I have long been fascinated by Macrobrachium shrimp. Most Macrobrachium species have a structured social hierarchy, one notable exception is M. kulsiense. Their structure has an alpha male, which has the largest, and darkest claws. Some species will have a sub alpha (such as M. rosenbergii), and dominate females. For breeding purposes, keep one adult male with two adult females. When remove berried females to hatch eggs in a dedicated nursery/grow out tank.
The larger species are difficult to keep in colonies, as adult males will go after each other. The general rule is, if an adult Macro species is longer than 4 inches, plan on them being ultra aggressive. Here are the species that I have kept in colonies; M. dayanum (possibly assamensis) commonly known as Red Claw shrimp, M. lamarrei lamarrei commonly called Whisker shrimp, M. scabriculum, and M. kulsiense commonly called Sand/Pearl/Snowflake shrimp.
I have been trying to find/purchase a blue claw strain of M. dayanum, but I have not yet been able to find a seller in North America, or someone willing to ship from Europe.
