orange Venezuelan cory catfish, no chill?

[Odd Duck]

On 3/12/2022 at 11:54 PM, Torrey said:

@Odd Duck were you able to catch the Members talk on cory venom?

I didn’t, but I’ve been reading up on it when and where I could since hearing about it.  I need to get my membership but I’ve heard it doesn’t sync across devices right unless you first sign up with a PC.  I need to drag out my aging laptop and fire it up, then it will want to update, etc, etc.  It will take hours to get it done.  I need to, but clearly haven’t gotten there.  I really want to watch the talk on Bettas as well.  My work computer system must have some blocks set up on them because I can’t get to YouTube or ACO on it to figure out how to sign up while I’m at work.  I’m rarely there at the same time as our IT guy since I’m Sunday, day, and Wednesday overnight.

 

I suspect some venom release at some point, may have played a part in the heavy losses I had with my orange laser cories.  I know they were freshly imported.  They passed gradually over almost 2 months time with not a mark or lesion on them.  I was not able to determine a cause of death, but I didn’t do post-mortems but wish now I had.

The typical deaths from Cory toxins appear to be almost immediate (within a few minutes) from acute inflammation that is thought to be from a soup of various prostaglandins released from what appears to be a venom gland behind and slightly below the pectoral fins.  Prostaglandins can act in a variety of different ways in the body, both good and bad.  But any cause of severe, acute inflammation is known to have potential to cause significant liver and kidney issues in a variety of species.  I’ve been wondering if that isn’t the cause of some delayed deaths in some cories.

Most of this info I got from a quite well-done study I found for a graduate student’s Master’s Thesis using sterbai cories.  It was very detailed and goes into great depth on the study methods and protein handling techniques.  Suffice to say, it’s doubtful we’ll ever have a tank-side test for these toxins.

So we can’t test for it, it typically acts very quickly with a mix of compounds that may increase uptake and cause severe inflammation.  I suspect it could also have potential for long-term side effects, and we would never be able to tell if we were buying a cory with a sub-lethal exposure for acute death, but could have had a less acutely lethal exposure that still caused liver or kidney failure over days to weeks.  🤷🏻‍♀️ Not much we can do about that but try to buy from local breeders with fish that are more acclimated to domestication and therefore less likely to get stressed enough to release the toxins.

Edited March 13, 2022 by Odd Duck