I did a search and didn't find much. I know the river will be over run with float tubes, but I'm going to be on the Frio next month and am hoping to catch a Rio. If I have to move to another river to accomplish this, I can, but I'm hoping to be in the water while most are still fighting a hangover!
So, I know little to nothing about the species. Any tips? I've seen some videos of sight casting. So far the majority of my flyfishing has been targeting sandies in water that I can't see into.
TIA

Rios are fairly easy fish to get after. Think small on flies; their mouths are pretty dang tiny. I use Rio Getters #10 and #12 as well as San Juan worms in the same sizes. Rubber legged Hare's Ears #10-#14 are also darn deadly as well. My setup is usually a popper dropper rig with a small Bett's popper for Guads and sunfish with about a 18 to 24 inch 4x or 5x dropper down to my nymph. I generally try and sight fish to them they stick out from the sunfish and bass mainly because in my opinion they look like little sheepshead. The barring on their flanks and contrast between their head and body stands out when their in the water.

These are some Rio Getters in #12


Heres a small Rio that attacked a bead head chami worm.

ditto on Bones72, I use riogetters almost exclusively for cichlids. But I've also had luck on nymphs in the furrier end of the spectrum.

The trick is getting the fly down. They won't rise to take it, and if it's too high you'll just be catching green sunfish and the like.

Been fishing and catching Rios for years. Great fighters. I do not fly fish but some friends who I fish with use fly rods. They use a fly called the Breamanator when fishing for the Rios.



Side Note: They seem to work well.

I saw your record and wondered if you would chime in.

I thought I had followed up on this post, after my trip, guess not!
I'll start by saying, clear water is a game changer!
I managed the first Rio I saw, after coming back to him a bit later. I tried two others and couldn't get them to bite. I have, since then, found another spot and managed to pick off a few.
I'll share some pics of the Rios as well as some great sunfish I've caught since June.

Nice Job!!! If the Rios are picky try sizing way down to something like a size 14 or smaller freshwater shrimp or scud type pattern.

I generally use very small, weighted nymphs. Slowly drag them -- direction doesn't seem to matter; uocurrent, downcurrent, or crosscurrent, and they will chase them and eat them. I sat at a pool one time on the San Gabriel and threw a Griffith's Gnat. If I floated it the bream ate it. If I let it sink the Rios ate it. As LastCastPodcast stated, the Rios generally won't eat off the surface. Just FYI, we have tons of Rios and Tilapia in our Montgomery County Drainage District #6 (in Spring / South County) channels. If any of y'all in the area want to try to catch a few get with me; I'll show you where to go and how to get there.

I was fishing the Pedernales one day and Rios were killing a small bluegill-sized gurgler i was throwing. Still, i agree that if you want to catch one then throwing top water flies is not a high percentage play. That remains the only day i have ever seen them hit topwater.