Ethically Culling Fish

[umfalcon]

Hello everyone,

I am really getting into breeding fish and before I get too deep I want to know how to ethically cull fish from people who actually have experience doing so. The Internet is all over the place on how to cull fish so I am turning to you all, my fellow aquarists. I ask about culling because I know when breeding enough, deformities, weak fish, and other issues will appear and make culling necessary, I just want to cull as ethically as possible.

[Daniel]

I had a baby angelfish with no tail once. It was in a batch of baby angelfish in a community aquarium where maybe 10 out of the original 500 baby angels survived being eaten by the other fish in the aquarium. The complete lack of tail didn't seem to cause the fish any problems. We called the fish 'Stumpy'.

Most of my baby fish are raised in community aquariums so only a few make it to adults. It is rare for a fish with a deformity to survive the growing up process in a survival of the fittest situation. If they survive then they have what it takes and I keep them.

[umfalcon]

@Daniel I hear ya. However, I trade the fish I raise to the local fish store and I can’t give him deformed fish. I guess I could just separate the culls into another tank but I don’t have a ton of room to do that.

[Daniel]

Just now, umfalcon said:

@Daniel I hear ya. However, I trade the fish I raise to the local fish store and I can’t give him deformed fish. I guess I could just separate the culls into another tank but I don’t have a ton of room to do that.

Stumpy was one of the Leopoldi angels I sold recently to my LFS and when I sold the batch I pointed him out as one of the fish. Somebody bought him.

[Ken Burke]

Ethics in fish keeping is a really tough subject to tackle in a forum.  You’ll find people have an wide range of opinions.  
 

Things to think about: (No need to answer to the forum)

• What criteria will you use to decide when to cull?  
• Are you ok with killing a fish that doesn’t meet your criteria?
• How will you cull the fish?

Questions to ask:

• if this fish spawns, how will it improve the quality of fish in the hobby?
• Other than the reason for culling, can this fish have a quality life?

 

at the end of the day, you are the one that needs to live with your decision.  Some fish, like @Daniel’s Stumpy, may go on to live long lives as cherished pets.  Others (especially in live bearers) could go on to weaken the species by passing on defects.

[lefty o]

you have to do what is best for your situation ethics are just that, ethics, not law. one persons ethical culling of fish is another's mass murder. maybe your local shop needs some feeders for its larger aggressive fish...

[Nataku]

Using culls as feeder fish to another fish or animal is my usual preferred option. This is how it happens in nature, and that their life is being used to sustain another is perfectly acceptable to me. I tend to keep a tank which holds carnivorous fish where I deposit culls as I find them in batches of fry, where they are consumed at the predatory fish's leisure. 

[H.K.Luterman]

I feed my culls to my ctenopoma and bichirs. 

[AdamTill]

When breeding goldfish 95%+ of fry get culled, so I looked into this a lot. I personally didn’t want a moment of terror as their last experience, so I chose  clove oil. It’s tough to know what fish feel, but I was comfortable with the choice ultimately.

 

[Charose]

I did my post-doc research in a lab studying lamprey and hagfish, we used tricaine for anesthesia and an overdose concentration for euthanasia. Not sure how easy it is to get or if it requires a license, but a veterinarian might be a source if all else fails (looks like you can purchase on internet) and you're really serious about ethical euthanasia.  http://research.uga.edu/docs/policies/compliance/oacu/UGA-IACUC-MS222-Guidelines.pdf

Edited December 27, 2020 by Charose

[Hobbit]

I’ve used both methods—clove oil as well as feeding to other fish. Both were cases where the fish had a deformity that made it very hard for them to eat. As long as they seemed happy I let them just carry on, but eventually both began to starve.

I have some experience with medical issues and death, and I personally feel that a quick death, even in a brief moment of fear, is much preferable to weeks or months of suffering that ends in the same way. ❤️

Culling for aesthetics is different of course, but just find a method that you feel comfortable with and that works well with your set-up.

I do think @Daniel makes a great point that some of the funny-looking fish end up being unique and special to someone. Maybe your LFS will take culls off your hands and sell them for cheap!

[Coronal Mass Ejection Carl]

1 hour ago, Charose said:

I did my post-doc research in a lab studying lamprey and hagfish, we used tricaine for anesthesia and an overdose concentration for euthanasia. Not sure how easy it is to get or if it requires a license, but a veterinarian might be a source if all else fails (looks like you can purchase on internet) and you're really serious about ethical euthanasia.  http://research.uga.edu/docs/policies/compliance/oacu/UGA-IACUC-MS222-Guidelines.pdf

I've been able to buy it in the US without a prescription.

People sometimes have trouble with clove oil and I suspect it's because they don't mix it with ethanol first.

[Jdogtrainer]

This is a good discussion, thank you for breaching this emotional subject. I'm new to the fish world - but dogs have been my life, and all things dog breeding related are decades familiar to me. Even culling.

I applaud breeders who will cull in the original sense of the word. Now with fish I would imagine a "cull" would be almost always for asthetics, not temperament/behavior. Medical culling, IMO, isn't culling - its being humane.

If you are educated enough on the fish you are breeding, and you have a very clear and reasonable vision of what you want I think culling is very reasonable. I think using the young fish that don't make the cut as feeders or euthanizing is a far better option than flooding your local market with your unwanted fish.

Edited December 27, 2020 by Jdogtrainer

[AdamTill]

3 minutes ago, Jdogtrainer said:

This is a good discussion, thank you for breaching this emotional subject. I'm new to the fish world - but dogs have been my life, and all things dog breeding related are decades familiar to me. Even culling.

I applaud breeders who will cull in the original sense of the word. Now with fish I would imagine a "cull" would be almost always for asthetics, not temperament/behavior. Medical culling, IMO, isn't culling - its being humane.

If you are educated enough on the fish you are breeding, and you have a very clear and reasonable vision of what you want I think culling is very reasonable. I think using the young fish that don't make the cut as feeders or euthanizing is a far better option than flooding your local market with your unwanted fish.

I decided early on that I wouldn’t let fish out of my fishroom that I wasn’t 100% proud of. I’ll admit that it’s an ego driven decision, but the goldfish world is brutal in terms of making sure your reputation is spotless.

We tried working with a few local stores to produce “grades” of goldfish, since even our later culls were nicer than what they could get from their suppliers. The problem was mainly that their demands weren’t constant, and it cost more to feed and house the young cull fish than we would make back in profit. We also couldn’t sell them ourselves for the reason I listed above.

For those so inclined, here’s a look at the process for one breed done by a master breeder. Ranchu and Phoenix types are even more demanding because dorsal fins want to pop out on these lines all the time (they should not be present in quality fish), and are an instant cull.

On the other hand, some breeders try to make money from these culls by using marketing terms like “shark ranchu”, and I have major issues with that personally.

 

[Jdogtrainer]

@AdamTill nice post, and very interesting!

[Fish Folk]

This is a delicate issue. We’ve faced this decision a few times breeding fish. Sometimes we’ve kept a shabby fish in a community tank out of compassion, but we’ve never sold one or allowed it to multiply for reasons explained already by others. We do have a tank full of African cichlids that occasionally get fed some culls. In the wild, this is the way it is. 
 

One observation: if we buy a pair of Rams at our LFS, set them up in a breeding tank, and raise hundreds of good, healthy fry for others to enjoy when we sell back to our LFS, we are really treating the original fish well, and multiplying their line, beauty, and enjoyment for many aquarists. Yes, some will need to be culled. Most culls we allow to live, do not live long lives. Occasionally one does. But where we euthanize some, many others are brought about because of good breeding care. Besides, the next customer who walked through that door behind us at our LFS when we bought the original pair might have been some... “Darla” ... (think Finding Nemo) who would have brought those rams home and brutalized them to death. 
 

I say, better off with careful breeders than the other option. 

[Mridul Singh]

Very delicate topic. I had a garage fishroom of 63+ tanks, and 9 of them at the time were dedicated to a guppy line I was developing. I started seeing mass numbers of deformed fish, and was very uncomfortable with culling them by killing them myself. I looked around for better ways to cull, and found three options that I still use today, or advise others to do.

1: set up a spare tank to put the culls in (I called it the retirement home). This was good for me because culls of any fish that were compatible all went in there.

2: (this is better for culling fish that have major deformities that would make the fish's life a misery, or a hassle) I kept three tanks, one with a large Angel, one with a few turtles, and one with an Oscar. Those were my cullers, and whichever fish survived in that tank I left there.

3: Similar to 2, but more geared towards using the culls as feeder fish. My LFS has a feeder tank, and they take culls. That's were some of my culls went as well.

[Jdogtrainer]

1 hour ago, Fish Folk said:

I say, better off with careful breeders than the other option. 

I agree that choosing breeders who are closest to breeding fish vision is really important. But genetics are hardly ever simple, and with fish many times you do not know what the genetics behind the adult fish are. Culling is still usually necessary. Hard culling (killing undesirable specimens) is sometimes the only way that someone can really accomplish a specific goal.

 

Edited December 27, 2020 by Jdogtrainer

[wendypizza]

I've been thinking about this a lot--one of my female ricefish has a hump back. It doesn't affect her QOL in any way: she is the biggest of the bunch, gets the most food, and honestly is a bit of a bully. I could (and maybe should) move her to the goldfish tank since she's not aesthetically 'perfect'; she's too big to be eaten by them, so it'd be just to prevent her from spawning, but I also don't want her to be lonely, lol. I haven't figured out the answer yet, though.

[Cory]

I personally add my culls to my turtle tank. If they evade the turtles thats fine. If the turtles eat them, that's fine as well. I now have a colony of 500+ endlers with the turtles. They seem to be too quick, it looks like the original deformed ones passed of old age. Other things have gotten eaten, it's a decent source of calcium for them. Other breeders will use a fish to do this. I like to use a turtle as it's less likely to pass any potential disease. 

[GardenStateGoldfish]

Thanks for posting this, I am a goldfish breeder (relatively new to breeding) and have been trying to save the culls because most of them still make great pets, its not sustainable and I am being a little over run with the not quite perfect baby's turn adults, cant let them be with the good stock because I dont want them to breed with the good lines. I have spoken with other goldfish breeders and they suggested a solution like cory, having another fish to feed them to or giving them to someone who keeps monster fish. That will likely become my approach moving forward its just a tough concept for me to accept however its necessary.

Edited December 27, 2020 by GardenStateGoldfish

[FrozenFins]

Feeding the fish to another fish. I have culled a few shrimp when they dont have the traits I'm looking for by feeding it to my angelfish or peapuffer. 

[AdamTill]

56 minutes ago, GardenStateGoldfish said:

Thanks for posting this, I am a goldfish breeder (relatively new to breeding) and have been trying to save the culls because most of them still make great pets, its not sustainable and I am being a little over run with the not quite perfect baby's turn adults, cant let them be with the good stock because I dont want them to breed with the good lines. I have spoken with other goldfish breeders and they suggested a solution like cory, having another fish to feed them to or giving them to someone who keeps monster fish. That will likely become my approach moving forward its just a tough concept for me to accept however its necessary.

Nice! What lines are you working on?

Goldfish rapidly make keeping every fry just completely impractical. There are some homes available for less than perfect fish, but they’re far fewer than fry numbers.

Then when you move to hand spawning to control crosses, and get 95% fertility on 500+ eggs every few weeks, it becomes borderline ridiculous.

Even when it comes to culling, I remember early on something that said new breeders look for faults, and experienced eyes look for keepers. Having had nights where I went through thousands of fry, and knowing that there were probably 6 cull passes that I’d go through at first before growing to selling size, I now understand the wisdom of that saying.

Edited December 27, 2020 by AdamTill

[Dawn T]

4 minutes ago, AdamTill said:

Even when it comes to culling, I remember early on something that said new breeders look for faults, and experienced eyes look for keepers. Having had nights where I went through thousands of fry, and knowing that there were probably 6 cull passes that I’d go through at first before growing to selling size, I now understand the wisdom of that saying.

As a former breeder of guinea pigs for show, this perfectly describes what I used to do when I culled "pet" stock from show and breeding stock. I looked for the "keepers". None of them were perfect, so if I had just culled for faults, I would've ended up with nothing to show or breed.

[AdamTill]

2 minutes ago, Dawn T said:

As a former breeder of guinea pigs for show, this perfectly describes what I used to do when I culled "pet" stock from show and breeding stock. I looked for the "keepers". None of them were perfect, so if I had just culled for faults, I would've ended up with nothing to show or breed.

Yep, exactly. At a certain point you’d never end up with anything fun or interesting either.

I also found it took at least a year to start to get even a feel for what a fault at one life stage looked like and resulted in. Some I let grow up just to be sure that it wasn’t a fault that “resolved”, or that something that looked like a fault at one point didn’t turn out to be something desirable later.

Taken to an extreme, after all, some things are terrible. Squashed faces on pugs or veiltail goldfish that have a tail too big to swim properly are variations on a theme.

I don’t think anyone enjoys culling, but it’s part of responsible breeding. I do much prefer the fact that I’ve never had an otocinclus baby I’ve had to cull, but I also did love seeing all the fun possibilities that came with goldfish.