The Salmon Dissection Takes Place...

Well, the real dissection took place today. There were 5 salmons, and each group get one. They were pretty small, unlike the one teacher used last week. However, as you know, salmons are usually big enough for dissection.

As for the dissection, I did about 80 percent of the cutting (everything except the gills). I cut and pull out all the organs except the gills and the tongues. First, we had to make a cut from its vent to its throat. It was very slippery and frankly, not easy. I did the cutting, barehanded, because nobody else in our group, including the ones that brought gloves, wanted to cut it. Then, I pulled out the milt sac, the liver, the spleen, and the entire digestive system including the esophagus, the stomach, the pyloric caeca, and the intestines. After that comes the swim bladder and the kidney, which is a long blob of black jelly stuck to the backbone. At last, we took out its gills, eyes, and its tongue (believe it or not). I included a brief description (no pictures, sorry about that) on each organ.

Mouth
Obviously, this is the first place that food is processed. Salmons don't have grinders in their mouth; they have only sharp teeth that snatch and rip the food. Their favorite food is herring - small fish that often travel in large balls with thousands of them.

Esophagus
This is the first place that food come in after it goes through the mouth. It's a passage way between the stomach and the mouth.

Stomach
Well, you all know this, but food digestion take place in the stomach. It's pretty much like our stomach, except that it's much smaller. It breaks down food chunks into tiny ones and pass them to the pyloric caeca. Also, we found nothing in it because salmons don't eat when they return to their spawning ground.

Pyloric Caeca
This spaghetti-like organ is sort of like our small intestines. Here, the nutrients and minerals in the food get absorbed into the body and turn into energy and other stuff. It's a very important organ, and it's appearance is very obvious - the first thing you might notice besides the liver.

Intestines
The intestines are the last step of digestion. It's pretty much like our large intestine, and it absorbs water and other stuff. The poop will just get pushed into the vent/anus and out of the body.

Liver
The liver secrets liquids to help digestion and it break down chemicals so that it can be turned into energy for the body. It's quite large compare to other organs, and you can just pull it out easily.

Spleen
The spleen is a tiny organ with lots of blood vessels in them. It's purpose is to produce white blood cells and to store extra blood in case there are emergencies. It's very tiny, and it's just right beside the pyloric caeca. It looks like a tiny version of the liver, but of course, it's purpose is much different.

Heart
Well, same as most animals, salmons have a heart. It's a tiny triangular shaped organ that pumps blood to the circulatory system. It's location is close to the head, and it's right beside the gills. Surprising, eh? Well, think about it, our heart is right beside the lungs, why? Because so that it can have the fastest access to fresh oxygen! That's the same in salmons.

Gills
The gills are one of the hard areas to dissect. It's pretty hard to cut it out, and what I did was I just ripped it out some of them. Also, my friend cut out some of the gills. Anyways, the gills are the lungs of salmons. Water goes through their mouth, and pass by the gills. There, tiny blood vessels absorb the oxygen from the water and transport it to other places in the body.

Swim Bladder
The swim bladder is like a balloon. It can inflate and deflate to support buoyancy for salmons. If you are careful enough, you can use a straw to inflate it. However, because when I was ripping out the milt sacs, I accidentally ripped a hole, we didn't inflate it successfully.

Kidney
The kidney cleans and filters the blood and produce urine from the waste that passes out of the vent. Unlike humans, salmons have only 1 kidney, and it's a long black strip attached to its backbone. It's very easy to get it out by running your finger along the sides of the backbone. Well, it's pretty gross too. However, I did it - and took out the "black jelly."

Eyes and other organs
Well, we took out the eyes and the tongue too. It's pretty easy to get the eyes; just poke it out from inside and then rip it. The tongues were a bit harder. I first opened the mouth, and then other people just pull it out from the throat. It's gross, I tell you, but not as disgusting as the internal organs. Also, salmons have brains too, but it's very tiny (about the size of a pea), and hard to dissect. We didn't do it because the teacher didn't allow us to do so. It's amazing how salmons can go back to the stream they were born by instinct and without any guide.

If you have any more questions about this, feel free to email me. Also, there's an exam on Thursday, so I'd better get to study... I heard that it is 10 pages long... Although it might not be, but it's better to study too much rather than not studying enough.

Anyways,
Have fun!