What type of silver dollars are these

[Guyb93]

can anybody enlighten me on the type of silver dollars these are , I know picture quality is poor as usual lol
They were sold as silver dollars and were to small to even plan on trying to ID them but now at 4-5 inches I’d like to know , not that it really makes a difference as all 5 are the same .
I was firstly leaning towards Metynnis argenteus now swayed towards Metynnis hypsauchen an almost identical fish but then the way these have grown in a month is making me paranoid that I have 5 myloplus rubripinnis (red hook) and there just too young to have the elongated anal fin I’m hoping not to be honest

 

[Corypower]

Looks like the red finned variety

 

[itiwhetu]

I think they are Metynnis Argenteus.

Silver dollars and their young

So you have a better idea of who I am I thought I would share this with you. After breeding fish for many years commercially I decided that the true test of a community system (furnished aquarium) was if the fish would breed and raise their young. This silver dollar picture shows the parents and...

www.fishforums.net

 

[Guyb93]

I think they are Metynnis Argenteus.

Silver dollars and their young

So you have a better idea of who I am I thought I would share this with you. After breeding fish for many years commercially I decided that the true test of a community system (furnished aquarium) was if the fish would breed and raise their young. This silver dollar picture shows the parents and...

www.fishforums.net

I was leaning that way also

 

[itiwhetu]

Mind you I have always thought mine were Argenteus but looking at my Atlas I might have been wrong and they could be Hypsauchen!!

 

[Guyb93]

Mind you I have always thought mine were Argenteus but looking at my Atlas I might have been wrong and they could be Hypsauchen!!

I couldn’t decide between the two they are very similar, any ideas on the full size of these chaps , they have packed on at least 2 inches in a month making them 4-5 inches am I to expect at least another 2 inches out of them

 

[itiwhetu]

6-8 inches, they are big fish.

 

[Byron]

There are several distinct species within the genus Metynnis that are commonly called "Silver Dollar" fish. They all share a similar shape and silver colour, and similar behaviours, habits and requirements; the long adipose fin distinguishes these species from all other Serrasalmidae. Along with the most commonly seen, M. hypsauchen, the other most frequently encountered is M. argenteus. It reaches a length of 5 inches (M. hypsauchen attains around six inches), and lacks the dark shoulder patch of M. hypsauchen. There is also a striped species and a spotted species.

I canot see if a shoulder patch is or is not present in the photo.

 

[Guyb93]

There are several distinct species within the genus Metynnis that are commonly called "Silver Dollar" fish. They all share a similar shape and silver colour, and similar behaviours, habits and requirements; the long adipose fin distinguishes these species from all other Serrasalmidae. Along with the most commonly seen, M. hypsauchen, the other most frequently encountered is M. argenteus. It reaches a length of 5 inches (M. hypsauchen attains around six inches), and lacks the dark shoulder patch of M. hypsauchen. There is also a striped species and a spotted species.

I canot see if a shoulder patch is or is not present in the photo.

I don’t believe they have any kind of shoulder patch

 

[Ichthys]

Actually there are at least two spotted species. The commonest dollars in the UK at least are Metynnis altidorsalis and M. hypsauchen. The third species usually seen is presumably M. argenteus, which isn’t commonly sold at all. They’re mostly M. altidorsalis here.
Hard to ID this one in the poor lighting...

 

[Byron]

I don’t believe they have any kind of shoulder patch

I don't know where you are, but as you used inches I'll assume more likely the US than UK, in which case the lack of the shoulder patch (and no previous mention of spots) likely means M. argenteus.

 

[Guyb93]

I don't know where you are, but as you used inches I'll assume more likely the US than UK, in which case the lack of the shoulder patch (and no previous mention of spots) likely means M. argenteus.

I’m in the uk lol inches just seems to be the unit used for measuring certain things here .. strange I know ahah il stick with the argenteus though as it was my first thought

 

[Guyb93]

Actually there are at least two spotted species. The commonest dollars in the UK at least are Metynnis altidorsalis and M. hypsauchen. The third species usually seen is presumably M. argenteus, which isn’t commonly sold at all. They’re mostly M. altidorsalis here.
Hard to ID this one in the poor lighting...

I also live in the uk but I know these were imports from where I don’t know

 

[FranciscoB]

From the single photo is nearly impossible to give a good guess at the species you have. Perhaps the only sure thing to say is that they are not M. maculatus, nor M. lippincotianus. Based on the high body, they are likely M. hypsauchen but better photos would be needed.
Please note that the name M. argenteus (Muller & Troschel 1844), although validly introduced, it is NOT a currently accepted name in Metynnis. Although one of the most commonly used name within Metynnis, specimens of 'argenteus' including the types, belong in several species of Metynnis. Thus it is a messy situation where argenteus is a junior synonym (in part) of several other taxa.

 

[itiwhetu]

From the single photo is nearly impossible to give a good guess at the species you have. Perhaps the only sure thing to say is that they are not M. maculatus, nor M. lippincotianus. Based on the high body, they are likely M. hypsauchen but better photos would be needed.
Please note that the name M. argenteus (Muller & Troschel 1844), although validly introduced, it is NOT a currently accepted name in Metynnis. Although one of the most commonly used name within Metynnis, specimens of 'argenteus' including the types, belong in several species of Metynnis. Thus it is a messy situation where argenteus is a junior synonym (in part) of several other taxa.

I all was thought they were argerteus. Just because.