Shark Smile Trivia Quiz

Answer:

Sharks belong to the subclass Elasmobranchii of the class Chondrichthyes, the cartilaginous fish, which also includes rays, skates and sawfish. Though they are among the most feared of sea creatures, their sinister reputation far exceeds the danger they actually pose: in fact, the survival of many shark species is severely threatened by human activity. Sharks are found in all seas (some also in freshwater), and come in a wide range of sizes, from under 20 cm (7.8 in) to over 10 m (32 ft).

The extant species of sharks are split among nine orders. The largest of them, the order Carchariniformes (ground sharks) comprises nine families. The Carcharinidae are generally large, powerful predators, commonly referred to as requiem sharks (probably from "requin", the French word for shark). The bull shark (Carcharinus leucas) and the lemon shark (Negaprion brevirostris) both belong to this family. The tiger shark (Galeocerdo cuvieri, family Galeocerdonidae) and the hammerhead sharks (Sphyrna sp., family Sphyrnidae) are also part of the order Carchariniformes. Of all these species, the tiger and bull sharks are definitely the most dangerous to humans, having been involved in a large number of fatal, unprovoked attacks. On the other hand, most of the hammerhead sharks are endangered - some critically so.

The sharks of the order Lamniformes are commonly known as mackerel sharks because herring, mackerel and related species are their preferred prey. The most notorious member of the family Lamnidae is the great white shark (Carcharodon carcharias), the "man-eater" by definition; the much less dangerous porbeagle shark (Lamna nasus) and the fast, powerful mako shark (Isurus oxyrinchus) also belong to this family. The long-tailed thresher shark (Alopias vulpinus, family Alopiidae), the very odd-looking goblin shark (Mitsukurina owstoni, family Mitsukurinidae) and the filter-feeding megamouth shark (Megachasma pelagios, family Megachasmidae) are also mackerel sharks.

The nurse shark (Ginglymostoma cirratum) belongs to the family Ginglymostomatidae of the order Orectolobiformes, also known as carpet sharks because of the patterned skin of some species. it is a bottom-dwelling shark that can reach a respectable size, and has often been involved in biting incidents when directly threatened by humans.

Of the fish species listed as wrong answers, one - the torpedo ray - is also a cartilaginous fish. The others are all bony fish (superclass Osteichthyes): beluga sturgeon, moray eel, sockeye salmon, wels catfish, and yellowfin tuna.