OK, thanks for your help! I've had a sturisoma panamense and I thought there was a huge difference physically first and in their comportement. Your answer help me to identify them and theirs specific needs.
Thank you!

I, I'm new in the forum. First excuse my grammar and vocabulary, I'm French and not fluent in English. I've bought to a aquariophile 3 juveniles (7 month old) sold as sturisoma aureum what I suspect to be 3 young rineloricaria eigenmani. They are 6cm nose to tail plus 1,5to 2,5 cm tail filament ...