Wednesday, February 3, 2010

Morals aside...

The fish dissection was terribly interesting. The poor creature was a sardine from Morrisons, and we began by inserting a probe through his (it had a sperm sack) alimentary canal. We were 'lucky' as the probe came out of his anus, and from here we cut up to its chin and opened it out. At first it was daunting, but soon I became accustomed to poking and pulling the corpse, so it was fine.

We then removed the sperm sack, the intestines and the heart, which was kind of pyramid-shaped. Following this were the gills which contained many red false-eyelash-like surfaces. Upon extracting these, we saw that they had a large surface area to enable gas exchange to take place adequately (this was, of course, the point of the dissection, so it paid off).

After examining the semi-inflated swim bladder which kept the fish afloat when swimming, we moved on to the eyes. At first it was a rather violent affair - we pulled the eye up using the surgical forceps and snipped the connections. After this, it was time to find the lens, and having rolled perforated eye ball around a little, out popped a perfectly spherical transparent ball. This was the fish eye lens, the origin of the eponymous camera lens. This was quite a specimen, and on hovering the lens over newspaper we could read the text, albeit with the distortion that one would expect from a fish eye lens (Google some fish eye lens images if you want to).

Finally, and most brutally of all, we cut open the sardine's head just above the eyes (or, rather, where they were before we ripped them out). Brain tissue was pulled out and we came across the hard cartilage, but then it was time for the ambitious task of removing the spinal cord. With my partner, Sara, grabbing the fish I used the surgical forceps to pull at the spinal cord with all of my supposed might, but, alas, we were cut short and forced to dispose of Lesley, our sardine.

Despite the spinal cord failure, it was a thoroughly enjoyable and enlightening experience, however I can't say I'll soon be cutting up anything outside the human food chain that has been killed specifically for dissection. After all, it's more beneficial to dissect a sardine than it is to eat it.

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