Characins of Panama

[duanes]

Been catching a lot of Characins lately in central and eastern Panama.
I use my field guide, Peces de las agues continentals de Costa Rica to ID them

Above appears to be from the genus Roeboides, possibly species ilseae, judging from the humeral blotch

The individual in the middle of the shot looks to be Hyphessobrycon panamensis.
Below lower left may be from the genus Bryconamericus.
This distinctions are rather hard to differentiate for me, and often 2 or 3 species will be pulled up in the same cast of the net.


As dither fish for cichlids they work well, as long as the shoal is large enough.
When kept as two or 3 individuals they tend to snipe at others, and not shoal at all.
But as a larger group, the dynamic totally changes.

 

[duanes]

As an aside, I tested all the rivers these Tetras came from, and the average pH was between 8 and 8.2, and there were never any detectable nitrates.
Water flow was moderate to quite strong, and ranged from warm in the dry season, to quite cool when rains began in the mountains of Panama.

They were found at depths of only a few inched to a few feet.

Even in this calm looking stream, you can see how fast the current pulls my weighted net , downstream.
Mamoni ! fbf3e2b0 b9a6 48b4 a83f 7b2234a335cf

 

[duanes]

The genus Roeboides are head standing scale eater Tetras, that with their prominent teeth easily grab a mouthful of scales from a passing fish, like the cichlids I kept with them, but causing minor damage.


They comfortably shared a 6 ft tank with slightly larger Andinoacara coerleopunctatus as tank mates, as they also share the same habitat in nature .


Above the Rio Utive, one of the many spots where they were found.
The genus ranges from the Central Pacific coast of Mexico thru Panama south into Colombia in S America, according to William Bussings guide, Peces de las Aguas Continentales de Costa Rica.