Hybrids/Crossbreeds

[Wy Renegade]

Really?? Lol! So how do fish breed so differently then? How do there genes unite
Differently??

Sorry not sure I understand the question? Fish don't breed any differently than any other creature in the wild. However as with all animals that are territorial in terms of mates or territory, individual offspring are driven out of home territories and must make their own way and establish their own territories. Hence they seldom interact enough to breed - perhaps mother natures way of reducing inbreeding. You have to remember that less than 1% of wild offspring survive in nature to the point of even being able to breed.

Trying to impose the rules/guides that work for selective breeding to wild populations simply does not work. Further, while dominance is just that, dominant; dominance has absolutely no correlation with frequency of occurrence in the wild gene pool - again, you cannot apply the rules/guides-lines of domesticated selective breeding and the occurrence of a gene in a captive population to the occurrence of an gene in a wild population.

If something as simple as dominance always determined type, there would be no blond hair, blue eyes or light skin color in humans. We would all have a widows peak, dimples, freckles, and six fingers and toes. Rather in a wild population we have to apply the distribution factor for genes as well; hence the use of the chi square when calculating the frequency of the occurrence of a gene within a given population.

 

[Wy Renegade]

Like i want to breed an octopuss to a shark

Perhaps you own reference to the understanding of other people spawned a bit of that? Nobody is saying that your stupid; what we're doing here is having a conversation between equally educated individuals. When we do that, we may not always agree, but to infer that others knowledge is less valid than your own in these conversations often puts one at a distinct disadvantage.

At issue here is the crossing of two completely different species - mbunas and peacocks for example while both Africans, are very different species, and perhaps the analogy is not quite so different from crossing an octopus and a shark as you might think, although perhaps two different shark species - say a Great White and Bull Shark would be a little closer to the mark.

 

[Fishguy2727]

IMO one of the biggest problems with this topic is the fact that as humans we went into nature where evolution is not done yet, we made up the idea of a species, and we now try to pigeon hole current animals into definitions that we made up. This leads to many issues with how we think of species.

Depending on how you define a species if two animals can produce fertile offspring then they are the same species, even if we as humans had thought they were not at one point (and perhaps still do).

IMO there is absolutely no measurable harm in most hybrids. So giving the benefit of the doubt that they are different species to the people who think they are there is nothing wrong with them. They are healthy fish that people enjoy having.

Here is a link to the article I wrote on this, based on a lot of scientific information that should be more understandable than some of the previous posts. The site isn't done yet but some of the articles are up, including this one:

Hybrid Fish are not Inherently Wrong

 

[Wy Renegade]

IMO one of the biggest problems with this topic is the fact that as humans we went into nature where evolution is not done yet, we made up the idea of a species, and we now try to pigeon hole current animals into definitions that we made up. This leads to many issues with how we think of species.

Depending on how you define a species if two animals can produce fertile offspring then they are the same species, even if we as humans had thought they were not at one point (and perhaps still do).

IMO there is abolsutely no measurable harm in hybrids, giving the benefit of the doubt that they are different species to the people who think they are. They are healthy fish that people enjoy having.

Here is a link to the article I wrote on this, based on a lot of scientific information that should be more understandable than some of the previous posts. The site isn't done yet but some of the articles are up, including this one:

Hybrids Are Not Inherently Wrong:
Hybrid Fish are not Inherently Wrong

Really? I was not aware that there is more than one definition of species. As far as what defines a species, there is more to it than simply being able to mate and produce fertile offspring. For instance, such individuals must also mate naturally in the wild, not just be induced to breed by humans.

Certainly I'm not arguing that hybridizing fish is wrong, I'm simply pointing out the most likely consequences of crossing two separate species. If we look simply at those hybrids which are and have been produced for years by such agencies as the National fisheries departments, we can see this in effect. Brook trout and Lake trout are different species, we cross them to produce a sport fish known either as a Splake or Brookinaw dependent on which parent is male and which is female. Cutthroat trout and Rainbows will hybridize or cross in nature, but their offspring known as Cutbows are typically, but not always sterile. Tiger Muskies (hybrid of Northerns and Muskie are another example). If there is a justifiable outcome, then it may be worth doing, provided the offspring are not being sold or passed off to unsuspecting individuals and are not in some way harmed by the experiment. This is inherently why I'm opposed to it from a hobbiest standpoint - most people have not done the research and don't have the understanding to have even a clue of how those crosses are going to come out. As megacichlid said, if one is going to attempt this, one should do lots and lots of research, not simply allow it happen because they are curious.

 

[Megacichlid]

Thankyou for actually reading my posts and not focussing on the "dog" argument,that has blindsided all my fans here

 

[CraigMac]

Ok, I'm confused! I'm not "trying" to cross-breed but.......I'd like to keep different African cichlids in the same tank and not necessarily all males. Those of you opposed to cross-breeding, do you only keep male only tanks or just one species?

 

[Fishguy2727]

If you read the article it explains my whole point fairly well, I hope.

Yes, there are multiple definitions for what a species is. There are so many (I learned about at least five in college, I graduated three years ago) because none of them work in all situations. Taxonomists have to consider what they are trying to differentiate and determine which definition to use. No matter what definition we try there are simply way too many exceptions to use it across the board.

IMO mbunas are not all different species. It is a large group of subspecies incorrectly described as multiple species. They are different, but not different enough to consider all different species. The same goes for peacocks.

My evolution professor said that he and many other scientists simply don't believe in the idea of a species anymore. It simply doesn't work, not thoroughly enough to be a scientific standard (and he has discovered at least 50 'species' of fungi).

IMO healthy fish that people like and want to buy qualifies as a justifiable outcome.

 

[Wy Renegade]

Ok, I'm confused! I'm not "trying" to cross-breed but.......I'd like to keep different African cichlids in the same tank and not necessarily all males. Those of you opposed to cross-breeding, do you only keep male only tanks or just one species?

There are many different ways to accomplish this; one can keep only males (extremely difficult to do since most cannot be sexed successfully as juveniles), one can keep a species only tank (most of mine are species only), or one can keep species whose physical appearance is significantly different enough that they do not attempt to cross (in this case sufficient males and females in the proper ratio of each species chosen should be included).

 

[Wy Renegade]

If you read the article it explains my whole point fairly well, I hope.

Yes, there are multiple definitions for what a species is. There are so many (I learned about at least five in college, I graduated three years ago) because none of them work in all situations. Taxonomists have to consider what they are trying to differentiate and determine which definition to use. No matter what definition we try there are simply way too many exceptions to use it across the board.

Read through it, but not sure I agree that what you've included are truly different definitions of species, but rather just different ways of saying the same thing. While there are currently a lot of changes being proposed in regards to classification, the elimination of species is not one that I'm currently aware of, at least not among the scientific community at large.

IMO mbunas are not all different species. It is a large group of subspecies incorrectly described as multiple species. They are different, but not different enough to consider all different species. The same goes for peacocks.

While I would tend to agree that not all mbuna or peacocks are separate species (even using the currently accepted definition of species), certainly many are.

My evolution professor said that he and many other scientists simply don't believe in the idea of a species anymore. It simply doesn't work, not thoroughly enough to be a scientific standard (and he has discovered at least 50 'species' of fungi).

While I don't doubt that that is your evolutionary professors opinion, his belief or disbelief in the idea of a species is not sufficient to simply throw the idea to the wind. In other words, the opinion of one person or "implied group" of people is not sufficient to do away with an accepted standard. One must keep in mind that all classification is simply man imposing order on nature so we can study and understand it. Ultimately I have no doubt that much classification will be reorganized in the near future based on genetic analysis. However at the core, we must keep in mind that this is a tool for our use - exceptions to many of the rules of science, especially biology can often be found. That doesn't mean we accept the exception as the rule. To do away with the current method of organization or to make it so complicated that it is so far beyond the ordinary person to understand (which currently has much more momentum than any movement to do away with "species" within the scientific community at large that I'm aware of) without proposing some other method of organization is to accept chaos. If you do away with the idea of species, you do away with scientific names as well - were does that leave us? Back to trying to reference things by common names?

IMO healthy fish that people like and want to buy qualifies as a justifiable outcome.

In an effort to not get too far off topic, and bring the thread back to the original topic I have to say that generally I agree here. However again, I emphasis that one should be educated and have conducted the research prior to conducting any such experiment. Allowing fish to breed and then saying "Opps, golly that didn't work - guess I'll dispose of these and start over" IMO is not acceptable, nor is simply throwing some fish in a tank, allowing them to breed just to see what occurs. Again, just my opinion.

 

[Fishguy2727]

In the article I mainly focus on the biological species concept, definition 2 below. The different ideas for species that I learned about are:
1-A group of organisms that naturally reproduce in the wild and produce fertile offspring.
2-A group of organisms that can produce fertile offspring under their own will (when we put them together they will, but they do not require us to use advanced techniques like in vitro fertilization)
3-A group of similar looking animals that can produce fertile offspring
4-A group of organisms with a unique genetic characteristic. This definition uses a 'genetic fingerprint' that is unique to the species, a specific sequence that can be found in all the individuals in a species and not found in individuals of other species, even within the same Genus. This one is harder to use and is used less often, especially with animals, but can be very useful and definitive.
5-I can't remember any of the others off hand, sorry.

I don't think there is a movement or desire to get rid of the concept of a species, I did not mean for it to come across that way. I think the issue is that the way that most people think of a species is not correct. There are too many exceptions, grey areas, etc. Too many people think of it as black and white, this group of animals are one species and this group is a different species. Even the animals themselves are 'confused'. Some species tend to never interbreed, but then a few of the individuals do, so then what?

What kind of education and good idea of the outcome are thinking of? To me I think that mbunas will produce healthy offspring, even if we don't know exactly what will come out of a certain cross, at least not with their coloration, and that counts as an educated good idea. But to me crossing a red devil and a severum to make a parrot fish is a 'bad' cross. It doesn't create a bunch of healthy fish. That cross was originally a blind guess/hope (accident?).

IMO it doesn't make sense to 'preserve a species' by creating a demand for wild caught specimens, the most reliable source of pure individuals. IMO you have an obligation to successfully breed those individuals to help supply the demand for 'pure' specimens. Buying F1, F2, F3, etc. fish from a breeder who purchased wild caught (P0) individuals is a great option if you really want 'pure' specimens. This doesn't directly create a demand for wild caught individuals and you still get fish that are 'pure'. Unless fish are known to definitely be wild caught or the offspring of wild caught individuals you have to assume they are 'hybrids', even if they look identical to the wild caught individuals.

 

[Wy Renegade]

While I agree that number 4 is the direction in which we are currently headed, I have to agree that there is currently not enough genetic analysis of different organisms available for this to be a "standard" at this point. #1-#3 appear to be parts and pieces of the same accepted standard, which to my knowledge was always "a group of organisms which look similar and mate in nature to produce viable offspring."

Not sure that I agree totally, but it does become a confused issue when people use parts and pieces of a whole rather than the whole. Too many people get confused by the fact that the tool is us imposing order on nature, not the order by which nature organizes herself. No fish says, "I'm my own species", as you've said, this is something we've imposed upon them for the sake of ease in study and understanding.

To me, if an individual is going to dabble in this type of thing, they should have a solid understanding of the knowledge that is currently out there. If I cross say a lab and an auratus, and then pass off a very pretty yellow striped fish (and don't reveal that it has a extremely aggressive nature and tends to kill off its tank mates), was it a good idea?

I agree that we should not be creating a demand for wild caught specimens, but disagree with the last part of your statement that appears to imply that pure lines have not be maintained and every captive bred specimen must be considered a hybrid. I think that goes back to the purity that breeders have kept/established within their bloodlines, and one can no more place all of them in the same group, than one can place all horse breeders, dog breeders, geneticists, or scientists into the same group.

 

[Fishguy2727]

I think farmed fish have to be assumed to be hybrids. Fish from a guy who breeds them in his basement fish room and bought P0 fish himself are different.

Definitions 1-3 are similar, but scientifically they are very different. The difference between interbreeding in the wild and in captivity is the exact difference this thread is concerned about.

I think that trying to pass fish off for what they are not is wrong. Trying to pass hybrids off as 'pure' or your cross as a lab or 'average aggression' mbuna is wrong.

So I think we agree pretty much.

 

[Wy Renegade]

I would agree that for the most part we agree on the concept - the actual practice may be a bit of a different story.

In regards to the whole hybridization question, while I agree that in and of itself it is not a bad thing, I really disagree with the idea of promoting it as something the average hobbiest should be engaging in. Too many don't bother to do the research to determine which types of fish are compatible in a tank, let alone what potential results might occur if two different species are allowed to interbreed. How many hundreds of humpbacked, reverse imbricated, sterile, or two-headed offspring may be produced that will have to be destroyed? And how many hybrids created by irresponsible hobbiests will make their way into the hobby under the guise of a "purebred" line?

Please explain a bit further in regards to your thoughts on farmed fish? If I understand correctly, you're making the assertion that all captive bred fish sold by large wholesalers are hybrids?

 

[Fishguy2727]

I am saying that I do not think that the farmed cichlids can be assumed to be 'pure'. I think if someone wants to stick with 'pure' stock they should go to a breeder who is breeding P0/wild caught fish or F1, F2, F3, etc.

 

[nedge85]

i have some un-intentional hybrid shrimp, black bee x red cherry. The result is a red cherry with a black head

 

[jetajockey]

I am saying that I do not think that the farmed cichlids can be assumed to be 'pure'. I think if someone wants to stick with 'pure' stock they should go to a breeder who is breeding P0/wild caught fish or F1, F2, F3, etc.

This is also making an assumption that the farm makes no attempt to segregate species. I mean they carry more than just the 'assorted mixed' tank, and if the basement tank guy didn't go to africa and get his own then they likely got their fish from similar sources.

 

[Fishguy2727]

Not if the private breeder bought wild caught fish or from someone else who did. All I am saying is you can't assume that the farmed fish are 100%.

Personally I don't care. If it looks like a sunshine peacock it is enough of a sunshine peacock for me. I don't buy that they are different species int he first place so 'pure' or not just means 2-3 times as much money and nothing else.