I just bought two young members of Callichytidae. They're about 1.75 inch (ca. 4cm). I spent a lot of time searching on PC and I think they're Dianema longibarbis or Hoplosternum littorale or H. punctatum. I already have one adult H. littorale and saw pictures of others at PC, but can't tell for sure what I bought since my new cats are juveniles.
Here's some pics. Any ideas?



Sorry for my english, it's not my native language.