Nature Blog Network

Sunday, September 9, 2007

A World Inside a Coconut

In November 2003, while an undergrad at University of California at Davis I was asked by my 2 of my Geology professors if I wanted to help them out on an expedition to hydrothermal vents on the East Pacific Rise. They knew of my interest in vents because they were teaching a 1 credit seminar on Hydrothermal Vents that I was participating in. My undergraduate major in Evolution and Ecology though and was planning on double majoring in Geology. It never happened though, mostly because I didn't want to stay an extra semester and take the two classes I needed to finish the major (coincidentally the same classes I would have needed to get a minor too - Paleoclimatology and Mineralogy).

This expedition was headed by the Field Museum of Chicago as more or less a collecting expedition and other parties with funding came along to share the cruise time. We used the famous Alvin submersible and sailed aboard the R/V Atlantis. Our role as the "geology contingent" was to oversee the night operations which included mapping the seafloor and flying TowCam, the towed camera system the we basically keep from crashing too may times into the seafloor or a cliff or something. It takes a photo every 30 seconds and also has equiptment to measure the alitude off the seafloor, distance of something in front it, particle scatter in the water column, conductivity and temperature. Except for the photographs, all this information is relayed up the cable to the control room where someone has to constantly have their hand on the controls to adjust the feed of the cable, keeping the camera at about 3-5 meters off the bottom. Not an easy task, but needlessness to say the graduate student and undergrad (myself) never crashed while the 2 professors who have done this for years... lets just say the close-ups were awesome!

Being that this was mainly a biology cruise was the real reason I was asked to go. I'm not really a geologist, just a biologist with a good deal of geological training. Being the least senior out of just about everybody on board I was affectionately referred to one French participant (whom I now work with on various projects) as the "ship's bitch". I was in charge of making a "best of" video for the expedition to show off to the Museum's patrons. Basically pulling out highlights and cool video from each dive. I also found my passion was sorting through rocks, sediment, snot, you name it and finding critters. I seemed to be very good at it as the Chief P.I. and other biologists seemed pretty please with my findings! Sorting is still something I take great pleasure in. I get all giggly when a box full of crap comes up from the seafloor, filled with various worms, gastropods, amphipods... its the "what new thing might I find if I keep looking?" that keeps my interests peaked. Other duties were as requested by whomever wanted help (like bleeding the giant tubeworm Riftia pachyptila). I reveled in it all!

Our nights were filled with work, but the daytime was spent waiting for Alvin to return from the bottom. We often peered overboard trying to spot marine life. Often floating debris from islands or continents far away would pass beside the ship with several colorful fish hidden underneath seeking its protection. One day a coconut floated by. I don't know whose brilliant idea it was, but one of the biologists netted it for fun I suppose. As it turned out this coconut was full of wonderful surprises!

All the images, except the picture of myself in Alvin, were taken by my friend and colleague, crustacean biologist T.A. Haney. Unfortunately, I cannot tell you what any of these are, none of the specimens were in my possession since the end of that cruise. I presume they ended up deposited in the Field Museum along with everything else. The barnacle appears similar to species in the genus Poecilasma, but has lateral plates, which I haven't seen in Poecilasma. The clam has a massive siphon! But I think the polychaete steals the show. I can try to ID the family and maybe genus, using Fauchald's 1977 key to polychaetes tomorrow when I'm in the lab.

I just wanted to share these photos for a couple reasons. One is that they have fascinated me since I saw them. All of their coloring is reminiscent of a coconut. Its almost as if they intended to live inside of a coconut hull and have all independently evolved "cocomaflage". It is rather uncanny. I think the currents at 8-13 north run east to west. I'm not sure where the equatorial counter current was at that time and that year, but we were probably above it. Therefore this microcommunity had to have come from Mexico or Central America or an island offshore. We were about 400km from the coast, so it had to travel quite far and all the inhabitants seemed healthy and were responsive. What did they eat in there? Did the species interact? They all appeared to be adult forms.

Observations like this open so many questions for me about connectivity in the ocean. If I end up staying in research after I finish my degree, I will be putting proposals in to study floating microcommunities such as this one. Just think of trolling the open seas in transects and picking up anything you can spot and seeing what lives there. There can be higher and more rigorous scientific questions posed too, other than mere fascination with discovery and natural history. For instance, how do floating communities affect genetic structure of animal species? We can take an island biogeographic model and throw in information about the frequency of immigration events such as these into the mix and see if communities can be sustained or recolonized after local extinction. The role of floating debris, whether natural or man-made, is an underappreciated question in marine ecology, in part of the ephemeral nature of the debris. Anyone want to write a grant proposal? Or give me a job at a non-profit, or a post-doc, or... to investigate cool stuff like this? (big cheesy smile)


  1. Observations like this open so many questions for me about connectivity in the ocean. If I end up staying in research after I finish my degree, I will be putting proposals in to study floating microcommunities such as this one.

    The grand-daddy of drifting oceab habitats, of course, was Heyerdahl's raft Kon Tiki. Pick up a copy of his book of that title sometime and read about the critters they had on and around them as they rafted from South America to the Pacific islands.


  2. That is one of my favorite books ever, even if his theory was ultimately wrong.

  3. Absolutely fascinating. There are very few things that peak my interest as easily as these kinds of isolated ecosystems (or partially-isolated at least.)

    Makes me wish I'd stayed in academia (and, you know, been in the right field to start with.)

  4. RBH, I've been wanting to read it for ages. Maybe after my comps I'll grab it from the library. I've the all the documentaries on it though. Cool stuff. I think his son was repeating the experiment?

    AC, you never know...

    Will, its never too late. Start a non profit and hire me as your scientific director! Just relate it to global warming and conservation and you'll find some money.

  5. Also makes me wonder what impact all that floating plastic has on these critters. Does it create more habitat? Degrade natural habitat? Do the organisms get confused and adhere to the wrong thing? Can they tell the difference between a coconut and floating basketball?

  6. Jason, the thing is that it is temporary habitat right? That coconut has to get saturated or degrade eventually and fall to the bottom. The question remains whether it will make landfall first or whether the coco-fauna will reproduce before they sink. These critters were living inside the coconut if i remember right. But it would be interesting not community composition of different substrates and their characteristics with in a biogeographic province for instance.

  7. How big was that snail shell? From the side it looks like a Carychium shell. Carychium is a land snail genus the members of which are less than 2 mm in length.

  8. Aydin,good question. I would suspect it to be around 1-2cm or less. This is based on the resolution of our dissecting scope (probably 4x) and thickness/transparency of the shell in the photo. Its been almost 4 years since we collected the coconut, I've been thinking about ever since! But my memory is fading.

    I hadn't thought that it could a terrestrial snail since we were a few hundred kilometers from shore and I don't think there were any islands nearby. That shell morphotype is similar to some vent genera too like Desbruyeresia (minus the sculpture) and Alvania. I am not as familiar with shallow water gastropods aside from some intertidal species and neritomorphs.

    I just looked some photos of Carychium and it certainly does look similar. Is it found on the west coast of Mexico and Central America?

  9. Carychium is a widespread genus, but they are never as large as 1-2 cm (or did you mean 1-2 mm?).

  10. Nope, I meant 1cm or less though. I doubt it was greater than 1.5cm. But this was so long ago, my memory is fading.

    I have found lots of microgastropods in some of vent research though. I'll have to post some of the crappy pics I have of them.

  11. Kevin - I sent a message out your way via your homepage contact form. no real need to respond, but just wanted to make sure it found it;s way to you (I've had several messages never be seen going through a "contact me" form)

  12. might i suggest leaving my brother on a raft out at sea for a few months without food or water to see what kind of ecosystem evolves inside him

  13. A fascinating proposal. I am sure it would get funded.

  14. Kevin
    One of your pictures reminds me of a line drawing of a coconut crab (Birgus latro) larva that I included in an article "The Coconut Palm, the Robber Crab and Charles Darwin: April Fool or a Curious Case of Instinct?", written over 20 years go, in which I suggested that both the land living crab and the coastal coconut achieved long distance, oceanic, dispersal together. I cannot now find the pdf document but I have uploaded a text version to if you would care to read it.

  15. Hugh, thanks for the article! I enjoyed reading it. I have a large interest in the history of science and of scientists. Please let me know if the line drawings become available. I would be curious to see the similarities.

  16. Did you manage to key the polychaete? If not, it's the pelagic amphinomid Hipponoe gaudichaudi. These guys are fascinating. Unlike standard issue amphinomids their neuropodia are directly ventrally and the modified setae are pronged hooks - all the better to hang onto their floating habitats. In addition they're protandrous hermaphrodites. Larvae are brooded in the grooves between segments so they don't have to go far to find a home. And no, they can't tell the difference between a coconut & a floating basketball. I took a couple off a hardhat in the northwest Hawaiian Islands.

  17. Incidentally, Martin Thiel has done a variety of work on rafting organisms, capped by a 2-part compendium:

    Thiel, M., & Gutow, L. 2004. The ecology of rafting in the marine environment. I. The floating substrata. Oceanog. Mar. Biol. Ann. Rev. 43: 181--262.

    Ibid, II. The rafting organisms and communtity, ibid. 43: 279-418.

  18. Thanks for the information Leslie! I never was able to key it out. I'll pass that information along to the Field Museum, where I think the specimens are housed. They may have tried to key it out, but I'm not sure there is a polychaete specialist there. I don't know if Todd Haney is still at LA NHM (Dr. Martin's student), he would know.

    I'm rally interested in rafting fauna, so I'll give those references a peek!

  19. Eveything's at the Field, darn it. Todd was under orders to pocket any interesting worms for me but he came back with nothing but images. He insisted that everyone was strip-searched before bedtime for contraband specimens. Todd is nominally still here at the NHMLAC and swears he will finish his ph.d. eventually. We rarely see him though...

  20. the bivalve seems to be a xylophaga
    not sure about id though.




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