Pseudacanthicus major, new species (Loricariidae)

[lfinley58]

Chamon, C.C. & Silva, T.C. 2018. Pseudacanthicus major: description of one of the largest known Loricariidae (Hypostominae: Ancistrini), a species from rio Tocantins basin, Brazil. Zootaxa, Volume 4387, Number three: 499-510.

Abstract:
The genus Pseudacanthicus currently comprises the following six [sic] species distributed in the Amazon and Tocantins basins, and coastal drainages from Guyana to French Guyana: P. serratus, P. fordii, P. histrix, P. spinosus, P. leopardus, P. pitanga, and P. pirarara. Herein we describe P. major, from rio Tocantins basin, one of the largest loricariid species known. The new species is distinguished from its congeners by the following combination of characters: having body color pattern with dark brown background without spots or blotches and dorsal and caudal fins with transversal white bands; anterior process of compound pterotic with no contacting with the posterior margin of the orbit and by the absence of a conspicuous crest on the posterior edge of parieto-supraocciptal. Other osteological characteristics are further used to diagnose P. major from others congeners. A discussion on gigantism and miniaturization in freshwater fish, ornamental fisheries activities, threats and conservation of the new species are also provided.

http://www.mapress.com/j/zt/article/vie ... a.4387.3.5

[bekateen]

Holy cow! I was just searching databases less than an hour ago! How did I miss this?!?

[lfinley58]

Time can be tricky - so much can happen in so little of it.

Re all of the genetic papers that you made note of - Interesting stuff!

Lee

[bekateen]

Time can be tricky - so much can happen in so little of it.

True, so true.

Re all of the genetic papers that you made note of - Interesting stuff!

Thanks, I just happened upon a publication of abstracts from a meeting. Lucky us so many papers studied catfish.

And to be honest, I only listed abstracts which have the word "Siluriformes" in their title. If any abstracts in that journal issue failed to use that word, I missed them. Maybe there are more gems to be found there... and it'd be easier if you speak Portuguese.

Cheers, Eric

[lfinley58]

Hi all.

The largest size listed for this species is 540 mm (21.3 inches) Standard Length!
Lee

[bekateen]

Is this fish

L186

?

[lfinley58]

Hi Eric,
Our minds are working together. I am just coming on to the site to note that the paper states that this fish is known by aquarists as L186.
In Ingo's Back to Guide to L-Catfishes he also notes that the number L064 is also applicable to this fish.
Lee

[lfinley58]

OOPs!
Regarding the size attained by this species: I initially missed seeing that one of the paratypes is 600 mm (23.6 inches) Standard Length. Sorry about that.
Lee

[bekateen]

Hi Lee,

I do not have access to this journal. If you have a copy, may I get it?

Thanks, Eric

[lfinley58]

Hi Eric,
It will be on the way. I'll use the address in the Sacramento Tropical News member list.

Lee

[bekateen]

Thanks Lee.

I'll use the address in the Sacramento Tropical News member list.

How did you find that? Do you get our monthly newsletter? ... *moment of silence while I look in a recent newsletter... You do! Ha! Wonderful. We should try and get you back sometime.

Cheers, Eric

[bekateen]

I changed the name from L186 to

Pseudacanthicus major

.

[lfinley58]

Hi Eric,
In this vein you might want to retire L64 also.

Lee

[lfinley58]

Hi yet again Eric.
I look forward to the club magazine each month. I really need to write something for it.
It may sound a bit clumsy, but it is an honor to be an honorary member of the club.
Lee

[bekateen]

In this vein you might want to retire L64 also.

Lee, I'm afraid that's above my pay grade and skill set. (1) The authors of this paper did not equate L064 with P. major, so without authority to do so, I hesitate. And (2) It's very easy to rename an existing entry in the CLOG, but fusing one to another, and transferring the registered users, is a little more complex. It might be within my powers, but given concern (1) I'd rather let the Gods of the internet handle this.

Cheers, Eric

[lfinley58]

Hi Eric,
I see where you are coming from with that situation.
I had mentioned Ingo's book using both numbers and double checked with the Wels Atlas Band 2 by him and Evers, who had basically the same info, apparently considering the L64 as the juvenile of L186.
Maybe we can get some feedback from others on this situation.
Lee

[Jools]

You're right to be cautious Eric.

L063

,

L064

and

L186

have mixed up pictures in our database. It is messy and I need some time to unpick it. As you say, once you combined registered keepers, you can't then separate them out again.

I am comfortable the described fish is L064 if we're going on the picture of the adult in the paper. However, I don't see the white bands in the caudal the paper describes. The picture of the holotype I am less certain of but again it looks more like L064 and than L186.

I would value @acanthicus 's perspective.

Jools

[Acanthicus]

Hi

L 64 and L 186 are the same species in my opinion, pretty sure about that. L 64 was published as being from Rio Tocantins, L 186 as being from Rio Tocantins near Cametá, so how should anyone distinguish those two l-numbers, it's impossible. The shown specimens look very, very similar to each other, having in mind one was photographed in Brazil, and one in Germany even the differences in colour are easily explained.

The shown, but released specimen in the paper therefore matches both l-numbers very well, the white caudal bands are not as clear as they are in Panaqolus or Hypancistrus and fragmented, but still there I'd say. "Bands" is possibly not the best term to describe the pattern.

Hope that is of any help?

[bekateen]

L 64 and L 186 are the same species in my opinion, pretty sure about that. L 64 was published as being from Rio Tocantins, L 186 as being from Rio Tocantins near Cametá, so how should anyone distinguish those two l-numbers, it's impossible. The shown specimens look very, very similar to each other, having in mind one was photographed in Brazil, and one in Germany even the differences in colour are easily explained.

Thanks Acanthicus.

I am comfortable the described fish is L064 if we're going on the picture of the adult in the paper. However, I don't see the white bands in the caudal the paper describes. The picture of the holotype I am less certain of but again it looks more like L064 and than L186.

Jools, from Ancanthicus' and your comments above, it seems that the two photos for L064 are indeed correctly labeled. Is it safe for me to combine L064 into the new species?

You're right to be cautious Eric.

L063

,

L064

and

L186

have mixed up pictures in our database...

From the details above, should I interpret your comment about "mixed up pictures in the database" to refer to

L063

? Do you think L063 should be combined with P. major?

Enjoy your BFD, and safe travels.

Cheers, Eric

[Acanthicus]

Hi again

L 63 is different to P. major, dont combine them please, its another species for sure.

(Btw: The photos I referred to were the ones from the DATZ publication, not from the cat e log.)

Have a good time!

[bekateen]

Thanks again.

Cheers, Eric

[racoll]

I'd be more confident assigning

Pseudacanthicus major

to the photos currently in

Pseudacanthicus histrix

.

For me that "histrix" fish has an appearance more consistent with P. major: the smaller, higher and triangular shark-like dorsal fin (with filaments), and the small eyes, i.e. also

Pseudacanthicus sp(l275)

and

Pseudacanthicus sp(l064)

.

The fishes in P. major look more like

Pseudacanthicus sp(l343)

.

I don't have my books handy so I don't remember what the original DATZ L186 looks like.

[Jools]

L064 should be combined with L186 but BEFORE we do that, we need to know where to put the pictures in that are currently in L186. @Acanthicus, could you look at

L186

here on Planet - I get the feeling a few of the pictures are

L063

?



Jools

[Jools]

@Racoll, I also agree that all images currently in P. histrix should be moved to P. major and have moved them.



Jools

[Acanthicus]

Hi Jools,

agree, the following ones need to be removed from P. major:
https://www.planetcatfish.com/common/im ... e_id=14974
https://www.planetcatfish.com/common/im ... e_id=14975
https://www.planetcatfish.com/common/im ... ge_id=4629
https://www.planetcatfish.com/common/im ... ge_id=3591

https://www.planetcatfish.com/common/im ... e_id=19940
https://www.planetcatfish.com/common/im ... e_id=19941
- Wasn't this specimen from the Belo Monte area?
It's coloured different to all we know, but I wouldn't leave it here either and move it to P. histrix. P. major is "lacking spots or blotches".

I am having a little issue with the distinction to P. histrix, colouration doesn't seem a trustable characteristic to me. The only chance to be sure about the ID of a living specimen is a dorsal view of the head if I understood the paper corectly.

cheers, Daniel

[racoll]

- Wasn't this specimen from the Belo Monte area?
It's coloured different to all we know, but I wouldn't leave it here either and move it to P. histrix. P. major is "lacking spots or blotches".

I am having a little issue with the distinction to P. histrix, colouration doesn't seem a trustable characteristic to me. The only chance to be sure about the ID of a living specimen is a dorsal view of the head if I understood the paper corectly.

It's a bit confusing. The diagnosis lists a whole load of osteological characters that distinguish major from all others (including histrix), but then the paragraph on histrix says nothing about osteology, just colour pattern. They only examined a single 7 cm example of histrix from the Xingu, and that was labelled cf. histrix. They state the Xingu histrix has no stripes in the caudal and dorsal fins, but the images of fishes online, purportedly from the Xingu all show spots and stripes, including Pseudacanthicus sp. "Belo Monte" in Wels Atlas II.

I would like to see more evidence to discount histrix. On the basis of Capello's illustration, they are almost identical, with the same large pectoral fins, the tiny eyes, the small triangular dorsal fin, and the plate-like procurrent caudal rays dorsally and ventrally to the caudal peduncle. No other Pseudacanthicus has these. It's a very distinctive fish, and P. histrix has been reported all over major rivers of the Amazon and Orinoco basins, so probably has a fair amount of colour variation.

[Jools]

agree, the following ones need to be removed from P. major:
https://www.planetcatfish.com/common/im ... e_id=14974
https://www.planetcatfish.com/common/im ... e_id=14975
https://www.planetcatfish.com/common/im ... ge_id=4629
https://www.planetcatfish.com/common/im ... ge_id=3591

Cool. Would you say move these to

L063

?

Having read the paper, I cannot say if

L064

is P. histrix or P. major thus expanding the range of the latter. Any views?

Jools

[Jools]

*bump* Is L064 = L186? I can't really see any differences?

Cheers,

Jools