Amateur fish autopsy

[Ira]

One of my Serpae tetras had been hugely bloated for a while and seemed to just be getting worse so today I decided to euthanize it and try and do an autopsy on it because it was the second time I'd had a serpae do something similar. So I put it in a glass and put it in the freezer to kill it then got a small knife and the camera then...Well, I didn't have a clue what to actually do with it so I just apologized to the fish and cut it down the belly then up the side on the front and near the tail to try and flip the skin up and expose the organs. My first thought was, "I have no idea what any of this stuff is." But the most obvious thing was a large solid mass that looked far too big to belong there and seemed to barely be attached to anything. But, with a fish that small I guess it wouldn't take much force to tear any tissues and vessels holding it in place. After removing the mass I still didn't recognize anything, but couldn't see anything blatantly obvious. In the upper rear section there looked to be a hollow clear organ that I thought might be the swim bladder and there was a small dark red blob I thought might be the heart, but other than that it just looked like a mess of tissue. I cut the mass open and it appeared to just be a solid pinkish mass.

After showing Jo she thinks that the mass I removed probably was the swim bladder with a tumor. She says it also looks like the heart and liver were a bit enlarged. Which blob the liver is, I'm not quite sure. So, I guess the fish had cancer.

Anyway, here are links to the pictures, they look a lot gorier than it actually was, the inside was a nicer looking pink(as far as guts go, I guess) than red. I think the camera decided to adjust the color balance a bit and made everything redder shown by the white cutting board the fish is on no longer being white. But, since it looks gory I'll just post the links.

The fish

Just after opening the fish's side

The mass(Look at that focusing job, isn't it great? Too bad it's focused on the cutting board instead of the mass)

Organs with the mass removed

After all this I had to apologize again to the poor fishy for making such a mess of him and buried him in the usual fashion with a burial at sea, down the toilet.

[Caryl]

The tfh "Handbook of Fish Diseases" by Dieter Untergasser tells you how to dissect fish and what to look for. Get yourself a copy, it may be useful.

[john1]

HI Ira

Don't be ashamed of not knowing what organ is what. According to Melbourne Bill, a pathologist, even medical students have difficulty what the difference between liver and kydney etc. is. But you should get yourself a microscope. I tried it with one of my dead guppies. The microscope was damaged by my 6 year old son. Put glue onto the lenses. The scalpel I had was blunt. The outcome, a horrible mess of blood and guts. So I gave up. The other fish, much bigger was easier to disect, but without a good working microscope you are back at square one. But it was quite interesting. By the way, I did not appologize to my fish :oops:

John

[Wayne]

Hi Ira.

the fish is really really bloated.

something to note is the diffuse haemorrhage( bleeding) lining the abdominal cavity n organs( peritoneum) that is not normal.

I'd b thinking of something septic like TB( tuberculosis), generalised septicaemia....it could b secondary to the tumour----also, it could b an artefact from freezing---haemoglobin imbibition.

Onto the mass, grossly, if it was indeed a normal misindentifed organ, it would have to b the liver. r u guys sure u saw the liver? It looks fatty n degenerate in this case.

also did u notice any tiny white spots all over the organs?

also, try adding some baking soda into the glass next time. the carbon dioxide anesthetises n basically euthanase the fish. much quicker n less 'painfull' than hypothermia.

just stir it in. 1-2 mins = unconscious.

10 mins ---heart stops.

keep an eye on your other live fish, esp for signs of TB