It is unlikely that a blue lobster will eat your shrimp. Blue lobsters are not the same species as regular lobsters; they are a rare genetic variant of American Lobster (Homarus americanus) with an extremely unusual, bright blue coloration caused by a genetic defect. Unlike normal lobsters, which have reddish-brown shells and claws, blue lobsters have electric-blue shells and claws. They also tend to be smaller than their brown counterparts, so it's unlikely that they would be able to overpower larger shrimp in order to eat them. Furthermore, although wild blue lobsters can sometimes feed on crabs and other small animals when necessary for survival, they typically prefer eating clams or other mollusks rather than other crustaceans like shrimp. Therefore if you want to keep your shrimps safe from being eaten by a lobster, then the best thing you can do is ensure that any lobster you put into the tank is not a blue one!