Jack D and RD-possible mating?

[Harry Tolen]

Once again, I fear we are confusing "line bred" with "hybrid". While there are certainly a few animals (mules, for example) that are actual hybrids, most genetically modified animals are just members of the same species bred back to their own bloodlines in order to emphasize certain naturally occurring traits.

There is no telling what you might get from the interbreeding of a JD and an RD. The eggs might never be fertile, you might get nothing but a batch of deformed "culls", or you might pick up some combination of the traits of the parent species. However, they will not breed true, and the second and third generations will almost certainly exhibit symptoms of genetic degeneration leading to early death.

I know, because I've had an experiment of my own running with this for the last 11 years (note: NO offspring have ever been sold or released beyond my own tanks). The original hybrid was a complete fluke, with two pairs of fish simultaneously breeding in opposite ends of a 125g tank accidentally cross-fertilizing one egg. Since then I have discovered that this hybrid is vigorous and fertile, but that his offspring are completely degenerate. Picture (of the original cross, and an offspring) follows. Can you guess what it's a mix of, and which is the parent?

 

[TTman]

how do u know that ONLY 1 egg got cross fertilized? or if it got cross fertilized at all. u know genetic mutations/variations do occur naturally.

Originally posted by Harry Tolen

The original hybrid was a complete fluke, with two pairs of fish simultaneously breeding in opposite ends of a 125g tank accidentally cross-fertilizing one egg.

 

[Harry Tolen]

Well, perhaps more than one got cross-fertilized, but only one survived. As it happened, very quickly after this spawning, I moved from an apartment into a townhouse, and in rummaging through the 125g where this all happened found about 10 miscellaneous fry before I drained out the last of the water. I put them together in a 29g in the new house, and this one was different from relatively early on. The others all grew up to be completely normal representatives of their respective species. Which are...

 

[undertow]

Saw the fish last night. They began grappling and locking jaws after the tank light was turned off. The JD was the more aggressive cichlid in this case. Clamping down hard on the devils lips and staying like that for over 5 minutes!! They where also twisting and writhing there bodies around each other. RD is pretty scarred up-looks like it's time for a 'love-door'!

 

[wayne]

brichardi and juli transcriptus?

 

[Harry Tolen]

Wayne: very close. It's a cross between N. brichardi and J. marlieri. Again, it's been a great fish -- over 11 years old now and still going strong. I have always kept it in a community Tanganyikan tank and it has always managed to keep breeding, usually with a spare marlieri female, but it's offspring have never shown consistent characteristics. And, although some of them have also been very attractive to look at (in fact, that's one just to the left of the original hybrid), ALL of the offspring have died of old age (or something that looks a lot like it) at a very young age. So hybridization does have its drawbacks.