Parr and Red attempted to jam the trace signal before the ship was targeted but it was too late as the Sentinels already homed in on the signal. At the impact, Parr got to the main deck and readied the EMP. Meade with the captain tried to buy some time until backup arrived, however the sentinels breached the firewall.
The Sentinels broke through every bulkhead and blockade the crew members set up. Parr's head exploded. One last crewman tried to run for the EMP but the nearest sentinel grabbed his arm and impaled him inches away from the button.
The ship looks like a crab, and so the name is derived from Calappidae, a family of crabs.