They do look like macrobrachium sp. Super cool!!!
here is a blurb from the site i linked to in your other thread:
[FONT=Arial, Helvetica, sans-serif]These shrimp, although they can become large in size, are usually quite peaceful, they can however be territorial and will compete for food, so shouldn't be kept with smaller or long-finned species of fish, like neon tetra and guppies. The larger species can cause damage with their claws, but, as long as their tank mates are of a suitable size, they are safe in a community aquarium. The smaller species of long arm shrimp are usually found in dealers tanks labeled as 'river shrimp', they are algae eaters and detritus scavengers, they are often sold as live feed. Given a little patience the large shrimp can become hand tame, taking pieces of prawn and smelt eagerly from your fingers. These shrimp should be fed a mixed diet, including sinking shrimp/crab pellets, supplemented with commercial frozen foods, like krill and mysis. They will hoard or guard any food that hits the bottom at feeding time, only allowing other fish access when they have finished eating.[/FONT]
