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I was told that electric blue jack dempsey were hybrids ... *** read that they are not ...and one LFS owner said that he wouldn't carry them because they are hybrids and that they dont grow large at all and they die premature !
This does not make sense to me :-?
 

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samnewb said:
I think its been proven they are not hybrids.
On the contrary, Blue Dempsey's are not found in the wild and are most likely hybrids. This is another case of fish being line bred to achieve or enhance a particular trait. In theory, line breeding does not include hybridization, but there's really no way to prove or disprove that any cross was introduced somewhere along the process and the fish really should be regarded as a hybrid IMO.
 

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Joea said:
On the contrary, Blue Dempsey's are not found in the wild and are most likely hybrids. This is another case of fish being line bred to achieve or enhance a particular trait. In theory, line breeding does not include hybridization, but there's really no way to prove or disprove that any cross was introduced somewhere along the process and the fish really should be regarded as a hybrid IMO.
Actually, they were genetically tested, and proven to not be hybrids.
 

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Fogelhund said:
Joea said:
On the contrary, Blue Dempsey's are not found in the wild and are most likely hybrids. This is another case of fish being line bred to achieve or enhance a particular trait. In theory, line breeding does not include hybridization, but there's really no way to prove or disprove that any cross was introduced somewhere along the process and the fish really should be regarded as a hybrid IMO.
Actually, they were genetically tested, and proven to not be hybrids.
Really?... Interesting to know. :D
 

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Fogelhund said:
Joea said:
On the contrary, Blue Dempsey's are not found in the wild and are most likely hybrids. This is another case of fish being line bred to achieve or enhance a particular trait. In theory, line breeding does not include hybridization, but there's really no way to prove or disprove that any cross was introduced somewhere along the process and the fish really should be regarded as a hybrid IMO.
Actually, they were genetically tested, and proven to not be hybrids.
of what I read on that it was only found that the maternal line was pure. (in the PFK article here ) so it is "possible"that its a hybrid on the male side, however I personally think its a natural colour morph

plus the argument on http://bluejax.co.uk/fof.aspx supports the recessive gene, more so than the hybrid argument.
 

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To date no one has claimed or validated that any Blue Dempseys have been found in the wild...

Since they are slower growing and brighter colored this isn't surprising. But 'Blue Gene' Dempseys (regular looking but carry a recessive gene for the blue coloration) can live in the wild and cannot be distinguished from regulars. It is generally accepted that this is how the gene has survived. Two Blue Genes can spawn, 25% will be Blue and will die (in the wild) and 50% will be Blue Genes to spawn and continue the blue quality, even though only in a recessive state.

It's accepted that two of these Blue Genes were caught and spawned together. Some of the fry were Blue... they were babied... and now we have Blue Dempseys... there is a lot of information out there if you want to do your own research...

Jeff Rapps had some DNA work done which resulted in confirming they are not hybrids.

Naturally this DNA work was challenged and believed by many to be inconclusive.

Cole, a member here, has pushed to have further DNA research done. This has also come back to validate they are not hybrids.

Naturally that has been challenged too...

To do such thorough DNA research to prove 100% they are not hybrid is simply so extensive no one will donate the time or money to do it. So they've done valid, yet not 100% validating, DNA testing. Not one ounce of DNA testing has shown that they may be hybrids, it has all shown these fish are naturally occurring...

Yes they do have genetic weaknesses. I personally do not believe this is due to the Blue gene but due to the excess inbreeding they experienced in the earliest days of their discovery, and the lack of selective breeding for health. But we're working on this ;) I also do not think we should judge those who did this inbreeding. They had a new fish they didn’t understand and only had one bloodline to work with. They had no other choice.

Yes juvis are weaker, slower growing and more prone to parasites, again I believe due to inbreeding.

You can try to tell my 7" male that he isn't 7"... but he is... at less than 2 years old (from birth not purchase).

You will also find pictures of many other full grown Blue Dempseys on the internet. Saying they do not reach full size is simply an ignorant statement.

People really should learn facts on a subject before rattling off their half *** opinions... it can really ruin the reputation of an amazing fish...
 

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nc_nutcase... is that a cut and paste from another thread? It's just that there's a couple of points in there that nobody talked about... like adult size.

The one thing that caught my eye in your thread was about not blaming the EB gene for the weakness but assuming that it is another gene (I know you say "inbreeding" but really there must be a gene or genes truly at fault).
Why do you think it can't be the EB gene at all at fault?
 

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Number6 said:
nc_nutcase... is that a cut and paste from another thread? It's just that there's a couple of points in there that nobody talked about... like adult size.

The one thing that caught my eye in your thread was about not blaming the EB gene for the weakness but assuming that it is another gene (I know you say "inbreeding" but really there must be a gene or genes truly at fault).
Why do you think it can't be the EB gene at all at fault?
See the first post of this thread... He talks about size right there...
 

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Ah, thanks... I see the connection now. LFS owner said they don't grow large...
They do grow as large, but slower.

Some general thoughts on the EB breeding...

The part I'm fascinated in is how the genetics must work in order to have a fully recessive EB gene, but then have something else that is a factor since EB xEB is a lethal mix (or effectively lethal).

It makes me think that there must be some real oddball thing going on. The only scenario that pops to my mind that can explain this based on info to date would be that there is a EB recessive that must be present, PLUS some other gene that must be there in a heterozygous state to allow the EB phenotype.
This "activator" must allow the EB gene to express, but be lethal in a Homozygous state...

If my imagination actually hit on the truth, then this is just so interesting...
 

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Ah genetics, too much for me too understand. Proven to be a color morph, however it is possible some hybridization of the species forms a hybrid simalar to the EBJD
 

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I have over a dozen Blue Dempseys, half a dozen Gold ones and half a dozen regular ones… not including fry…

I’m toying with approaches to strengthen the current line of Blue Dempseys available along with a few other members here as well as the Blue Dempsey site. I wrote the post for this thread and unfortunately think way too much about their genetics all too often…

One of my theories is that since these fish were originally discovered they have been inbred far more than typical hobby fish. I don’t ‘blame’ anyone for doing this as for some time no one even understood how they bred and there was only one pair to produce possible breeders. But I now think it’s the hobby’s turn to put energy into removing those effects of inbreeding…

Yes everything is essentially traced back to a gene… or genetic combination…

I have personally bred Blue x Blue and with no extra care from me the fry lived 11 days, which is about the same age as my regular JD fry usually last without outside care. I do accept that Blue x Blue produces weaker offspring and a higher percentage of deformities. But is this because both parents are Blue, or because they are both the results of many generations of inbreeding. It could be either… but let’s not assume either way.

I believe that if we take great care to only spawn the strongest of the Blues with the strongest regulars, after enough generations they weaknesses associated with Blue Dempseys can be bred out. Both their delicacy in regards to parasites as juvenals and their weaknesses associated spawning.

The way I understand things, it is not very likely that a color gene would also contain ill effects on spawning, or parasitic immunity. This is why I believe there is a strong chance these are common traits, but based on different genes or genetic combinations. If we can capture the Blue Genetics from the absolute strongest fish… and cut that fish’s genes with the strongest regulars available… then it is possible to upgrade the health genes without loosing the Blue coloration… if, and only if, my original thought of these being separate genes, holds true…

It may also be a big fat waste of time… but you know… I’m enjoying my hobby now more than ever so it’s worth it either way.

I do want to add that I am not a scientist, not a doctor, and not a fish breeder. I’m just some dude addicted to fish that fell in love with the Blue Dempsey…

Sorry if we got off topic a bit but really it’s an elaboration of the topic. I’ve asked many others familiar with fish breeding and the Blue and Gold Dempseys seem to spawn out the same way color morphs spawn in other species such as Apistos or even convicts. This, to me, is further evidence that they are a natural color morph and not a hybrid. Hybrids tend to make fish that look like both parents… where Dempsey color morphs have a logical percentage of each, but no blends of both… They’re either Blue or they’re not, not sort of Blue… they’re either Gold or their not, not sort of Gold… Hybridization will give a wide range of blends of the two…
 

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Something that might help conceptualize this better is to think about more common examples of this phenomena in other places. For example, certain breeds of dogs are prone to things like hip problems or certain populations of humans are more prone to things like sickle cell anemia. It has nothing to do with outwards appearance but instead has to do with the history of the population, which usually included a period of isolation that caused inbreeding. Not that all inbreeding is bad, but if there are negative recessive traits present in the original population, inbreeding will increase the frequency of that trait in the descendants of that population. There's actually a formula to calculate this.
 

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I love these threads! :D

nc_nutcase said:
Sorry if we got off topic a bit but really it’s an elaboration of the topic. I’ve asked many others familiar with fish breeding and the Blue and Gold Dempseys seem to spawn out the same way color morphs spawn in other species such as Apistos or even convicts. This, to me, is further evidence that they are a natural color morph and not a hybrid. Hybrids tend to make fish that look like both parents… where Dempsey color morphs have a logical percentage of each, but no blends of both… They’re either Blue or they’re not, not sort of Blue… they’re either Gold or their not, not sort of Gold… Hybridization will give a wide range of blends of the two…
There is no clearer way to put it.

Mauro1 said:
I was told that electric blue jack dempsey were hybrids ... I've read that they are not ...and one LFS owner said that he wouldn't carry them because they are hybrids and that they dont grow large at all and they die premature !
This does not make sense to me :-?
Basically, people from around the world fall on both sides of the issue. Most the people who think they are hybrids would never own one. Most the people who own one do not think they are hybrids. Some stores wont carry them because they think they are hybrids. Jeff Rapps carries them, because he has done DNA work, and he thinks they are a color morph. Ask a scientist what they think, or a molecular biologist. Ask 100 of them, and 50 will say they are hybrids, and 50 will say they are not.

When asking the question are EBJDs hybrids or color morphs, you are basically asking, was the late Hector Luzardo intentially misleading people. Was the late Hector Luzardo a liar?

From all accounts, he was a hard working family man, who was a painter by trade. He claims his only merit was recognizing a few odd fry. Does someone like this become famous for lying, or do miracles just happen to good people?

Cole~
 

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In the latest issue of Cichlid News, there is an article on Dempseys by respected author on Central American cichlids, Juan Miguel Artigas Azas. Juan ads a paragraph to the end of his article. He mentions the respected Hector Luzardo as well as the Blue Dempsey. If I recall the paragraph correctly, I believe Juan Miguel is correct in his assessment, he doubts this is a legitimate pure bred fish.

Where is this DNA report that has been subject to peer review by the scientific community?? It seems someone did some work, but this mean nothing without review.

Have you ever noticed the biggest proponents of the Blue Dempsey are the ones who sell it or keep them? I suspect there is some bias here. I don't see this type of support from those who don't.

If you keep or sell the fish, that's your choice. We're glad you are here participating. :)

I have some respected friends who are very serious and respected aquarists who have gone down to South America to check out these breeders. There were four serious breeders there at the time. I believe what they told me. The Blue Dempsey is a cross between three different fishes. They agreed not to release the information in turn for being able to view the operation at hand.

I don't blame you if you don't believe what I wrote above is true. It's good enough for me. In fact, the observations of this I have made and the behavior they exhibit is enough for me. Not to mention all of the "mystery" that surrounds them.

Don't worry about "inbreeding" in this fish. There are plenty of Blue Dempsey coming out of South America to satisfy the demand here. As time goes by, the secret wil become less of one and we will all know the truth. It's only a matter tof time. :)
 

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eric said:
I have some respected friends who are very serious and respected aquarists who have gone down to South America to check out these breeders. There were four serious breeders there at the time. I believe what they told me. The Blue Dempsey is a cross between three different fishes. They agreed not to release the information in turn for being able to view the operation at hand.
Well, I'm another supporter of the Blue Demps Color morph theory... I have 7 Blue Demps. And I hate to break it to you, your "respected" friends are full of ****, because we all know... Ormed, prolly the most prolific Blue Jack Breeder only uses 2 fish to get his blue demps...

So, the whole 3 fish theory cross should be thrown away along with the "respected" part of your friends visit to South America.

And as far as DNA... start here:

http://bluejax.14.forumer.com/viewtopic.php?t=537
 

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HAHAHA...

Another thing, I'm not sure who actually knows the process of making Blue Jacks... Its pretty simple, just time consuming...

Take a normal and a electric... breed... then breed the offspring to another Blue Jack... So...... without the use of another type of fish at all, I think the hybrid theory is about as stupid as jumping out the 38th floor window to escape the fire. :thumb:
 

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if you were to do what jake just stated, keep breeding the blues to other blues, then eventually the offspring would be all or mostly electric blues. its the same with dogs. pit bulls have been bread with mastiffs and curs all through history, however, they are still registered as american pit bull terriers. it would take time, but eventually it would happen!

oh and jake, if the building was on fire, im jumping, i hear burning to death hurts alot more than the sudden stop at the end of the 38 floor leap, just my opinion though! Haha!!!!
 

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Number6 said:
The one thing that caught my eye in your thread was about not blaming the EB gene for the weakness but assuming that it is another gene (I know you say "inbreeding" but really there must be a gene or genes truly at fault).
Why do you think it can't be the EB gene at all at fault?
Just to clarify, the observed weakness in EB Dempseys is extremely unlikely to be a single gene trait (especially unlikely to be the very same recessive gene that is responsible for the blue colouration).

Whilst colour is often a single gene trait and is inherited in a Mendelian fashion, the virility of an organism is due to a complex set of interactions between several genes. It is easy to illustrate this through differing heights in humans - there is not a single 'tall' gene or 'short' gene.
 
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