crossing severums

[Sarah88]

lol a 3 yr old thread

on the topic though, my rotkeil female and gold male have spawned dozens of times over the past 2.5years. i never raise the fry and they are eaten by tankmates

haha, wow yeah usually i catch those things lol ZOMBIE THREAD!!!!!

 

[David R]

Been done here because the breeder couldn't find a male rotkeil; http://www.trademe.co.nz/Home-living/Pets-animals/Fish/Fish/auction-300919027.htm

The guy has a reputation for making up names for african cichlids and incorrectly identifying fish. I sold him the female rotkeil a couple of years ago hoping he'd just hand onto it until a male became available, but instead he crossed it with a gold male claiming that "the gold gene is recessive", on what grounds I'm not sure because he didn't grow out any fry before writing the ad and selling them. The few I have seen don't look anywhere near as good as a pure rotkeil, and if my limited understanding of genetics is correct, I think the second generation (if you crossed two of the hybrids together) would create a pretty varied bunch of offspring.

I know its an old thread, but crossing two fish just for the fun of it is a bad idea IMO, if you do then don't go selling the young until you have a chance to see what they turn into.

 

[glenbo]

Interesting, anyone have any hybrid pics?

 

[hamfist]

I have a red-spotted gold and a wild-caught turquoise which I'm hoping will breed in the coming months. the male is defo very interested. They are the best of friends but I think the female is not quite mature enough for spawning. They are both about 4" (SL). What size do sevs usually start thinking about spawning ?

 

[David R]

What do you hope to achieve from crossing those two fish? Are you going to continue to selectively breed them to produce a new variety that has a point of difference from other sevs (eg the super reds), or are you just doing it to see what happens?
If it is the later I sincerely hope you don't release the fry to the general public, even if you are upfront about their mix. The last thing this hobby needs is more confusion from unscrupulous breeding...

 

[fishfarm]

OK once again, The domestic Heros severum is a hybrids of several wild type fish, when they were first introduced many years ago everyone thought they were the same species, the gold is just a color morph of the domestic green (ie same fish, different color). Calling all Heros species severums is just wrong and I will correct it every time someone does this, Hybridizing wild fish to "see what you get" is not always a great idea.
There are numerous discribed wild species (efasiatus, notatus, severus (not severum), appendiculatus (turquoise) plus just as many undiscribed species (including rotkiel)and these wild types should all be kept as pure as possible. The generic term severum should only be used for the hodge podge domestic bred greens and golds.

 

[hamfist]

What do you hope to achieve from crossing those two fish? Are you going to continue to selectively breed them to produce a new variety that has a point of difference from other sevs (eg the super reds), or are you just doing it to see what happens?
If it is the later I sincerely hope you don't release the fry to the general public, even if you are upfront about their mix. The last thing this hobby needs is more confusion from unscrupulous breeding...

Definition of unscrupulous ... "oblivious to or contemptuous of what is right or honorable."

Rather an extreme response I think. I am well aware that the "trade" severums are a mixed bunch of variants of H.efasciatus, with there being a lot of argument even about whether "species" such as appendiculatus even exist, or are just colour variants of efsciatus etc.
My red is a fine specimen, and if he will breed with my wild-caught turquoise, I thought that it might be an advantageous thing to add some wild genes into the strain, to increase hardiness. Yes, I don't know exactly what the fry might look like but I do see the sevs sold in shops and many of them are clearly genetically weak, through too much inbreeding, with bad spines, odd shapes, odd mouths etc, caused by too many generations of captive breeding with too small a gene pool.
There is also a demand within the trade for interesting colour variants of severum, not for breeding necessarily, but just by owners who want a nice, interesting colourful fish. I was hoping to provide a genetically strong fish (with it's wild genes) and with interesting colouration. If they were extremely bland for any reason, and not attractive for people to buy, then I clearly would not sell them.
I think you are writing purely from your own perspective and not appreciating the perspective of the general fish-owning public out there.
My thoughts were that I would not be affecting the "true strains" of sev that others were keeping in captivity, but would just be adding to the mongrel populations which many people seem to like to buy and own (which is not inherently a bad thing as far as I understand it).

I am open to criticism and others ideas, and would appreciate any well thought out responses.

 

[hamfist]

these wild types should all be kept as pure as possible.

My question would be ... why ?

pure strains of anything kept in captivity almost always end up genetically weak through too much inbreeding.

If the reason is to maintain an endangered or extinct species, or strain, then I see the benefit, but not otherwise. The best, and strongest populations will always be found in the wild, with all the gene-mixing that naturally goes on.

If we look at domestic dogs, for example, a lot of the breeds that have been around for a time are genetically weak, and have well known weaknesses that have arrived purely by selective inbreeding. Its the mongrels which benefit from a great mix of genes, giving health and vigour. They are all the same species, just different breeds of it.
I don't hear suggestions that dog breeders should selectively breed to be as near wild-types as possible. Why should that be the case with fish ?

Please educate me if I am well off the mark. I am not a commercial fish breeder. Nor am I hugely aware of what state the wild populations of these fish are in. However, I am a scientist and an experienced fish-keeper, and I am interested and keen to learn.

 

[ChilliPepper]

I agree with hamfist (hello hamfist, I recognise you from another forum )

To be honest I think it far better that two completely different types bred, rather than all the interbreeding that seems common practice in fishbreeding.

I read a lot that people buy a load of fish from the same batch hoping to get a pair, then sell off the rest. They hope this pair will breed so they can raise the fry and sell them on. These babies are inbred, so how can that be right?

I suppose interbreeding happens in the wild, who knows. I suppose it depends on the fish and how dense their populations are. I know guppies would with no hesitation, but I think Sevs are more choosey, so maybe they don't.

I have a Red Spot and a Green, who are both small at the moment, but if they breed when older then so be it. They are from completely different batches (different areas of the country, so hopefully!) bought at different intervals, so I don't see the harm. Maybe both are inbred anyway? I know the Red Spots are supposed to be quite rare, so...

 

[David R]

Definition of unscrupulous ... "oblivious to or contemptuous of what is right or honorable."

Rather an extreme response I think.

Didn't intend for it to be taken in the literal dictionary sense of the word. I was stuggling to chose the right word, perhaps "random" would have been a better choice, and less offensive to you.

My red is a fine specimen, and if he will breed with my wild-caught turquoise, I thought that it might be an advantageous thing to add some wild genes into the strain, to increase hardiness. Yes, I don't know exactly what the fry might look like but I do see the sevs sold in shops and many of them are clearly genetically weak, through too much inbreeding, with bad spines, odd shapes, odd mouths etc, caused by too many generations of captive breeding with too small a gene pool.

Right intentions, but if it aint broke don't fix it. Even with the small population [fish and people] here I am yet to see a deformed sev from inbreeding, maybe its different in the UK where they are mass-produced in larger numbers? If you were breeding fish on a commercial scale and started regularly noticing defects within a particular species/variety then "outcrossing" as you suggest would be a good idea. But doing it as a hobbyist just because you "thought it might be advantageous" is totally unnecessary. I'd recommend doing some serious research about outcrossing and linebreeding before you go playing matchmaker with different species.

There is also a demand within the trade for interesting colour variants of severum, not for breeding necessarily, but just by owners who want a nice, interesting colourful fish. I was hoping to provide a genetically strong fish (with it's wild genes) and with interesting colouration.

If thats your intention then go for it, but if you are trying to develop a new variety (rather than just create an interesting hybrid) then its going to take more than just mating two different fish and hoping for the best.

I think you are writing purely from your own perspective and not appreciating the perspective of the general fish-owning public out there.

Of course I am writing from my own perspective, as a serious hobbyist and a bit of a purist, I have never claimed otherwise. It would be rather foolish for me as an individual to try to speak for the general fish owning population.


Hope that meets your criteria of a "well thought out response", its nothing personal, but living in a small country with restrictive borders makes me somewhat passionate about the problems associated with creating hybrids, intentionally or otherwise.