Freshwater Blu Shrimp (Neocardina?) A few Q's

Hey there, we recently got a 5 1/2 galon tank setup running. Started off with two Neocardina/Blue Shrimp from petco. Later we added a plecostamus and a beta (dont ask us why, we dont even know)

My first question would have to be, what denotes male or female freshwater shrimp? And what if anything can I do to support the birth of shrimp. I hear that this particular variety gives live birth, although I may be wrong.

Last question pretty much already got answered, but one of the blue shrimp lost a limb somehow and I wanted to know if it will regenerate. I read here that it will as long as its molting, but how many molts does a shrimp have? (info was over in the marine forum, about coral banded shrimp, does it still apply?)

I wanted to get either another shrimp or a crab to put in the tank, I was told a crab would be a bad choice due to fighting... but in that case which is at a greater risk? The crab or the shrimp? Would another shrimp (perhaps another species) be just as bad as a crab?

- Bobdolemite

We have a 100 gal at home with a 14 " pleco inside hehe, this one is a little guy, maybe an inch and a half give or take. Didnt think I would have to worry about moving him until at least another six months or more, what do you guys think?

We had hoped to be able to afford a 20 gal at least sometime in the near future, but that is to be seen with college constantly giving us issues hehe.

So you guys think its more likely the pleco took the claw rather than the beta or the other shrimp? Didnt think the beta was too much of a problem, watched the shrimps and the beta go at it a few times, but the beta has barely escaped with his fins intact, now he hangs out on the thermometer or other various things.

I know whole fish had dissapeared in the big tank at home, always suspected the pleco was the only one big enough to actually do the job, but I thought they were bottom feeders only hehe.