winemilleri or altifrons or ...

[duanes]

Those look like Sahyadria denisoni (the Denison barbs,AKA Roseline sharkss).
They are from small, cool, highland streams of India, and prefer temps in the high 60's F, although they can take higher ones.
Not a geographically correct species for an Amazon basin tank, or a great temp match for Amazonian Geophagines.
There are plenty of S American convergent species from the basin that look similar and would fit the biotope better, like those of the genus Nannostomus that barely reach 3" to Semiprochilosus that reach 14", if that's an important factor in stocking.

 

[jake37]

Those look like Sahyadria denisoni (the Denison barbs,AKA Roseline sharkss).
They are from small, cool, highland streams of India, and prefer temps in the high 60's F, although they can take higher ones.
Not a geographically correct species for an Amazon basin tank, or a great temp match for Amazonian Geophagines.
There are plenty of S American convergent species from the basin that look similar and would fit the biotope better, like those of the genus Nannostomus that barely reach 3" to Semiprochilosus that reach 14", that would fit the biotope, if that's an important factor in stocking.

Thank you. I'm not strictly biotope person but generally prefer to stay with sa fishes; also i would never mix a cold water fish with a hot water fish no matter how appealing they might be. I think i will stick with my original stocking plan until the rummy get eaten unless someone finds a problem with it. I realize the rummy generally are not a high current fish.
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Also i should be careful with generic names as there appear to be Petitella bleheri and Hemigrammus bleheri though i'm not sure there is a huge difference between the two.

Thank you for your assistance.

 

[duanes]

Although Geophagines will occasionally eat small fish, they don't make a habit of it or even eating large pellets, unless trained or forced to do so to survive by the aquarists, and would prefer small items found in the substrate.
Not to chase down prey.
Their secondary set of jaws, found in the throat (pharyngeals) are evolved to process and grind small items.

In a substantial tank of that size, there is plenty and enough room to escape, and fast fish like tetras, won't get cornered so easily as they would in an average size 6 ft, or smaller tank.
Ability to keep a wide varity of different sized tanks mates together, is about the size of tank (space) more than anything else.
Azul imovie edit

 

[neutrino]

G. altifrons are generally the largest of the geos, they can get 11-12 inches, occasionally a bit more; winemilleri are generally more like 8-9 inches, occasionally a bit more. Also, geos differ in their water current preferences, as you can see in the video guide below. They do not all like "heavy flow." As noted in the video (about the 39 second mark), they're often found in "reasonably fast moving rivers" --BUT "usually the high bodied species occur along the beaches in the slack water zones (see 2nd video of wild altifrons as an example) and the more slender species are rheophiles that live directly in the rapids." Altifrons and winemilleri are both among the taller bodied species, rheophilic species would include argyrostictus and taeniopareius. It doesn't mean they dislike or can't handle moderate flow, I've seen wild video of this also, but they're not in the rapids. In a tank they're fine with moderate flow, but they don't need heavy current.

Geophagus - Guide to Amazonian Eartheaters - nearly all Geophagus species ! - YouTube

Geophagus Altifrons (Eartheater Cichlid) in the Wild - YouTube

 

[jake37]

G. altifrons are generally the largest of the geos, they can get 11-12 inches, occasionally a bit more; winemilleri are generally more like 8-9 inches, occasionally a bit more. Also, geos differ in their water current preferences, as you can see in the video guide below. They do not all like "heavy flow." As noted in the video (about the 39 second mark), they're often found in "reasonably fast moving rivers" --BUT "usually the high bodied species occur along the beaches in the slack water zones (see 2nd video of wild altifrons as an example) and the more slender species are rheophiles that live directly in the rapids." Altifrons and winemilleri are both among the taller bodied species, rheophilic species would include argyrostictus and taeniopareius. It doesn't mean they dislike or can't handle moderate flow, I've seen wild video of this also, but they're not in the rapids. In a tank they're fine with moderate flow, but they don't need heavy current.

Geophagus - Guide to Amazonian Eartheaters - nearly all Geophagus species ! - YouTube

Geophagus Altifrons (Eartheater Cichlid) in the Wild - YouTube

Thank you - is there any real difference between altifrons and winemilleri in their requirements, water condition or behavior? I read the blurbs on seriousfish between and it sounded vaguely like winemilleri were a little more flexible and altifrons more blackwater ish but it was hard for me to really tell. My initial water conditions will be a bit on the harder side (tds 120) but i can move it down to 60 or 80 in a month or so mostly it just depends how fast i add the ro water to dillute the tap but i don't really want true blackwater for htis tank and will visually generally keep it clear so not so much leaf litter.

 

[neutrino]

Thank you - is there any real difference between altifrons and winemilleri in their requirements, water condition or behavior? I read the blurbs on seriousfish between and it sounded vaguely like winemilleri were a little more flexible and altifrons more blackwater ish but it was hard for me to really tell. My initial water conditions will be a bit on the harder side (tds 120) but i can move it down to 60 or 80 in a month or so mostly it just depends how fast i add the ro water to dillute the tap but i don't really want true blackwater for htis tank and will visually generally keep it clear so not so much leaf litter.

True to a degree from what I understand, at least in the wild winemilleri apparently come from more widely varied water conditions vs true altifrons. I've seen people keep altifrons at higher pH (near 8), not sure of hardness, and they apparently did fine. Not something I'd do myself, but I wouldn't consider them black water restricted. Some people find altifrons to be more aggressive, but not everyone. Might be due to a few variables, including differences between populations, or a function of tank size, group size, or individual fish. There are slight breeding differences, winemilleri wait a bit longer before mouthbrooding.

Both are really nice species. The common advice that geos need to be in groups is kind of exaggerated. Ime adult pairs, especially, are quite content to themselves in a compatible community.