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Discussion Starter · #1 ·
I have a pair of J. Transcriptus in my Tang Community tank and recently, the female Juli bred with a lone male N. Brichardi, not once but 3 times. Has anyone ever heard of this before?
 

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Augustus67 said:
I have a pair of J. Transcriptus in my Tang Community tank and recently, the female Juli bred with a lone male N. Brichardi, not once but 3 times. Has anyone ever heard of this before?
Yes. These fish can hybridize for sure, and there has been all kinds of crazy mixes over the years.
 

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Discussion Starter · #4 ·
I'm assuming that being hybridized across genera will result in sterility so I guess there is no danger in keeping a few for visual interest. I can't cull so whatever the Calvus don't get are new additions.
 

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They will not be sterile. I would separate the hybrids and the fish that created the hybrids or the problem will continue. Why not rehome the brichardi?

If the tank is large enough you could add a group of 5 Synodontis multipunctatus to perform fry patrol.
 

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DJRansome said:
...They will not be sterile...
You can't make a blanket statement like that, for reasons outlined below.

Augustus67 said:
...I'm assuming that being hybridized across genera will result in sterility...
Not necessarily; it depends largely on how closely the parental fishes are related. If their karyotypes are very different, heteroploidy in the progeny will likely result in hybrid sterility. However, if the parental karyotypes are similar (i. e. meiotically stable), the hybrids may be fertile. There is no way to know in advance, and just because we assign species to different genera does not mean that they cannot produce fertile hybrid progeny. That's the root source of the hybrid problem in Rift Lake cichlids.
 

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Thank you for the additional information.
 

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Discussion Starter · #9 ·
Thanks for the info everyone. I am going to rehome the Brichardi to prevent this from occurring again.
 

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sir_keith said:
DJRansome said:
...They will not be sterile...
You can't make a blanket statement like that, for reasons outlined below.

Augustus67 said:
...I'm assuming that being hybridized across genera will result in sterility...
Not necessarily; it depends largely on how closely the parental fishes are related. If their karyotypes are very different, heteroploidy in the progeny will likely result in hybrid sterility. However, if the parental karyotypes are similar (i. e. meiotically stable), the hybrids may be fertile. There is no way to know in advance, and just because we assign species to different genera does not mean that they cannot produce fertile hybrid progeny. That's the root source of the hybrid problem in Rift Lake cichlids.
From experience, they won't be sterile. Blanket statements cannot be made, but when you've seen... you've seen.

The biggest shocker I've seen, was a fertile Tropheus x M. auratus hybrid.
 

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...From experience, they won't be sterile. Blanket statements cannot be made, but when you've seen... you've seen...
Well yes, sort of. What you've seen are anecdotal observations, relevant only to the small number of particular crosses that you've seen. Those observations in no way contradict the vast body of scientific literature concerning hybrid sterility to which I referred.
 

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Is the hybrid sterility, when it occurs, a "thing" with egg layers?
 

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Is the hybrid sterility, when it occurs, a "thing" with egg layers?
Not at all. It's a general biological phenomenon, not confined to particular kinds of fishes, in fact, not confined to fishes, or even animals, at all. Google 'hybrid sterility' and you'll find a wealth of information on the topic.
 

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The biggest shocker I've seen, was a fertile Tropheus x M. auratus hybrid.
I don't think that cross is really that surprising, at all. There both members of the same tribe. Haplochromini.
And Haplchromines are probably the most common and most easily hybridized cichlids in the aquarium hobby.
I think this cross is more of a shocker: Convict and Terror Hybrid - How did this happen?! It's a cross of more distantly related cichlids. A CA x SA cross that belong to different tribes. Therapsini X Cichlasomatini Though whether the offspring are sterile or not, we really don't know yet.
Even more surprising is a substrate spawner X mouthbrooder cross. Coptodon X Oreochromis crosses were known as far back as the early 80's. In the preface to Ethelwynn Trewavas' book on Tilapias, the editor mentions that she was very surprised that such crosses were possible. How research scientists got around the different breeding methods I do not know, but I would imagine it was done in vitro (??). This link shows some of the crosses that were tried(pg.73).Biodiversity Dynamics and Conservation Male Coptodon tholloni X Oreochromis niloticus and male C. tholloni X O. mossambicus both produced female offspring and male O. aureus X C. tholloni did produce a few fry. Many of the crosses with in the genus Oreochromis produce mostly, or almost exclusively male (desirable in aquaculture production).
Today, Oreochromis and Coptodon are not even considered to be part of the same tribe. Oreochromini and Coptodonini are seperate tribes as DNA shows they are not all that closely related:https://edoc.ub.uni-muenchen.de/15478/1/Dunz_Andreas.pdf
 

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Regarding the question as to whether hybrids are fertile, I was surprised to hear that about Tangs because I thought all Malawi hybrids were fertile. But I never spawned one...I do my best to prevent hybrids let alone allow them to spawn.

So are we saying most Malawi hybrids are infertile as well?
 

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Regarding the question as to whether hybrids are fertile, I was surprised to hear that about Tangs because I thought all Malawi hybrids were fertile. But I never spawned one...I do my best to prevent hybrids let alone allow them to spawn.

So are we saying most Malawi hybrids are infertile as well?
In most cases, it's going to depend on how closely related the cichlids are. Distant enough and they may only produce one sex (even a crosses in the same genus).Distant enough and the offspring are sterile. Even more distant crosses, and no offspring will be produced. But really can't make any blanketed statements.
Lake Tanganyika has numerous cichlid lineages.Different tribes. A Lamprologini X Lamprologini cross (such as the OP's) are fairly common in the hobby and at least some are known to be fertile (if not most?). But as far as I know, nobody has crossed different tribes from lake Tanganyika, such as a Haplochromini X Lamprologini (which according to the DNA work that has been done so far,would actually be more closely related then a cross between Orechromini X Coptodoni).
The lake Malawi Haplochromine flock is thought to have evolved fairly recently (some researches say that the Malawi and Victorian Haplochromines evolved from a Tanganyikan Haplochromine ancestor(s).) They are all closely related. What we know from experience in the hobby is that most of these Malawi Haplochromines when crossbred produce fertile offspring.....but we really don't know for certain that every single possible cross will.
Sometimes a successful cross depends on which is male or which is female. My second link (pg.73) shows that male Haplochromis nubilis X female Haplochromis burtoni is described as a lethal cross but when the sexes are reversed, male Haplochromis burtoni X female Haplochromis nubilis , then it is a successful cross (F1 viable and F2 viable and fertile).
 

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In most cases, it's going to depend on how closely related the cichlids are. Distant enough and they may only produce one sex (even a crosses in the same genus).Distant enough and the offspring are sterile. Even more distant crosses, and no offspring will be produced. But really can't make any blanketed statements.
Lake Tanganyika has numerous cichlid lineages.Different tribes. A Lamprologini X Lamprologini cross (such as the OP's) are fairly common in the hobby and at least some are known to be fertile (if not most?). But as far as I know, nobody has crossed different tribes from lake Tanganyika, such as a Haplochromini X Lamprologini (which according to the DNA work that has been done so far,would actually be more closely related then a cross between Orechromini X Coptodoni).
The lake Malawi Haplochromine flock is thought to have evolved fairly recently (some researches say that the Malawi and Victorian Haplochromines evolved from a Tanganyikan Haplochromine ancestor(s).) They are all closely related. What we know from experience in the hobby is that most of these Malawi Haplochromines when crossbred produce fertile offspring.....but we really don't know for certain that every single possible cross will.
Sometimes a successful cross depends on which is male or which is female. My second link (pg.73) shows that male Haplochromis nubilis X female Haplochromis burtoni is described as a lethal cross but when the sexes are reversed, male Haplochromis burtoni X female Haplochromis nubilis , then it is a successful cross (F1 viable and F2 viable and fertile).
Well said. (y)
 
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