Poll: Hybrid Fish

[Watcher74]

I saw a beautiful rainbowfish at the LFS yesterday that was labeled Melanotaenia Marci. I originally thought is was simply one species of rainbowfish. Upon research however, I discovered that it is a man made hybrid.

From what I've read it seems many people are disgusted with this practice.

I'm of the opinion that as long as the fish keeper knows that the fish is a hybrid, does not breed it with a true species, and does not sell it to anyone else without them knowing this, then what's the harm?

 

[mogurnda]

I breed much of what I keep, and hybrids just make a mess of the gene pool.

 

[Celura]

I think it's cruel, and I don't like the practice.

The first time I saw a blood parrot I couldn't get over how cute it was. Luckily the one I saw was it's natural colour and not a jellybean. I will say I thought he had the most adorable little face in the world, and I wanted one. Then I discovered what they are.

I don't like that people play God and breed things that wouldn't occur in nature to amuse themselves. I'm also adamantly against painted, injected or dipped fish. I think it's inhumane and very cruel to torture an animal for entertainment value or to make it more pleasing to the eye.

I will never own a hybrid.

 

[dwf73]

Im neutral on this one - One one hand, some people get very into it - on the other, I am not so bored with naturally ocurring specimens that I need to make new animals . With some fish, like discus for example, I do not think there need to be any "imporvements" - they are already striking.

I do not have a lot of technical experience with breeding hybrids, so I would like to know what the genetic tradeoff is. Do the lines degenerate or is it a benign variation? I suppose that makes all the difference for me- I would not mind so much if it is a relatively harmless procedure.

 

[happychem]

Celura, I seldom disagree with you, but in this case, I do.

There's much evidence that a lot of evolution thus far has resulted from natural species crossing. I fail to see how it's cruel. If the species are compatible and choose to mate, it happens in the wild, I fail to see why it becomes cruel because they're living in a glass box.

While this may be less of an issue with fish, interspecies mixing is the best way to weed out species specific weaknesses. Pure bred is all well and good, but the idea that species purity gives the animal an advantage is crap.

I'm trying to think of a good example, but I don't want to open another can of worms, ahem.

Oh, dogs.

Golden retreivers, gorgeous creatures, extremely prone to canine hip displasia (I think that's what it's called, I'm no vet), bad hips in any case. Pure breds are highly susceptible to these species traits because both mother and father can carry the "weak hip gene". If a golden were crossed with another compatible dog, the progeny would be less likely to suffer from bad hips later in life.

If it is possible to produce a beautiful fish in captivity that is more resiliant, what's the harm. Certainly there's no objection to people who breed pure strains in captivity?

 

[daveedka]

I don't like that people play God and breed things that wouldn't occur in nature to amuse themselves. I'm also adamantly against painted, injected or dipped fish. I think it's inhumane and very cruel to torture an animal for entertainment value or to make it more pleasing to the eye.

Hybrids have always been some part of animal husbandry, and while some people may view this as playing God, I disagree. God only allows certain things to happen, still can't get a cow to cross with a horse, but donkey's and horses make for very fine Mules. There are limits and drawbacks to Hybrids, but they aren't all bad and if the prospective owner knows what they are getting, then I see no problem. Genetically altered, dyed, or manipulated animals are a far different case in my book, and I don't think much of these. Hybrids occur on a wide scale in nature, but generally don't thrive due to the defects created, In most cases natural hibred's prove to be sterile. In the fishing world, DNR programs have released some very nice hybrid's that enhance the sport with very little environmental impact.

 

[Celura]

Maybe I should clarify...

If two fish are put together and choose to breed, then ok.

If DNA is spliced here and there to make something that would not occur naturally in any way, I have a problem with that.

That's my opinion. If we differ, that's ok.

 

[daveedka]

If two fish are put together and choose to breed, then ok.

If DNA is spliced here and there to make something that would not occur naturally in any way, I have a problem with that.

That's my opinion. If we differ, that's ok.

I would definately agree with all three quotes above

 

[happychem]

Looks like we're on the same page Celura.

To quote Corax: +1

 

[mogurnda]

While this may be less of an issue with fish, interspecies mixing is the best way to weed out species specific weaknesses. Pure bred is all well and good, but the idea that species purity gives the animal an advantage is crap.

I think there's a mixup between species and breed here.

For a species to succeed in the wild, it has to be strong enough to do so. In general, hybridization leads to sterile, weak progeny that are quickly removed from the gene pool. Or, as Alcock says in Animal Behavior , "Hybrid offspring are likely to develop poorly, if at all, and even if they succeed in reaching maturity, they usually have scrambled adaptations that match neither parental niche and leave the hybrids at a disadvantage in the competition for resources." That's why there are behavioral mechanisms for species separation in the wild. In regions where closely related species overlap, one often sees these mechanisms amplified, such as increased differences in the frequencies of mating songs. There are naturally occurring hybrids, such as the "red wolf" or some baboons, but these are the exception, rather than the rule.

On the other hand, dog breeds are all part of the same species. Dachsunds and great danes are all Canis familiaris. Many breeds have such small gene pools that deleterious mutations are exposed at a very high frequency. Same thing would happen if brother and sister marry. It's also why zoos keep registries of rare species, to optimize genetic diversity. And why mutts tend to be more vigorous.

As far as fish go, I just want to know what I have. Once species hybridize, it's impossible to unmix the DNA, so subsequent generations will be a genetic gamisch. Plus, it makes it hard to predict the appearance of the progeny.

This is feeling a lot like GCC.