cross breeding

[Janne]

Larry,
In another answer you agreed on something else ;)

I am actually of the opinion that nearly all described subspecies should be considered separate species. Can you diagnose the group? Fine, call them a species. You can't? Well, they're a population.
With fish subspecies tend to be distinct & diagnosable - in other words, species.

My first choice would be to recognise all independently evolving, monophyletic groups as separate species, no matter how small the difference is, and providing data are presented and defended in concordance with our current knowledge of the systems involved.

Is the above Peckoltia sabaji enough different to be 2 species? They are 2 different and separated large populations... or is't to early to separate them as 2 specis and we have to wait until the evulotion increase the differencies "enough"?

Janne

[racoll]

Is the above Peckoltia sabaji enough different to be 2 species? They are 2 different and separated large populations... or is't to early to separate them as 2 specis and we have to wait until the evulotion increase the differencies "enough"?

I think I answered that in my previous post, although you might have missed it due to us posting at the same time?

[Janne]

Exactly, and this does not mean they cannot be split further in future, but this would have to be subject to finer scale analysis using live colour patterns and DNA. But until these data are available, I think Dr Armbruster et al. have taken a defensible approach, and chosen not to inflate the number of names, potentially creating confusion and work for other taxonomists to clean up.

Ok, but isn't confusing to give the same name to a species that not have been analysed that another species have? Different "populations" that obviously is different can be split in the future into 2 species, isn't better to not include other populations than the one investigated to avoid future confusions until a finer scale analyis is made? Logical, would it not be better to keep all not "enough" investigated species as undescribed species to decrease the confusion? Why include several populations that risk to be splitted in the future in the same scientific description, why not just mention there is other populations that could be the same species and only include the holotype as the new species?

I think I answered that in my previous post, although you might have missed it due to us posting at the same time?

Yes, I missed your answer due to posting and thinking

Janne

[Suckermouth]

Ok, but isn't confusing to give the same name to a species that not have been analysed that another species have? Different "populations" that obviously is different can be split in the future into 2 species, isn't better to not include other populations than the one investigated to avoid future confusions until a finer scale analyis is made? Logical, would it not be better to keep all not "enough" investigated species as undescribed species to decrease the confusion? Why include several populations that risk to be splitted in the future in the same scientific description, why not just mention there is other populations that could be the same species and only include the holotype as the new species?

I believe that's exactly what they did in the paper. P. sabaji was described from the Essequibo, Orinoco, and Negro, but the type series only includes Essequibo specimens because of the possibility that Orinoco is different. Also, the paper doesn't even talk about Brazilian specimens in the paper.

[Jon]

"Hi Jon,
And this is different from Hypancistrus, how?"

I didn't say that there was a difference. I was just correcting the statement. However, if I were to make the argument, I'd say that most of the hypancistrines are not per se isolated geographically, much like the various populations of O. clarki. Look at all your belo monte numbers--66, 399, 400, apparently 236 (I was not aware of this), etc...they look different, and you can see distinct "strains" for lack of better terminology. What about the distinct Rio Jari specimens? Or the tapajos? Or Curua? They are notably different, and at least this should insinuate mate choice.

EDIT: and it's not really applicable anyways, since there has been little in the way of genotyping of hypancistrines.

[Jon]

"Quite a bold statement. Care too elaborate? If you conceptualise species, not as a absolute truth, but as a scientific hypothesis, it becomes much easier to reconcile the seeming conflicting information.

A species to me represents a macropopulation with an independent evolutionary trajectory. To recognise a species one must demonstrate, using supporting data, limited gene flow and divergence. Recognising populations on the cusp of independence will always be difficult to justify, but as long as hypotheses are supported with data, this is not problem."

The term species is a product made to box in and definitively characterize things into discrete blocks of "evolution", if you will, despite the fact that the natural world is anything but. To conceptualize and hypothesize upon the concept, you have to put in defined features. Where do you draw a line? What constitutes a species? I guarantee that anything you scope out, there is going to be not just one or two, but a plethora of counterexamples. Even using terminologies such as" macropopulations with independant evolutionary trajectories", you run into trouble. There are animals considered of the same species that do not interbreed, which means they are no longer macropops. And I mean like, sans typical biologically involved polymorphisms, 100% genetically similar. Running with Larry's example, take temporally isolated run-salmonids. Even with the haziness that is the species concept, you cannot in good conscience refute them to be different species, yet they never interbreed (in certain species--it wold be unfair to lie to make an example).

You think it's bad with vertebrates, try prokaryotes. It's a nightmare there. Even though the two shouldn't even be comparable, the same "species" terminology is used here as well. Like I said, it's not a fine tuned system.

Granted, with all the whining, I cannot come up with a better alternative, so take it as you will.

[Janne]

I believe that's exactly what they did in the paper. P. sabaji was described from the Essequibo, Orinoco, and Negro, but the type series only includes Essequibo specimens because of the possibility that Orinoco is different. Also, the paper doesn't even talk about Brazilian specimens in the paper.

Yes, in this species it was, I think it's we hobbyist's that mess things up also when we put different spp together as one species without any real good evidence just because they look "similar". Thats a big problem in the hobby and maybe for the science too, hobbyist's is interbreeding different populations that in their mind is the same species, I'm also sure that this happens at some proffesional breeders supplying the ornamental trade too. The example with P. sabaji was just one "species" and the most correct would be to separate them as different species until all of them have been scientific analyised. In this case that means that L75 Tapajos, Xingu (LDA02?) and L124 Orinoco is three different undescribed species and L301 Essequibo is Peckoltia sabaji even if science "think" they could be the same species. Am I correct when I state that?

Janne

Edit. Forgot 1 species and put the river systems for each one.

[MatsP]

Yes, in this species it was, I think it's we hobbyist's that mess things up also when we put different spp together as one species without any real good evidence just because they look "similar". Thats a big problem in the hobby and maybe for the science too, hobbyist's is interbreeding different populations that in their mind is the same species, I'm also sure that this happens at some proffesional breeders supplying the ornamental trade too. The example with P. sabaji was just one "species" and the most correct would be to separate them as different species until all of them have been scientific analyised. In this case that means that L75, L124 is two different undescribed species and L301 is Peckoltia sabaji even if science "think" they could be the same species. Am I correct when I state that?

Janne

Yes, but Jon's e-mail hinted that he's about to publish a paper to the effect that they are the same species with a wide distribution. However, Mark Sabaj didn't quite agree. Here is the whole e-mail chain as of this moment:

This species is described from the Guyana shield and Rios Negor and
Orinoco. However, in the fish hobby, there are fish that are very
similar also found in Rios Xingu and Tapajos.

Would you say that they are likely to be the same species, or should
be considered a "net yet described" separate species?

Yes, they are definitely much wider spread (hopefully I will get my pub done on this one of these days). We have looked at them carefully and can't find anything to separate the Brazilian Shield ones form the Guyana Shield ones. We did find them in some pretty big rivers, so my guess is that the fish can move relatively easily.

Yes - I have seen 'sabaji' like specimens from the Xingu and Tapajos. For now I would call them Peckoltia cf. sabaji - as I am not sure whether they are conspecific or new....

Of course, this is the OPINION of two scientists that work with these fish. Only once their work has been published and accepted by the other scientists in majority.

--
Mats

[Janne]

Of course, this is the OPINION of two scientists that work with these fish.

Exactly.

Only once their work has been published and accepted by the other scientists in majority.

Yes, and even if they write a paper state them as one and same species the risk that they will be splitted in several species in the future is quite high... if you read this discussion we have had carefully I think they will write a paper showing them as new species and not the same. If not, there are no logic in this discussion.

We should not accept any hints, opinions without any evidence behind for "similar" species include them as the same species as another species, only accept the holotype species which have been (I think) finer analyised.

Janne

[MatsP]

Janne,

I agree that there is a chance it will be split later on. Or it may not - it would depend, to a certain degree, on the funcing for various scientific projects, as well as what those projects actually find, if they are ever started.

There is also the argument that although the science consider them the same species, that different populations should be considered different for breeding purposes. I think this is the case for several of the Lake Tanganyika Cichlids, they have one species, which is regionally variable, and the different populations are not (supposed to be) bred together- Tropheus duboisi comes to mind.

--
Mats

[Carp37]

We should not accept any hints, opinions without any evidence behind for "similar" species include them as the same species as another species, only accept the holotype species which have been (I think) finer analysed.

I'm a bit confused by this- the holotype is a single specimen. Do you mean the population from which the holotype came?

I see no reason why different populations shouldn't be treated as discrete entities (the L/LDA-numbers concept provides a potentially useful identifier in this respect, although I realise that not all L numbers are necessarily different populations- they're just pictures of individual fish when it comes down to it), with efforts by aquarists to maintain the purity of stock from a particular location. However, I don't really agree that geographically isolated populations with minimal differences necessarily require to be classified as different species- Rupert (racoll) gave a very good argument for this much earlier in the thread relating to the subspecies taxon, but I personally feel that there needs to be significant divergence between populations to identify them as separate species; the flip-side to "my" interpretation is that it's always going to be judgement call as to whether a population is just that, or whether it's sufficiently different to be classified as a separate species.

I seem to remember that Whitley classified one particular shark over 10 times around Australia in the 1940s (all of which are now junior synonyms)- I'd thought this was the bull shark (Carcharhinus leucas but Fishbase only lists 3 synonyms by Whitley, so it must be another carcharhinid.

Although I wouldn't say we've really got anywhere with this thread, I've very much enjoyed reading others' comments and interpretations, from both a hobbyist's and scientific perspective. The thread is so long, I think, because there's no "right" answer to it.

[Janne]

Do you mean the population from which the holotype came?

Of course I ment that.
Species that not have been analyised by science should always be considered as not described species how similar they even look to each other when it comes to different locations, both of the science and hobbyist's.

Janne

[MatsP]

Yes, I agree that they should be considered different until material is published to say that they are the same. And Jon's e-mail implies that such a paper is on it's way, but not out yet.

--
Mats

[Carp37]

sorry Janne- I was possibly being a bit pedantic, but my point was that there have been many instances in the past where one or more paratypes (or even worse, syntypes) have been subsequently found to be different species to the holotype. Hopefully that's a thing of the past- it was particularly prevalent when big expeditions collected fish, preserved them, and then the fish were described when "they" got back to the lab a year or so later. The current situation (at least with regards to catfish) has improved somewhat since then.

[Janne]

And Jon's e-mail implies that such a paper is on it's way, but not out yet.

And how is't that are working on this paper?

Yes, I agree that they should be considered different until material is published to say that they are the same.

Absolutely, I think it's smarter to keep them separated as their own species and that day they are scientific desribed either as the same species or another we should lump them together or still keep them apart. Like it's now many species is lumped together without anyone knowing for sure they are the same or different species.

Janne

[MatsP]

I don't know who (besides Jon) is working on the paper. As far as I read the original mail I received, which is copied in my post, it appears that the paper is essentially ready for publication, it's more of a case of finding something to publish it - but that's reading between the lines, and I may be misreading it.

So, now comes the question: Should we take the one species[1] in the Cat-eLog, and split it into three or more separate species[1] entries?

[1] I use the term species here to mean "cat-elog database entry", rather than species in the strict scientific sense.

--
Mats

[Suckermouth]

Yes, I agree that they should be considered different until material is published to say that they are the same. And Jon's e-mail implies that such a paper is on it's way, but not out yet.

--
Mats

If it is done being written, depending on the journal, it could be over another year before we see it. Copeia apparently has an enormous backlog. However, I'm pretty sure what Jon is saying is that he hasn't finished writing it (and possibly hasn't started). Sometimes we use "pub" to mean a scientific paper, so if he's not done the paper then he's not done writing it. I could be wrong but that's how I read what he said. I suppose I'll ask him about it.

There is also the argument that although the science consider them the same species, that different populations should be considered different for breeding purposes. I think this is the case for several of the Lake Tanganyika c*****ds, they have one species, which is regionally variable, and the different populations are not (supposed to be) bred together- Tropheus duboisi comes to mind.

This I can quite agree with.

So, now comes the question: Should we take the one species[1] in the Cat-eLog, and split it into three or more separate species[1] entries?

If the regional populations have different L-numbers (as I think Janne noted?), shouldn't we just split them by L-number? As it is, the current P. sabaji article appears to list the distribution as only in the Essequibo, Negro, and Orinoco, so I was assuming we already weren't including Brazilian populations.

[MatsP]

The list of distribution sort of covers "and river of Para State flowing north into the Amazon downstream of the confluence with the Rio Negro" - that would indicate Rios Xingu and Tapajos just as examples. The Occurrence data (the links below the textual information) is also covering this by "Lower Amazon".

Edit: And the "Common names" list is

L075, L124, L301, LDA02, Para Pleco

.

--
Mats

[Janne]

The list of distribution sort of covers "and river of Para State flowing north into the Amazon downstream of the confluence with the Rio Negro" - that would indicate Rios Xingu and Tapajos just as examples. The Occurrence data (the links below the textual information) is also covering this by "Lower Amazon".

Did Jon Armbruster have access to species from Rio Tapajos and Rio Xingu when he wrote the description of P. sabaji?

If the regional populations have different L-numbers (as I think Janne noted?), shouldn't we just split them by L-number?

Yes, I mean it's better to keep the species apart in the hobby using the L-number code until it's a real fact that they are the same or different species, almost no one in the hobby and many proffesional breeders don't separate them because they consider them as the same species and they are backup by science without any real papers that prof it. This is not just P. sabaji, it's just a good example... there are several other species lumped together too with different localities and considered to be look alike species. Hobbyist's should keep these species apart until science catch up with their work, sometimes even the hobbyist's is a step before science and thats no good.

Janne

[apistomaster]

It has long been customary to maintain Killiefish of the same species separated and propagated based on their collection locations.
Interbreeding different populations devalues them and they are forever after accepted as only "aquarium strain".

[Suckermouth]

Did Jon Armbruster have access to species from Rio Tapajos and Rio Xingu when he wrote the description of P. sabaji?

The P. sabaji description includes no mention of specimens from either river.

[Janne]

Maybe not even speciemens from Rio Orinoco and Rio Negro either, just the collected speciemens from Essequibo river?
Some of you that have participated in this discusson are working within this field of science, can you give a straight answer what you think would be correct with species not yet analyised if they should be treated as separated species or as the same species they look similar too? Have species (populations) not yet described the status as an exclusive species separated from all other as long there is no prof or evidence presented that state something else?

Janne

[apistomaster]

I am among the least qualified to answer you Janne.
Going to do it anyway.
In this particular instance, where there is a Guyanese, an Orinoco and Amazonian version of ostensibly the same fish,
I would define each as a separate species which only happens to be obviously related to each other.

[MatsP]

I do believe scientists in general treat species that are outside the distribution as "X cf. y" or "X aff. y" - they are similar, and may be the same species, but they are technically not yet described, so therefore, until a description is actually published (and believed to be correct!) they should really be different species.

In the case of P. sabaji, I'd say we need, at least for now, a different species entry for the ones captures south of the Amazon - that would be L75 and LDA02 localities. We probably also need an entry for Rios Xingu and Tapajos that I couldn't find an L-number for in my book.

The specimens examined in the original description originate from (this list is simplified to make it more readable than the original description. :
Holotype: GUYANA: Rupununi (Region 9), Essequibo River Dr.

Paratypes: All localities GUYANA, Essequibo River Dr.: Upper Demerara-Berbice (Region 10)
Essequibo River at Kurukupari, east bank Rupununi (Region 9)
Simoni River - 4 sites from 6.6 km SE to 3.2km W Karanambo
Rupununi River 4.6 km NW Massara

Nontypes:
GUYANA: Takutu River - Rio Branco - Rio Negro Dr., Rupununi (Region 9)
VENEZUELA, Río Cinaruco - Río Orinoco Dr., Apure, Río Cinaruco in Laguna Larga
VENEZUELA: Río Siapa - Río Casiquiare - Río Negro Dr., Amazonas
Río Siapa immediately below Raudal Gallineta, Departmento Río Negro

In the original description, there is a map showing the species distribution.

--
Mats

[Janne]

In this particular instance, where there is a Guyanese, an Orinoco and Amazonian version of ostensibly the same fish, I would define each as a separate species which only happens to be obviously related to each other.

I do believe scientists in general treat species that are outside the distribution as "X cf. y" or "X aff. y" - they are similar, and may be the same species, but they are technically not yet described, so therefore, until a description is actually published (and believed to be correct!) they should really be different species.

I agree on that, but it would be nice if the scientific people spoked the same language as the most hobbyist's understand, I would want a statement that say clearly: All separated populations of fish species not yet described shall be seen as exclusive species not mixed in with other similar species from other locations. The academic language is like politic for the younger generations, they need clear spoked words to understand (not all but many enough).

Janne

[racoll]

can you give a straight answer what you think would be correct with species not yet analyised if they should be treated as separated species or as the same species they look similar too?

I do believe scientists in general treat species that are outside the distribution as "X cf. y" or "X aff. y"

Even with a large distrubution, I would call fishes from other drainages that aren't identical something like Peckoltia cf. sabaji "Rio Tapajos L075". I would keep the name P. sabaji restricted to Essequibo drainage, until a more thorough assessment can be made.

The L number system has its weaknesses, but I think more information is better in most cases.

This is just my opinion though, and many are of a more "lumpier" persuasion than I.

it would be nice if the scientific people spoked the same language as the most hobbyist's understand,

Scientists are not here to serve the aquarium industry, although hobbyists are probably the largest "consumer" of loricariid names and scientific publications.

The recent description of Danio tinwini included the trade name of that species, so scientists are beginning to tailor their writing to the people who actually read their publications.

[Suckermouth]

The recent description of Danio tinwini included the trade name of that species, so scientists are beginning to tailor their writing to the people who actually read their publications.

Indeed, the common name and L-number were noted in B. beggini's description.

[Janne]

Scientists are not here to serve the aquarium industry, although hobbyists are probably the largest "consumer" of loricariid names and scientific publications.

I know, but it's us hobbyist's and the ornamental trade/industry that mess things up from what we read or not read from scientific publications. Sometimes even the scientific paper mess things up and when we read it we make it worse. The best thing for us would to keep all other species apart not yet included in any scientific paper, with the example of P. sabaji that many people are trying to breed they just buy L75-L124 put them together because everyone say they are the same species. In the hobby and ornamental business is "hybrids" produced both unconscious and with awareness to create "new species", the last we can not do so much about but the first we can.

Janne

[MatsP]

Janne, I do agree with what you are saying. However, I do believe that EVEN if the fish are scientifically the same species, the different localities should not be crossed in captivity - which means, you have to buy the fish at the same time (or at least make sure they are from the same locality when you buy them).

Shops/exporters/importers are of course also able to mess this up, by mixing "similar" fish when they arrive to their place - and I don't think this is based on reading scientific papers as much as "they look the same, so they must be the same".

--
Mats

[Janne]

Janne, I do agree with what you are saying. However, I do believe that EVEN if the fish are scientifically the same species, the different localities should not be crossed in captivity - which means, you have to buy the fish at the same time (or at least make sure they are from the same locality when you buy them).

Yes of course, before or in the past (maybe not among species from South America) where populations considered or described as a subspecies, for the aquarist that is aware is populations and subspecies the same "technically", if the hobby shall apply population instead of subspecies we need a clear definiton of "population" or something that make it easy to understand that even the same species is not the same if they are from different populations.

Shops/exporters/importers are of course also able to mess this up, by mixing "similar" fish when they arrive to their place - and I don't think this is based on reading scientific papers as much as "they look the same, so they must be the same".

More and more the exporters and importers are trying to put the right L-number, C-number or scientific name using sources like "expert hobbyist's" and in some cases people withing science working in this field. Another example, in Sweden it's not allowed by law to sell any species without the correct name... ops? of course no one can supervice that kind of laws because there are no knowledge. We will see new regulations and laws in a near future where the scientific name will be much more important than today not only in Europe. But my main worries was more pointed to the profesional breeders supplying the ornamental trade.


Janne