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Is the EBJD a Colour Morph? To start things off, here is a copy of the original story published by T.F.H. about the discovery of this colour morph: Tropical Fish Hobbyist
April 2000 Vol. XLVIII, No. 8, #52
Marcelo Casacuberta
Blue Jack Dempsey
I remember my first acquaintance with the hottest novelty in the South American fish trade: the blue Jack Dempsey. It was at a small fish exhibition in Uruguay, and a young pair was shown in a 25-gallon tank.
My first impression was that they were misplaced among other freshwater tanks, since they seemed to be reef fish, so strong was their bright turquoise color. That was back in 1986, and since then this fish has occasionally been available, but always in limited numbers. No one seemed to know who was breeding them (although it was said that they came from Argentina), and the few people who tried to get a successful spawn from them (including myself) faced complete failure.
Even when the eggs hatched, the feeble fry were never able to swim, dying after a couple of days. The blue Jack Dempsey slowly acquired a legendary status, and speculations started to flow. Was it a new species, a mutation, or a sterile hybrid from two different species? The situation was much like what happens today with the blood red parrot. I had to wait more than a decade to meet Mr. Hector Luzardo, the man we could call the creator of this colorful morph, to find out the real story behind this unusual fish.
It all started in 1985 when Mr. Luzardo received a mated pair of young Cichlasoma octofasciatum as a gift from a friend. They had already spawned in the community aquarium where they lived, but the eggs disappeared in a few hours. It was a nice pair of young adult fish, but they were nothing to write home about. As soon as they were installed in their own tank, they produced a huge spawn of about 2,000 eggs, and the fry were removed to another tank after the eggs hatched. When the fry were about 20 days old, Mr. Luzardo removed a couple of young fish that were floating in the tank, their fins ripped and many scales torn.
Their color seemed to be paler than usual, but he thought it was due to the missing scales. The next day there were about four fish in the same condition, and still more the day after. Soon it was clear that this was more than just the weaker fry being attacked by the tougher ones. There were some fish in the tank that looked and behaved very strangely.
A closer look revealed about one-fourth of the fry gathering in one corner, looking smaller and thinner than the rest of their siblings. They were immediately transferred to another tank. After a couple of weeks the pale creamy color of the young fish slowly turned into a bright turquoise blue, growing into something completely different from their parents. A whole new type of fish had arisen.
Having bred them for over ten years, it is now clear that color is only one of the differences. The blue Dempsey's usually have a more elongated body, show more individual variations in the dot pattern, and lack the large lateral spot. They aren't always hungry, as are the standard kind, and they grow slower, although they reach the same adult size in the end. They are also mild-tempered, but only if you compare them to regular Jack Dempsey's. In fact, these fish are sometimes called the Pacific Dempsey by the local traders as a reference to their peaceful natures. In the local trade they have also been called blue Jack Dempsey's, although turquoise would be a more accurate word to describe their color. Baby blue Dempsey's are so lightly colored that it's hard to notice when they have white spot, a disease they are prone to catch during their first four weeks. They are easily cured if kept at 90°F (32°C) for three to five days. After their first month they become as strong and healthy as any other member of the genus, thriving in neutral, slightly hard water around 75°F (24°C).
In spite of the obvious differences from the rest of their siblings, young blue Dempsey's are not treated differently by their parents, who seem to recognize those pale fish as their own fry, treating them just like they do their ordinary fry. The reason nobody was able to breed the fish is that a pair of two blue Dempsey's will always produce sterile spawns or very weak wrigglers that will die within a couple of days. To succeed, Luzardo mates a blue fish with a common one that carries the "blue" genes. This way about 50 percent of the offspring are blue. If you have two common fish that carry the blue genes, only 25 percent of their descendants will turn blue. Care must be taken when pairing mixed couples, as the blue individuals can suffer from the rowdy behavior of members of the normal type. As strange as it may sound, this beautiful fish is barely known outside South America. They are only being bred by Mr. Luzardo, who has about 20 mated pairs, so it has always been available only in small numbers. A serious attempt to distribute this variety in North America and Europe has yet to be done.
Recently a shipment was sent to Germany to test the interest among the German hobbyists. I believe it is only a matter of time after introducing this outstanding animal to the cichlid fans before they become an excellent addition to their tanks. Soon they will become a sought-after item for all cichlidophiles worldwide.
Copyright © 2000 T.F.H.Publications Inc.
Reservados todos los derechos.
Revisado: 14 Jan 2007 20:30
Now for a bunch of quotes from Jef Rapps (the biggest importer of EBJDs in the States) taken from various forum discussions: "The blues are not hybrids. They are the result of a mutant, recessive gene that came up from a pair of regular dempsey - as stated clearly in the original TFH article by Marcelo. The original breeder of this fish has told me long ago that his only merit is that he noticed some different-looking fry in his spawns of dempsey and raised them up. There are no other species involved. The rumors of crossing a tetracanthus, haitiensis, etc. are just that - rumors. Those species would not have been available to these guys to work with anyway. The blues have a hard time breeding with each other because they are the result of recessive genes. Although they can spawn, fertilization is very poor. Not 100% infertile, but few fry will free swim and it's likely none will last more than a few days. However, when bred back to a regular dempsey, the resulting fry are robust. These fry (from a blue x regular dempsey) will appear nearly normal in color, but carry the gene for 'blue'. I have seen them and they are actually more blue than regulars, but would never pass for a 'blue dempsey'. Now when these fish are raised up and spawned to either each other or back to another blue, the resulting fry will contain up to 25% blues. The rest will again appear nearly normal in color, but again, carry the gene for 'blue'.
(I'm adding a Punnet square here to clarify this statement - Ed.) Key: B = Dominant normal colouration gene b = Recessive electric blue gene Cross: Bb x Bb Expected percentages: 25% normal fry (BB), 50% heterozygous fry (Bb), and 25% electric blue (bb)
The folks who breed this fish do not circulate the 'normal-looking, blue gene-carrying' fish - sorry. They are culled in mass to slow, but not restrict, the line-breeding of blues by the aquarists.
If one who assumed these fish were hybrids could see these fish, there would be no further doubts as to the validity of the blue. Hybridization would cause resulting fry to appear non-uniform - with some fish resembling one species body/color, some another, and lots of others that would look like neither (but different from each other in shape and color). While the markings of any given blue are unique, they all look alike and there is no doubt that they are siblings and all dempsey.
And that's about all I have to say about that."
Or is it? Here's Rapps explaining why he stopped importing long-finned EBJDs for Argentina in preference for regular-finned ones: "The original breeder of the blues began to see a few individuals with longer fins. He worked on breeding that trait out, just as was done so many years ago with angelfish. So yes, it was accidental at first, but he intentionally worked on developing these veil fins. However, upon receipt of my first shipment of the veils years ago, I noticed a high post-shipping attrition (lots of them died - Ed.). Following that, I saw mortality that could not be explained. I immediately pointed out to him that the veils were a weak strain of the fish and that their 'beauty' was not comparable to their health.
After that, the regular-finned ones were brought back."
Here's a post on the DNA testing that Rapps had done to prove that EBJDs and normal JDs are one and the same: "[I received] the below email from the group who are conducting DNA studies on relationships of American cichlids. By the way, the results of this study (not specifically the work on the blue dempsey - that was a personal favor) will be published in a scientific journal to be named later. First, the results of this study will be presented in Brazil at at an ichthyological symposium this summer.
"You can't make a blue dempsey from two other species, it is exactly the same as wild Cichlasoma octofasciatus. I haven't included N. tetracanthus in the study yet, but the closely related C.haitiensis is not even in the same clade. So they are not even closely related, and certainly not close enough to be a hybrid of the parental species of N. tetracanthus and/or H. carpintis. I will
include H. carpintis in the study later.
The DNA analysis I did totally invalidates any claims that Cichlasoma octofascaiatus is the daughter species of N. tetracanthus and/or H. carpintis. If it was a hybrid of two other species, it would have been very apparant in the study. It would have been nested right in between those two. Or at least next to closely related species of those two, and it isn't. I'll send you the phylogenetic tree as soon as this is all done and go over what it means with you.""
And finally, the last word from Mr. Rapps: "The late Hector Luzardo was the one who first bred this fish. He and I became quite close in the years before he passed. He was a dedicated father, husband, grandfather, and lifelong painter. His virtues were admirable and we trusted each other without question. He did nothing special to produce a blue dempsey. His only merit was that he recognized a few lighter colored, smaller fry in the spawns produced by his pair of regular dempseys.
The reason that blues cannot reproduce with each other is the consequence of recessive genes that are too weak to result in viable, healthy offspring. I have set up more than one individual that has successfully produced blues in dozens or hundreds of spawns. They breed them back to regular jacks. The progeny of this spawn will appear normal, but have the 'blue gene'. A breeder would then raise a few of these and cull the rest. These fish are bred to a blue and the result would be at best 15-20% blues in a spawn. The actual % is usually around 5-10% blue. Again, cull the normal looking dempsey fry and raise only the blue. If folks made a practice of marketing the 'normal appearing' dempsey with blue genes, then everyone could and would have blues already.
I made the decision many years ago to not attempt to produce the blues in commercial numbers. The sheer volume of breeders and rearing tanks required to get just enough to make this a worthwhile commitment for me would take up far too many of my tanks. I enjoy the variety of species I work with, so I let the folks who want to specialize in the breeding of the blues to continue their efforts.
In regards to the DNA sequencing of the blues - the analysis was done using two mitochondrial genes: COI (cytochrome oxidase l) and 16S (a ribosomal subunit). A large number of American cichlid species were subjected to the same DNA analysis. To make a long story short, according to the mitochondrial DNA, there is no difference between a normal colored dempsey and the blue morph. Mitochondrial DNA is inherited from the maternal line. There can be no doubt that the blue morph is a direct part of the maternal lineage of species octofasciatus.
That's the story in a nutshell. You can post this where needed. It's been posted many times over the years on several major cichlid discussion sites. Due to the die hard critics who cannot understand or do not wish to understand this, as well as the new influx of aquarists who would not have been active on such sites years ago to have read this, the debate still goes on."
Things to note: The results of the mitochondrial DNA test carried out by Dr. Prosanta Chakrabarty have been made public and are viewable in the 'Hybrid or Colour Morph' section of the EBJD Forum.
My arguments in support of this explanation: Let's clarify some things before we get too carried away. Mutations. In biology, mutations are changes to the base pair sequence of genetic material (either DNA or RNA). Mutations can be caused by: a) copying errors in the genetic material during cell division; b) by exposure to ultraviolet radiation, ionizing radiation, chemical mutagens, or viruses; or c) can occur deliberately under cellular control during processes such as meiosis or hypermutation. In multicellular organisms, mutations can be subdivided into germline mutations, which can be passed on to descendants, and somatic mutations, which cannot.
Mutations create variation in the gene pool. Deleterious mutations are removed from the gene pool by natural selection, while beneficial ones tend to accumulate, resulting in evolutionary change. Neutral mutations are defined as mutations whose effects do not influence the fitness of either the species or the individuals who make up the species. These can accumulate over time due to genetic drift. The overwhelming majority of mutations have no significant effect, since DNA repair is able to mend most changes before they become permanent mutations, and many organisms have mechanisms for eliminating otherwise permanently mutated somatic cells.
Selective breeding: Selective breeding in domesticated animals is the process of developing a cultivated breed over time. In the wild, many factors influence which individuals get to breed and hence whose genes are passed on to the next generation. Natural selection acts to promote the reproduction of genetically fit individuals over that of individuals who are less fit. In captivity, it is man who decides which individuals get to breed, either through careful selection and pairing of individuals that express the trait he desires, or simply as a result of having a finite number of individuals at hand. This process is artifical selection (or selective breeding). Now, back to the EBJD argument... Hector Luzardo (now sadly deceased and unavailable for questioning) discovered EBJD fry in a spawn from normal JDs. The only way this could happen is if both parent JDs carried a recessive electric blue gene (i.e. they were both Bb fish). A simple explanation for both parents carrying this gene is that they were siblings and one of their parents was a carrier for the electric blue mutation: Parental genotypes: BB x Bb Offspring: 50% BB, 50% Bb (like both of Luzardo's fish) Basically, all that's required for Hector Luzardo's story to be true is for one lucky fish (the granddaddy of all EBJDs!) to have been heterozygous at the colour locus. Not impossible, given that mutations accumulate in species over time, and that in this particular case we are not talking about a beneficial mutation. An EBJD in the wild wouldn't last five minutes! So the electric blue gene can be considered deleterious for wild populations, and neutral at best in captivite situations. Here's a fab forum post (by Ted Judy) to give you an idea of how lucky Luzardo was: "A spontaneous mutation has a rate os 1 / 1,000,000 base pairs during DNA replication, but that probability becomes even more unlikely when you consider:
- The mutation has to take place in a base pair that is a part of an actual gene... most of the DNA in a cell is not used for anything (that we know of)
- The mutation has to be be missed by the cell's revision enzymes that actually read the DNA and correct mistakes
- The mistake occurs in a gene that is not essential for the survival of the organism (like the haemoglobin gene)
- The mistake takes place during gamete production so the gene actually gets passed on (a mutation in a skin cell will not be passed on)
The chance of a random mutation producing the blue dempsey is arguably so remote that it should never have happened... but it did. It is even more unlikely that the exact same mutation would occur in someone elses tank somewhere else in the world.
Why so quick to condemn Mr. Lozardo? This has been debated over and over again without anyone ever offering proof that the blue dempsey is a hybrid. The genetics bear out." Now I want to show you a photo: 
This photo is significant because it shows an EBJD that looks so far removed from the EBJDs we see for sale today, it's hard to believe. Now imagine, if you will, that Hector Luzardo's first EBJDs were much more like the fish above. Perhaps then it wouldn't be such a leap of faith to believe that this electric blueness is the result of a mutation. After all, no-one said that the first EBJDs had as much blue as the ones we see today. This is where selective breeding comes in. It should be fairly easy to imagine that if you had a number of fish like the one above and you'd just made this fantastic discovery, you would pick the most blue ones and try to breed them. Then when you found that the blue ones didn't breed together very successfully, well you might decide to breed them to wild-type JDs. Anything to hang onto this amazing colour. With luck you'd get some more EBJD fry. You could then scour these spawns and pick the most blue individuals again. In fact, you could repeat this process over and over until you had a fish that looked much more like this: 
We've all seen the results of selective breeding so many times before. Look around any discus or angelfish dealer's tanks; look at how many long-finned strains we have (rams, danios, barbs, oscars); look at guppies! In all these cases the fish are genetically identical to the 'normal' varieties. They are the same species. All the differences in colour and finnage are down to artificial selection by breeders. You can breed long-finned fish to short finned fish, no problem. Likewise different discus and angel strains produce viable offspring (they might not be so pretty, but they can go on to breed themselves!). Which brings us to an interesting question: Assuming that all the above is true and that EBJDs are a colour morph, why is there a persistent rumour that two EBJDs can't breed together to produce viable fry? In actual fact, this isn't necessarily the case: recently a new member on the EBJD Forum (DEMPSEYDAN) confirmed for us that he had succeeded in raising the fry from an EBJD x EBJD pair to over 2" in length. He stated that the juveniles were unattractive in appearance and as a result they were culled. He has since changed his focus to breeding EBJD to normal JDs in order to promote health and vigour in his line of EBJDs. Other members on the forum have also had spawns from EBJD x EBJD live for over 10 days before being eaten by either the parents or other tankmates. Now for some interesting facts relating to reduced reproductive vigour in cichlids (Ted Judy again): "The genetics of getting a blue dempsey do not support the theory that they are hybrids. A very similar genetic relationship exists in more than one angelfish phenotype/genotype (the most notable being the black/gold gene) where the homozygous genotype for black (DD) are less hardy and has less reproductive vigor than the heterozygous black (Dd) fish do. The difference in this case is that the black is a dominant color. No-one has ever found a black angelfish in the wild either (that I know of). I have not seen any documentation of the black/gold gene 'popping up' from wild stock of angelfish either (not to mention the other really oddball angelfish genes), and many many more wildtype angels are bred than jack dempseys. As mentioned before, the blue dempsey popped up in [Hector Luzardo's] tanks in 1985. Considering the fish were not offered commercially from him in reliable numbers until 2005 would indicate that he spent twenty years on the strain. If we are conservative and go with one year per generation egg to breeding, that is 20 generations of creating heterozygotes and crossing back to the homozygote. No one knows how blue the original fish were, but it is possible that they were not as blue as the fish Lozardo is producing now. The subsequent selection of fish with more blue and choosing the hardier fish from those very blue fish over twenty years has probably improved the vigor of the strain.
When I was breeding angels heavily in 1980's a DD balck female was basically infertile, or at least so rare that we did not even look for them, and used a gold (dd) female with a DD black male to get Dd black (and hardy) angels. 20 years later a fertile DD female is not uncommon, though they are still not as good a breeder as Dd females.
The point is that once a gene is isolated a selective breeder can improve the strain over subsequent generations... and Mr. Lozardo has been working on the blue JD for a long time." And a post about changes in appearance: "Mutations...can often have multiple effects. Pink grapefruits are a [mutation] of the regular grapefruit. However, not only does the pigment of the juice change but the juice tastes less astringent. Sweet corn is a single mutation of dent corn that also produces a wafer thin seed that requires more care to raise.
Genetic changes are often disadvantageous and we see that in the blue JD's, which are weaker than the normal JD's. The black mutation in angelfish, when doubled up in recessive form, produces a velvety dark fish that is also weaker." Here's a post from Ormed (one of my heroes and one of the first to breed EBJDs outside of a commercial venture): "A hydrid would likely throw back a % of whatever it was spawned to (I haven't seen anything but JDs from from thousands of fry), or they would end up sterile, EBJDs do not do either.... I created my line of EBJDs from the begining with a regular female JD X EBJD. They are not a hybrid
EBJDs seem to have some genetic weakness, which is particularly expressed when they are younger. As the grow and mature, they seem to pretty much grow out of it. If bred together (Though I haven't done this), the weakness may just be too much for them to overcome. The Chromosome responsible for color just happens to be on the same gene that carries color. It's not that unusual. Some albinos also have inherent weakness...
I believe that this weakness is why they are seldom seen in the wild, or in the hobby. They probably occur, but die early cause they don't compete well against regular JDs. I am able to raise them because of the carefull (not always) attention I pay to them." There are a lot of rumours about female EBJD being infertile and EBJDs having reduced aggression levels. Through our work on the EBJD Forum we have since dismissed both these rumours as based one the experience of a few individuals. Female EBJDs have been demonstrated to be fertile, both in parings with normal JDs and in pairings with EBJD mates. As for aggression levels, breeding EBJDs are every bit as aggressive as a normal. One more thing worth noting: all the DNA tests carried out to date to test whether or not the EBJD is a hybrid have come out in favour of them being a colour morph of Rocio octofasciata.
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