Please ID fish from Santerem and Xingu

[Mike Wise]

A. similis was described by Wolfgang Staeck in 2003 (a very poor description, I might add). The type material was collected in the Rio Yata system (west of the Rio Mamoré) in northern Bolivia. It (or something close to it) was collected by both Staeck and Jeff Cardwell in the Rio Itonamas (a southern tributary of the Rio Guaporé) of northeastern Bolivia. On fish from the Itonamas, the caudal pattern is less regular than on the Yata population. The fish are found in clearwater biotopes in jungle covered streams and associated overflow pools (pH 6.6, <1º dH, <10 µS/cm). Breeding is considered easy, like A. inconspicua. If truth be told, there is not a lot of difference between simils & inconspicua other than the extra dorsal spine on simils (a rather poor reason to erect a new species in my opinion). The Itonamas population's distribution even overlaps that of A. inconspicua. The Yata population overlaps that of A. linkei.

 

[Peter Lovett1]

Hi Mike,

A small update on the fish you thought was red cheek.

I now have some better pics of a female with fry and I think it may not be red cheek could you confirm.

 

[Mike Wise]

It definitely has 16 dorsal spines, so I will say that this is A. similis, the form that Staeck brought back for description. The form that Jeff Cardwell brought back has a more irregular caudal fin pattern.

 

[Peter Lovett1]

So Mike you are saying that

are both A. similis.

These fish came in from what was said to be different locations and to be honest when you see them close up they are very different. With the fish in the second pic being very much more elongated than the first. does similis have this much variation in them

 

[Mike Wise]

Now I'm confused. I thought that the female (bottom photo) came in the same bag with top fish. The top fish is definitely a commbrae-complex fish that corresponds to A. similis. The second photo doesn't show a distinct double caudal spot (it does have a sooty smudge in front of the caudal spot, however), but I thought that it was just the mood of the fish at the time. These features come and go. Now you can understand why it can be difficult trying to ID fish from only 1 or 2 photos. So I guess the question is: which male in your photos belongs with this fish? Let me know & I'll start over.