Inbreeding is it a problem?

dave · Post by **dave** » Sun Mar 12, 2006 11:10 pm

Thanks for the idea Rob, I'm taking it up.

Currently I'd say no, although not an ideal situation, but most people at the moment I presume are breeding off wild.

F2's will eventually arrive on the market, and I guess this is some time off if the time to reach maturity is as long as has been suggested.

Here the problem I think arises, or maybe at F3's who knows, and this is a fish that will never be cheap, will people cull fish they would not be prepared buy themselves?

C. Moori (Blue Dolphin) from Lake Malawi, is near extinction in the wild. I have lept a line of these going for over 10 years, occasional introduction of new blood, but with a bit of selectivity, the young are snapped up.

Discus and Koi, probably the most inbred fish ever, yet you get some superb fish.

Lets face it, many species face extinction, so whatever we can do in any way or form is a plus.

All opinions welcome

Dave

thebuddy · Post by **thebuddy** » Mon Mar 13, 2006 12:21 am

now heres a good questoin how many generatoins should be bred and rebred before you should add new fish from a differnt line or family or whatever it is that you call it (is there a scientific word for this

)

Raul-7 · Post by **Raul-7** » Mon Mar 13, 2006 1:49 am

thebuddy wrote:now heres a good questoin how many generatoins should be bred and rebred before you should add new fish from a differnt line or family or whatever it is that you call it (is there a scientific word for this )

Yep; it's called genetic variation or recombination.

EDIT: I actually remember talking to a Gourami breeder (and biologist) from a university in Florida and he told me that in reality that inbreeding is actually over exaggerated in the aquatic trade; in fact it will take many generations before deformities will arise. But of course we settled on the fact that variation is almost always best.

zebra046 · Post by **zebra046** » Mon Mar 13, 2006 7:02 am

Dave,
Labidochromis caeruleus (Elkectric Yellow) pretty much started out with just two fish in captivity and has produce millions out of two fish to this day I can still find magnificent speciments that are as spactacular or even better than there wild counterpart as long as we keep sellectively breeding the good traits and rejecting the undesirable once, it would still be a long while before we would have to worry about inbred problems.

madmoroccan · Post by **madmoroccan** » Tue Mar 14, 2006 6:05 pm

Inbreeding is a dodgy one...

From all the sources related to fish that I have looked at, there seems to be no physical evidence that it can harm the fish.

Though if you look at human inbreeding from the class system days 1700's to late 1800's, high class families only married wealth cousins (for financial reasons). This caused that particular familys features to be exaggerated... i.e. big noses... square jaws... ect... FACT...

Not sure whether or not that could harm fish in the long run, though, the best thing to do is not to risk it at all. And selectively insert a new gene strain every couple of generations.

I hope you find this information useful. I will look into examples of the human inbreeding and document it here if I get the time between all the other stuff I need to do.

Kind regards

Bader.

Plastic Mac · Post by **Plastic Mac** » Tue Mar 14, 2006 6:19 pm

Though if you look at human inbreeding from the class system days 1700's to late 1800's, high class families only married wealth cousins (for financial reasons). This caused that particular familys features to be exaggerated... i.e. big noses... square jaws... ect... FACT...

Are you implying something about our Royal family?

Plastic Mac

19wiggles86 · Post by **19wiggles86** » Tue Mar 14, 2006 9:17 pm

Hi everyone,

Just thought I'd jump in on this forum, as inbreeding was lectured on at length in one of my university genetics lectures recently. (It was the Royal Family Plastic Mac lol).
I don't know what people know and don't know on this subject, but to sum it up simply in a few words, it isn't good. In humans it caused some members of the royal family to suffer from haemophilia (a disease that doesn't allow your blood to clot). Just to clarify, it didn't cause the creation of the disease, just lead to some members of the royal family suffering from it. I can go into more details on a genetic level of why things like this are caused later if people wish...
Obviously fish weren't discussed when I learnt about the subject, but I do know some on the subject of pedigree dogs. Generations of inbreeding with these species has lead to particular ailments for particular species. Its one of the reason why non-pedigree dogs (I couldn't think of a just phrase as mongrel I feel is derogaroty uneccessarily) are healthier.
So it happens in humans and dogs, I don't see any reason why it shouldn't happen in fish.

@ zebra046. If I were to give a hypothesis on the Labidochromis caeruleus you mentioned, it would be thus. If the original two fish had good genes i.e. with no recessive alleles and one or two other good bits and pieces of their biological makeup then it would be possible to inbreed them with no difficulties. However, unless you analyse them on a genetic level there is no way of knowing this. Also, if you did get a random mutation and people continued to breed from these fish they may hit problems. However, I won't go into Darwinism and mutations, as thats another story...

Adam

Oh strangely enough now that I think about it fish were mentioned in my lecture. It was said that in some fish the female has XY chromosomes and the male has XX (the reverse of humans). Whether this is the story for zebras, I have no idea.

thebuddy · Post by **thebuddy** » Tue Mar 14, 2006 10:41 pm

brother and sister humans having kids can cause deformatoins
so this dosnt happen in fish easily? good

Shimmy · Post by **Shimmy** » Wed Mar 15, 2006 10:53 pm

The point about our inbreed royal family is an interesting one!

You have to be careful about inbreeding and what you actually mean. As dave pointed out he has breed a rare fish for 10 years and had no issues. The case for the pedigree dog is another issue. They have purposely been inbreed over decades to produce the best quality features, i.e staffs, they were selectively bred to ensure their chest stand proud and the snout is short. These are qualities dog breeders look out for and say make a quality specimen whereas the historical form of this dog was very different. What they have created is a creature that ticks boxes for competitions but has respitory and heart problems.

Nature has a way of keeping a balance, in years to come zebras will become a common plec commanding a high price approximately £50-£75 because demand will always be high but even to quality profesional breeders will not be able to creat large volume.

If you breed an F3 from a major singapore trader with one of your own F1s will you get an inferior fish?

There are several examples in nature where inbreeding is common place!

thebuddy · Post by **thebuddy** » Wed Mar 15, 2006 11:38 pm

yes breeding differnt species creates a hybrid (correct word?) and they are considered inferior and most wont tolerate them wether they look nice or not

McEve · Post by **McEve** » Fri Mar 17, 2006 5:45 pm

Shimmy wrote: If you breed an F3 from a major singapore trader with one of your own F1s will you get an inferior fish?

You will get F1 frys from this combination, as you have bred two unrelated fish.

If there's no deformities in either fish there's no reason why you should get an inferior fish as a result.

It's not, as far as I know, right to compare the effects of inbreeding in mammals to fish, as a mammal seem to be much more vulnerable to defects from inbreeding than fish are. Mind you, livebearers seeem to have suffered from inbreeding and selective breeding (long fins, fancy colors so forth). They sure aren't the fish that tolerate any conditions and still breed like rabbits anymore

Still - breed unrelated fish and the problem will never arise

Better safe than sorry - as always

madmoroccan · Post by **madmoroccan** » Sat Mar 18, 2006 12:07 am

@ Plastic...

I "might" have refered to a certain family that is well known by the tourists... Maybe...

@ All interested...

The inbreeding thing is a potential danger... Do you really want your fish to look like prince Charles... The prince of Wales indeed... They would have big otodontes... long fins... not to mention a taste for 15 year old whisky... and ugly women, "precilla" or wotever her name is!

The tragedy!

Now, would you want to risk that?

Frontyking · Post by **Frontyking** » Sat Mar 18, 2006 3:25 am

No not me, that's why I have sourced a couple more zebras, this time sub adults, to hopefully have different bloodlines.

Nick.

Zebrapl3co · Post by **Zebrapl3co** » Wed Mar 22, 2006 5:22 pm

It kind of disturbs me how many people think that you have to see deformities to say that inbreeding it bad.
The fact is, a perfectly healthy looking fish can breed horribly deformed frys. That's because that fish could've had extremely poor recessive alleles and it just happens to lucked out.
Also, I think the gold fish is a poor example. Just the colour of the fish alone is an indication of a fish horribly inbreed. The natural colour of a gold fish is just like any other normal fish. A dull greenish ting colour.
It's in my oppinion that once you've hit F3 and on, your fish have already step off the plateform from the rest of the wild fish. It may look in every way the same as the wild fish, but I will know for a fact that it's genetic makeup are diverging from it's wild bretherns.

onemisterchristian · Post by **onemisterchristian** » Thu Mar 23, 2006 12:18 am

what's the furthest anyone has gone with inbreeding and still resulted in fish with (visually) no deformities. I realize that it's quite obvious that many people breed F1s with a very small percentage of deformed fish.

However, just to clarify I'm not completely sure if this is where the problem lies but...
If mother two fish breed and one or both carries a recessive trait for a deformity, then it is more likely that their spawn will carry this trait also. If this spawn breeds with either the F0 or a fellow F1 and both of these new parents carry the trait, then this is where the problem lies. Then fore sure their spawn will have a much greater chance of having both alleles for the trait thereby resulting in an expressed (visually or internally) deformed fish.

Correct? Please correct me if I'm worng or unclear.