The blacktip reef shark (Carcharhinus melanopterus) is a common shark found in the tropical waters of the Indo-Pacific. Their bodies are streamlined, making them powerful swimmers, and—as the name suggests—the tips of their fins are black. They usually inhabit shallow waters and are very curious as a species. They will often approach divers to investigate, which has led to numerous attacks, giving the species a bad reputation. However, as with all sharks, the odds of being attacked by one are still extremely low.

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Although it is one of the widest ranged sharks, the blue shark (Prionace glauca) may be threatened by over-harvesting. They migrate seasonally, moving from cooler to warmer waters. Blue sharks sometimes circle prey before attacking and they will gather in large numbers to eviscerate whale or porpoise carcasses. They can also be found following trawling boats, stealing the caught fish. The blue shark is known as a shark species that will attack humans, but just like with any other sharks, getting bitten by one is relatively rare.

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New Zealand Eagle Ray (Myliobatis tenuicaudatus)

Photo © Matthew Oldfield

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Round stingray (Taeniura grabata)

Southern Stingray (Dasyatis americana)

Bullhead and horn sharks belong to the order Heterodontiformes, and are small, bottom-living sharks. The most popular species is Heterodontus portusjacksoni, the Port Jackson shark. There are only nine species within this order.

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Spotted ratfish, Hydrolagus collei

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The whale shark (Rhincodon typus) is a graceful, slow-moving giant and the largest fish in the world. At 1.5 m wide, its mouth is large enough to fit a human inside, but it is a harmless filter feeder that eats only plankton and small fish. Accounts of these giants describe sightings of individuals up to 20 m in length.
To obtain the huge amount of food it needs, it sucks water into its mouth and pumps it out over its gills, where particles of food become trapped by bony projections called gill rakers and are later swallowed. This shark has the thickest skin of any animal, at up to 10 cm thick. Prominent ridges run the length of its body, and it has a large, sickle-shaped tail. The pattern of white spots on its back is unique to each fish, enabling scientists, through analysis of photographs, to identify individuals. While little is known of their ocean trabels, satellite tagging has shown that some whale sharks migrate across entire oceans. Whale shark eggs hatch inside the mother, and she gives birth to live young that reach up to 60 cm in length.
Every year, around April, whale sharks migrate to Ningaloo Reef off northwestern Australia for a plankton feast. The plankton explosion results from a simultaneous mass spawning of the reef’s corals, possibly triggered by the full moon.
Whale sharks are killed for their meat and fins (used in soup), although they are legally protected in some countries. 

Photo © Ken Knezick & Erik Schlögl

The tiger shark (Galeocerdo cuvier) is the second most dangerous shark to humans, after the white shark. It is huge and has a heavy head and a mouth filled with serrated teeth that have the characteristic shape of a cockscomb. One reason it is so dangerous is that it prefers coastal waters and is also found in river estuaries and harbors, and so it frequently comes into contact with humans. It is reputed to eat almost anything—including smaller sharks, even its own young, other fish, marine mammals, turtles, and birds, it is an inveterate scavenger, and a huge variety of garbage—earning them the nickname “the garbage cans of the sea.” The young, born live after hatching from eggs inside the mother, begin life marked with blotches, which become “tiger stripes” in juveniles and fade by adulthood.

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Sawfish, such as the smalltooth sawfish (Pristis pectinata) pictured above, are elongated rays with a long, flat, sawlike snout, or rostrum, which they use to slash through shoals of fish and dig for shellfish and invertebrates. Like all rays, they have gill slits on the underside of the body rather than the sides. Females give birth to live young, which are about 2ft long in the smalltooth species. The saws of the pups are sheathed and flexible at birth, in order to prevent injury to the mother.

The smalltooth sawfish lives in coastal waters but also swims up river estuaries. Numbers of this species are severely depleted and it is listed as Critically Endangered on the IUCN Red List of endangered species.

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