Line Breeding Cichlids

[flowerpower]

Is it possible to correct the degraded genetics of heavily inbred fish by selective line-breeding?

While we may never be able to re-capture 'what nature intended' it certainly seems possible to take a fish that has been inbred for several generations and, by selectively breeding with unrelated specimens for several generations, produce offspring that possess very few, if any, flaws.

I also see fish being sold as 'German bred'. What does that mean? What are they doing in Germany that's worth any merit?

Any thoughts on this?

 

[Modest_Man]

http://en.wikipedia.org/wiki/Outcrossing

 

[flowerpower]

Interesting. Never heard that term before.
I guess that leads me to my next question.
At the current rate of habitat loss and contamination wouldn't it be better to 'outcross' and know, in detail, the genetic background of a fish than to assume that wild specimens possess the most genetic diversity when in some cases they may not?

I'm also still very curious as to the meaning of 'german bred'.

 

[Modest_Man]

Outcross with what? And what do you mean by "knowing the genetic background of"?

Any sort of line breeding isn't going to tell you the genetic background.

The most logical thing if you're worried about habitat loss and extinction in the wild is a program like CARES that the ACA has set up where you can trade and cross unrelated stock as close to the wild as possible.

http://www.cichlid.org/index.php?pageid=aca_cares_preservation_program

 

[flowerpower]

Cool! The useful info is great, the condescension not so much. I'm willing to look past that though.

What I mean by 'genetic background' is that one would know the lineage of a particular fish and that no faulty traits have been passed on from generation to generation.

By 'outcross' I mean selectively breeding fish from unrelated sources to diversify the gene pool rather than only with those locally available and likely from the same source.

If I breed a fish that I bought locally and distribute the fry locally, either to a LFS or to hobbyists directly, without any record of where they came from or where they went, the opportunity for inbreeding is substantial. After all, an entire region can be supplied for years with fry from a single spawning pair of fish.

Likewise, If a group of juvenile fish are collected at a single point on a small river, lake or lagoon there seems to be a good chance that they are less genetically diverse than one might think. Especially if their habitat doesn't span as widely as it once did.

Either way, nobody knows (and perhaps nobody 'cares').

The CARES program seems to address much of this. I never really knew exactly what it was until now, so thanks.

It is certainly much more effective for a large group of people to organize and keep track of these pedigrees than for Joe Shmoe(me) to do it himself.

Now, how do 'German bred' cichlids fit into all of this you ask?

Well, when I see someone selling a fish as 'German bred' I catch myself lauding them like German built cars without really knowing anything about them.

Is it nothing more than just a way of indicating that they are 'new blood' or are they selectively bred to improve the 'quality' of the fish?

 

[dogofwar]

German bred just refers to line bred strains of fish developed in Germany - peacocks and rams come to mind. No different in my mind than the super red peacocks from the far east - intentionally bred to be different ("better"?!) than what's found in nature (redder, bigger, longer fins, etc)

Matt

 

[uncwnells]

in theory this would be interesting

 

[Modest_Man]

Cool! The useful info is great, the condescension not so much. I'm willing to look past that though.

What I mean by 'genetic background' is that one would know the lineage of a particular fish and that no faulty traits have been passed on from generation to generation.

Who was being condescending? Me? Or CARES?

The problem with your statement there is you will always hit a wall when working backwards to whatever fish you use to start the "program" or "lineage" with. Any time you add any stock not already in the "program" (including wild) you'd have no idea of the background. Be it wild or tank raised you have no idea of the genetics, and then even the best you could do would be to say that "X group of fish hails from Y population".

 

[Toby_H]

In wild conditions...

Every adult pair of fish will only produce two offspring that will become become full adult breeding fish... or else the overall population will be increasing.

Thus thousands upon thousands of offspring are "weeded out" in terms of "survival of the fittest"...

Then of those who have what it takes to survive have to compete with each other for the opportunity to spawn.

Wild Caught stock are not highly regarded because of "genetic diversity", they are highly regarded because they are the direct result of millions of generations of "survival of the fittest" produced after millions of generations of "natural selection"...

Two unrelated less than ideal tank bred specimen will offer "genetic diversity", but will not offer the "genetic superiority" of wild bred, wild born, wild raised fish...

In the same way wild caught babies have not proven themselves through the process of "survival of the fittest" the way wild caught adults have... thus I would suggest that fish caught in the wild as adults should be held in much higher regard than fish caught in the wild as babies...

 

[flowerpower]

Excellent point!