Nature Blog Network

Monday, July 16, 2007

My PhD in Bean-Counting

Photo courtesy of C.R. Fisher, Penn State

Pascal over at Research at a Snail's Pace posted a spontaneous "8 things" blog meme. This post started as a comment that I just decided to post here, mostly for bragging rights. He states
"I have counted more than 10,000 individual snails and sieved through more than 200 kilograms of mud for my dissertation."

Impressive young Jedi. Let me just recall my last two field seasons of JUST THE GASTROPODS ONLY (don't even get me started on the freaking polychaetes!).

Lepetodrilus schrolli-37,666 (321.67g)
Olgasolarus tollmanni-7,114 (229.88g)
Symmetromphalus sp. nov.-713 (14.08g)
Bathyacmaea sp. nov.-424 (1.36g)
Pseudorimula marianae-72 (0.3g)
Desbruyeresia cancellata-70 (1.12g)
Shinkailepas sp. nov.-43 (0.98g)
Eosipho desbruyeresi-11 (273.57g)
Provanna buccinoides-6 (0.75g)
Bruciella globulus-6 (0.01g)
Phymorhynchus sp.-4 (0.16g)
Lurifax sp.-4 (<0.01g)
Pachydermia sculpta-3 (<0.01g)
Venstia tricarinata-3 (<0.01g)
Planordibella depressa-2 (<0.01g)
Leptogyra inflata-1 (0.01g)
Laeviphitus sp.-1 (<0.01g)
TOTAL # - 46,143 (843.89g)

These snails and limpets, by the way, are from the Lau Basin hydrothermal vent are are associated with communities of chemoautotrophic mussel (Bathymodiolus brevior) and snails (Alviniconcha hessleri and Ifremeria nautilei, counted >1000 each for sure). As an evolutionary biology/statistician friend of mine says, my dissertation is in bean-counting.

The purpose of all this counting and weighing though is to test hypotheses about how communities associated with chemoautotrophic foundation fauna are structured. At this particular locality there are three dense bed-forming foundation species. Each foundation species forms the structure or substrate for a community of associated organisms. I'm in the process of analyzing my data from 2 expeditions right now and will keep you posted on the progress and results!

Initial results look pretty interesting though, some clear cut patterns. For instance, one foundation species, A. hessleri, inhabits the hottest (up to 37 C perhaps) and most toxic (highest concentrations of sulfide) parts of the vents. Its community of associated fauna is very much different than the communities associated with I. nautilei and B. brevior. Both of the latter inhabit low temperature areas with lower concentrations of sulfide (the energy source for the endosymbiotic bacteria inside the chemoautotrophs). In fact their communities are very similar and overlap in Bray-Curtis nonmetric multidimensional scaling plots.


  1. Boohoo...I had count so many individuals. For my dissertation, I measured over 7500 individuals of snails all less than 1mm in height to 2 decimal places.

  2. Well Mr. Craig, no one said anything about measurements! But since you bring it up...

    For my dissertation, I've made 2-4 shell measurements on

    Bathymodiolus brevior 506
    Alviniconcha hessleri 679
    Ifremeria nautilei 1,263
    Total-2,448+46,143 from above=48,591

    Plus over 400 ash-free dry weights.

    Its not 7,500 microsnails, that is truely grueling. Just IDing microsnails is tough enough.

    My official spineless kudos to you Craig.

  3. Hey sorry to comment spam, but I'm not sure if you got my email. would you be interrested to have your song included in our podcast????

  4. Hi AC,

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