Wood, It’s What’s For Dinner

Figure from Hoyoux et al. Munidopsis andama from a woodfall. Note the spoon shaped claw.

Figure from Hoyoux et al. Munidopsis andama from a woodfall. Note the spoon shaped claw.

A deep-sea crab walks into a pub and asked, “Where’s the bar tender?”

ResearchBlogging.orgFew deep-sea organisms rely on food originally from land.  Most deep-sea dwellers rely on  marine snow (detritus raining from the surface), large food falls like dead whales, or chemosynthetic pathways like those at hot vents and cold seeps.  This makes sense.  How much land plant material makes into the deep sea?

Apparently enough to make a living on.  When chunks of wood make it to the seafloor, they form specialized communities, i.e. wood-fall communities.  As the wood degrades, bacterial mats form, clams bore into it, and a host of other organisms come in to feed.  New work in Marine Biology suggests that the most dominant group after mollusks, the crustaceans, may also be feeding on the wood.  Researchers found wood in the gut of Munidopsis andamanica, a squat lobster commonly found at woodfalls.  Further work indicates that a resident gut microflora of bacteria and fungi exist that may aid in digesting wood fragments.  However to eat wood a species is going to need a robust digestive system.  Roughage, indeed!  Detailed anatomical analysis revealed that the mouthparts and gastric mill, i.e. stomach, were modified to be stout enough for a lumber diet.  The claw is also spoon shaped and thought to serve as a utensil to bring wood bits to the mouth.

M. andamanica thus represents another  pathway by which carbon cycles derived on land cycles into the deep sea.

From Hoyoux et al. Cross sections of material from the gut.  If you remember anything from high school biology, you will know that those blue-green clumps of circle are plant xylem

From Hoyoux et al. Cross sections of material from the gut. If you remember anything from high school biology, you will know that those blue-green clumps of circles are plant xylem

Hoyoux, C., Zbinden, M., Samadi, S., Gaill, F., & Compère, P. (2009). Wood-based diet and gut microflora of a galatheid crab associated with Pacific deep-sea wood falls Marine Biology, 156 (12), 2421-2439 DOI: 10.1007/s00227-009-1266-2

Dr. M (1743 Posts)

Craig McClain is the Assistant Director of Science for the National Evolutionary Synthesis Center, a National Science Foundation supported initiative. He has conducted deep-sea research for 20 years and published over 50 papers in the area. He has participated in and led dozens of oceanographic expeditions taken him to the Antarctic and the most remote regions of the Pacific and Atlantic. Craig’s research focuses on how energy drives the biology of marine invertebrates from individuals to ecosystems, specifically, seeking to uncover how organisms are adapted to different levels of carbon availability, i.e. food, and how this determines the kinds and number of species in different parts of the oceans. Craig’s research has been featured on National Public Radio, Discovery Channel, Fox News, National Geographic and ABC News. In addition to his scientific research, Craig also advocates the need for scientists to connect with the public and is the founder and chief editor of the acclaimed Deep-Sea News (http://deepseanews.com/), a popular ocean-themed blog that has won numerous awards. His writing has been featured in Cosmos, Science Illustrated, American Scientist, Wired, Mental Floss, and the Open Lab: The Best Science Writing on the Web. His forthcoming book, Science of the South (http://www.scienceofthesouth.com/), connects cultural icons of South such as pecan pie with the science behind them.


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8 comments on “Wood, It’s What’s For Dinner
  1. That is really cool… how common are these woodfall communities, and is there any general rule of thumb about where they are found? For example, are they more common in estuarine environments, or shallow bays near land?

  2. DeLene,

    The woodfall communities discussed here are on the deep-sea floor, past the continental shelf and over 200m deep. As whether certain areas possess more woodfalls than others no actual data exists. Speculating, you would expect more where the continental shelf is small and the deep sea is closer to land or where at major river outputs.

  3. Okay, I totally should have known that (past the continental shelf = deep sea = this is the Deep Sea News blog) but that is nuts to find wood so far out… That would make a lot of sense that you would expect more where the shelf is smaller/narrower. Thanks for the insight!

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