Review of Peckoltia

[Silurus]

Armbruster, JW, 2008. The genus Peckoltia with the description of two new species and a reanalysis of the phylogeny of the genera of the Hypostominae (Siluriformes: Loricariidae). Zootaxa 1822: 1–76.

[panaque]

So,

Peckoltia sabaji

is now Hemiancistrus sabaji. And I wonder what this means for Peckoltia l-numbers: "The name Peckoltia is often applied to a wide variety of fishes by scientists and aquarists, but the true Peckoltia are fairly rare in collections and are rarely exported for the pet trade. Most species that masquerade as Peckoltia are species of Panaque (Panaqolus) or Hypancistrus." I suppose this is why species like l134 were not named and described in this paper.

[MatsP]

I personally believe that L134 is a yet undescribed species, and that Armbruster's comments above are more closely related to the exporters in South America that provide just about any of the smaller Loricariidae under the genus Peckoltia (and as a consequence of the exporters naming them such, often provided by wholesalers and shops under those names - since no one wants to take the responsibility of "correcting" a wrong ID).

Some of the H. sabaji relatives that are currently called Peckoltia will/should probably be put in the Hemiancistrus genus - time will tell, I suppose.

Is P. lineola the name of Peckoltia sp(L202)?

I have no idea what P. caenosa could be.

--
Mats

[racoll]

And I wonder what this means for Peckoltia l-numbers

Nothing really. They are just numbers and photographs; the genera they are assigned to are a prediction that will have to stand up to scientific scrutiny. Sometimes they do, sometimes they don't.

Even after this work, Peckoltia is still a poorly defined genus, and aquarists will have a lot of trouble trying to assign L numbers to the genus, when even the world expert is not happy with what a Peckoltia actually is.

I suppose this is why species like l134 were not named and described in this paper.

The collection of new taxa was probably beyond the scope of the study, as it was based on museum specimens, and concentrated on defining the genus.

It would be interesting if anyone has a mouth-shot of L134 that is better than the one in the cat-elog, to see whether the dentary matches the 90deg definition.

[husky_jim]

I didn't have the time to read it in depth but is my impression that L205 is 'falling under' Peckoltia Brevis?

[MatsP]

I didn't have the time to read it in depth but is my impression that L205 is 'falling under' Peckoltia Brevis?

Yes, I think you are right. Good spot.

--
Mats

[bronzefry]

What is a character state matrix?(Appendix 1)
Amanda

[panaque]

What is a character state matrix?(Appendix 1)

It is a matrix with characters (e.g spotty nose; angle of dentition<90 etc) as columns and species as rows. Each character can have several states like 0=not spotty, 1=small spots etc. So what is given in appendix 1 is the states for each species for each of the characters. This matrix is what is used to infer the phylogenetic trees in the paper.
I am not sure if that helps but that is what they are...

[MatsP]

That matrix would certainly be helpful for identification.

--
Mats

[racoll]

That matrix would certainly be helpful for identification.

They are not presented in a user friendly format - just strings of 0s and 1s in a text file.

On their own, each character state has little information; it is only when they are tested against one another for congruence in the framework of an evolutionary model that they begin to inform a phylogenetic hypothesis (and therefore the definitions of each genus).

This is how you detect homoplasy !

[MatsP]

Yes, I meant "help with computerized diagnostics" - humans are not particularly good at figuring out if position 38 in a long string of digits are the same or not over a huge range of such strings. Sorry, too fast in thinking, not fast enough in the typing..

--
Mats

[Jools]

Another look at L147 as well methinks...

Jools

[bronzefry]

What is a character state matrix?(Appendix 1)

It is a matrix with characters (e.g spotty nose; angle of dentition<90 etc) as columns and species as rows. Each character can have several states like 0=not spotty, 1=small spots etc. So what is given in appendix 1 is the states for each species for each of the characters. This matrix is what is used to infer the phylogenetic trees in the paper.
I am not sure if that helps but that is what they are...

That helps a lot, actually. Thank you. I was hoping L-147 would come up in this discussion.
Amanda

[Mike_Noren]

Even after this work, Peckoltia is still a poorly defined genus, and aquarists will have a lot of trouble trying to assign L numbers to the genus, when even the world expert is not happy with what a Peckoltia actually is.

Yes, I was surprised that he reviews the genus, acknowledges that it lacks definition and is non-monophyletic but does not correct it. To me it feels as if the paper isn't finished; certainly the job isn't done.

[racoll]

Yes, I was surprised that he reviews the genus, acknowledges that it lacks definition and is non-monophyletic but does not correct it. To me it feels as if the paper isn't finished; certainly the job isn't done.

I guess this stems from the "publish or perish" philosophy in modern science. He's obviously invested a lot of time and effort into this project and must account for it. Could be wrong though, just reading between the lines.

This case seems like a good opportunity to explore loricariid relations with molecular techniques...

[panaque]

I guess this stems from the "publish or perish" philosophy in modern science. He's obviously invested a lot of time and effort into this project and must account for it. Could be wrong though, just reading between the lines.

This case seems like a good opportunity to explore loricariid relations with molecular techniques...

Yes, scientists who only publish once they have resolved everything will not remain employed for long. Also, although this paper doesn't resolve all the problems with Peckoltia, it does a good job of spelling those out and of providing a large body of new information worthy of publication in my view.

I agree that the molecular methods are the way forward. I have just received a grant for loads of dna sequencing (of insects) and I might just try to sneak some tiny fin clippings of my own fishes in. If it works I might be back with requests for more samples, but that is still some way of.

[racoll]

Also, although this paper doesn't resolve all the problems with Peckoltia, it does a good job of spelling those out and of providing a large body of new information worthy of publication in my view.

Definitely. Despite being inconclusive, the data is much more valuable when published.

[Borbi]

Hi,

unfortunately, there is only one picture in the catelog, but:

Did anyone consider Ancistomus sp. "LDA20/LDA21" (or Peckoltia or Hemiancistrus, if you like) for "Peckoltia" caenosa?
To me, the description as well as locality fit nicely. Unfortunately, there is no color picture in the paper, but the description of vermiculations on the underside as well as that of the head markings would fit. There are a few other species of Ancistomus coming from that general area, but none of them seems to fit both of these characteristics.

Any comments on that strange idea..?

Cheers, Sandor

[Yann]

Hi Borbi!!

That was my initial thought also...but I found LDA20 to be somewhat "flatter" than the fish
Plus pic I have seen from LDA20 lacks the bony plate extension on the head!!
But it is really closed and made me wonder!!
Cheers
Yann

[Janne]

Maybe LDA20/21 never should have been recognised as an Ancistomus, I have never seen this species alive but the pictures I have seen it remains like a typical Peckoltia species...nor any Ancistromus / Hemiancistrus at all.
So you may be right Sandor

Janne

[bronzefry]

Another look at L147 as well methinks...

Jools

Just a thought: is it possible that L-147 could be more than one species?
Amanda

[Borbi]

Hi Amanda,

well, at least there is Peckoltia sp. "L 387". This one is hard to tell apart from A. sp. "L 147", if not fully grown (since Ancistomus become only enlongate as compared to Peckoltia when fully grown). The only sure difference based on colouration is underside colouration. But this morphological difference between a juvenile and an adult Ancistomus could certainly produce a lot of irritation.
However, in a recent discussion with another catfish enthusiast the problem of origin emerged. There is no species of Ancistomus known from Peru, no species is found further west than L 147, but that´s still something to go from Columbia/Venezuela..

I also feel to recognise A. sp. "L 147" (or Peckoltia or Hemiancistrus, just as you like) in Peckoltia furcata. But this is merely based on the description of colouration and the stated maximum length (which makes me believe that either there is a "false" type specimen in the collection or P. furcata should better be placed in Ancistomus, provided you recognize this genus) since no "true" Peckoltia reaching a TL of 20cm has ever crossed my eye.

Just my two cents,

Sandor

[Janne]

L147 I hope will not be described as a Peckoltia species, Hemiancistrus/Ancistomus seems to be more right if they have change P. sabaji to Hemiancistrus sabaji...they reach the same size and if not twins they are cousins L147 reach 20 cm TL without any problem, the male larger then the female but maybe better to wait until we have more information...I have seen what I think is a Peckoltia species from Amapa (Brazil) that reach 20 cm TL so it's probably not impossible.

Janne

[bronzefry]

Thanks Borbi and Janne,
I take both of your input seriously. It's worth more than 2 cents. I asked the question because of the P.furcata. I was thinking of the two species below. It sounds as if there is a lot of work that needs to be done in this area. I'm glad it is being addressed.


I'd say we are approaching 20cm with the above L-147.(showing the tail for the fork-she doesn't come out much).



A similar tail on the L-387. This fish is much smaller than the L-147, about 10-12cm TL. These L-387s seem to eat everything including each other. The L-147 is a bit fussier with food:bloodworms and squash. They both tear the squash apart. They don't rasp.

What is the dentition of other Peckoltia spp.?
Amanda

[Borbi]

Hey Amanda,

I´m slightly confused by your post (regarding identification), sorry:

This is how I understood it: the first fish is A. sp. "L 147", while the lower two pictures show P. sp. "L 387"? And the L 387 are around 10-12cm?

Okay, now back to topic:
I had the opportunity to talk to Ingo Seidel about this publication, yesterday and his conclusions and opinions will be published in the next issue of the "Amazonas" magazine which will appear beginning of September (in german only, of course).
Since I believe that Ingo would not be exactly glad if I spread his thoughts before they are published, I would prefer not to comment on the two new species.
I would be happy to summarize the main conclusions, once they are published though, of course.

But back to the Peckoltia furcata things:

Amanda, you are right, these are the two species that immediately came up for me, as well, when I saw the new pictures of syntype material. Provided, they are identified correctly (the syntypes), of course, they fit both.
But my big BUT regarding P. sp. "L 387", besides the uncertainty in "type" locality, could you examine (or better, take a picture) of the underside? You would (should) find, that the underside of P. sp. "L 387" is markedly spotted, a trait that is present neither in Peckoltia furcata according to description and pictures, nor is it found in Ancistomus sp. "L 147". This is probably the easiest way to distinguish the two species in juveniles, when the Ancistomus still look like Peckoltia.

And just an additional note: Ingo and I also found an oddball Peckoltia multispinis, it is clearly a Peckoltia that probably already has an L-number. Unfortunately, my memory just doesn´t cooperate: It either looks like L 9 or L 49 which are not the same species (as reasoned until yesterday).

So far the latest news and thoughts from my side regarding Peckoltia furcata. I believe to unambiguously clear this point, an inspection of the holotype by a knowledgeable person would be a good idea, I would really like a second opinion besides Armbrusters on this one. Also to make reasonable sure that the displayed syntypes really are identical to P. furcata (sorry, I´m doubtful by nature.. ).

The next point that came up recently would then be the "wormlined Peckoltia", which is P. vermiculata (this one is clear to me), P. braueri, P. cavatica and the question regarding "their" L-Numbers, L 121, L 135 and L 305 who are all identified as P. braueri in the catelog. Personally, I don´t feel them to be identical, at least I believe, that L 121 and L 135 should be split from P. braueri. L 305 in turn, I believe to be P. braueri.
But what about P. cavatica? I know that there are pictures of one specimen in the catelog. But I´m not sure at this point wether it is not just a variant of P. braueri and the "missing" vermiculations reappear on the compound pterotic.
This one should be "easiest" cleared by aquarists: organize a decent group of P. cavatica, grow them out, breed them, and we should be able to tell if the head markings stay different or if P. cavatica is just a morph of P. braueri.
Anyone got a nice group of P. cavatica, by chance? I would happily volunteer to give breeding a try!

Cheers, Sandor

[bronzefry]

Sandor,
I doubt your memory is failing you. It's more likely the confusion we are all experiencing at the moment.

The L-387 photo below was taken in the quarantine tank. They are in the caves today-I don't want to disturb.


The L-147 photo was taken a while back when the specimen was a bit smaller:


Neither photo is great, but spots are visible on the underside. I doubt either are Peckoltia spp..and I doubt this particular fish sitting in my 75 gallon tank is an L-147. I look forward to Ingo's comments. Drink, Sandor?
Amanda

[Janne]

Amanda,

You meen that your fish id as L147 could instead be L387? Is very possible because even that L387 normaly is quite nice coloured as young more yellow and orange when L147 is quite boring in his colour, the experience I have had of L387 is that they are very changable in their colouration. I think this depends on water chemistry, temp etc, as adult the L387 is more orange and brownish and loose their strong contrast of colour.

janne

[bronzefry]

An excellent point, Janne. It will be interesting to see how these other fish grow in the months to come. It will be interesting to see if their colors dull, too as the other fish did. The L-387s are still quite bright in color.
Amanda

[Borbi]

Hi all,

so, now that the latest issue of "Amazonas" has appeared around here, I am free to share Ingo´s (and my) view regarding the Peckoltia revision.

As I already believed before, Peckoltia caenosa is identified by Ingo to be Ancistomus sp. "LDA20/LDA21", as well. Although there are some ambiguities regarding dentition, Ingo still prefers to put that species into Ancistomus rather than Peckoltia. I second him on that, based on body shape and "overall appearance". Unfortunately, this feeling of appearance is not really scientific.. But, anyways, I´m not an ichthyologist, so I´m allowed to "feel".

Regarding Peckoltia lineola, Jools was the one to first publicly identify it with L 202 (LDA57, LDA79), I believe, and Ingo believes the same.
Based on the fimbriae found on the lips of some Peckoltia sp. "L 49", Ingo identifies this species as P. multispinis. I personally am not 100% convinced on that one, since I feel this to be some kind of age marking or something like that, and not really sure yet, that this is a truly unique trait of P. multispinis. But on that one, only time can prove me wrong.

There is also some interesting news to be expected regarding Peckoltia braueri and Peckoltia cavatica. Ingo quotes a contribution by himself not yet published, where he will show that Peckoltia cavatica should be recognized as a synonym of P. braueri, while Armbruster and Werneke identified P. braueri as L 121 and L 135 while P. cavatica should be L 305. It appears that Ingo bases his oppinion not only on outward appearance but also on the shape of some bones which are supposed to prove the identity of P. braueri and P. cavatica. So, I´m definitely looking forward to that publication.

And finally some notes regarding P. furcata, that are not based on the publication of Ingo, but are the result of my own investigations:
I continued researching into this thing, and finally decided that the fish shown by Armbruster in detail is most likely not the same species as the Holotype of P. furcata based on morphology. Unfortunately, there is only this one picture of the holotype and also, the individual countings and measurements of the holotype are not given by Armbruster. Thus, comparison of the mean measurements with those of the holotype are not possible. However, based on the outward appearance (again, such a "feeling" thing), I believe that the fish pictured by Armbruster is in fact an Ancistomus sp., while the Holotype might be a "real" Peckoltia. But that last thing is hard to tell without additional pictures of this type.
What was more exciting (although not really helpful in identification of P. furcata) is the fact, that I almost certainly found the fish pictured by Armbruster (unfortunately, I cannot show any pictures as comparison, because these are not available online, but are published in an older aquarium magazine from 2005, "Amazonas" issue 7, if my memory doesn´t trick me).
In this contribution, there is a fish shown that is designated as Ancistomus sp. "Rio Nanay" that perfectly fits Armbrusters fish. As a sidemark, this is the only species of Ancistomus known so far from Peru. Additionally, there is a very similar looking type of Peckoltia (body markings are very similar indeed), termed Peckoltia sp. "Santa Maria" (caught near a town called Santa Maria) also from that area. Thus, we have Armbrusters fish from the Rio Itaya, Ancistomus sp. "Rio Nanay" from the Rio Nanay, Peckoltia sp. "Santa Maria" from the Rio Nanay (all separated by at most a few hundred kilometers) and we have Peckoltia furcata from the "Rio Ucayali basin", where Nanay and Itaya are in fact tributaries of the Ucayali.
Now, without additional information on the holotype, an identification is clearly not possible. However, my working hypothesis right now is, that Armbrusters "P. furcata" is in fact Ancistomus sp. "Rio Nanay", while the real P. furcata may well be Peckoltia sp. "Santa Maria" (or something completely different).
Is there any ichthyologist around to volunteer on remeasuring the quoted specimen..?

So far,
Cheers, Sandor

[MatsP]

I've just added a new species, Peckoltia furcata, as I couldn't find a single species in the Cat-eLog that was a close match.

I believe L387 is exported out of Colombia, so I'm not sure how close to Rio Nanay that is...

--
Mats