When I was in Central Brasil on the upper Rio Araguaia (Town of Aruana, near Goiania), I saw nothing of anything that looked like this. However, the Araguaia runs north about 1,400 miles, and empties into the Tocatins, which empties into the Atlantic almost at the same point that the Amazon empties into the Atlantic, at the city of Belem. The fish in question in my earlier picture was exported from Belem, which would support it coming from the Araguaia, or its drainage into the Tocatina.S. gibbus was described from the Rio Araguia. Is that where the fish is from? I seem to recall you saying the fish was from Belem or exported from there?
Honestly I don't remember, I'll have a look tonight...Adrian, since you have the fish in front of you, what is that sticking out in the belly region near the anal opening? Are those spines?
When it concerns S. rhombeus........yah, I hate their growth morphology as much as some Pristobrycon.BTW about s. gibbus, do you remember this pic I send you few month ago ? 6", smaller spots and kind of very elongated rhombeus... You first thought was s. gibbus. But those 2 fish are totally different Does it bring something new (except more confusion) ?