3.  Small, rarely-seen dogfish shark  Cigar-shaped body  20 inches in length  Large eyes with green pupils  Live from the surface – 11,500 ft deep

4.  Inhabits warm, deep waters of equatorial oceans, primarily in coastal waters near islands  Inhabit deep water during the day and migrate into surface waters at night

5.  Bioluminescent belly  Glows a pale blue-green that matches the background light from the ocean's surface  Serves as camouflage to creatures beneath it  Has a small non-luminescent patch (appears black)  Deceives the shark's prey, smaller predatory fish (like tuna), into thinking the shark is an even smaller fish

6.  Derives its name from the shape of the bite marks it makes in its prey  Removes small circular plugs of flesh and skin from cetaceans and large fish  Attaches with its suctorial lips and modified pharynx  Then rotates its body to achieve a round, symmetrical cut

8.  Listed as a species of Least Concern by the IUCN  Not really a threat to humans  Occasionally mistake man-made objects for prey  Submarine's rubber sonar dome