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Dardeau, M. R., & R. W. Heard Jr. 1983. Crangonid shrimps (Crustacea: Caridea), with a description of a new species of Pontocaris. Memoirs of the Hourglass Cruises 6 (2): 1-39.
The Great Biological Survey has a long tradition in taxonomy. A collection of researchers and their associates travel to a far-off exotic location* where they spend their time greedily grabbing specimens of everything they can possibly find, before heading back home where the fruits of their labours are sorted, preserved and (hopefully) identified to give an extensive view of the biodiversity of the area surveyed.
*Well, not necessarily that far-off or that exotic. But it can be, and probably a lot more students are drawn in by the prospect of trips to central Africa or the depths of the Amazon than the small patch of remnant bush in the local council park.
Biological surveys are alive and well - I've commented on the results of recent examples here and here, and a current project to recreate the Beagle voyage of Charles Darwin plans to run one on the way (though [a] they're talking about DNA barcoding, a concept that rather raises my hackles - more on that later - and [b] hopefully the captain doesn't shoot himself this time around). Marine biology in particular has a proud history of surveying expeditions, with such examples as the Challenger to look back to.
The "Hourglass" survey began in Western Florida in 1965 and lasted for 28 months, during which samples were taken at regular intervals from stations on the continental shelf of west Florida. Results from this survey were published in a series called Memoirs of the Hourglass Cruises that came to my attention after I picked up a pile of issues of it that had been put into the "free to a good home" pile at the university library. Together, the various articles provide fairly good coverage of the marine fauna of the northern Gulf of Mexico. The Dardeau & Heard (1983) issue is typical in that it not only covers the Hourglass specimens, but takes the opportunity to review the entire Gulf of Mexico fauna (seeing as only one species of Crangonidae, Pontophilus gorei, actually turned up in the Hourglass survey, it could have been a very short paper otherwise). The one aspect that caught my eye was the description of the new species Pontocaris vicina. This species does not seem to be uncommon if the distribution records listed by Dardeau & Heard are to be believed, but had previously not been recognised as distinct from Pontocaris caribbaea. According to Dardeau & Heard, "The two species must have similar but not identical ecological requirements; although taken in successive trawl hauls, they were never taken together in the same haul".
Credits: The photo at the top comes from Wikipedia. Though a crangonid, it is not one of the Gulf of Mexico species. Rather, it is the north-east Atlantic Crangon crangon, one of the more commonly fished shrimp species in Europe.
That last quote was interesting because by 1983 they would not have yet known about the extensive gas/oil seep communities that are now appearing to span from 500 to 3600 meters. The Gulf of Mexico also hosts large abundant deep sea coral reef (mostly Lophelia pertusa) communities, in addition to various sediment communities (i.e. pogonophoran fields, burrowing sea urchins, carbonate outcrops jam-packed with anemones and other coral and antipitharians). The seeps and reefs are major structures forming large communities (our lab is working on both!) that were unknown at that time. So in hindsight, it is not surprising at all that 2 seemingly ecologically similar species should never be found together. They probably occupy different habitats!
ReplyDeleteit's fossilized poop! Also known as a coprolite
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