Take Heart!
From Christian Vegetarian Association (CVA)

Crustaceans Feel Pain

Crustaceans, such as crabs and lobsters, do feel pain. This is the conclusion researches came to after studies showed that crabs are capable of remembering unpleasant experiences and therefore take action to avoid pain. These findings have tremendous implications for consumers and the food industry where crustaceans are boiled alive or their limbs reaped apart as if these creatures were mere objects.

Please visit Lobsters and crabs can feel pain and take action to avoid it happening again:
http://www.dailymail.co.uk/sciencetech/article-2263712/Lobsters-crabs-feel-pain-action-avoid-happening-again.html

Crustaceans, like any other of Godís sentient beings, have been endowed with the capacity to feel pain. If we ignore this simple fact and instead we choose to continue causing unnecessary pain to these creatures, I think we are dishonoring God and making a mockery of His/Her love for animals.