Questions About the Electric Blue Jack Dempsey

By C. Moormann

Cichlasoma octofasciatum species

Note: This page is set up as notes that I add to as I find out more information. A date indicates approximately when the section of the page was written.
The most recent update is at the end -- 06-06-2012
One of the breeders in my area produces the Electric Blue Jack Dempsey. In dealing with him I find that either he knows very little about the genetics or is keeping the details secret. It would appear from the way he sells the 3/4 inch fry, they must all be males and the reported percentages of 10% or so electrics compared to regular appearing dempseys does not match the normal expected percentages of 25%, 50%, or 75%. He does not sell any of the non-electric fish (heterozygous with hopefully some with one electric gene). You have to produce them yourself by crossing the electric with a regular female? He said he heard that one in a thousand of the electrics could be a female and possibly you could find someone selling the heterozygous ones for $200 each on the internet. My guess from this little bit of data is that the electric gene is recessive and possibly works differently on the 'X' and 'Y' chromosomes. With "e" representing the electric gene and "r" the regular color, a male which received an electric "x" (ex) from his mother and an electric "y" from his father would represent the "xEB-yEB" or colored dempseys with "xEB-xEB" females not developing past the embryo stage. Heterozygous would have males as "yEB-xnon-EB", with females as "xnon-EB-xEB". A "xEB-xEB" female would have some lethal development of the embryo. Similar genetic reactions exist with all or most calico cats being female and most humans with color blindness being male.

Links to some other Electric Blue Dempsey sites:
(starts out negative but answers get progressively more informative -- if lacking in data such as actual percentages)
(nothing negative but not even suggesting the eating/weakness problems of the previous forum thread -- no indication of genetic issues -- if you read this article only, you would be unaware of any difficulties).
another site with a forum on EBJD info
(This appears to be comprehensive database on the Jack Dempsey with info on all subjects.)
(agrees with my suspicion that it is a recessant/sexlinked gene.)

Here are a few of pictures of the Electric Blue Dempseys:
Electric Blue Dempsey
Small ones available locally for under $10 Click to Enlarge
Electric Jack
Larger Jack Click to Enlarge

Blue Gene Dempseys
A pair of blue genes Click to Enlarge
Electric Blue Jack (father of most shown here?)
Larger EB Jack Breeder Click to Enlarge

Electric Blue Dempsey Fry
Small ones available locally for under $20 (Note that they start out gold and start turning blue at the gills at about 1 inch) Click to Enlarge
Electric Jack fry
Larger Jack Click to Enlarge

We are selling some of the little ones here for $8.00. If you have more info on EBJD genetics -- share it -- enquiring minds want to know. We can post it here. Email us at
Update 01-20-10 CDM
I have recently been made aware of some of the secrets and have some limited experience breeding them now. Life is unfair and I found that even though the old guy mentioned above would not sell me any of the first generation breedable fish (just the males requiring at least 2 generations of work before a payoff) he allowed someone else to end up with 26 or so heterozygous (breedable in one generation) dempseys given to him apparently for just helping out. Two other guys bought or traded them from him and the lucky breeders would not sell them to me either but later they relented and I ended up trading for a breeding pair of the 'normal-looking' but electric gene carrying fish (trading $300 worth of fish at wholesale). This type of EBJD would be heterogenous for EB and otherwise called 'blue gene' rather than 'electric blue'. They have bred 4 times for me (about once a month) and some info can now be reported. They laid eggs in a large flowerpot and after the eggs hatch, the female moved them into another flowerpot (both pots laid on their sides with the eggs on the bottom one third of the pot). It is obvious when they are near spawning since the female will become almost entirely black. At this point look for the eggs. When the fry become free-swimming, they will be seen as a large cloud at the bottom directly beneath the parents. The first spawn I siphoned out to split with a fish friend to settle a debt. I was attempting to groom this friend to take over the management of the business and he made the deal over my objections and when the management prospects became untennable, we split up the EBJD stock. I was not hatching nauplii at the time so I moved my half into a tank in my greenhouse that I thought they would do well in -- they did not. I originally had some regular dempseys from another source and eight electric fry at about 3/4 inch for wholesale ($8 each for these babies) from my older friend mentioned above. At the time of the split only 5 had survived -- some with goofy eyes and variable coloration appearing after they got over one inch in size. Three of the originals died and one perfect one that grew like a weed and was 5 inches long while the remaining four never quite reached 2 inches in the same tanks and feeding conditions. By this time it was clear from my studies that the electric gene is indeed a 'y' chromosome trait and all of the EBJDs I had were probably males. I had a regular female in with the large EB male and it looked like a possible success but a limited success since it was going to take two generations. All of the fry of the regular cross would be getting a EB 'y' or 'x' gene from the EB male and can only get Regular (non-EB) 'x' genes from the female. The fry would all be non-electric colored but all carrying one EB gene (with the EB male contributing one EB gene and the female contributing only a non-EB gene). Since a visible electric fish has to have two EB genes ( 'xEB' and a 'yEB) none of these would show the coloration but would be valuable as 'known' heterozygous for the gene -- otherwise known as 'blue gene' jack dempseys. Follow along here on the next generation. Any pair of the heterozygous fish would normally generate fry with three different types of gene pairing. One half would have received an EB gene from one parent and a regular gene from the other parent. This half of the fry would be exactly like their parents (heterozygous with either an 'x' or 'y' gene as EB and the other a regular JD color gene). The remaining two groups of the fry have the real distinctions. One group would represent fry that got a regular gene from each parent and would be regular dempseys and homozygous (no EB genes at all). The remaining one fourth would have received an EB gene from each parent. Here is where it gets squirley since apparently any embryos that have two 'xEB' genes (and would of course be all 'xx' and females) does not develop and these embryos do not normally hatch. Only the embryos with one 'yEB' gene and one 'xEB' gene develop and will of course be 'xy' and all males. This appears verified when watching the eggs I have seen in the flowerpot develop an interesting random sprinkling of white eggs that don't hatch --- probably all of the 'xEB-yEB' embryos. So continuing on here a spawn of 800 eggs would generate 400 heterozygous fry and 200 homozygous non-EB fry and 100 EB fry (all males and homozygous for EB). How would you be able to tell the 200 regulars from the 400 heterozygous fish? This is where the known heterozygous fish would be potentially valuable since to determine which fish in the next generation were carrying the EB gene, it would seem that you would have to pair up fish and look for EB fry in their progeny -- an expensive and time-consuming process.
A discussion of the development of the homozygous EB fish (the original 8 mentioned above) is in order. As stated the coloration as well as the eyes and finnage varies greatly and would appear to corroborate the claim that originally all EB fry were considered culls. Note also that the EBJD fry do not start out with the blue color but are gold with the blue starting to appear around the gills at about 3/4 of an inch and gradually spreading out over the entire body and fins and usually becoming a dark blue. Our experience is that the EB fry will grow slower than the other fry and may end up as food for the normal colored and larger dempsey fry. This is a good thing since they would not be pool-raisable and could not be economically supplied by fish farms. If any fry of the spawn die it will almost certainly be the EB fry first so optimal conditions are recommended (I now have nauplii available). I have had a few with some of the gill cover missing on one side -- this appears to be a common flaw -- but not otherwise fatal. If it was clear we could call them 'electric blue blushers' -- but no such luck.
So if you have been following along, I had two pairs of dempseys (one with an EB male and regular female) and the other a heterozygous pair (not exhibiting the EB color but each with one EB gene) and the heterozygous pair had a spawn of small fry. Attempting to have the wisdom of Solomon, I gave my manager the EB/reg pair and half the heterozyous pair's fry. Neither one of us has any EB fry from the split -- my guess is that in the non-optimal setting, all of the EB fry have expired. These guys need special attention. I have about a dozen normal looking fish in the greenhouse and 3 more normal looking fish from the second spawn. So far my manager has not gotten the EB/reg pair to spawn and he does not report having success raising up any of his fry. [note 8-2010 he finally reported back to me that the female killed the large male when he tried to breed them -- not unexpected I guess since the adult male was probably a cream-puff also]
The second and third spawns of my '$300 pair of blue jeans' each had a good cloud of fry for a few days then all but 3 were gone from the second and all disappeared from the third. Questioning the guys that supplied us with the heterozygous pair gave more information. They report that allowing the parents to raise the fry up results in a smaller and smaller group of fry and I have to wonder if the non-uniform appearance of the fry confuses one or both of the parents. Anyway for the fourth spawn at my house I have removed the male (they are wrigglers so far and well taken care of by the female). Another reported issue was that the males occasionally killed the females. I noticed this in my pair and gave the female many places to hide. The male would chase her around and when she finally came around she would change to the black color form and they would swim around together. After they spawn the female will not allow the male to get to the eggs. The last piece of information I got from my breeder friends was given under promise not to disclose to the public. They also claim to have acquired EB females and gold colored dempseys -- I have since heard that they have had problems keeping them alive. I am conflicted on whether or not to disclose the information anyway since my intention in writing this article is to dispel some of the mysteries of the EBJD. I wondered how commonly the EBJD pair eats all of the fry. I have had to struggle to figure this out and perhaps potential EBJD breeders should struggle like I have. Without directly revealing the secret I can say that it has to do with how to tell the regular non-EB fry from the heterozygous fish. It is important since knowing this would avoid extra pairings and multiple fry raising to verify an EB producing pair (but note that a sprinkling of dead eggs in the mass of eggs would possibly be an indication of EB genes contributed by both parents -- the female eggs would be the white ones). It also avoids actually having to have a displaying EB fish as one of the pair -- you can produce EB fry from the heterozygous fish (my manager with the EB/reg pair has still had no spawning -- he said the regular female beat up the male and there may be an eyesight problem). When you are in on the secret a look at some of the pictures on the web of ERJD pages makes you laugh as the secret is hiding in plain sight if you are looking. If you are a student of my website this may have some meaning to you:
Oops, CDM.

I will add to this page when I have some experience raising up the fry from spawn number 4. After the fry were free swimming for one day I removed the female as I could not really be sure which of the pair got the last two spawns. I have since decided that most of the losses with the male removed were due to the fry getting sucked into a hole in the powerhead tubing on the undergravel filter -- what a bunch of dummies.
On the 5th batch of EBJD fry after careful management I raised up a large cloud of them in a 60 gallon tank to about 1/2 inch in size and sorted them for science. There was a total of 1440 fry with 180 electric blues (gold colored at this point). This would appear to exactly match the genetic percentages above with 12.5% electric blues (with an original total of 25% but with all of the female embryos not surviving). The 1260 non electric blue colored fish should break down into 2/3 hetereogenous ('blue genes') and 1/3 regular jack dempsey with no EB genes. To round up the numbers for easier understanding -- a spawn of 1600 eggs from a 'blue gene' pair would give 400 homogenous EBJD (with the 200 xx females dying in embryo), 800 heterogenous 'blue genes' (males and females each with on EB gene -- xEB for the females and yEB for the males), and 400 regular jack dempsey fry with no EB genes. Most breeders feed the non-colored fry to large fish since if they sold the fry off as regular jack dempseys -- someone would be getting a windfall on the fish we paid good money to acquire. The 6th and 7th spawns I lost due to hydra. The spawns were in the same 60 gallon tank after removing the 5th spawn and apparently the heavy feeding of nauplii got a colony of hydra going in the brown gravel that I could not see. It took me some time to figure out what was going on by moving some fry to a bare-bottomed ten gallon tank with a sponge filter. In that tank I could see the hydra on the glass (in just a few small areas) and saw a few hanging like flags on a flagpole and one with the hydra letting go of the glass but still hanging on to the fish. These fry were 1/4 inch long but unlike their namesake -- they must have glass jaws. Hydra have small venomous spines in their grasping arms that apparently paralyzes the fry immediately. Having had some experience with hydra in the past I can state that hydra does not come in with the nauplii and is quarantinable and controllable. My experience is that the hydra comes in on plants you get from your friends. I removed the plants and put in a large koi and a couple of one-foot trinidad plecos in the tank and after a few weeks without feeding the plecos, the hydra was gone but the plecos had a hard time of it with one of them developing red lips and both usually gingerly hanging on the glass sides with just the lower tip of tails touching the gravel. I could have used salt but I still was not able to see the hydra in that tank and needed the indirect evidence provided by the behaviour of the plecos. Copper and medications like Clout (tm) could work but it is hard to figure the dosage since the organics in a tank with gravel is problematical since the carbon in the organics soaks up the copper. I currently have spawn number 8 in the tank and they are progressing well except that the sizing is more random. To avoid another hydra outbreak I have been feeding less live nauplii (mostly just when the EBJD fry are very small) and using more crushed flake food and freezing the nauplii first. I try to feed in one end of the tank where the tank is bare-bottomed so I can see the food and any developing hydra colonies. So far the quarantine works but the fry have a considerable difference in size and I will have to start pulling out the largest ones fairly soon to avoid cannabilism.

8-15-2010 Note on non-standard fins and eyes:

Don't let the issue of culls stop you from trying to breed these fish. If you do experience issues, why not be in it for the long-haul and attempt to cross the EB strain you have with a non-EB strain and see if the culls are gone. I have no knowledge of the history of the strain I have. I do know that there have been no outcrosses in the last few generations -- remember my outcross attempt was lost in the manager divorce listed above and the custodial parent did not properly supervise and that science experiement was left uncompleted. Part of the mystery of the EBJD is in its origins. One myth is that someone found a strain of them in a remote lake or river and perhaps all of the fish produced so far have been from this probably highly-inbred strain and that although outcrossing is possible, none has occurred in the stock I have or in the stock referenced by others with culls. Your outcrossing could produce the best EBJDs available yet. By the way, I sold a 1.5 inch EBJD today which had the usual eye-problem I have experienced and the customer wanted it since it was so unusual. The eyes look perfectly normal until the fish is about an inch long and then the eyes start to bulge out at the back of the eye -- leaving the fish with two eyes pointed forward kind of like he is wearing glasses. The eyesight was un-impaired since this was one of the faster growing fish in the batch and the color and finnage was perfect. Report back to me on any data on culling issues in other EBJD stock and especially if you perform the science experiment above and outcross.

Electric Blue Gene and Regular Dempsey Fry
What is it worth to you to get fish that will immediately produce EBJD fry?? Click to Enlarge

8-15-2010 Update on plans to offer the 'blue gene' fry and 'regular' mix fry for sale.
Times being what they are, I need some cash and I am presently offering the non-EB-displaying fry for sale from this website and on Aquabid. As stated above, they are a mixture of 66 2/3% 'blue gene' (or heterozygous for EB fish -- the same as the parents) and 33 1/3% totally regular jack dempseys (not carrying any EB genes). The EBJDs will have been previously been sorted out (they look gold) but the 'blue genes' and regulars look identical at any size less than 2 inches. I have some fry from each of the last 3 batches and are 100 at 2 inches, 200 at 3/4 inch, and 1000 at 1/2 inch. I will offer the 3/4 inch fry on Aquabid but anyone interested can negotiate for some of the other sized fish. I also have 2 large males and 4 large females (all sorted visually as 'blue gene') but not proven. I paid $300 for the pair I am getting all the small fry from. I paid about that for the extra fish but have not raised up any fry to prove these guys 'bona fides'. Sorting is the real trick here and there are two ways to accomplish it:

1. Raise them up to over 3 inches and in the proper lighting the basic color of the head and body will appear purple/pink -- this is really obvious on 5 inch fish and larger. Oops, I have disclosed the secret. One problem here is that paired up or breeding fish get and stay really dark and are still hard to sort until larger.

2. The sure way to know that you have a pair of 'blue genes' is to pair up some fish and raise up some fry to at least 1/2 inch and look for 'gold-colored' fry -- these are pure electric blues and prove that you have a pair of 'blue genes' worth at least $300 dollars.

Email Rhonda at if you are interested.
06-06-2012 I have as customers both of the original breeders who created the local strain of EBJDs here. The first owner of the program is a Bruce Armstrong and he gave most of them to Sorenson who then set up Bob Allen. Bruce has been out a few times to buy some amano shrimp and nerite snails. When he was out here a few weeks ago I asked a series of questions to fill in my gaps in the mysteries of EBJDs. His information was not very encouraging -- but here it is: He still has a few but says there is no market for the fish. He says without special conditions probably only 1% survive to a normal sized adult. He says there is some enzyme deficiency in their digestion that makes them weak and he says most die because of internal parasites. He says you must use a UV sterilizer to keep the parasites down and feed spirolina type flakes. He says he makes his own food for them. He says the fry must be on live brine shrimp for at least the first 6 weeks or they will have many development issues such as deformed eyes and bent noses. (this explains why Bob does fairly well -- he feeds newly hatched or frozen brine shrimp almost exclusively). He says the females are present but so much weaker that they usually die first. He says he has had good luck with the Golden Pearls sold by Brine Shrimp Direct (see my links page). On the question of the purple as an indicator of a blue gene JD -- he said that it was their normal breeding color but that he and Sorenson had thought they might be on to an indicator in the ring of dots around the eyes. He showed me one of mine that had an almost complete circle -- and that dots around 10 or 11 pm on the clock may indicate the blue gene. He thinks non blue gene dempseys do not show those dots. I will try to set up some of my fish in tanks where the colors and dot patterns are clearly visible and see if the system works. That all fits in with my prescription -- soft water but high calcium in their diet. I questioned him on water temperature because of what he said about parasites. He was running the water just under 80F and I asked him if he knew how the asian discus breeders cure their parasite issues. They run the fish at 100F for a few weeks -- with plenty of circulation and aeration -- and it appears to kill all of the parasites -- round worms in this case -- in their guts. It fits into my Antarctic research station analogy -- in the fall once you have been at the station for a couple of weeks after the last chopper and supply ships have left -- no one has a cold or flu until the next choppers in the spring -- and you can visit the other countries research stations with no fear of catching viruses either. This is what happens with fancy guppy breeders and discus people -- once the viruses are gone they can trade in safety as long as they keep strict quarantine procedures.
My blue gene breeding pairs were sold (really traded) last year and now all I have left are lot of good sized 66% likely blue genes in relatively dark tanks as I also sold off 7000 gallons of tanks last year (mostly plexiglass 24x48x12 inch 60-gallon flats that I had to climb ladders to even feed them -- they were moved there when we closed ours shop a couple of years prior). My plan is to build some more of the flats with the 1/2 ton of 1/4 inch glass I still have left and free up more tanks in my basement where the RO system tanks are and sort out the fish into likely pairs. I will be looking for the purple and or the eye circles and see if I can easily pick out some newer pairs. I should by now have more info on the output of the original pairs and their offspring -- but I offer my only excuse for my lack of data -- the following sad story: The original pairs that formed the basis of the start of this blog/article I originally offered for sale to a local couple who appeared very interested in them. They bought a lot of the fry at $2 each at 1/2 inch (I don't raise them up past that size as when you get them up to a larger size you either loose a lot of them or have a lot of deformities -- still searching for info here -- but I may try some of the latest info from the original local breeders of the EBJDs). The couple (Bill and Brandie ODell --a good aquarist name I thought) that took the big breeders offered me an irristible deal for a Nascar fan. They had an extra set of tickets to the Las Vegas Nascar event last spring (2011) and offered to take me with as a passenger and even had an extra room in a condo as part of the deal. The condo was owned by another couple who were their friends but were in Afganistan and Bill and Brandy were making a combination trip/vacation to help their friends get their stuff out of the condo into storage and close out the lease while cleaning up the condo to get back the cleaning deposit. They said I did not have to do any of the work and not even have to do any driving. I really enjoyed the vacation and they were great hosts and even let me drive one of their cars home (a Mitsubishi sports car that had a passenger compartment like a jet cockpit).
After the vacation I saw a lot of them. They seemed like really good people with the only off-putting issue I had was that I distinctly remember them coming into my store years ago and acting seriously like they were going to buy it. My usual sales method included saying everything in the store was available -- including the store as I had not intended to run it myself but Rhonda went blind in the first year. I brought up the issue of what I remembered and they both claimed not to remember which was nothing in itself as I may be forgettable to some people. They had recently made a decision to build a large building behind their house and needed a lot of stuff to populate the fish house. He claimed to have formerly run a roofing company and I needed some roofing repairs and he offered to trade his labor on the roofing for a bunch of the extra stuff I had that he could use in his fish house. After they ran up a bill for $600 he broke both of his wrists by falling off of a motorcycle. That delayed things but his prognosis was for a full recovery but over the next couple of months or so some of the issues in his dealings became more apparant. He had a beautiful voice and could have read children's books professionally but some of his actions began to trouble me. First they had quite a few fish coming up from their explosion into fish breeding and said they wanted me to sell them as they did not want people coming into their house (oddly enough in this case a pre-fab home on property they got really cheap). They spent somewhere between $8000 and $10000 on the fish, building, and equipment by this time. I tried to get an estimate on the roofing job and twice he came out and took measurements but never gave a price for his labor. He wanted me to get two other bids first and then he would beat the offers but my take was that if we were really friends he would just give me his best rate and try to get the materials for me at cost. It was about this time that I was in his living room (he still had casts on both wrists) and we were discussing his tank of Moba Frontosa in front of us. I mentioned that I had seen a couple of other tanks of expensive Frontosa in the past and the experience was that there was $2000 dollars spent to buy a male and 9 females but if they ever bred -- only one of the females bred and it would take a long time to recover the original expense -- I am sure he spent at least that much on his fish. I said that Frontosa were kind of hard to condition for breeding since brine shrimp and flake in excess enough to fatten up the females could kill them all off in a week. They are not as bad as Tropheous but approach them in difficulty. I said I had heard some people used blood-worms with success with Tropheous and wondered if that would work with them. He perked up and said he had heard that too but said he had never seen frozen blood-worms. At this point I should mention that they had been in the hobby for just six months or so (I don't know what they had years ago when they came into my store but it could not have been much). I said we had some that we sold out of our house and he proceeded to ask a whole bunch of questions eventually getting at what I paid for the stuff and how much I had. He could not even imagine how large a box of 10 500 gram flat packs would take up in his freezer and asked me to bring out a sample. A day or so later I brought out a box and this is where my problems with the ODells began. I asked for $40 for the case of 10 which is about $7 per kilo to replace (buying $250 worth to get a price break). He paid me $30 cash which was not what I wanted but I had traded for this batch and I was not loosing money on the deal but it became apparant that once he thought he knew the lowest cost on something -- he would pay no more. A day or so later he called and told me to bring out the remaining cases of bloodworms -- for $30 per case. I told him I did not get the blood-worms and brine shrimp just for him and that we were running a business -- not money-laundering. He blew up and ended the phone call. Thinking an email might with the facts may help I sent links and pictures from BrineShrimpDirect of what the stuff costs and got this email in return:
Bill ODell 7/25/11
to me
I don't need to see that shit u don't tell someone or charge someone a price and then raise it so thanks but no thanks
I sent a reply on 7/25/11:
Craig Moormann 7/25/11 to Bill
We have had a failure to communicate here. If you had listened to my side of the story you would have heard:
1 I traded to get the bloodworms because some of my customers were asking for them -- I did not get them just for you..
2 I have been selling them to them for $7 per pound and getting it.
3 You asked how much I had left when I was not able to go look in the freezer to give you an exact amount. I forgot that guy withers took two boxes for his angels -- if I had those two boxes I would have given them to you -- but they are gone.
4 As I recall you did not think you had room for more than one box.
5 I gave you one box at my cost -- leaving me with 1.5 boxes left.
6. I am sorry that I could not give you my entire inventory at cost and make no profit to pay bills and have nothing for any of my other customers -- who I got the damn stuff for. 7 I totally understand that you are offering to take all of the bloodworms I have at cost -- I am not sure I ever offered all of it at cost.
Craig Moormann 7/25/11 to Bill
his reply:
bish o 7/26/11 to me
Well I see your true colors come out you told me 3 dollars a pack when I called you then when I called you back you doubled the price so I don't deal with liars or cheats please no more emails or calls Thank you!
Well, unfortunately he has broken off all contact (ripping us off for $600) and I have no further info on the original breeders or how they came out. I suspect he has had no luck with them without my input as I have not seen any fry of any size offered for sale from them. I did write up a document threatening to take them to small claims court and had it delivered by certified mail. His reply by certified mail was that he did not owe me any money -- said the bill he ran up for $600 was further payment to him for the Nascar vacation!! -- Who is the real liar and cheat??
I may still start the court action but he was such a charming liar on first meeting that I worry that the judge will not believe me. I do have the bill he ran up with some of the stuff listed in his own writing as he took but court may be a gamble. There must be a name for this type of business dealing where the person drives and drives to find out the true lowest cost and will pay no more. All of their tanks and equipment were bought at fire sale prices due to the economy and probably if he sold all at the real value -- he would make a good profit -- because he never really pays real value. And in court it could end as Clinton's impeachment with a debate on the meaning of a word -- is. Clinton's claim was that oral sex was not considered sexual relations in the political community and he did not purjure himself -- another Bill (Odell) could also be that persuasive.