Pimelodus absconditus

[JamesStuddart]

Hi all,

I am looking for an Id on this pim, I think its P. absconditus, but people have told me it "can't" be...

I have two of these



link to album: http://s1209.photobucket.com/albums/cc3 ... Pimelodus/

Thanks for any help

[Jools]

I think its

Pimelodus absconditus

, but people have told me it "can't" be...

Can you give me some background why - on both counts? Getting a firm ID with only a photo (especially with a genus such as Pimelodus) is risky. FWIW, I am not sure P. absconditus has a black spot at the base of the dorsal fin spine.

Jools

[JamesStuddart]

IMO I have done some 'googling' not the best resource I know, but I found some pages from abroad which these fish on (pictures, but I dont have the links) and also looking at the specimen shown in the Cat-eLog (although it is a dead specimen) the markings are very similar.
I can find no similarities in the markings to pictus, which someone said it was, I know it isnt pictus.
I originally thought it might have blochii but I doubt that on further research.

The reasons given for it not being absconditus as that the people who have said this have never seen a live specimen, but there was no real authority from them, for all I know they were some kid who look at the cat-eLog and saw 0 registered users and decided no.

[MatsP]

What shop did you get it from?
Is the shop able to tell you what country it came from?

Imports from Argentina are rather rare, but not unheard of (and P. absconditus is only known from Argentina) - but a shop that gets stuff from Argentina would KNOW that they came from Argentina, because you don't just happen to get them by accident [unless there is a mistake in the wholesalers - which means you have two unlikely events coinciding: the wholesaler has fish from Argentina, and the wholesaler makes a mistake of what fish to ship to the shop].

I'm often told off for using "it's unusual, comes from a country that isn't exported from, etc" in my analysis of "what is this fish", but I do believe that in this case it is a valid way to look at it.

Having said all that, looking at the key for identification of Pimelodus species from that area in http://www.scielo.br/pdf/isz/v97n4/a18v97n4.pdf (sorry, but that's in Portuguese - I use google translate to make any sense at all):

2. Body with spots of different sizes, always small, overlapping, irregularly distributed and more conspicuous in the anterior two-thirds of the body, 19 to 23 gill rakers (mode = 20); eye diameter greater than interorbital distance. -> P. absconditus

I think (looking at the photo) that the interorbital distance (distance between the eyes) is greater than the eye diameter on your fish. Which would rule out P. absconditus. Since we currently don't know where your fish is from, I don't think following the key to try to key out a species, as it only covers species from the southern parts of South America.

--
Mats

[Jools]

Well, I'd call it

Pimelodus blochii

becuase (a) it's a very variable wide ranging species, (b) it's the common import after P. pictus and (c) the dorsal base spot would be good enough for it not to be P. absconditus (in addition to Mats' data) and, finally, (d) P. absconditus isn't from an area that exports a lot of fishes. It is a new area where fishes are being exported from, but, unless I knew this fish was from Argentina, I wouldn't consider it.

That said, I've never seen P. absconditus alive.

Jools

[JamesStuddart]

Thanks

Maybe I should trust my initial instincts

These were picked up from a Maidenhead Aquatics who had a customer bring them in, and if the P. absconditus is collected from a relatively new area then I doubt they are those.

thanks for the help

[MatsP]

Since it's a "return" to a shop, it's unlikely we'll ever find out where it came from.

--
Mats

[Viktor Jarikov]

My experience may not reflect the whole of US nor overseas, but 99% of the fish looking like that almost invariably turned up to be just blochii. Blochii vary in coloration what I would call greatly and also quite age-dependently. Perhaps, or even likely, the taxonomy of these guys is incomplete.

I've owned around 10 of them at some point, many looking differently in coloration. Even the body shape changes with age. My two biggest were ~ a foot TL, and were strikingly taller/deeper in the body, in the mid-section, than all of my other ones.