Sterbai Corydoras can commit venom water bath deaths if stressed??

[Rocky998]

So I knew that corydoras had venomous spines but I didnt know until recently that they can actually "shoot-out" their toxin in the water and then basically commit suicide when doing this in confined spaces (small tank, bag, ect...). I know it takes A LOT of stress for them to actually do this but I just want to be ready...
So if I'll be transporting and putting 15 sterbai into a 10g (WHICH IS JUST A QUARANTINE UNTIL THEY GO INTO THE 40G), will they do this then and if so, what do I do and how should I make sure they have the least stress possible when moving them? Should I use a net??

 

[sharkweek178]

I think I would tell the store to not put too many in a single bag. And when I got my corys, my thinking was to get them out of the bag as soon as possible. So when I got home, I poured them from the bag into a plastic colander then into the tank.

 

[Rocky998]

I think I would tell the store to not put too many in a single bag. And when I got my corys, my thinking was to get them out of the bag as soon as possible. So when I got home, I poured them from the bag into a plastic colander then into the tank.

Yah, I plan to get them straight from the cooler when they get shipped to our lps... I talked to the owner of the store about it and he even agreed...
But I want to ask if they can separate them into 5 separate bags in groups of 3 as well as double bagging them.
But if they cant I guess thats also fine cause I'd be taking them straight from the cooler.

Id have to ask my mom if I could use her strainer .
I dont think she'd like the idea of me using it on fish and fish water... But thats a great idea!!

 

[sharkweek178]

Yah, I plan to get them straight from the cooler when they get shipped to our lps... I talked to the owner of the store about it and he even agreed...
But I want to ask if they can separate them into 5 separate bags in groups of 3 as well as double bagging them.
But if they cant I guess thats also fine cause I'd be taking them straight from the cooler.

Id have to ask my mom if I could use her strainer .
I dont think she'd like the idea of me using it on fish and fish water... But thats a great idea!!

I bought a collander specifically for my corys. I got it for like a buck at a yard sale. Other fish I would use a net. But since corys have spines, I didn't want to risk them getting caught in a net. Since then, I've gotten a brine shrimp net specifcally for corys. Which I'll need when I get some new ones and have to transfer them from a quarantine tank.

 

[Byron]

I never had this problem with any of my cories, but it is well documented as something that can occur. Stress of any kind can trigger it. And I believe it is an issue with all species, they have a pectoral spine (the first ray of each of the pectoral fins) which is extremely sharp.

Fewer fish in each bag is said to help, which makes sense; if one fish is stressed and releases the toxin, other fish in that bag will succumb. At home, pour the bag with the fish into a bucket, and the fish can be netted out into the aquarium or use a plastic container. Tr to keep as much of the bag water out of the tank.

 

[Rocky998]

I never had this problem with any of my cories, but it is well documented as something that can occur. Stress of any kind can trigger it. And I believe it is an issue with all species, they have a pectoral spine (the first ray of each of the pectoral fins) which is extremely sharp.

Ah ok! Nice to know!

Fewer fish in each bag is said to help, which makes sense; if one fish is stressed and releases the toxin, other fish in that bag will succumb. At home, pour the bag with the fish into a bucket, and the fish can be netted out into the aquarium or use a plastic container. Tr to keep as much of the bag water out of the tank.

Yah... What I might do is do temperature acclimation and then just pour the bag of fish into a net over a bucket... Then immediately put them into the tank...
Would this be sufficient?

 

[Byron]

Ah ok! Nice to know!

Yah... What I might do is do temperature acclimation and then just pour the bag of fish into a net over a bucket... Then immediately put them into the tank...
Would this be sufficient?

When using a net, always place the entire net in the tank water and let the fish swim out on its own. This is much less likely to cause the fish to erect the spine and get tangled.

 

[Rocky998]

When using a net, always place the entire net in the tank water and let the fish swim out on its own. This is much less likely to cause the fish to erect the spine and get tangled.

Yup! Got it! And if they dont go out after a while, I may gently move the net back so they can drift out

 

[Byron]

Yup! Got it! And if they dont go out after a while, I may gently move the net back so they can drift out

I find that once the net is submerged, try to keep it fully extended. You can usually achieve this by gentling rotating or moving the net in the water. The fish obviously need to be facing the open side of the net in order to swim out.

 

[Rocky998]

I find that once the net is submerged, try to keep it fully extended. You can usually achieve this by gentling rotating or moving the net in the water. The fish obviously need to be facing the open side of the net in order to swim out.

Awesome! I THINK I got it!
If by rotating you mean actually turning the net handle around like you would with a marshmallow on a stick when making a smores...

 

[seangee]

These guys get shipped all over the world. I have bought cories in store and on-line and never had an issue. As others have said - not too many in a bag.

 

[TwoTankAmin]

This phenomenon is known as self poisoning. Not all cories do it. Sterbai are one species that does. It is a defense mechanism in the wild. One of the Ph.D. members acted as thesis advisor for a Masters degree. The paper is titled "A PROTEOMIC ANALYSIS OF CORYDORAS STERBAI SECRETIONS AND TISSUES" which concluded sterbai do secrete several things a defense mechanism. When this is done in a confined space, especially a shipping bag, it will cause the fish to self poison.
https://www.proquest.com/openview/0...9940d/1?pq-origsite=gscholar&cbl=18750&diss=y

In the wild along, with defensive spines it gives a small cory a fighting chance. But the secretions are quickly diluted and become harmless.

There is a method one can use when shipping sterbai and other species which can release the cocktail of things the do. It is know as "kick the bucket." I know it works because I came into 5-+ adult breeding sterbais when I expected juveniles. I got the to sell et a wekend event and then to keep a few for myself. I had to ship some I sold and then to transport them to the event and to bag them for buyers so they would not self poison.

So how is it done? You start about an hour before you will bag them. You put the fish into a bucket of clean water and then you give the bucket a few quick sold kicks. You are not trying to score a goal, just scare the heck out of the fish. Then wait about 5-10 minutes (with more water/fish longer and less water/fish shorter) and change most of the water in the bucket and repeat the kicking. Do this one more time for a total of 3. Then bag the fish in clean water and ship them. I normally throw a piece of PolyFilter into shipping bags. It absorbs a lot of nast stuff. I usually have about 8-12 fish in two gal.s of bucket water.

If you have a lot of fish use multiple buckets or else change the water sooner and perhaps add a 4th kicking but shorten the time after each kick.. The goal is to induce the fish to exhaust their supply of toxins. I did not lose a single cory from that batch of sterbai and I had a few fry as well that were not expected. I know there are other cory species which can self poison, but I must admit I am not sure which.

 

[GaryE]

It's hard with fish from a store. At wholesalers, they often slap the tank glass 5 minutes before bagging, not using tank water. I've een that in a couple of places. For expensive Corys, they single bag or use small screwtop plastic jars. If you have wide mouthed gatorade bottle around, bring those and the store will single pack. Otherwise, they will hate you. Try to get them to pack with water from another tank, in case the fish fire off the fear hormones when the net goes in.
Pour the water off through a dollar store collander, and in they go.

Btw, I have seen many Cory shipments from SA single bagged. The shippers in South America know the problem better than most hobbyists here, and for the more expensive, uncommon Corys, they take measures. They also put a few pieces of quality carbon in.

 

[Rocky998]

It's hard with fish from a store. At wholesalers, they often slap the tank glass 5 minutes before bagging, not using tank water. I've een that in a couple of places. For expensive Corys, they single bag or use small screwtop plastic jars. If you have wide mouthed gatorade bottle around, bring those and the store will single pack. Otherwise, they will hate you. Try to get them to pack with water from another tank, in case the fish fire off the fear hormones when the net goes in.
Pour the water off through a dollar store collander, and in they go.

Btw, I have seen many Cory shipments from SA single bagged. The shippers in South America know the problem better than most hobbyists here, and for the more expensive, uncommon Corys, they take measures. They also put a few pieces of quality carbon in.

Well I can't do the Gatorade thing lol...
Also, I'd be getting then STRAIGHT out of the cooler from the petstore right when their delivered to them. They get their shipments on Wednesday and they ask for all special orders to be put in on Monday and then ask you to be here on Wednesday when the shipments come in.
They have black bags at the store that I can put the fish shipment bags into and then I'd put that into our cooler wrapped with towelson the inside. It would make it so much less stressful for them!

This sounding a lot more complicated the more we get into depth on it (not what I just said, but as far as it goes for the corydoras committing suicide and preventing that or dealing with it when it happens)

 

[CaptainBarnicles]

I had no idea this was a thing