I had identified amphipods after its remains (there was two or three legs, half a head, part of the coxas and so), and is feasible, but not easy. Inside the chilean complex of this species would be even more dificult. High school students can't really do it, and local fishermen do not have this knowledge or the tools to adquire it.

I can think only in one reason to not contact the chilean biologists, or visit Chile, and is a language barrier, easy to overcome since we have google translate and similar tools.

On the other hand, amphipods are really easy to keep in aquariums for many months. Females incubate its eggs under the legs in a sort of pouches (kangaroo style) and there is often a clear and obvious sexual dimorphism, so their reproductive life is not dificult to study at all. You can easily observe the breeding behaviour, clutch size, embriology, hatching, season and number of generations by year. Why they didn't it in all of those years is a mystery to me. (Shrug) maybe fear that the species would be disclosed as belonging to a yet described species and became a synonym?.