We caught combrae outside of Bella Union, Uruguy in a series of ponds flowing directly into the (big) Rio Uruguay (called Laguna la Pedrera). The water feeding the ponds was nearly 100 degrees F in early December and was basically run-off from the sugar fields. The combrae were breeding very close to the shore (a few inches of water) with a pretty muddy substrate and lots of plants.
What was interesting is that the pond nearest to the river had only combrae while the next pond back (more vegetation) had both combrae and borelli.
Fish Collected in La Pedrera:
Gymnogeophagus “High Dorsal” (rhabdotus-type)
Pimelodella cf. gracilis
Corydoras cf. paleatus (high fin)
Corydoras cf. aeneus (only a few)
Tatia sp. (wood cats)
I'll try to upload some pictures...