Wednesday, November 4, 2009

Be brave, like prawn


Menu boy no be coward, like shrimp; menu boy be brave, like prawn.
-The Simpsons, Episode CABF01, "Lisa the Tree Hugger"
I took a picture of this giant freshwater prawn (Macrobrachium rosenbergii) at the Smithsonian National Zoo in Washington, DC, specifically so I could make a motivational poster for Lisa. Having completed my mission, I'm now filled with rage - it turns out that Macrobrachium and many other so-called "prawns" are not true prawns at all: they are freshwater shrimp. Some helpful Australians have provided clarification:
...there is one sure way to tell them apart. In shrimps or carideans the side plate of the second segment of the abdomen overlaps the segments in front and behind. Prawns, most of which belong to the family Penaeidae of the group Dendrobranchiata, have all the abdominal side plates overlapping tile-like from the front. A more fundamental difference but one impossible to appreciate in a single specimen is that female prawns do not brood eggs but shed them into the currents where they develop independently. It would therefore make sense to call all member s of the Penaeidae "prawns" and members of the Caridean "shrimps" and this is what most Australians do....Confusion arises when we hear Americans refer to prawns as "shrimp".
So that settles questions of anatomy, but not courage. Is there any relationship between location of abdominal segmants and strength of character? I leave that to the decapod philosophers.