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Does anyone recognize these fish? I bought them in August at 1 1/2" long as Liosomadoras oncinus - Jaguar catfish. They are now approximately 2"TL. Somehow I don't think it was an accurate ID. TIA!

Look in the CAt-E Log under Trachelyichthys

There are two described species, T. exilis and T. decaradiatus.

Trachyelyichthys are certainly a member of the Auchinipeteridae. While neither are common imports, T. decaradiatus, from Peru, is the more common of the two. T. exilis is from Guyana and is considered rare in the hobby. Excellent find.

BTW: at 2" long, they are now adults!

I have exactly the same fish, and thought they were some sort of Centromochlus. Bought six for $3 a piece, with the intention of breeding them. Has it been done?

Rusty

I've had matings and eggs in the past with this species; the male wraps himself almost completely around the female, and the eggs -wich are laid later; internal fertilisation- are minute.
unfortunately those were eaten by the other fish, and back then I only had a single tank.
fun fish! they can reach quite a few years, but I lost mine due to old age and foodcompetitors.

Lee Finley and Martha Clark have both gotten fertile eggs from this fish. I've had plenty of copulations but didn't find any eggs. I have since (2 yrs ago) lost my group of four.

Per Lee's description (in person): Once laid, the eggs swell rapidly to 5mm diameter and are nearly completely transparent. The embryos developed, movement was seen inside the eggs, but they were then lost (no explaination provided).

Sid, this could be the difference if the eggs are fertile or not. If your's didn't swell up, they may not have been fertilized.

Rusty, where in the world did you find them for $3! Can you buy me 20 or so?
BTW: I see there is more than one Ray Troll fan on PC!

Hi Paul,

I think you are right with the genus ID. Over here the species is called T. decaradiatus, but it is shipped sometimes from Belem. According to Eschmeyer is the original location for T. decaradiatus the Karanambo area, Rupununi, Guyana, and for T. exilis the Río Mamón, a trib. of Río Nanay, about 25 km west of Iquitos, Peru. So, Belem is a bit off the original location of both. But in Brazil fishes are shipped through the whole country and you can never be sure if they are collected from the area from where they are shipped from.

Best Wishes

Erwin

Erwin, do you have the references to the original descriptions? I would love to look them up.
I apparently got the locations for the two species mixed up. I thought T. decaradiatus was from Peru. I am going off of memory from a second hand reference though, not the original descriptions.

Jools

I'd like to thank everyone for the replies. I had looked through the PC gallery before posting but only checked the Tatia and Centromochlus species. I'm lucky enough to bump into Lee Finley every few months, so now that I know what species they are, I can ask him about his experiences with this fish. Thanks again to all.

Lovely fish...As a matter of interest we had some of these arrive in the shop today from a wholesalerdescribed (and ordered) as Liosomadoras oncinus, with a price to match of course.

It seems likely that they originated from Peru as we have had them before listed on the exporters lists as Oncinus.

Still they are not only pretty but interesting enough to work with, so it shouldn't be a disappointment I guess.

Hi Paul and Jools,

The references for the original descriptions are:

Greenfield, D. W. & G. S. Glodek (1977): Trachelyichthys exilis, a new
species of catfish (Pisces: Auchenipteridae) from Peru. Fieldiana Zool.
v. 72 (no. 3): 47-58.

Mees, G. F. (1974): The Auchenipteridae and Pimelodidae of Suriname
(Pisces, Nematognathi). Zool. Verh. (Leiden) No. 132: 1-256, Pls. 1-15.

Jools, the drawings show the elongation of the head in both species a
bit drastically. So far I had twice the chance to take pictures of a
Trachelyichthys. According to your drawing I would say that both are T.
exilis, but I am not sure. The first one got a bit longer snout or is it
just the different angle in which the picture was taking from?





I would say it has a shorter snout as the one in Jools drawing, but is
it shorter as in the original description of the species? I don't know.

Erwin

Monty wrote:It seems likely that they originated from Peru as we have had them before listed on the exporters lists as Oncinus.

BAS has also recently had some in which were down as L. oncinus on the price list

I bought 6 of these yesterday:



Are they T. exilis, T. decaradiatus or something completely different such as Parauchenipterus leopardinus ? My guess is T. decaradiatus, but I'm not sure. BTW. they are about 5-6 cm TL now.

Is it just that we all are posting on these fish now, or has there been a sudden glut of these exported recently?

Rusty

The only time I have seen them available is when there is snow on the ground in the Midwest U.S.! (Nov. through Feb. typically) They appear to be seasonally collected.

I'll have to keep a close eye on the wholesale lists for the next couple of months.

Plesner, your fish is definately a Trachy! No doubts about it. Which species? Can't tell I haven't looked up the refs. that Erwin posted yet. But definately Trachelychthys.

Hi,

imo definatly Trachelyichthys exilis. The fish are very variable in colouration, also depending on the background. Fish i kept in bare glassbottom tanks with light grey Plastic tubes to hide turned nearly white.
I have that species too. They breed successfully for some months now. Its important to keep them at a low pH (Blackwater) and a higher temperature (27-29°C), otherwise they will not spawn or the eggs will not hatch. A description of the natural habitat is given in the species description.
I have fertilization rates of >90%, but less than 50% hatch, most of them die because of bakteria/fungi etc. Unfortunatly i can't lower the pH to less than 6,5 at the moment. Nevertheless i have ~80 youngsters swimming. The fry is easy to raise with Artemia and frozen food.
For all german ppl: I will give a talk about the species at next years Welstreffen in Negast.
English aricle will follow on my page as soon as the first F1 fish have grown adult (next spring i guess .

Greetings,

Achim

Achim wrote:Hi,

I.M.O. definatly Trachelyichthys exilis.

I'm not disagreeing with you, but what are you making that ID upon? Congratulations on the spawning BTW, that's a good one.

Jools

Erwin wrote:Jools, the drawings show the elongation of the head in both species a
bit drastically. So far I had twice the chance to take pictures of a
Trachelyichthys. According to your drawing I would say that both are T.
exilis, but I am not sure. The first one got a bit longer snout or is it
just the different angle in which the picture was taking from?

I would say it has a shorter snout as the one in Jools drawing, but is
it shorter as in the original description of the species? I don't know.

I do see differences in the bottom picture from all the other fish posted in this topic. Especially the humeral process looks different - but I too am also dubious of the distinction between these two species. I will read the Mees description again when I get home. I do not have the other one.

Jools

Hi Jools,

I'm not disagreeing with you, but what are you making that ID upon? Congratulations on the spawning BTW, that's a good one.

Thanks Getting the eggs to hatch was really a challenge with my water...
I checked with the description when i got my fish, and they matched perfectly, so i didn't have any reason to doubt it. Mainly the head shape and form/length of cleithral process, as you already pointed out. Trainers fish look exactly like mine, and the head shape/shape of the cleithral process (whats visible) matches the pictures in the description.
In addition (that hasn't much meaning however), all fish i've seen at the importers here were T. exilis (or what i identify as T. exilis), i've never seen a fish that matches T. decaradiatus yet. They were all sold as T. exilis, whats kinda funny considering that all Trachelyichthys Erwin saw yet were sold as T. decaradiatus
Unfortunatly i dont have CLOFFSCA yet, could someone check what Ferraris says about the distibution of both species there?
If your interested Jools, i can send you a copy of the description of T. exilis.

To another former post (forgot wich one : non fertilized eggs swell up to 5mm like fertilized eggs, they even seem a little bigger, though they are not so perfectly transparent as fertile. Fertile eggs are difficult to see, even on bare glass bottoms, due to their nearly perfect transparency. Infertile eggs have a white spot and look milky.

Greetings,

Achim

Hello Achim

I checked CLOFFSCA for distributions :

T. exilis : Rio Nanay basin, Peru
T. decaradiatus : Rupununi River basin

Nothing else

Hope this helps.

Mfg

Charly

Achim wrote:

Hi,

I.M.O. definatly Trachelyichthys exilis.

Jools Wrote

I'm not disagreeing with you, but what are you making that ID upon?

Head and body shape, lack of an adipose fin, very long anal fin, high anal fin ray count and general coloration. I am convinced it's a Trachelyichthys.

Jools, not that you are argueing or even disputing the ID;
I am certainly not one to argue over the ID of a fish from a photograph, in fact that is a bit of a pet peeve of mine that actually drove me off of the Apistogramma mailing list. Two Aquarists (neither one taxonomists) coming to a flame war over the species ID of an Apisto from a photograph of questionable value for diagnosing the fish in question! This is a group of fishes where no two taxonomists see it exactly the same way! (Species, species complex, whatever!)

Without knowing collection locale, that's why I'd only offer to ID it to a Genus, and not to a species.

I checked CLOFFSCA for distributions :

T. exilis : Rio Nanay basin, Peru
T. decaradiatus : Rupununi River basin

Nothing else

Hope this helps.

thanks Charly!

I hoped there may be some additional information about the distribution in it.

Greetings,

Achim

I just realised that I got within my archive another picture of a Trachelyichthys, and I think this time it is definitively T. exilis, because it came from an Peru shipment.

That's the picture:



The strange thing about it is, that the fish on it owns the longest snout of all three specimens. So I believe more and more, that all three show T. exilis. And I also should tell you that I had stored this picture before under Trachelyopterus leopardinus. I identified it after a picture in the Aquarium Atlas Vol.5, p.238. And I am sure now that the picture there is wrong identified, and also shows T.exilis. T. leopardinus should reach 18 cm (acc. FishBase), what T. exilis never does.

Erwin