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Hypostomus from Rio Iguaçu

Posted: 30 Jun 2012, 00:04
by Silurus

Re: Hypostomus from Rio Iguaçu

Posted: 30 Jun 2012, 00:53
by The.Dark.One
Thanks for the heads up. Could these be Hypostomus myersi? They were from Iguazu National Park, Argentina, which is formed from the Iguacu/Iguazu River. They seem to match the pictures in this paper and locality is correct.

http://www.scotcat.com/thedarkone/loric ... iguazu.jpg
http://www.scotcat.com/thedarkone/loric ... guazu2.jpg
http://www.scotcat.com/thedarkone/loric ... guazu3.jpg

Re: Hypostomus from Rio Iguaçu

Posted: 30 Jun 2012, 01:45
by Silurus
The.Dark.One wrote:Could these be Hypostomus myersi?
I think they are.

Re: Hypostomus from Rio Iguaçu

Posted: 30 Jun 2012, 15:51
by The.Dark.One
Thanks :d

Re: Hypostomus from Rio Iguaçu

Posted: 30 Jun 2012, 22:43
by mifune
Hello,

I have two Hypostomus myersi imported from Argentina. Ingo Seidel identified them as H. myersi. They look a little different compared to the pictures you posted, as far as I can tell by the view of the pictures. My fish have a wider (and flatter) head compared to the length of the body; the spots are smaller and paler. The biggest of my fish is around 180 mm, I had a third wich died with 210 mm. I have them since around 20 month, they hardly grew at all in this time. If you look in the paper you posted, you'll see, that only very few of the myersis they collected exceed 210 mm. The fish in the picture would be an extraordinary large specimen.
Do you have a dorsal view of the fish? Myersis have quite a unique head- and bodyshape for a hypostomus. Maybe then it is easier to tell the species.

Re: Hypostomus from Rio Iguaçu

Posted: 30 Jun 2012, 23:06
by The.Dark.One
I have, but it is not a very good picture

Image

Re: Hypostomus from Rio Iguaçu

Posted: 01 Jul 2012, 17:39
by mifune
Hello,

I do not think this species is a H. myersi, the body is to elongated compared to the width of snout and head. My guess would be H. albopunctatus. Very nice fish by the way!

Re: Hypostomus from Rio Iguaçu

Posted: 01 Jul 2012, 18:10
by The.Dark.One
Ingo said he had never seen them before so I think he would have suggested albopunctatus. Going on your way of ruling out myersi then I think the same can be said why it might not be albopunctatus. The other thing that put me off albopunctatus is the shape of the markings and the small dorsal fin on that species.

Perhaps it is because this specimen is much larger and sexually mature that its snout appears long? It comes from the right river system but from below a waterfall (I think?) so perhaps that is where all the adult fish congregate and that is why only small specimens have been sampled in the paper and your specimens?

Re: Hypostomus from Rio Iguaçu

Posted: 01 Jul 2012, 18:54
by mifune
Since I can not see a change of body or headshape between fishes of 14, 18 or 21 cm nor by pictures of adult specimens in a magazine, I would be very surprised if the snout becomes longer when they get older. I agree, that the fish is not a albopunctatus, if the pictures here at planetcatfish for this species are indeed albopunctatus. I saw a picture of albopunctatus in a magazine that were quiet different - but this specimen was not an adult. So not very reliable...
Good luck on the further search!