Zebra sharksStegostomatidae

The striped shark and the spotted shark are the same animal at two different ages.

A young zebra shark is dark brown with pale bars running across it, and that is where the name came from. Somewhere under a meter long the bars break apart into a scatter of dark spots on pale tan, and the adult looks like a different species altogether, which is why a good part of the world calls the grown animal a leopard shark instead. The two forms were originally described as separate animals, and the tangle that created has only recently been straightened out; the scientific name of this shark changed within the last few years as a result.

It is also one of the few large sharks here that lays eggs rather than giving birth. The case is a dark leathery purse about the size of a hand, and it comes with an anchoring system: tufts of fine fibers along the outside catch on coral and rock and hold it against the surge for the months the pup needs to develop and cut its way out.

And it does not strictly require a male. A female at an Australian aquarium bred normally with a partner for years, was separated from him, and then, after several seasons alone, laid eggs that hatched. The pups carried her DNA and nobody else's. Virgin birth has since been recorded in other sharks, but she was the first known to switch to it after a career of ordinary reproduction, which raises an uncomfortable question about populations fished down to scattered females.

One species, and it is uncommon here: a slow bottom shark that spends the day lying motionless on sand at the foot of a reef. It is listed as endangered, and it is also the first shark anyone has tried to put back, with aquarium-bred pups hatched and released into the wild in 🇮🇩 Indonesia.