1 bioluminescence: n. light that is made by living creatures
2 navigate: v. to move from place to place
3 torches: n. lights carried in the hand
4 firefly: n. a flying insect that emits a flashing light
5 larvae: n. the immature forms of some insects
6 twilight: n. a term usually used to mean the time between day and night. In this passage, “twilight zone” means the part of the ocean between the shallow, sunlit part of the ocean and the deep, dark part of the ocean.