This image shows the head of a goblin shark with its jaws extended. DIANNE BRAY / MUSEUM VICTORIA

When someone says "shark," the first images that come to mind for many people are rather typical – great whites, bull sharks and tiger sharks. But there are some species lurking beneath the sea that look a little, well, different from their cousins.

Most people think of the aforementioned species because of shark attacks. Although they rarely happen – there were just 69 unprovoked bites worldwide in 2023 according to the International Shark Attack File – attacks by great whites, bull sharks and tiger sharks are sometimes fatal because of their sheer size. But there are millions of these predators in the ocean, and it's the ones that aren't seen as often that can be among the most fascinating – both in character and in looks.

You can't miss this shark's most distinctive feature - its mouth. According to the Australian Museum, their mouths can retract under their eyes and also extend forward to the length of their very long and flat snouts. Goblin sharks are found throughout the Pacific, Atlantic and Indian Oceans and like to stay near the sea floor at depths from about 800 to over 3,000 feet.

These extremely rare tiny sharks are known for their creepy, snake-like teeth, giant eyes, glowing bellies and gaping jaws that allow them to swallow their prey in one bite. Viver dogfish sharks have rarely been found, but when they have, it's been near Japan, Taiwan and Hawaii. In 2018, five of the sharks were found along Taiwan's coast, according to Newsweek, although all but one were dead with the final shark dying a day later. They're known to live at depths of up to about 3,300 feet.

Otherwise known as "carpet sharks," this species is clearly defined by the unusual fringe along the front of its head and its camouflage pattern. The Tasselled variety is just one of 12 wobbegong shark species, according to Abyss Scuba Diving, and the animals are known for being ambush predators that wait for their prey to get close enough for them to attack. This particular wobbegong species lives at depths of up to 131 feet on the continental shelf, as well as reefs, in the western Pacific, and are often seen in the northern Great Barrier Reef.

How many shark species are there?
According to the Shark Research Institute, there are more than 400 species of sharks. These animals, like all species, belong to a certain scientific classification. Sharks belong to the classification Chondrichthyes, which are fishes that don't have bones, but instead have skeletons made of cartilage – the same tissue found in human noses, ears and joints.

And while sharks are often described in monolithic terms, no two species are the same. There are varying attributes from everything, including where they live, what they eat, how they interact with people and even how they reproduce – some are actually cannibals in the womb and eat their siblings.

But many of these species are at risk of demise – largely because of habitat intrusion and climate change. A 2022 study found that if greenhouse gas emissions – a primary driver for rising global temperatures that fuel extreme weather and agriculture among other things – are not limited by the end of the century, nearly every marine species will be at risk of extinction. Sharks and other large predators are among the most at risk, the report found.


This image shows a viper dogfish, with the person who provided the image saying that it came from Hawaii. STEPHEN M KAJIURA


A Tasseled wobbegong lies on a reef in Raja Ampat, Indonesia. This tropical region is known as the heart of the Coral Triangle due to its incredible marine biodiversity. / GETTY IMAGES