Krill. The Crabeater Seal does not eat crab, it only eats krill. The seal earned the misleading name because of unusual teeth they have. The multi-lobed teeth of the crabeater seal interlock to help them feed upon krill in the Southern Ocean. They filter the water through their tightly-locked teeth, capturing the miniature krill that are the staple of their diet. Crabeater Seal teeth are so unusual that many researchers consider them to be the most specialized teeth of any carnivore.