Crab question?

[deep_six]

Hello all,

Recently after months of hunting I was able to remove four evil crabs from my main tank. I couldn't just flush them so I decided to throw them into my sump. My question is this; will they/ can they reproduce? My biggest nightmare is that these horrible little things will somehow get their seed back into the main tank and repopulate . Maybe I'm just being paranoid.
What do you guys think?