It's not that easy to sex shrimp to the untrained eye. First of all, they have to be adults (it's next to impossible to sex young shrimp). The males are "skinnier" and smaller, whereas the females are "fatter" and their carapace extends down further into their pleiopods ("swimmerettes"), their pleopods also hang down more, especially after carrying eggs.
And here is the shocker: If your three shrimp have been together for quite a long time and none of them have been carrying eggs, then you either have all males or all females. I'd go with all females since females occur more often than males in shrimp species.
If I were in SEA and had those kind of options, I would have gotten 2 dozen, and then sit back and enjoy them. They would be a beautiful addition to any tanks (provided that there are no predators in the tank, of course)
One would ask how would a resonable amount of time before you expect your shrimp to be carrying eggs? Or think about adding new shrimp to possibily start breeding if you have all one one sex. I havent had any of mine carrying eggs yet, though i noticed one shrimp is getting bigger and turning more red which is beautiful!
I agree...it does look like a male. However, it could also be an immature female. So...if the animals is mature, it's a male...if not...then you will have to wait until it matures.
