I have been doing a lot of work on the dissection journal for the past four weeks. The original dissection subjects I used where my american cockroaches. I had read somewhere that these animals needed to exposed to CO2 to put them to sleep and make it more manageable. I decided to use the house hold refrigerator. I placed my subject in the blue box and sent them to slumber in the refrigerator.
I then removed the roach from the refrigerator unit and found my specimen stiff and hard. So I decided to reanimate it using hot water and a heating pad.
Once the animal was heated and seemed tender enough to use for the activity I noticed that its antenna was moving and feet were also kicking. So I decided to finally mount it on the cork board in fear that it may recover. These animals are really amazing.
For the first dissection I made I decided to go and look at the digestive tract of the animal and any other structures present. I actually tried to cut the body at the middle. The problem was that I had damaged one of the organs. So I had to repeat the same procedure on my second dissection.
The second dissection went well I got another specimen and had cut the exoskeleton at the one side but I didn't do the other this was another problem since the fats tend to cling to the attached portion. I could now I dentify the organs and they werent damaged. But the smell from the first and second dissection was really bad like fish gone bad. I had to dowse the speciment in alcohol to reduce the stench.
My new problem with the second dissection was that I had not seen the respiratory, circulatory and nervous structures. I tried to look at other resources from the net and found that some readings said that I could go in dorsally or ventrally it depends on what I would like to see.
Third Dissection Week 12
I decided to do my third dissection dorsally and I followed the same procedures and still saw that the roach moving even after 15 minutes in the freezer. The picture below is the dorsal dissection of the american cockroach.
I found it easier to do the positioning of the scissors for the dorsal cut. When I had cut the middle of the dorsal section of the cockroach the crop just went out thru its back. I had to hurry up and cut a larger portion or risk damaging the organ when it gets squeezed.
The organs where exposed easily than in the ventral dissection but I realized that the nervous fibres and respiratory system resides in the dorsal section.
So my efforts were all for nothing. I decided to make some more research for the dissection methods to expose the systems of interest to me.
I started doing the write up for the dissection manual after the second botched dissection and had researched that digestive system of the cockroach is also called the ailmentary canal. It consists of the saliva ducts and glands, mouth, oesophagus, crop (gizzard) , proventriculus(grinder), gastric caeca(enzyme producer), ventriculus (Stomach), colon (Water retention) and rectum (waste disposal).
I also tried to look at my previous samples and found out that most of the tissue of the first and second dissected specimens had shrunk apparently like us roaches also are composed of water. The stink from the samples was far worse than that of the newly dissected sample. So I guess that all the labeling work and drawing should be done directly after the dissection.
I also noticed that proventriculus is the only bulge on the dried up specimen.
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