Salminus Franciscanus (Golden Dorado)
- Thread starter kendragon
- Start date
You're quite welcome
Yeah you haven't updated us since last year!kendragon what’s the plans for these guys this year ?
C
Chicxulub
,
I agree that head shape is not a good deciding factor for Frankie vs Brassie. However, the scale count is still a bit confusing.
Perhaps head shape and scale count holds true for the real original dorado and not for the farmed or non-native variety.
Please see below picture from an article about aquatic invasion.
Head shape appears Brassie. Article claims it to be Brassie (non-native). But yet I counted 14 scales which indicate Frankie. I think this is in agreement with your are saying a few post back about hybrids.
Now the below totally agrees with a true Frankie. Scale count and head shape.
There is a slight possibility that my Frankies gained a few rows of scale from their feeding habit.
Thoughts?
I agree that head shape is not a good deciding factor for Frankie vs Brassie. However, the scale count is still a bit confusing.
Perhaps head shape and scale count holds true for the real original dorado and not for the farmed or non-native variety.
Please see below picture from an article about aquatic invasion.
Head shape appears Brassie. Article claims it to be Brassie (non-native). But yet I counted 14 scales which indicate Frankie. I think this is in agreement with your are saying a few post back about hybrids.
Now the below totally agrees with a true Frankie. Scale count and head shape.
There is a slight possibility that my Frankies gained a few rows of scale from their feeding habit.
Thoughts?
Hybrids are certainly possible, I would have to agree. Still though, both species can possess 14 scales, which is what I counted for this fish as well.
I would be inclined to think that the above fish is what the researchers claim that it is. Hybrids are possible, and I would think likely tbh, but we must have evidence to support a claim of their existing before we can assert their presence. I suspect that if we're right about the presence of hybrids, some publication will be available before too long.
Another point of fact about hybrids- with how recently it's been discovered that S. franciscanus is seperase from S. brasiliensis, it's entirely possible at this point that most of the Brazilian fishes are now a massive hybrid swarm that strongly favors the introduced brassie populations, but which still exhibits some frankie traits in their physiology.
Either way, I find the current situation with the golden dorados to be quite fascinating. There's a lot of interesting mixing going on here. It's entirely possible that by the time this is all said and done, a third species of Salminus could have come into existence; S. brasiliensis sensu stricto in the waters south of Brazil, S. franciscanus in Rio São Francisco and a new species to emerge in Brazilian waters that originated through anthropogenic allopatric speciation and hybridization. What we'd call it, I don't know. This is well established in science as a viable method of speciation, and I wouldn't be surprised to see it happen here.
I would be inclined to think that the above fish is what the researchers claim that it is. Hybrids are possible, and I would think likely tbh, but we must have evidence to support a claim of their existing before we can assert their presence. I suspect that if we're right about the presence of hybrids, some publication will be available before too long.
Another point of fact about hybrids- with how recently it's been discovered that S. franciscanus is seperase from S. brasiliensis, it's entirely possible at this point that most of the Brazilian fishes are now a massive hybrid swarm that strongly favors the introduced brassie populations, but which still exhibits some frankie traits in their physiology.
Either way, I find the current situation with the golden dorados to be quite fascinating. There's a lot of interesting mixing going on here. It's entirely possible that by the time this is all said and done, a third species of Salminus could have come into existence; S. brasiliensis sensu stricto in the waters south of Brazil, S. franciscanus in Rio São Francisco and a new species to emerge in Brazilian waters that originated through anthropogenic allopatric speciation and hybridization. What we'd call it, I don't know. This is well established in science as a viable method of speciation, and I wouldn't be surprised to see it happen here.
I think behavior is probably more reliable than headshape at this point lol. I don't think scale count would change from WC to CB, also think it's unlikely as the fish grows but I suppose possible. I originally counted 17 in the start of this thread and I still counted the same in one of your fishes. I don't think they'd lose scales. As chicx stated the scale count does overlap a little which indeed can cause us confusion. I strongly think hybrids are possible since they are farmed. But I know very well as chicx stated, we can't make such accusations without proper proof. We can only speculate for now.
