HydropsychidaeThis particular species is predatory and do not appear to rely heavily on a retreat. I was able to observed one predating a Leptophlebiid larvae on the underside of a rock. Similar behavior was easily observed in collection jars. They are very common in riffles in the headwaters.
Hemiptera ("true bugs")
Decapoda (shrimp and crabs)
Aeglidae (Aegla uruguayana)
Aegla are probably the dominant invertebrates in the Rio Cuareim (and all of Uruguay). Juveniles are common in riffles and adults can be found in rocky bank zones. Carapace color is highly variable, ranging from green to rusty brown.
Trichodactylidae (Trichodactylus panoplus)
While seemingly not as abundant as Aegla, Trichodactylidae are common along rocky bank zones and are readily collected at night.
Not pictured: Aeshnidae (Odonata), a very small Ephemeroptera, a small Plecoptera, a huge Belostomatidae, multiple mussels and invasive clams.