.  They proposed that the eels probably attacked the shark after it had been hooked and was dangling, distressed, from the longline.  They had some evidence that the shark was probably resting on the bottom, which may have made it easier for the eels to find.  The pugnoses somehow gained entry (hypothesised to be through the gills) and made their way to the heart, where they dined on the beasts blood up until it died.  Maybe they would have burrowed out again after the animal expired, maybe they would have suffocated (remember - the eels had be swimming in and breathing the sharks blood once they were inside, how bizarre is that?).  We'll never know because the carcass went in the fridge, which ended things for the eels, but also led to this amazing discovery.

The horrifying part is that the shark was almost certainly alive as the eels made their way into its flesh and began to consume its life blood from the inside.  It would have been a long, slow and nasty way to go out.  It just goes to show that even when you are at the top of the food chain, you're never really at the top of the food chain...

Caira, J., Benz, G., Borucinska, J., & Kohler, N. (1997). Pugnose eels, Simenchelys parasiticus (Synaphobranchidae) from the heart of a shortfin mako, Isurus oxyrinchus (Lamnidae) Environmental Biology of Fishes, 49 (1), 139-144 DOI: 10.1023/A:1007398609346

When acute gives way to chronic, Deep concerns for the Gulf set in

Just five days before the Deepwater Horizon oil rig exploded in the Gulf of Mexico, I wrote a piece for this blog about a different oil spill in Australia, when a Chinese coal ship called the Shen Neng1 ran aground in Queensland and spilled thousands of gallons of fuel oil onto a section of the Great Barrier Reef.  The gist of that post was that, horrible though they may be, there's no great cause to worry about acute events like that, because many marine ecosystems show remarkable resilience in the face of singular disturbance events.  About a week later when the BP spill started, therefore, I had confidence that the well would swiftly be capped, the oil would dissipate, Gulf life would return to normal and folks would all move onto the next media-hyped panic-fest.  But, as the days have dragged into weeks and the weeks are now dragging into two months and counting, and as the estimates rise of the amount of oil that continues to leak, and as successive attempts to cap the thing have failed, that confidence that the Gulf can recover to the same state it was in before the spill has started to get ever more shaky.

Now, I like to be a positive person; I try to see the upsides in most situations and not get caught up in negativity, which I consider one of the greatest and most utterly pointless malignancies of modern society.  But, following the coverage in the mainstream news and on excellent blogs such as DeepSeaNews and Observations of a Nerd and thinking about the problem in terms of ecological processes, it seems to me that we may well have passed a tipping point and that the ecosystems of the water column, benthic (bottom) habitat and coastal marshes may never return to their former states, even if they could stop the flow right now.  This principle has been elegantly captured by the "rolling ball" analogy, wherein an ecosystem has, by virtue of its structure and complexity, a sort of "potential energy" like a ball on a hill and that, if disturbed hard enough, you can start cascades that see the system diverge - the ball rolling down hill - until it settles in a new organisation - a dip in the hillside.  The important point is that getting the ball back up the hill to the former state is next to impossible, or at least requires inordinate amounts of energy and a thorough knowledge of the organising principles, which we lack.

What does all that mean for the Gulf, though? If a Spartina marsh isn't, then what is it?  What happens in the water column?  On the bottom?  That's where research comes in, and I was encouraged to read on the NSF website and by conversations I had with NSF and NOAA Fisheries Service program officers yesterday that they have spent all available money on rapid response grants, most recently an NSF multi-institutional cruise coordinated by UGA to study microbial responses in the water column.  Its not enough though, and the slowness of the peer review-based funding systems we have just can't meet the needs of a crisis of this magnitude fast enough, once the rapid response fund is tapped out.  It really needs executive intervention: if the White House can propose a Wall Street or Auto industry bail-out, why not a rapid response research and rehabilitation fund?  We can bill BP later!

Where is this all headed, and what should we expect to see in a "new" and different ecological regime in the Gulf of Mexico?  No-one can be certain at this point, but a hall-mark of such reorganisations is loss of diversity, and in any worldview, that is something to be lamented.  Lets hope it doesn't come to that, but at this point any concerns you may have that the damage to the gulf is irreparable could be forgiven, which is more than I can say for those responsible for this mess.

The solution to Bit-o-Critter round 23a

Well the last BoC was a double header and the first one went off quickly.  Miriam got it right first time - a pycnogonid or sea spider.

That just leaves the fish in 23b.  It might take you some searching to get it right, but there's enough info there for a full species ID.  Good luck!

Play Bit-o-Critter Round 23

OK folks, double header this time, and you can only guess at one of them, so make your choice carefully...

23a - general group will do

23b - full scientific name if you please

The solution to Bit-o-Critter round 22

Well I really have to hand it to juliebug.  I was sure I would have stumped you guys on that last one, but no!  Julie nailed it - it was a sea pig, a bizarre deep sea holothurian, a sort of sea cucumber.  These pallid little blobs inch their way across the abyssal depths, eking out an existence on the snow of detritus raining gently down from above.  Great job Julie, truly impressive.

Best. Torch job. Ever.

I've been humming and hawing about whether or not to post this, but I just can't resist.  A colleague at a university where I used to work recently retired, and the dean sent around invitations to his retirement luncheon.  Well, it seems our retiree was not leaving with the best taste in his mouth, so he sent the following (to the Entire School!).  Since he seems to care little who knows, I share it with you here in the hopes that you may enjoy it.  (I have removed the names to protect the innocent, and the guilty)

“Dear [Current dean] ,

I do not know how to tell you this, but my heart is not in this retirement celebration shindig. I will not be there at the lunch that you are planning for me. I hate [distinguished professor]. I hate [former dean]. I hate the entire Mechanical Engineering Department. I hate the way you all treated me over the past 43 years. I think that it is disgraceful that you are asking people to pay for their own wretched lunches to come to honour me. How uncivilized can it be? After all the millions of dollars I brought into this univesity [sic], can't it afford to pay for a lousy luncheon in my honour? I never got a proper promotion or a meaningful raise in salary while inferiour individiouls [sic] got promoted and bloated into disproportionate levels [sic]. I got a copy of the latest [University] magazine. According to it, the average salary (9-10 month) of a full professor at [University] is 125,000 dollars. Mine isn't even 100,000! Thanks a lot!!!!!!!!!!!!!!!!!!!! My linternational [sic] famous laboratory (see your own write up) was invaded and destroyed by in January 2007 and I was put out of scientific research for good in order to take care of a newly brought assistant professor. I say, the hell with you all. I hope the [University] stink will not stay on my skin when I leave here and go happily to Hawaii.


With nothing good to say about any of you at all, I remain

[Disgruntled retiree]"

Check out this crazy footage of silver carp!

I guess they don't like the electrofisher much...

Zoiks! A 5 year ban on the Southern New England lobster fishery?

I've been part of research efforts on lobsters in southern New England on and off since 2002.  The fishery is in dire straights due to a range of problems like overfishing and infectious and metabolic diseases likely brought on by a changing climate.  But I was still surpsrised today by this article outlining a proposal to the Atlantic States Marine Fisheries Commission by its lobster science committee to suspend the lobster fishery south of Cape Cod for at least 5 years to allow it to recover from these recent dramas.

Quite honestly I can't see the proposal getting approved.  It would kill whats left of the existing fishery and I agree with the lobsterman quoted in the story that the infrastructure would simply go away (they could convert to trawling or dragging for scallops, but that ain't much of a fishery these days either).  Maybe that's what it needs.  Maybe it would never come back.  Maybe there IS no lobster fishery in SNE anymore.   I don't know, but it certainly speaks to the seriousness of the state the fishery has come to.

Testing, testing...

I'm posting this video I took of a whale shark in Mexico, to test the embedding of YouTube videos in Blogger posts.

Play Bit-o-Critter, round 22

OK folks, try this one on for size.  A common name will do, this time around. Post your best guesses in the comments section, the winner gets bragging rights and the undying admiration of their fellow readers.

The solution to Bit-o-Critter round 21

We have a new face in the BoC winners circle this week.  Sarah F. correctly identified the critter from round 21 as a stargazer.  That's a pretty impressive effort, because I didn't give you much to go on.  If you've never met one before, stargazers are bottom-dwelling fish that are the consummate lie-in-wait predator.  And when I say bottom-dwelling, I mean IN the bottom.  Usually all you can see is the grumpy looking eyes and mouth, both of which have migrated to the top of the head over evolutionary time, because they bury the rest in sand for camouflage.  They are not related to flounder or other flatfishes, though, which becomes abundantly clear if one ever leaves the sand to hit a passing bait or fishing lure; no, they are a beefy bulldog of a fish.  The other important difference from flatfishes is that the eyes and mouth are truly on the top of the stargazer's head, whereas the eyes of flounder have both migrated to one side of the head (this process can be seen during development) and the mouth remains terminal.

Nice job Sarah!

Tampa, here I come!

This weeks victims of Dr. Dove's parasitological prattle are the students of the Diseases of Warmwater Fishes course, held by the fine folks at the University of Florida Vet School and the UF Institute for Fisheries and Aquatic Sciences Tropical Aquaculture lab in Ruskin.  Its a bit like AQUAVET in that students stay put and faculty rotate through, but this one doesnt include inverts or coldwater fishes or any marine mammal stuff.  So its a lightning trip down to Tampa to lecture on principles of fish parasite identification, or something like that...

While we're talking lobsters

Shell diseased lobster
Originally uploaded by para_sight1

I was going through my Flickr collection and came across this shot of a lobster, Homarus americanus, showing typical signs of epizootic shell disease. This is an emerging problem in Southern New England, wherein lobsters show these unsightly ulcers that erode down into their shells, eating away the hard parts until,all thats left is like rice paper. This one is mostly typical in that the lesions start in the middle of the back. Why? Its not well understood, but it is the only part of the body they can't reach to groom, so that may be part of it. Current evidence says ESD lesions are caused by bacteria and that one bug in particular, Aequimarina homari, is pretty important, but the environmental triggers are unknown. Any way you slice it, its not good for lobsters and certainly no good for the lobster industry.

The solution to Bit-o-Critter round 20

Juliebug identified the round 20 Bit-o-critter as the green turtle Chelonia mydas.  With that, she takes a commanding lead in the BoC stakes.  Will no-one challenge her supremacy?  Ya gotta be in it to win it folks...