What sex am I?

[Reginator]

Here are some pics of my Pterygoplichthys Etentaculatus (known by the name "Leviathan" ) & I'd love to know what sex the beast is... Any help gratefully received...






Will try to get better pics for the cat-e log....

[MatsP]

Hard to say - and I'm also wondering how you came up with the exact species - I thought almost all albino forms of

Pterygoplichthys pardalis

- but without either natural capture location or natural colouration, it's very hard to say.

Here are some pictures that may help out.
http://www.planetcatfish.com/catelog/ca ... h=papillae

There is also a description of sexing here:

Pterygoplichthys gibbiceps

which should also apply to any other fish of that genus.

--
Mats

[Reginator]

I think it seems so pink due to the lighting/camera, it's actually quite a golden colour & hasn't got red eyes, so didn't think about it being albino. In my tank I've got a powerglo & an actinic tube, so colours that are subtle tend to be changed a bit, any way to tell for sure if it's what I think or not?

[MatsP]

You mean the eyes are like this:
?

That image is listed as "albino", but it looks like it's got colour in the eyes.

In the meantime,

Pterygoplichthys etentaculatus

is really not a common import. Albino commons are produced by the tankfull every week, and not at all rare. Unfortunately, there aren't a lot of pictures of living fish. One I found is here:
http://www.datz.de/L0lNR19aT09NP0ZJRD02 ... BCBF1682F3

There is a key to Pterygoplichthys here:
http://www.scielo.br/scielo.php?script= ... en&nrm=iso

It appears that it's fairly long from dorsal to adipose fin (interdorsal length) compared to some other Pterygoplichthys, and that it has a relatively short head-length.

--
Mats

[Richard B]

Am i being bit stupid, but surely all true albinos have red eyes - or is this just humans? Pigmented eyes show colour morphs, xanthic forms or those without melanin eyc.

As an aside does the fish look a little hollow bellied in pic 3 behind the pelvis fins?

[MatsP]

Am i being bit stupid, but surely all true albinos have red eyes - or is this just humans? Pigmented eyes show colour morphs, xanthic forms or those without melanin eyc.

As an aside does the fish look a little hollow bellied in pic 3 behind the pelvis fins?

Yes, TRUE albinos have red eyes. I'm not sure that they so called albino commons are true albino's, however. There seem to be only a few (labeled correctly) images on the web of Albino Pterygoplichthys pardalis - I'm sure there are more pictures of them under differnet names, but then comes the problem of ID.

--
Mats

[Reginator]

So, how can I (try to) identify Leviathan? Any indentifiers to look for?

[MatsP]

So, how can I (try to) identify Leviathan? Any indentifiers to look for?

By following the "Key" that is in the link above?

What makes you think it IS P. etentaculus? It certainly has the body pattern of a P. pardalis/disjunctivus (in the light parts) - and these are bred in the millions in asia, including albino ones - they are more "mid-orange" than "white", but they certainly are still albino in genetical terms.

--
Mats

[apistomaster]

The specimen appears too young and under-nourished to sex accurately, identification problems aside.
Most albino catfish can vary from white pink to almost orange, depending on their diet.
This has been especially true of my experiences with Ancistrus cf. cirrhosus, common albino BN Plecos.
Only non-pigmented eyed fish(pink eyes) are true albinos.

[Reginator]

Ok, so I read the key in the link above & felt like I'd encountered a new language Any chance of someone who understands it to explain in simple terms? I "identified" it by looking through the cat-elog until I found a pic that looked like Leviathan, which was the etentaculus. I got given it by my LFS as they're well aware of my catfish obsession and it was a rescue from a very small tank. I've been trying it on courgette & carrot, it does eat it but slowly (and has cleaned the tank completely of algae). I also put a couple of spirulina tabs in at night & they always vanish. The photos are from the first day, its belly looks a little better now but still not as full as I'd like. It's a good 12" long from nose to the base of its tail, has something like 13 - 15 dorsal rays (not counting the first) & a long top & bottom ray on the tail.....

[apistomaster]

Hi Reg,
Think of a key as a stack of sieves large openings at the top and fine mesh at the bottom.
You can pour a bucket full of different species through it and by using the different characteristics in the key, at the bottom of the stack of sieves, only one species reaches the bottom.
Keys rely on many technically described sets of characteristics and were never designed for use on live fish. The keys normally are derived from the studies of preserved specimens. Keys do not lend themselves well to identifying live fish which may resemble others within their genus. Even with keys, not all ichthyologist are in agreement when it comes to some species and even the concept of what constitutes a species is still not universally accepted on this 200th post-Darwin year.
I do not know much about the large Plecos so I can't help identify they Pleco in question. It is different than any wild type I have seen but is does have a resemblance to some of the xanthanistic(gold) varieties being cultured but I am sure enough to say it doesn't really match any commonly cultured pleco.

[MatsP]

Assuming your count of dorsal rays are correct, that rules out P. etentaculus, as rule #8' says "max 12" dorsal rays.

9. Light spots on dark background. Ventral surface consisting of light and dark vermiculations with light vermiculations wider than dark vermiculations or with light spots on a dark background......................................................................... 10

9'.Dark spots on light background. Ventral surface with dark spots on light background or with light and dark vermiculations of same width or light vermiculations narrower than dark vermiculations...................................................................... 11

10. Abdomen usually with a complex network of light and dark vermiculations. Light areas on body wider than dark areas. Rio Paraná drainage ................................................................................ ...................................... P. anisitsi Eigenmann & Kennedy, 1903

10.' Abdomen with white spots usually separate, at most two to three combining. Light areas on body narrower than dark areas. Rio Tocantins drainage .................................................................................. ..................................................... P. joselimaianus (Weber, 1991)

11. Dark spots discrete, never coalescing or forming dark chevrons on posterior half of body .............................................................. ................................................... P. multiradiatus (Hancock, 1828)

11'.Dark spots often coalescing to form vermiculations and/or lines on abdomen and head and chevrons on caudal peduncle............................................................................... 12

12. Adults with a geometric pattern of light lines on head. Spots on abdomen of adults mostly discrete, usually no more than five spots coalescing to form short vermiculations. Lateral spots coalescing to form chevrons that outline the posterior border of the lateral plates (particularly strong ventrally posteriorly to the pectoral fin). Juveniles with chevrons laterally, abdominal spots separate ......................................................... P. pardalis (Castelnau, 1855)

12'.Adults with spots and blotches on head and no geometric pattern of light lines. Nearly all spots on abdomen of adults coalescing to form vermiculations (spots may be separate in juveniles). Lateral spots usually separate, not forming chevrons. Juveniles with spots or blotches laterally ........................................................ P. disjunctivus (Weber, 1991)

The species above are the ones that are possible [assuming it is a described species] based on 12-14 dorsal rays.

I still think it's one of the last two.

--
Mats