sentences:  Based on its smaller dorsal and caudal fins, the largetooth cookiecutter shark is believed to be less active than "I. brasiliensis" and an overall weak swimmer.Much of its body cavity is occupied by an enormous oil-filled liver, which allows it to maintain neutral buoyancy in the water column with little effort.Unlike "I. brasiliensis", this shark possesses binocular vision, which may allow it to target its prey with greater precision.