cross breeding
Posted: 30 Sep 2009, 12:10
has any crossbreeding from any kind of catfish happened? i'm just a bit curious if it has happened
This has happened many times by man's intervention, with many species either by the fact of housing species in restricted environments ie- tanks & having it occur naturally (which is unusual, depending on how closely related the sp are) or by intentional design. If you look in cat-e-log you can see examples of pims & syno hybrids. There are even some bizarre hybrids coming out like pang x RTC or TSN x O niger, or pang x clariid!!!!! I wish with all my heart man would step away from these abominations.....DJ-don wrote:has any crossbreeding from any kind of catfish happened? i'm just a bit curious if it has happened
i get number 2 but what do you mean by food? to give to bigger fish to eat or to feed on eggs?Richard B wrote:Hybrids are created for 2 purposes (mainly, & please correct me if i'm wrong)
1 - food
2 - selling in the aquarium trade to make lot's of money
People breed hybrids for aquaculture for people to eat.DJ-don wrote:i get number 2 but what do you mean by food? to give to bigger fish to eat or to feed on eggs?
I am on another site trying to find out if L46s can be cross bred with other fish to produce nicer looking fish and came across this,what a coincidence.I had a L260 and a L46 cross and it produced a very cool fish.
Not the same thing at all. All domestic dogs are one species, Canis lupus familiaris, so they are not crossbred. Crossbred usually refers to the crossing of two different species. To crossbred a dog one would have to cross it with a jackal, fox or coyote. Crossing a dog and a gray wolf would not be crossbreeding as they are the same sp. Hope that sheds some light on what aquarists mean by "crossbreeding."its just like what happened with all the dogs. there is a high amount of crossbreed dogs and there isn't that much contreversy.
Considering the relatively close relationship among Hypancistrus species, my guess is that they will be fertile... Those fish look rather interesting, though.PlecoCrazy wrote:I posted the pics of the L46/L260 on my original post of the event. They are coming up on three years old and there are around 10 of them so I'll probably be finding out in the next year whether they reproduce or not. I'm hoping not but we'll see.
That would partly depend on the particular definition of species. If we assume the mammal method of "they produce viable offspring", then I expect all Hypancistrus can be lumped into a single species. I don't think anyone on this forum follows this particular definition, but that would be the only simple and strict rule one could apply. We get into a much less clear area of taxonomy when we start discussing "how much different does it need to be to be a species".apistomaster wrote:How do we know whether or not many of the Hypancistrus spp. found in nature, say those of the Rio Xingu, are not actually hybrids between fewer species than we currently believe are endemic to that river? There are many forms that appear to be intermediates between better defined species. The genus could still be in considerable flux, especially those from the same or nearby streams. It would explain why it is often so difficult to identify many of them.
Yes. L-numbers are NOT species - as I'm sure you are aware - but rather a pseudo-species definition. And there are no strict rules as to what encompasses a new L-number and what doesn't - the same species of fish, from the same river could very possibly have different L-numbers simply because one specimen (or group of specimens) is exported from Colombia, and the other from Peru, Venezuela or Brazil - even if all the fish were caught on the same day, lumped together, and only split at the "distribution central" where the fish are collected together before shipping to the epxorter proper... By scientific measures, that's OBVIOUSLY not two different species. But since exported fish's capture locality is often vague or non-existant, export location is a much easier measure to use to define where they are from.It looks to me like many Hypancistrus spp are are recent, in geological time, and still very much undergoing radiative speciation.
The reproductive barriers between species appear to be low. Low enough to question whether or not there are as many species as there are Hypancistrus L-numbers.
Even without any special knowledge within systematic I do agree with you, special the area from Altamira downstreams couple of miles north of Belo Monte. If we start at Altamira, we will find a few species with quite good distance between each of them (Hypancistrus) the more north and closer to Belo Monte the more "species" we will find and both south and north of Belo Monte you find many different L-numbers of Hypancistrus at the same locality. Around Belo Monte you find L46, L66, L173, L236, L333, L399, L400, L287 and L345 is mysterious... probably mixed up with other L-number of the guy that put these L-number. What is called Hypancistrus sp "Lower rio xingu" in the Cat-eLog is also from the same area around Belo Monte.Larry wrote:How do we know whether or not many of the Hypancistrus spp. found in nature, say those of the Rio Xingu, are not actually hybrids between fewer species than we currently believe are endemic to that river? There are many forms that appear to be intermediates between better defined species. The genus could still be in considerable flux, especially those from the same or nearby streams. It would explain why it is often so difficult to identify many of them.
It looks to me like many Hypancistrus spp are are recent, in geological time, and still very much undergoing radiative speciation.
The reproductive barriers between species appear to be low. Low enough to question whether or not there are as many species as there are Hypancistrus L-numbers.
It's almost impossible to compare with mammals, mammals have so many subspecies and in this case Loricarids has no subspecies at all, a Lion from Africa pairing with a Lion from Asia will probably get fertile offspring's or a Tiger from Siberia pairing with a Tiger from Sumatra. Different species of Zebras will probably also get fertile offsprings and so on.Mats wrote:That would partly depend on the particular definition of species. If we assume the mammal method of "they produce viable offspring", then I expect all Hypancistrus can be lumped into a single species. I don't think anyone on this forum follows this particular definition, but that would be the only simple and strict rule one could apply.
This is correct. It is possible for two species, especially closely related species, to have DNA that is similar enough to produce fertile offspring.DJ-don wrote:and also how could 2 different species crossbreed in the first place?? the 2 fish must hav the same kind of dna or something (not really sure on which it is dna genes etc )
Wow, that is actually quite a few types to find in one locality. It's interesting that there are even that many phenotypes in just one location of such closely related fish. I agree that the genetic distinction between them is likely difficult to see as these species are likely recently diverged; perhaps entire-genome comparisons would be necessary, rather than single gene comparisons as in DNA barcoding.Janne wrote: Around Belo Monte you find L46, L66, L173, L236, L333, L399, L400, L287 and L345 is mysterious... probably mixed up with other L-number of the guy that put these L-number. What is called Hypancistrus sp "Lower rio xingu" in the Cat-eLog is also from the same area around Belo Monte.
Only with the help of a human I suppose, if happen in nature these offspring's would extinct them self.Milton wrote:Viable but infertile offspring still would allow biological and genetic separation of two groups into species.
Yes, quite interesting I think but maybe not totally impossible if you consider that the whole stretch between Altamira and Belo Monte is more or less rapids and waterfalls, offspring's from species reproducing uppstreams either they want or not will be flushed with the current down to Belo Monte... after Belo Monte no rapids just a very large lake.Milton wrote:Wow, that is actually quite a few types to find in one locality. It's interesting that there are even that many phenotypes in just one location of such closely related fish.
This happen every year in many coral reafs, why not in some few extreme places like the rapids between Altamira and Belo Monte? It's not only the pattern that is variable within Hypancistrus from Rio xingu, body shape, head shape and size and colour of their eyes. 99% of all Hypancistrus from Rio xingu was collected between Altamira and Belo Monte when they was allowed.Larry wrote:two different species that evolved in the same range would rarely interbreed in the wild.
My point exactly. Species would remain separate as those hybrids would not reproduce.Janne wrote:Only with the help of a human I suppose, if happen in nature these offspring's would extinct them self.Milton wrote:Viable but infertile offspring still would allow biological and genetic separation of two groups into species.
Now I'm very interested. That is fascinating. Separate rivers would allow separation of species but the collection of various, closely related species in a lake could cause species to intermix. Cool. But what you are describing is a source of species and a sink of species, which is pretty interesting.Janne wrote:Yes, quite interesting I think but maybe not totally impossible if you consider that the whole stretch between Altamira and Belo Monte is more or less rapids and waterfalls, offspring's from species reproducing uppstreams either they want or not will be flushed with the current down to Belo Monte... after Belo Monte no rapids just a very large lake.Milton wrote:Wow, that is actually quite a few types to find in one locality. It's interesting that there are even that many phenotypes in just one location of such closely related fish.
Janne
Not to derail the topic since this isn't related to the point you're trying to make, but so far as we know, there is very few known examples of Neotropical fish species that have evolved in sympatry. In other words, there are almost no two different species that have evolved in the same range. Examples of related species being in the same place are as a result of evolving in separate ranges and rejoining. Also, related species of the same genus in the same place are rarely each other's closest relatives. Unfortunately, since the "if" clause of your statement isn't fulfilled, your "then" clause is irrelevant (I put brackets in your quote to indicate where those would be).apistomaster wrote:To put a finer point on what I was suggesting is not that wild hybrids are common but that the Hypancistrus we have L-numbered that are from the same river system or adjacent ones, I suspect represent many fewer species with naturally occurring wide variations in patterns and colors. I doubt there are any biological barriers preventing variants from interbreeding but by my definition of a species, [if] two different species that evolved in the same range [then they] would rarely interbreed in the wild.
Yes I know, but my point is; why cant similar hot spots exist in freshwater even if they are very rare.Larry wrote:What you say about many reef fish is true although I would say their are extenuating circumstances involving the peculiarities of how many reef fish spawn that makes hybridization more frequent than among fresh water fish. Many Chaetodon, Pomacentridae Angels, to chose a few examples, spawn at dusk, en masse and do not practice brood care. The chances of random cross fertilization are very much higher between related species spawning simultaneously in the same immediate vicinity.
Yes they have a totatlly different reproduction behaviour, if there are any natural crossbreeding in Rio xingu it's around Belo Monte, not upstreams at all... just one area. If species offspring's upstreams follow the current and rappids downstreams they will somewhere be gathered together... right? At this locality there are a mix of species and of reasons we don't know yet but they interbreed with each other, there can be many reasons; for example the population of all these Hypancistrus is so high that they marely can avoid each other, one sex can be over represented, opportunistic reproduction when keeping several species in aquarium is not a question if it will happen... it's just a question of time, the same in nature if the population is to high at the same locality.Larry wrote:In the Hypancistrus, there is a more elaborate courtship phase which would seem to me to help reduce the chances of random hybridization. Only more information can tell us whether or not the Rio Xingu Hypancistrus species found between Altamira and Belo Monte actually frequently hybridize.
Yes, it should make anyone working in this area excited.Milton wrote:Now I'm very interested. That is fascinating. Separate rivers would allow separation of species but the collection of various, closely related species in a lake could cause species to intermix. Cool. But what you are describing is a source of species and a sink of species, which is pretty interesting.