The second pic, is (in the post above) is a catfish Trichomycteris striatus
AKA Pencil, or Parasitic catfish, loosely related to thee Candiru of the Amazon
I agree it looks like one (but there are no loaches endemic to, or are found in the New World (western Hemisphere))
A perfect example of Convergent evolution.
The other catfish, I believe is Pimelodus (AKA Rhamdia) guatemalensus.
above adult (8¨), below juvie (3¨)
or in the past I have caught Pimelodus chagresi (below)(but thats a stretch, the dorsal band is the giveaway)