The Vein of a Shrimp

I was sitting in front of my computer, browsing one page after another with regard to the neural system, when a sudden thought dawned upon my collection of neurons... (Eerm, not exactly a thought, but a recollection of a previously unanswered question)

What actually is the black line down the back of a shrimp?

For years I have always thought that it's a vein or some kind of circulatory system, so I savoured all the prawns / shrimps with no qualms. Prawns are definitely one of my all-time favourite, and here in Melbourne there are times I miss prawns so much because of its exorbitant price. But whenever I have them, it's always a rewarding experience.

One day when Xuan Ni and I were in the Queen Victoria Market, we came across this label called "De-veined prawns - 16 per kg". Then there was I asking her why in the world people cared to remove the vein in prawns, when we normally cook all the bloody gory chicken or beef without caring the least about the bloods. She replied, to my surprise, that the veins are actually their, eerrr, shits.

** shock **

** disbelief **

It was a rather disconcerting piece of information, but I soon got over it (as with most things that I ever came across). But today, somehow this question popped out in my brain again when I was reading this page. I decided to take a well-deserved break and look it up using Google. And that's how I had the moment of truth.

They say the truth is ugly, but they forgot to mention that sometimes it's also disgusting. I mean, I've heard of a crab log, but a shrimp log is something entirely different. The absolute straight dope is that the black line found in most shrimp is its intestine. And yes, sometimes that puppy is so full as to threaten to practically burst, taking out the shrimp and anything within several inches of it. Not a pretty sight, but welcome to the shadowy trenches that lie between science and journalism.

To be accurate (and this is the Straight Dope, after all), the black stuff is the contents of the intestine and not the intestine itself. If you've ever spent any time preparing shrimp, you would know that after tearing off their heads, ripping off their shells, and then eviscerating their little corpses, every so often you come across one without the dreaded black tract. That's because the actual colon is a transparent tube of cells and that particular shrimp's colon was empty. More demonstrable evidence can be found in those shrimp whose intestinal contents are incomplete; sometimes that little black line looks more like a sequence of dots and dashes instead of one long continuous line. Yet, when you remove one, it all comes out, held together by a nearly-invisible strand.

And here I am, 20 years of shrimp intestines.

I guess next time I will spend the extra 2 dollars for some "deveined" prawns. :P


ps: I stumbled upon another enlightening page about the differences of prawns and shrimps. I never knew that they are actually not the same.