PlanetCatfish.com

It's not good at all. But it's not always done deliberately - the problem is that there are too many people dealing with these fishes who THINK they know what they are doing. Often, they don't. And more information about them has been learned during recent years. Some people are too stubborn to listen to new information and new ideas, and they just keep doing what they're doing.

Crossbreeding Hypancistrus is already a widespread fact in captivity. Similar looking forms from Xingu are crossed by accident all the time - even by big, trusted companies and names.

Your fish can be a nice form of L066 - it will be hard to proove There are several strains of so-called L173 in captivity, and that can be because around Belo Monte you can find very similar looking L173 that may actually carry quite different genes. This will show itself when they are bred further in captivity. But the breeders will sell all their offspring as L173 even though only a few of the fish look like their nice parents - because they see no other way to get rid of them.

Several large-scale breeders of L066 and L399/400 have reported that sometimes very beautiful individuals occur, which could certainly explain where rarieties like L173 and L236 come from.

It's not possible to give your fish a 100% accurate number or name, unfortionately. You should probably treat them as Hypancistrus sp."Xingu", and perhaps it would be best to not put them together with any other similar looking strains or forms, to avoid further mix-ups in the future. I know this is disappointing, but I believe this is how cases like this should be treated...

Haakon

An interesting thread as i didn't realise the situation with L numbers was quite as bad as suggested here

Richard B wrote:An interesting thread as i didn't realise the situation with L numbers was quite as bad as suggested here

Well, what's actually been said that you are referring to? I've not yet met a hybrid l-number that we know of for sale.

Jools

Yes, it's absolutely not as bad as the Syno hybrid situation. Aside from Hypancistrus, most Loricariidae are wild-caught. And I do believe nearly all breeders of Hypancistrus are breeding pure species. Whether this particular fish is a hybrid or not, I can't say.

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Mats

I don't think anyone can say. Maybe L173, L250 and other "special" fishes are natural hybrids, which is one route to speciation. (Captive) selective breeding is different from deliberate hybridisation but this is, to a point, academic in the absence of defined boundaries (e.g. all Hypancistrus are described). However I've not encountered anything that would make me think hybrid Hype-ancistrus are being deliberately marketed.

As to Mats point, I think you're forgetting our friendly common Ancistrus. You know my view that this is hybridised beyond recognition (globally). It also also my opinion that this is the case for Pterygoplichthys, Hemiloricaria and Sturisoma too.

I prefer not to get into the rumour factory either.

Jools

Jools wrote:As to Mats point, I think you're forgetting our friendly common Ancistrus. You know my view that this is hybridised beyond recognition (globally). It also also my opinion that this is the case for Pterygoplichthys, Hemiloricaria and Sturisoma too.

I think Shane has quite clearly stated that he doesn't believe that there are as many hybrid Ancistrus as it's said to be. But sure, I think fish that has been bred so many times in captivity, and with so many very similar species [and often with just one or two pictures in a common aquarists book - before most realized just how many different species there are out there - my old Swedish (originally written in England, however) Aquarium book has, I think, 4 species of Loricariidae in it], it's entirely possible that mixing of similar species has happened more than once. And of course there are a few Hypancistrus that are similar looking from differend locations.

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Mats

MatsP wrote:I think Shane has quite clearly stated that he doesn't believe that there are as many hybrid Ancistrus as it's said to be.

Sure, and I've countered that several times. With the greatest respect to Shane (and we've chewed this over in person more than once to, at least from my point of view, check for holes in my thinking) he's not at the cutting edge of fish auctions or indeed the Scottish, UK, European or USA auction scene which is where the bulk of this happens. Tell me the last time you went to an auction and saw a common bristlenose identified to species correctly? Or sold with lineage or locality information. They usually only care if they are brown or grey and are male or female. Furthermore, are you telling me that all false L144, long fin, albino, piebald, calico and variants thereof are all, 100%, pure bred species?

Not looking for a big discussion on this, as it will get off topic, but there are good reasons for my view.

Jools

Jools, I know what you are saying, and I'm not directly disagreeing with you - just saying that there are other opinions. I must say that I have not been catching fish in South America, nor have I spent much time at auctions [hope to go to CSG on Sunday, which will be my third auction]. Nor have I seen much fish outside of England.

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Mats

Sorry for Offtop

Just for information about hybrids in Ukraine:

1. We have so called “Common Sturisoma” or “Sturisoma panamense” in sale. But in fact it is hybrid of Sturisoma panamense and Sturisoma aureum. I know this for sure, because I spoke to the breeder that crossbreed them long time ago and filled our market with their fries (He did so because hybrids are more productive in spawning. Quite sad story ). A huge number of Ukraine breed Sturisoma are these hybrids.


2. “Ancistrus sp L181“: There is theory that we have in our market Hybrid of Ancistrus sp L181 and A. Dolihopterus. But it is only a theory.

3. I know one man that has crossbred “Ancistrus cf. cirhosus albino form” and “Ancistrus sp L181” by accident. Male was A. cf cirhosus, female was “Ancistrus sp L181”. At the end all the fries died.


Also I know that some breeders from Moscow crossbreeds different hypancistrus species on purpose. Very sad story:(

I've split this off to a new topic as while very interesting, it was getting right off topic.

Jools

In Asia, crossbred Hypancistrus are offered openly. The aim appears to be to create fish with more white and less black, as well as certain patterns that are sought after over there. And each fish has a single price...it's about the same way they do it with Koi Carps.

In Germany, a few cases of crossbreeding have been well documented:

http://www.l-welse.com/reviewpost/showcat.php/cat/120

Haakon

Just another thought about hybrid fish...

We call all these different fish, that have been named by whomever it is that does so, different "species" without really understanding what that means. Most definitions of "species" include a population of individuals which can breed to produce viable offspring.

Our catagorizing fish with very small differences in their appearence or genetics or perhaps based solely on their location of origin is not the "natural" way of defining species as most of the fish from certain families CAN and WILL interbreed, producing viable offspring that can pass their new combination of traits on to the next generation, in a sense outcrossing, like breeders of highly domesticated fish do to strengthen the genetic lines. I think it's more appropriate to think of the L-numbers classification (within family) as a sort of racial profile. I am white, so I might have a different L-number than my hispanic friend. Make sense?

Understand, I am not advocating crossbreeding. I believe that responsible fish breeders should make every attempt to preserve the beauty of fish created by God in nature without our influence. But really, is there such a thing? Are there any bodies of water not affected by humans? Is it reasonable to conclude that there are any places humans have seen that we have not affected the natural order of things, including breeding behavior of native fish?


Anyways... that was a little off topic I think! As I was saying, I believe good stewadship of pet ownership includes preserve the purity of the genetic lines occuring in nature, but that doesn't mean that I believe all crossbreeding is wrong either. It's a fine line.

What do you all think??

Bunnie1978 wrote:Just another thought about hybrid fish...

We call all these different fish, that have been named by whomever it is that does so, different "species" without really understanding what that means. Most definitions of "species" include a population of individuals which can breed to produce viable offspring.

This is not entirely true. It is indeed one definition of species, but for various reasons it is not a viable concept in science, even if it was true for all "species" that we know of [and it is not - there are plenty of species of animals that are scientifically described as a species, where it can and will cross and form viable (and fertile!) offspring with another described species]. The other way around is true - if two individuals (that are otherwise healthy and fertile) can NOT breed and form viable, fertile offspring, they are indeed NOT the same species. And it is still the definition given in most start/medium level biology books - you need to get fairly high into the education of biology before the detailed distinction between this definition and a more upto-date and more accurate definition gets meaningful for the general public.

The main problem with this principle, besides the conclusion that all Hypancistrus are one species - which I think nearly all serious fish-scientists will agree they are NOT, is that it's very difficult to prove in science. Some animals are VERY difficult to breed under ideal "laboratory" circumstances, e.g. a salmon that travels several thousand miles on it's journey from feeding to breeding grounds - so you take two supposedly different species and reproduce this travel effect. And if they breed, you then have to reverse the travel, then do the same thing again, and maybe 3-4 years later we could have viable offspring. And I'm sure that's not even the worse scenario. Large animals like whales would be nigh on impossible, likewise animals with large territory and aggressive behaviour. And we have plenty of plecos (and other fish) that have never been bred in captivity - if we as hobbyists can't breed them, the scientists that have little experience in keeping fish outside of alcohol and formaldehyde, it seems unlikely that they will have more luck... How would you describe a single fish - it's clearly different from everything we've found, but they live at 4000m under sea-level, and they only got a single one, because food is so scarce that they can't get another one [and it was dead when it got to the surface, due to the pressure loss in being dragged up to surface!]

Further, if you try to scientifically describe, using the above principle, say, Hypancistrus zebra, how many different species would you have to "try" before you can determine for sure that it's not going to breed with it's similar species? How long do you keep the male or female H. zebra with each opposite sex other species?

I don't believe it's even possible to have a (relatively simple) single species concept that covers fungi, plants, bacteria and animals. I've got some reading material that I've received from a scientist on this particular subject (which is part of a 500 page book, but I've only got "the best bits"). It's not particularly easy to digest, so I've only read about a quarter of it so far, and it would be very unfair to try to describe what my understanding is until I've at least completed ONE of the two articles I'm trying to read.

Our catagorizing fish with very small differences in their appearence or genetics or perhaps based solely on their location of origin is not the "natural" way of defining species as most of the fish from certain families CAN and WILL interbreed, producing viable offspring that can pass their new combination of traits on to the next generation, in a sense outcrossing, like breeders of highly domesticated fish do to strengthen the genetic lines. I think it's more appropriate to think of the L-numbers classification (within family) as a sort of racial profile. I am white, so I might have a different L-number than my hispanic friend. Make sense?

L-numbers do make a difference based on location. Scientists do use this to HELP define a species, but if there is no difference other than location, in science, that is the same species. If there is tiny differences between one population and another (e.g. the spots are slightly more yellow in one population and more white in another), then that would PERHAPS mean that it's a different species. It would depend on the scientist examining the fish - it becomes a judgment as to how much of a difference makes a different species, and what isn't.

I don't think we can really compare humans with wild-caught fish, as the general difference between humans is their (historical) location and adaption to that (lighter skin further north, to allow Vitamin D production, darker skin further south [assuming northern hemisphere] to avoid skin cancer). But in an L-number concept, then yes, humans that originate from different parts of the world would definitely be classified as different L-numbers [no matter where they are NOW, just like L129 is L129 whether you live in the US or live in England - it is L129 because it was caught in a particular river in Venezuela, not based on where it was, for example, purchased or bred].

Understand, I am not advocating crossbreeding. I believe that responsible fish breeders should make every attempt to preserve the beauty of fish created by God in nature without our influence. But really, is there such a thing? Are there any bodies of water not affected by humans? Is it reasonable to conclude that there are any places humans have seen that we have not affected the natural order of things, including breeding behavior of native fish?

I do agree that humans have in various forms meddled with nature for a long time, and there are very few places in the world that isn't AT ALL touched by humans. However, that is different from the subject of this discussion, which involves the INTENDED breeding of species [loosely defined] that are distinctly different in shape and/or pattern and/or location. I don't suggest that humans should unnecessarily interfere in nature, but it's certainly not the same thing that the native population in South America catches fish in the river, and us trying to breed "prettier" versions of wild fish...

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Mats

I wasn't talking about fish only bred in captivity at all. I was merely pointing out that the distinction of one species of fish (L-number) is a subjective, human-created concept, which nature does not obey. It may very well be that one L-number fish might be just another color variety that developed over several hundred, or just several, generations in nature through what would be distasteful if done intentionally.

That's right. An L number is given when a fish, unknown from that location, arrives in the hobby. So of a certain Loricarid lives in the Rio Xingu and the Rio Tapajos - 200 km from each other, the fish will get 2 L numbers

Personally I think that is a good idea - after all, the question whther the fishes from these 2 localities are the same species is a scientific question - which wil lbe answered in the description of the species

Further, I think varieties should be kept pure - so hysridisation within a species is just as wrong as among species

The entire concept of "species" and "genera" and "family" is also entirely a way for humans to classify and distinguish things, just like L-numbers are.

But there is a concept that can be observed in nature: different populations of similar creatures (be it fish, insects or mammals) from different places are different - one may be stripey, the other spotted. Sometimes there are distinctly different populations in the same place, that have similar behaviour and generally looks the same, but are still distinct enough that we (or most people) can agree that they are sufficiently different that they are different species. Where you draw the limit for this is harder to say.

But I think what you are trying to say is that the species concept that is used in science isn't reflecting "true" species if the fish can breed together (and have fertile offspring), and thus and - despite being very noticably different, are the same species - they just happen to look different, because they have lived apart [by about 1000 miles currently] for long enough to form some genetic differences to make their size and colour slightly different. Something that most well-known scientists in the area of Loricariidae probably won't agree with.

And I don't believe, either, that the fish that come from one river, have managed to form distinctly different body pattern, and yet are (frequently) cross breeding in nature - if they are cross-breeding in nature, then they would eventually merge into some sort of intermediate form [assuming it's not just the odd spawn once in a while]. Speciation happens, generally, because a population is isolated from it's congeners long enough to become different. Yes, this happens over many generations. But it starts out by isolating one group from another by some sort of barrier - usually geographic, but sometimes it starts by some part of the population adapting to a different form of feeding or breeding, which eventually leads to a completely different form.

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Mats

MatsP wrote: But I think what you are trying to say is that the species concept that is used in science isn't reflecting "true" species if the fish can breed together (and have fertile offspring), and thus

Hypancistrus zebra

and

Hypancistrus debilittera

- despite being very noticably different, are the same species - they just happen to look different, because they have lived apart [by about 1000 miles currently] for long enough to form some genetic differences to make their size and colour slightly different. Something that most well-known scientists in the area of Loricariidae probably won't agree with.

I have to completely disagree with you there, the concept of specie isn't about not producing viable offspring, it's about 2 population not breeding together in their natural setting. If we followed your argument, bison and cows would be the same specie since they can breed and produce viable offspring that are fertile. It's even a problem in the united States where many Bison herds are in fact herds of hybrids. Even more extreme, many Orchids can be bread not only between species but between genera. For example: sophronitis coccinea and cattleya skinnery, not only are those 2 plants extremely different but they would never meet in nature and do not grow in the same environment and do not flower at the same time but produce fertile decedents when we breed them. We have to remember that an aquarium is not a natural setting and that normal protections from hybridization that protect the integrity off a specie are mostly not present. Things like sexual preference, time of breeding and habitat separation can be easily overcome and pairing that would never or very rarely happen in nature will happen. Off course, speciation is a continuum and finding a limit to what a specie is a judgment call. But really the capacity to be bread together in a aquarium should have little bearing on it. It's in nature that it counts.

Myric: I agree with your definition (at least as a basic principle). Of course, that's not all-encompassing either. Consider the roach (Rutilus rutilus), which is quite wide-spread over large portions of europe. Now, I can guarantee that the species in Sweden never meet with the ones living here in England. So are those not the same species? Or even the ones that live in a Lake in the south of England are a different species to the ones a few miles away across a ridge that prevents water from one side to meet with water from the other side...

This is what I mean by "Most scientists wouldn't agree with this..." - I was just trying to show how the idea of "can breed and have viable, fertile offspring" is not workable for many different forms of life.

I really need to read those two articles that I've got - and write down something that we can put up as an article in Shane's world, or at least in the FAQ section to define "species" in a relatively short and simple form [for catfish, at the very least].

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Mats

or at least in the FAQ section to define "species" in a relatively short and simple form [for catfish, at the very least].

This I think would be very tough(to keep it simple)...going by the many discussions every year on this very subject which never really come to a definite conclusion. Many almost says the same thing but with slight variations or there are varying opinions even among the known scientists on PC. Not saying a basic outline would be a bad thing but I think once one got into it where would you stop. You may have to outline the different modes of thinking.

Birger

Like I say at work sometimes: if it was easy, anyone could do it.

However, the first step will be to finish reading the articles. Hopefully I can do that tomorrow.

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Mats

Hi

Well this topic seems to be fairly active, to define a species in my mind is fairly simple.

To start with I don't think anybody would class a chimpanzee and a human being as the same species, yet from what I recall we share 98% of the DNA.

DNA testing is, it seems accurate enough to detect members of the same family, the percentage I guess here is approacing 100%. Somewhere between 98% and 100% there is a percentage lets say X, that above which is a human being and below is a chimpanzee.

It seems logical to me that if the difference in the DNA between two different animals is greater than a particular figure then it is a different species.

Not sure if this is the right thread but there seem to be quite a few overlapping at the moment.

I know that the resources to undertake DNA testing of all the similar fish in our aquariums is prohibitive, but distinguishing, hypancistrus with minute differences is purely guesswork. Just as putting all L25's together.

Mongo

To the best of my understanding, one of the problems with DNA analysis is that SOME parts in the DNA chain changes quite a bit, where other parts don't change much from one fish to another. So the problem when defining what is one species or not, would be to understand what part of the DNA to look at - if it's something that changes quite a bit from one generation to another, then all you get is noise. If you look at bits that don't change at all within a large group of species, then you get no difference... And with millions of places in the DNA to actually look at, it's a bit of "haystack and needle" type stuff.

And then you need to test LOTS of fish that are definitely the same species to discover how much difference there is within a population, and then compare that to the difference to another species...

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Mats

MatsP wrote:Consider the roach (Rutilus rutilus), which is quite wide-spread over large portions of europe. Now, I can guarantee that the species in Sweden never meet with the ones living here in England. So are those not the same species?

Yes, biologically speaking they are two separate species. Biologically speaking the cessation of interbreeding means they have diverged into separate evolutionary trajectories, although the separation is so recent (the UK separated from the european mainland, what, 3000 years ago?) that no detectable differences have yet accumulated in the two fledgling species.
The fact that the English and the Swedish roach can not be separated from each other (diagnosed) means that from a scientific point of view they must still be considered the same species, Rutilus rutilus, even though biologically we can deduce that they're not. Because we can't name things we can't identify.

If the UK and mainland Europe remain separated for some tens of thousands of years, then the two species will have accumulated genetic and morphological differences, and so be diagnosable, and so requiring separate names.
If the sea level was to drop and the UK and mainland Europe populations of roach meet again, then in all probability they'd mix and once again coalesce into a single species.

As for DNA identification of species, it's mostly straight-forward and sometimes not. Logically it is so that members of a species, being an interbreeding group, should be more genetically similar to each other than to members of other interbreeding groups. As it turns out, this is generally the case; with the COI gene the typical pattern is that members of the same species are less than two percent dissimilar to eachother, but ten percent or more dissimilar to members of other species.
Unfortunately nature doesn't always play by the rules. So for instance a number of clearly different species in the genus Sebastes are 100% identical in the COI gene.
Even more amusing is that when there is clear genetic evidence that two groups of animals are separate species, there is pretty much always also clear morphological evidence that they're separate.



Summing up:

* Ability to interbreed means nothing wrt if two groups of organisms are different species or not. Speciation is reversible until such time that the two species have accumulated so many differences that the hybrids have significantly reduced fitness.

* There is no qualitative difference between species and population, they grade into each other. The only difference is that if we decide something is a species, we give it a name.

* If two groups of animals are diagnosable, ie individuals have unique characters which allows identifying group membership, they should be considered separate species. A corollary to this is that most subspecies should in fact be considered full species (e.g. there's not one species of tiger in the world, there's five).

* Genetic analysis is a valuable source of evidence, but it's no magic bullet, and most of the time it's no more accurate than classical morphological analysis. It is however much faster and easier than classical morphological analysis.