Portal:Sharks/Did you know

Shark related facts that have appeared in the Did you know? column of the main page can be added here. Once a set has five facts, the random portal template component for did you knows should be updated on the main portal page.

Set 1

... that the zebra shark is striped when young and spotted when mature?
... that the blurred and smooth lanternsharks form a species group distinguished from the rest of their family by the shape and arrangement of their dermal denticles?
... that the leopard shark feeds on anchovies by swimming into their schools with its mouth open and waiting for them to accidentally enter?
... that relative to its body size, the horn shark has the strongest known bite of any shark?
... that the title for Peter Benchley's best-selling 1974 novel Jaws was not agreed until 20 minutes before it went into production?

Set 2

... that the whitetip reef shark may have contributed to the Hawaiian myth of ʻaumākua, family guardian spirits, due to the "loyalty" of sharks that stay in the same area for years?
... that individual smalltooth sand tigers have been documented returning to the same location off Lebanon every summer?
...that Mustelus hacat is a species of smooth-hound shark discovered in 2003 in the Sea of Cortez, off the coast of Mexico?
... that during the summer the finetooth shark is found exclusively in water less than 10 m (30 ft) deep?
... that the Canary Islands are one of the few places left where there are still substantial numbers of angelsharks, once common all around Europe?
...that whilst most sharks are poikilothermic, species in the family Lamnidae are homeothermic?

Set 3

... that the whitefin dogfish has light-producing organs on its upper eyelids?
... that the spinner shark is named for the spinning leaps it makes out of the water as part of its feeding strategy?
...that John Singleton Copley's painting, Watson and the Shark, was based on a real-life shark attack that occurred in Havana, Cuba in 1749?
... that, like the related cookiecutter shark, the kitefin shark sometimes feeds by taking bites out of animals larger than itself?
... that the first successful artificial insemination of a shark was performed in the cloudy catshark?

Set 4

... that the velvet belly lantern shark has proteins in its liver that can detoxify heavy metals such as cadmium, copper, mercury, and zinc?
... that at night, the Pacific angelshark may use bioluminescent plankton to target its prey?
... that the Galapagos shark is often the most abundant shark around oceanic islands?
... that the blotched catshark exhibits fluorescence, with spots that glow yellow under blue light?
... that the grey reef shark is the first shark species known to perform a threat display to warn off divers who are too close?

Set 5

... that when captured, the tawny nurse shark often spits a jet of water into the faces of its captors?
... that the swellshark bends its body in a U-shape and sucks in water to double in size and avoid attacks from predators?
...that shark threat display is an exaggerated swimming style exhibited by some sharks when they perceive they are in danger?
... that almost a quarter of the brown lanternsharks found in Suruga Bay, Japan, have both male and female organs?
... that the blacktip shark can reproduce asexually?

Set 6

... that the taillight shark has a gland on its belly that releases clouds of luminescent blue fluid?
...that the Jersey Shore shark attacks of 1916 killed four people and inspired Peter Benchley's novel Jaws (1974)?
... that the presence of the rare bigeye sand tiger in the Pacific Ocean was first suspected based on teeth recovered from the ocean floor?
... that the rough skin of the nursehound was once used as an abrasive called "rubskin", which cost a hundred times more than sandpaper?
... that the epaulette shark can survive for an hour without oxygen?

Set 7

... that the spadenose shark exhibits the most advanced form of placental reproduction in fishes?
... that the dark, puffadder, brown, and Natal shysharks of South Africa are so named because they curl into a ring when threatened and "shyly" cover their eyes with their tails?
... that the daggernose shark can adjust the timing of events in its reproductive cycle by several months?
... that the lollipop catshark is shaped like a tadpole and has an almost gelatinous body?
... that the Australian swellshark can survive out of water for more than a day?

Set 8

... that the milk shark is so named because of a belief in India that eating its meat improves lactation?
... that the silky shark is the most common source of ornamental shark jaws sold to tourists in the tropics?
... that the southern African frilled shark preys mainly on smaller sharks, which it swallows whole with its greatly distensible mouth?
... that more than 90 percent of the night sharks caught off northeastern Brazil contain mercury concentrations higher than that considered safe by the local government?
... that the largetooth cookiecutter shark has the largest teeth relative to its body of any living shark?

Set 9

... that no more than 250 mature northern river sharks are estimated to live in the wild?
... that the closure of the Tethys Sea 10–14 million years ago led to the sicklefin lemon shark and the lemon shark becoming separate species?
... that the spined pygmy shark, dwarf lanternshark and pygmy ribbontail catshark are candidates for being the smallest shark in the world, all maturing at under 20 cm (8 in) long?
... that most attacks on humans by the blacktip reef shark consist of people being bitten on their legs or feet while wading in shallow water?
... that the egg capsule of the crested bullhead shark has paired tendrils extending up to 2 m (6.6 ft), greater than the length of the adult shark?

Set 10

... that the Portuguese dogfish is the deepest-living shark known, found as far down as 3,675 m (2.284 mi)?
... that the single known specimen of the Irrawaddy river shark was generally dismissed as an abnormal bull shark until 2005?
... that the green lanternshark often preys on squid and octopus much larger than itself, which it may overwhelm by attacking in packs?
... that the barbeled houndshark is the only shark with a spherical placenta?
... that the cookiecutter shark may use the absence of bioluminescence to attract prey?

Set 11

... that male Arabian carpetsharks competing for a mate have been known to bite the claspers of their rivals?
... that the porbeagle has been known to "play" with kelp fronds, pieces of wood, and fishing floats?
... that the blind shark and the bluegrey carpetshark close their eyes when taken out of the water?
... that male Arabian carpetsharks competing for a mate have been known to bite the claspers of their rivals?
... that the whitefin, Cook's, Australian reticulate, spotted, leopard-spotted, painted, flagtail, speckled, saddled, and narrowbar swellsharks were all scientifically described in 2008, more than doubling the number of species in the genus Cephaloscyllium?

Set 12

... that the draughtsboard shark has been known to bark like a dog?
...
...
...
...

Set 13

Portal:Sharks/Did you know/13