How to preserve body for autopsy?

[GHsaltie]

@Paul B, I will have you know that you were the one who planted the thought for this necropsy. I saw your posts in the thread for that school copperband and it convinced me to take the leap into dissection. I'm not sure whether to thank you or shake my fist!

 

[Lionfish Lair]

When you freeze a body whole, it very hard to do a necropsy on them at a later time.

 

[Paul B]

@Paul B, I will have you know that you were the one who planted the thought for this necropsy. I saw your posts in the thread for that school copperband and it convinced me to take the leap into dissection. I'm not sure whether to thank you or shake my fist!

Most of the time you don't have to get too crazy because the things the fish exhibit just before it dies can usually give you a clue as to what to look for. I mean unless you want to find out if the fish was on LSD, was drunk or had a social disease it should not be too difficult to see what it died from. The vast majority of times it is parasites and you can easily see that in the gills with a jeweler's loupe of magnifying glass. Most bacterial infections on fish will be seen on their surface. If it does from some viral thing, good luck figuring that out. You only need to look very deep if you suspect a swim bladder disorder, intestinal worms or possibly a liver problem. But for us novices, the liver can only be diagnosed as to color and maybe texture if you have a healthy one to compare it to. I often find internal bleeding and can only guess as to the cause. But that usually shows up eventually on the outside of the fish and there is no cure. For other internal problems we most likely will not be able to diagnose it unless we went to medical school and I personally did not.

 

[Be102]

Most of the time you don't have to get too crazy because the things the fish exhibit just before it dies can usually give you a clue as to what to look for. I mean unless you want to find out if the fish was on LSD, was drunk or had a social disease it should not be too difficult to see what it died from. The vast majority of times it is parasites and you can easily see that in the gills with a jeweler's loupe of magnifying glass. Most bacterial infections on fish will be seen on their surface. If it does from some viral thing, good luck figuring that out. You only need to look very deep if you suspect a swim bladder disorder, intestinal worms or possibly a liver problem. But for us novices, the liver can only be diagnosed as to color and maybe texture if you have a healthy one to compare it to. I often find internal bleeding and can only guess as to the cause. But that usually shows up eventually on the outside of the fish and there is no cure. For other internal problems we most likely will not be able to diagnose it unless we went to medical school and I personally did not.

Guilty of also thinking of @Paul B when I originally saw the idea to cut the fish open. I saw the picture and was like 'I couldn't do that' but thought of Paul's words. "its already dead so if you don't learn from it, its a waste' (something along those lines)

 

[Paul B]

You could always eat it.

 

[Humblefish]

His was the quickest death I have seen as of yet. When I came into the store in the morning he was fine. Swimming around completely normal, no blemishes or marks, ate both mysis and nori. I think it was about 2pm or a little bit before I looked at him again, still normal. 3pm comes around and I'm checking up on everybody, he was on the bottom gasping and with the red marks. I net him out to euthanize him and he started having spasms, reminded me of a seizure, and then he passed away.

You just jogged my memory about something. Several months ago I got a group of sick fish from Petco - one of them was a YT. The manager told every YT they had been getting in for weeks would develop these red streaks and then die the same day. I documented everything here: https://www.reef2reef.com/threads/oxygen-while-using-meds.258949/

The fish were all treated with CP, praziquantel, metronidazole & kanamycin. Long story short... I realized I had accidentally overdosed the fish in QT and near the end appetite suppression was pretty bad. The YT had stopped eating but never looked "bad" after a few days in meds. After medicating all of them for 12 days, I decided to do a transfer into a holding tank (out of meds) in order to assess the situation. This photo was taken just 30 mins before the transfer:



The YT had a very bad reaction to a FW dip I did on all the fish (to double check for flukes) before being placed in the HT. 6 hrs later he developed these red marks (photo below) behind his pectoral fins (both sides) and died :



I never was able to do a necropsy (strapped for time) to determine if his liver ruptured from overmedicating, or this was a bacterial disease/infection that was kept at bay by the concoction of meds. But quickly returned once the fish was taken out of meds.

 

[GHsaltie]

Third yellow tang is about to die, same exact symptoms as the previous two. It's real small so it will be difficult to do a necropsy but I'm going to give it another go.

 

[Lionfish Lair]

I'll be interested to see if the organs are as dark as the other photos.

 

[Humblefish]

I'll be interested to see if the organs are as dark as the other photos.

Are you thinking Tuberculosis/Mycobacterium? Or something else?

 

[Lionfish Lair]

Im missing my books, right about now. I had several horses with confirmed myco and the innards didn't look like that. Congested organs/old blood can look like that, but I would expect more frank blood in the cavity. Necrosis can be dark, but that has the "old blood green" to it, so I don't think it's organ death. Not much about those organs look right though.

Lemme see if I can access my online drive....

 

[GHsaltie]

Fish passed away 3 minutes ago, the first sign of the symptoms were about 40min ago. The fish is in a freshwater dip right now, just because , but I'm about to head home so the body will be a lot fresher upon dissection. Is there anything I should specifically look for? I have a small microscope so I can take a scraping or samples, but a little bit of guidance would be appreciated . This has thoroughly piqued my curiosity!

 

[Humblefish]

Im missing my books, right about now. I had several horses with confirmed myco and the innards didn't look like that. Congested organs/old blood can look like that, but I would expect more frank blood in the cavity. Necrosis can be dark, but that has the "old blood green" to it, so I don't think it's organ death. Not much about those organs look right though.

Lemme see if I can access my online drive....

Appreciate it, Renee. All my "good stuff" is on my primary desktop in storage, and I'm in a hotel working off a laptop.

 

[saltyfilmfolks]

This has thoroughly piqued my curiosity!

Me too.

drive faster.

 

[Lionfish Lair]

Maybe scrape some cells off the skin and see if you note something odd. Sometimes you can move an iPhone over the eyepiece to snap a picture. I don't think you'll find much, but you never know. Did you see a little ballon type organ towards the top? I don't see a swim bladder. It may have ruptured during the necropsy, however and the silver tissue you see towards the tail could be it. Where the gut ruptured, it's a distinct possibility.

 

[Lionfish Lair]

The fresh specimen may give us a better idea of overall organ color. Hemorrhagic septicemia is a possibility.

 

[Tautog]

I've seen this before on wild fish, and based on Humblefish photos, and the fact that all your fish have died from the same thing, I'm thinking it's a parasite. Usually, once the host(your fish) dies, the parasite transfers to another host. A new fish, or stressed would be the ideal host for such parasites. I fish on wrecks in the ocean where I catch Tautog, aka Blackfish. Many of these fish have the same red lines, but are still living in the wild, whereas other species caught on the same wreck have none.
I'm more concerned about how dark the organs are, maybe something they got during collection.

 

[GHsaltie]

@saltyfilmfolks don't encourage speeding I can only go so fast! Besides I had to make a stop on the way home to get some l-lysine for my immune deficiency cat, poor baby feels like crud.
About to start, it's been 1hr 53min since the tang died. This time I'm going to be much more gentle, much more thorough, and take a lot more pictures. Let the investigation begin!

 

[tyler1503]

So....how did that fillet taste?

 

[GHsaltie]

I got a little bit of skin sample.


Right after passing. I also noticed the fins are ragged.


I accidentally poked the intestines again, oops.


Is the pink thing the stomach or liver?


What's the black globule? Is seemed to be attached to the intestines and the pink organ. It leaked green fluid when I accidentally busted it. Do fish have gal bladders?

 

[Lionfish Lair]

Nice job! That coloring is SO off. The pink is probably the liver. Yes, they have gallbladders, but was that towards the front or towards the back of the organs when it was just sitting in there? I see the swim bladder this time and it looks intact. That gut looks necrotic. I wonder if it could be some sort of viral hemorrhagic septicemia. I can't look at type at the same time, so I'm going to go look a little more closely.