My Brachyplatystoma filamentosum (Disscussion)

[blackbullhead]

A missing piece to all of this are the B. filamentosum from the Orinoco River...I don't recall ever having seen one before, but I would predict they are an intermediate between the Amazon and Suriname varieties.

 

[GiantFishKeeper101]

A missing piece to all of this are the B. filamentosum from the Orinoco River...I don't recall ever having seen one before, but I would predict they are an intermediate between the Amazon and Suriname varieties.

So it is just theory or there's a source to this?

 

[blackbullhead]

Based on a study of Pimelodidae by Lundberg and colleagues, genetics show B. filamentosum from the Orinoco and Suriname to be more closely related to each other than either is to the Amazonian filamentosum.

http://www.bioone.org/doi/abs/10.1635/053.161.0110

But that's just genetics, without any discussion of morphological differences.

 

[GiantFishKeeper101]

Based on a study of Pimelodidae by Lundberg and colleagues, genetics show B. filamentosum from the Orinoco and Suriname to be more closely related to each other than either is to the Amazonian filamentosum.

http://www.bioone.org/doi/abs/10.1635/053.161.0110

But that's just genetics, without any discussion of morphological differences.

Same as the poorly studied Zungaro sp. DNA shows different genetics between Z. jahu (parana river) & Z. zungaro but no discussion about their morphological differences.

Back to filamentosum, there's no morphological study on them. This is my first try on the topic. That's why Grant want to posed my "study" to Lundberg, says he would discuss with his friends in Manaus. But it would take years for the papers to be published.

As far as the Suriname-Orinoco goes, maybe there's difference but we'll just wait & see for the morphological reports. Unless I could get my hands on one of em haha

 

[blackbullhead]

In this case, I would say it is most likely that B. filamentosum from each region are all the same species...the branches between all of these are very short (indicating close genetic similarity). Also as we all appreciate, B. capapretum is quite similar to filamentosum and the description of B. capa involved a detailed analysis of numerous specimens of filamentosum.
However, it's possible that the different variants are subspecies...

 

[vincentwugwg]

An update on the little guy, finally started eating. Idk what but seen a bulge on his belly.

Even in a lighter substrate, he maintained the dark colour, spots visible from mid dorsal to caudal fin, same as Brazil but too early to tell if it is even Suriname. Surely he ain't a Peru.

Anybody here have any experiences with small Suriname before?

The Piraiba from Suriname seem to have a greenish sheen when younger.. just like the one in this video.

 

[GiantFishKeeper101]

The Piraiba from Suriname seem to have a greenish sheen when younger.. just like the one in this video.

Nope, he turn to this. As I stated before, colors are not usable in identifying Piraiba.



Here's a video of a Suriname in a shop earlier this year. There's actually lighter color Suriname. Or could be from another collection point

 

[GiantFishKeeper101]

Update:

Suriname & Peru are mixed in one tank, the 120g growout. No aggression between the them, swimming together but from day 1, the Suri hasn't eaten anything.

The Peru have no problem eating, meaning there's nothing wrong with the food. My theory, the Suri have been subjugated by the larger Peru. So I clean one of my pond & transfer the Peru. He is now alone in the larger pond.

After a while, there's a difference in Suri's belly, he ate something. So my theory are true, even in juveniles, there'll be dominance.

The problem lies if the Peru will be put with the larger Brazil, would they show the same thing. If so, its mistake for me having 3 piraibas at once.

 

[thebiggerthebetter]

Not necessarily. The fish may adjust and start feeding eventually. The dominance has to be violent enough and stressful enough for the subjugated specimen to stop feeding.

My Peru pair has always been together. One dominates the other. Both feed.

 

[GiantFishKeeper101]

This is by far the worst piraiba I've kept. No wonder he's the last to be sold, have problem eating. Have to moved the wels & the hybrid to the pond with the Peru. Hopefully this time, he'll eat something