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Infertile "hyprid" offspring of hypancistrus

Posted: 19 Jul 2005, 12:42
by a-ok
Hi

Some months ago I had a little accident where a L-270 and a L-333 paired, resulting in a brood of â??hybridâ?

Posted: 19 Jul 2005, 13:26
by MatsP
There's a lot of discussion about hybrids and the relevance of hybridisation when it comes to defining closeness in specie relations.

Ability to hybridize and fertility of the off-spring is no indication in this case. You can prove that two individuals are a different specie by proving either that they are unable to reproduce or that the off-spring is infertile, but not the other way around (like the failed-logic saying "All dogs have a tail, so therefore everything with a tail should be a dog").

From what I understand, the loss of the ability to cross-breed is actually an evolotunary step that is caused by closeness geographically. So two species that are originating with the same fore-fathers, that diverge in the same geographic region will eventually form a cross-breeding barrier, whilst species that are developing geographically separated will not form this barrier (as it serves no purpose to keep the specie separated by this barrier if there's no chance of cross-breeding). [This paragraph is based on what Ian Fuller wrote in the Cory forum a few days ago on the subject of cory's hybridizing. It's not expressed with the same words, but I think I express the same basic idea, and I'm not taking any credit for the original idea].

There are plenty of examples of fertile off-spring from hybridization, not least in fish. Take for example all the varieties of livebearers that are able to reproduce hybridized and also get viable hybrid off-spring.

Finally, if we have fish that look different, such as L66 and L333, just as an example, even if these were to be described as the same specie (which is an unlikely outcome, but let's pretend that it may happen), we should still keep those fish separate in breeding terms, so that we don't get all sorts of cross-bred mongrels mixed in with the wild-caught varieties. If you want to mix different looks and make your own breeding experiments, keep to something that is already inbred and genetically messed with, like guppies or gold-fish, rather than the Loricaridae family...

I do understand that this was an accidental, and the above is more aimed at the fish-breeding community as a whole, rather than the original poster as such.


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Mats