Pseudeutropius, not Neotropius; Schilbeidae, not Bagridae

[Dinyar]

Multiple booboos related to two entries (one fish) in the Catelog: "Neotropius atherinoides" and "Neotropius acutirostris".

"Neotropius atherinoides" is actually Pseudeutropius atherinoides, and is a Schilbeid, not a Bagrid!

"Neotropius acutirostris" is a junior synonym of Pseudeutropius atherinoides.

Pseudeutropius are pretty cool fish. Sort of like Asian debauwie cats.

• Easy to keep because they eat whatever's on the menu, are peaceful to tank mates and relatively undemanding of water conditions,
  Prettier than debauwie cats because they have an iridescent sheen,
  Don't get too large but are large enough to be readily noticeable,
  Diurnal so you see them all the time,
  And midwater swimmers so they nicely fill out a catfish tank.

Should be more popular than they are.

Dinyar

[Silurus]

No mistakes there. Neotropius atherinoides and N. acutirostris are valid species (one is Indian, the other is Burmese). Together with the scale-eating N. khavalchor, they are members of the Bagridae (I know they don't look it, but they ARE bagrids).
Pseudeutropius is a schilbeid, but only refers to the Southeast Asian P. brachypopterus and P. moolenburghi, which are far more delicate and more demanding of water conditions.

[Sid Guppy]

I had a shoal of about 7 years ago, combined them with 8 Pareutropius and 10 Physailia in a 650 liter tank, and tons of other fish.
It was awesome; all those midwater swimming cats.
Unfortunately that tank busted when moving house, so...

[Dinyar]

No mistakes there. Neotropius atherinoides and N. acutirostris are valid species (one is Indian, the other is Burmese). Together with the scale-eating N. khavalchor, they are members of the Bagridae (I know they don't look it, but they ARE bagrids).
Pseudeutropius is a schilbeid, but only refers to the Southeast Asian P. brachypopterus and P. moolenburghi, which are far more delicate and more demanding of water conditions.

I stand corrected. Your point is especially interesting in light of the fact that Fishbase, Eschmeyer, every other web source I checked and all the books in my fish library (admittedly not vast) claim that atherinoides is Pseudeutropius. FB lists N. khavalchor as a Schilbeid as well. Was Neotropius moved recently? When and by whom? Why, when and by whom were the Indian species in Pseudeutropius moved to Neotropius? And perhaps the question that intrigues me the most, why was Neotropius moved from Schilbeidae to Bagridae?

From my layperson's point of view, looking at N. atherinoides as a Bagrid, I suppose one can see something Bagrid in it, but the dominant impression is of a Schilbeid. In fact, we have some experience with Pseudeutropius as well (I'll try and post a pic of what I think is P. moolenburghi), and to my eye, N. atherinoides and P. moolenburghi look and ACT very similar.

Finally, I would like to suggest that when we make a classification in the Cat-elog that is at variance with popularly accessible sources, we should explain our reasons and cite valid references for doing so. Otherwise less informed people (like me) are apt to think it's the Cate-log that's wrong and not them.

Dinyar

[Silurus]

The answers are all in Mo (1991). The chapter covering the Bagridae I wrote for the Catfishes book also has Neotropius in the Bagridae, but that was only because the analysis in there was very largely based on Mo's data.

Anyway, midwater, schooling bagrids are not unusual. Hyalobagrus is another.

[Dinyar]

So is it that FishBase, Eschmeyer et al. do not accept Mo for some reason, or is it just that they are >12 years out of date?

Dinyar

[Silurus]

Eschmeyer (Catalog of Fishes) list the two species as valid and in Neotropius (although it does assign it in the Schilbeidae still).
The inherent lag with FishBase has been discussed before.

[Dinyar]

As I read Eschmeyer, it claims that Neotropius is monotypic, containing only N. khavalchor.

Dinyar

[Silurus]

If you search the online version of the Catalog of Fishes at http://www.calacademy.org/research/icht ... earch.html, you will find Silurus atherinoides and Pseudeutropius acutirostris placed in Neotropius (note: this is misspelled Neotroplus in the case for acutirostris, and a search with "Neotropius" as a query will not reveal this species).
There is also Pseudeutropius mitchellis, which should also belong to Neotropius as well (but is retained in Pseudeutropius here).

[Dinyar]

Yeah, it's a bit odd -- if you search Eschmeyer for the genus Neotropius, you get only one species -- N. khavalchor, but if you search for Pseudeutropius, you get P. atherinoides.

The entry reads:

atherinoides, Silurus Bloch 1794: 48, Pl. 371 (fig. 1) [Naturg. Ausl. Fische v. 8; ref. 463]. Tranquebar, Tamil Nadu, India. Holotype (unique): ZMB 3013. Type catalog: Paepke 1999:127 [ref. 24282]. On p. 38 of Bloch's Ichthyologie, v. 11 [ref. 21381]. Valid as Pseudeutropius atherinoides (Bloch 1794) -- (Shrestha 1978:39 [ref. 15970], Burgess 1989:99 [ref. 12860], Rahman 1989:181 [ref. 24860], Talwar & Jhingran 1991:606 [ref. 20764], Indra 1994:420 [ref. 24015], Sen 1995:569 [ref. 23778], Rema Devi et al. 1999:159 [ref. 24758], Menon 1999:227 [ref. 24904], Rafique 2000:326 [ref. 25220], Karmakar 2000:33 [ref. 25662], Yadav 2000:41 [ref. 25661]). Valid as Neotropius atherinodes (Bloch 1794) -- (Mo 1991:133 [ref. 19952]). Neotropius atherinoides (Bloch 1794), Schilbeidae. Habitat: freshwater.

So what exactly does it mean when earlier on it says "Valid as Pseudeutropius atherinoides", and then lower down it says "Valid as Neotropius atherinodes"?

To what extent is Mo accepted as definitive? And whatever happened to him? After the publication of his 1991 treatise, has he published again? Is he still alive?

Dinyar

[Silurus]

So what exactly does it mean when earlier on it says "Valid as Pseudeutropius atherinoides", and then lower down it says "Valid as Neotropius atherinodes"?

It means that the list of references after "Valid as Pseudeutropius atherinoides" place the species in Pseudeutropius and Mo is the only reference that places the species in Neotropius. The Catalog of Fishes is not meant to make judgement calls on what goes where. This is a job for a more comprehensive database in the works (the Annotated Checklists).

To what extent is Mo accepted as definitive?

As far as the Bagridae is concerned, no one else has studied the group with as much detail as he has, and so there is no one else who disputes his results much (he did a pretty good job, but there are still gaps). The same cannot be said of the siluriform phylogeny in the same study, as there have been at least three studies subsequent to his (de Pinna, Diogo and Britto) that do not agree with his results.

And whatever happened to him? After the publication of his 1991 treatise, has he published again? Is he still alive?

He is very much still with us, earning more money in the finance industry in London than he ever could as an ichthyologist.

[Dinyar]

Read your Bagridae article with great interest and learned a lot from it. I'm still more than a bit confused by the placement of Neotropius (and Horabagrus), though. I haven't thought through these questions carefully and don't know if they're asked in the right way, but off the top of my head:

1) Re. Neotropius, is Mo's implication that it has NOTHING in common (no synapomorphies?) with Schilbeids such as Pseudeutropeus, and its previous placement in Schilbeidae was without any valid basis? This is the position implicit in your paper according to my (not necessarily correct) reading, and frankly, that leaves me feeling somewhat surprised and unsatisfied (since to my untrained eye, Neotropius and Pseudeutropius look and act extremely similar). If we are saying that Neotropius and Pseudeutropis have no/few syanopomorphies and belong in distantly related families, how does one explain the apparent similarities between the two? Adaptive evolution? Mere illusion?

2) Horabagrus is another Bagrid species which has been classified as a Schilbeid. Are there any synapomorphies between Neotropius and Horabagrus? Your Mo-ist cladogram on p. 445 claims Horabagrus to be a sister group of Cranoglanis (interesting, though I haven't the foggiest notion of what characterizes Cranoglanidae) and Neotropius to be close to Mystus and Olyra (about as counterintuitive as you can get, in my lay eyes, having some aquarium experience with all three), which implies to me that no, Horabagrus and Neotropius share few synapomorphies and the fact that they have both moved between Schilbeidae and Bagridae is merely coincidental.

3) Does the fact that these two genera seem to share characteristics of Bagridae and Schilbeidae imply any consanguinity between these two families? If so, what? If not, why not?

Thanks for your help in straightening out my understanding of this.

Dinyar

PS: Is Cranoglanidae the only extant Silurform family not represented in the Catelog?

[Yann]

Finally, I would like to suggest that when we make a classification in the Cat-elog that is at variance with popularly accessible sources, we should explain our reasons and cite valid references for doing so. Otherwise less informed people (like me) are apt to think it's the Cate-log that's wrong and not them.

Dinyar

I also think it should be a good idea... I also had comment from people stating that the nomenclature was not always correct here. It would also be a good thing reagarding the use of Isbrücker new genus. Also the one used by Armbruster and Weber.
Cheers
Yann

[Silurus]

1) Re. Neotropius, is Mo's implication that it has NOTHING in common (no synapomorphies?) with Schilbeids such as Pseudeutropeus, and its previous placement in Schilbeidae was without any valid basis? This is the position implicit in your paper according to my (not necessarily correct) reading, and frankly, that leaves me feeling somewhat surprised and unsatisfied (since to my untrained eye, Neotropius and Pseudeutropius look and act extremely similar). If we are saying that Neotropius and Pseudeutropis have no/few syanopomorphies and belong in distantly related families, how does one explain the apparent similarities between the two? Adaptive evolution? Mere illusion?

Actually, the reclassification of Neotropius as a bagrid had been proposed by Tilak (1964). Since we cannot find any apomorphies in common between Pseudeutropius and Neotropius that is not found in other catfish groups, there is no reason to suppose that they constitute a monophyletic lineage within the Schilbeidae.
I am no longer convinced that two fish looking and behaving almost identically should belong in the same family. Case in point: Olyra (Bagridae) and Heptapterus (Heptapteridae). They look almost identical (except for Olyra possessing nasal barbels), and behave almost identically (prefer currents, extremely aggressive to conspecifics), yet they do not share enough synapomorphies to be placed in the same family.

2) Horabagrus is another Bagrid species which has been classified as a Schilbeid. Are there any synapomorphies between Neotropius and Horabagrus? Your Mo-ist cladogram on p. 445 claims Horabagrus to be a sister group of Cranoglanis (interesting, though I haven't the foggiest notion of what characterizes Cranoglanidae) and Neotropius to be close to Mystus and Olyra (about as counterintuitive as you can get, in my lay eyes, having some aquarium experience with all three), which implies to me that no, Horabagrus and Neotropius share few synapomorphies and the fact that they have both moved between Schilbeidae and Bagridae is merely coincidental.

The relationship between Horabagrus and Cranoglanis is an artefact of my using the two taxa as outgroups to root the cladogram (i.e. their relationships are not "correct" in any sense). The relationships between outgroups are not important in any discussion of relationships...it's the ingroup we are after.

3) Does the fact that these two genera seem to share characteristics of Bagridae and Schilbeidae imply any consanguinity between these two families? If so, what? If not, why not?

This question can only be satisfactorily answered with a study of the phylogenetic relationships of all siluriforms. Since there are recent studies forthcoming, we'll await the publication of these studies with baited breath.

PS: Is Cranoglanidae the only extant Silurform family not represented in the Catelog?

No, there's also the Austroglanididae.

[Dinyar]

Heok Hee,

Very interesting. I always learn lots from these exchanges. Thanks.

Dinyar

PS: "Bated breath"

[Shane]

Me too guys. Keep it up. Damn I miss Asian fishes!
-Shane