I have two wood shrimp one have been carrying eggs for about a week and a half (or more), so that would make her female and the other male.
Ok, now other then the one that I carrying the eggs I still can't see any difference in them, no bigger legs on the other shrimp or lower slung carapace on the one with eggs.
A common question about these shrimp is how to distinguish males and females. The answer is simple. With fully grown animals the males have a much larger first pair of walking legs (see pictures for comparison). Additionally, the females are plumper and their carapace extends further down at the pleopods to accommodate eggs.
Just gonna throw this one out there but what if you have two females? Just because she's carrying eggs doesn't mean they're fertile, or do you think she would have dropped them by now?
I might be wrong but I think Eric is right on this one. As stated above
males have a much larger first pair of walking legs
as well as the other body differences. Unless you have a rare hermaphrodite, I think they may both be female. Is this the first time any of them has carried eggs? Could someone please let us know how long the eggs are carried.
If your "males" don't have the longer claws shown on the photo in the shrimp varieties page they are either females or perhaps they haven't matured enough yet? I'm not sure at what age they are sexable.