What traits make sharks and rays in subclass Elasmobranchii successful predators?

The elasmobranchs are distinguished by separate gill openings, http://www.answers.com/topic/amphistylic-vertebrate-zoology or http://www.answers.com/topic/hyostylic-vertebrate-zoology jaw suspension, and sensory http://www.answers.com/topic/ampulla (of Lorenzini) in the head region. also the lateral line system. their are probobly other characteristics but this is a good short list