PlanetCatfish.com

Aquarium Glaser has from Peru (does that species really occur in Peru?),which they claim are not parasites, and I'm sorely tempted to order a group.

However, they also say "one should better keep no Corydoras - especially C. pygmaeus - along with Tridensimilis" - what do they mean by that? It's a facultative parasite of Corydoras?

as long as you keep it in a species tank, you're OK

they're not parasites in the sense that they can adapt to regular food (they like bloodworms for example), unlike true bloodsuckers like Vandellia

however!
if you put em in with other fish they will start feeding on scales, fins and mucus in addition to bloodworms and the like

they're quite sensitive to foodcompetition as well; it's a fairly fragile fish.

Interesting to note they mention that particular Cory species, in the two times I've seen this fish for sale, it's been as a bycatch of C. pygmaeus. I've kept them, and with tetras, they are hardwork feeding wise, but I found would only parasitise (is that a word?) if not eating other foods (live daphnia, frozen bloodworm eventually). I did think that keeping them with another fish helped them learn what was being offered by me was food.

Jools

Hallo Jools
Just to remark that in Peru we have those Tridensimilis brevis.
I call them Golden pygmy canero.
And you are right, they come as by-catch with the pygmaeus.
I usually keep them separated from others and feed them with tubifex, so I dont know if this is a good idea to keep them in a comunitary tank.