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Blue Dempsey's


phatoscarlover

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Hey guys, just wondering if anyone is keeping or breeding blue dempseys? I didnt think they were around but they have shown up in a shop in Melbourne and was just wondering if they have been sighted in Sydney yet? dntknw.gif Anyone got any pics? (Looking for private pics not website pics wink2.gif ) Thanks.

Cheers Andy

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I've not read anything about them lately (in the last 6 years lol!!!) - what has been 'decided' about them - where did they come from? What are they really, are they hyrids or mutations (or both lol)? What's the low-down on them?

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As far as i understand it its a mutation that has been line breed to throw 100% blue fry. I cant find any articles on them anymore that suggest they are a hybrid? Personally i think that was just hearsay. As far as i can find out they were line breed by a guy called Hector Luzardo in the early-mid 90's. If anyone else has any usefull info feel free to share. thumbup.gif

Cheers Andy

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ak i take that back about the hybrid thing.couldnt find what i read, must have been one of those things where no one knew what it was so they yelled hybrid. relly nice fish, definatly one ill be lookin into.anyone found any yet? dntknw.gif

james

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Yeah - reason I asked is that when this post turned up I went looking again and found something saying that blue demp. x blue demp. is an infertile paring but when bred back to normal demp. you get some fertility. This kind of pattern is consistent with a hybrid where there is some mismatch in chromosome count. E.g. according to A.P.Greys book "Bird hybrids " pheasant x chicken can be done and there are some male individuals that are partly fertile while others are sterile and the partially fertile ones must be line bred back to either the pheasant or the chicken (depending which species you are trying to 'improve') to improve the fertility of the lines. The gist of it is something like in the first generation the males (because there are lots of sex-linked genes associated with poultry crosses) all have reduced fertility and the females are sterile for the first 4(ish) generations then the females of the back crosses start having reduced fertility. The male's fertility increases with each generation by backcrossing until eventually, if for example you were trying to change the chicken, you could cross them with normal chickens without any apparent loss in fertility (there was some talk on the poultry genetics forum I am part of to try and introduce the gold colour of the golden pheasant into into chickens like canary breeders did to introduce the red colour from the weavers - yeah yeah - I have no life...). So you can cross both the chicken and the golden pheasant with the silver pheasant with some fertility. Then by backcrossing you establish 2 strong fertile lines. Mortality is generally quite high early on with reduced mortality in each subsequent generation. Even that article on the blue dempseys shown here mentions that early on the fry lacked vigour and is hardly conclusive evidence that they are infact a mutation or a recessive gene. For a start the origin of the parents that were received as a 'gift' is unverified and it seems strange, that unless in the homozygous form there is a lethal gene in there somewhere that the spawn from blue x blue is always sterile (although the 25% ratio of blue to normal from heterozygous parents and 50% from the hom. recessive x het. parents is consistent with a recessice gene being present (funny though that it seems to have a multitude of effects from the blue colour to elongating the body, extending the fins and reducing aggressive behaviour)). My bet is that in the not to distant future fertility in the blue dempseys will have increased and they will become fertile in their own right allowing blue x blue to be possible.

I still smell a 'flower horn'-come-blood parrot type beast. You'd think that someone would take it upon themselves to prove once and for all by means of sampling their DNA whether they are mutts or mutations once-and-for-all wouldn't you. Sounds like a job for a cichlid society with greater resources than most individuals wink2.gif

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That actually makes sense now that you put it that way - though dempseys are a pretty elongated fish to start with & I can't think of a longer blue one to be crossed with?

Perhaps the dempsey's body elongation gets exaggerated when a JDxTexas crosses back with a pure dempsey or another JDxTex? Their finnage could come from a really spiffy texas perhaps?

What other blue neotropicals are there? You wouldn't think Geos (brazilnesis) would you?

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mmm.. interesting indeed.. confused.gif

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.

Surely, others who bought the siblings of the parents would have had a similar experience? It can't be that only ONE person decided to breed from that batch? Who knows. Beautiful fish but more info is needed at the moment I think.

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Hi Guys,

I remember hearing a few years back that the theory was that Nandopsis tetracanthus (cuban cichlid) had been used in producing the Blue dempsey, it wouldn't have produced the overall blue colouration but the markings around the head on some of the photos of the BD's that I've seen is similar to tetracanthus.

You will find some pics here of the cuban cichlid.

Also have a look at his "Archocentrus octofasciatum blue dempsey" I think you will see what I mean about the markings.

http://www.tangledupincichlids.com/photo.html

Cheers,

John.

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  • 8 months later...

I'm pretty sure the ones I saw were $140, but dont quote me on that. The same store also has Zebra plecs for $750.

Adam

Wow, just rang St Kilda Aquarium, they have one pair left, not for sale, but he said the pair would go for $800 if they were being sold.. Ouch!!

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