In this series, the Shark Trust will be sharing amazing facts about different species of sharks and what you can do to help protect them.

Written by guest contributor – Yolanda Evans.

Mysteriously slithering around the dark mesopelagic of the western Pacific, the glorious Goblin shark swims in search for their next meal. This illusive shark is one of the most unique-looking sharks to ever exist, having a long snout called a rostrum and protrusible jaws, hailing them their common name, Goblin. Their rostrum is covered with small pores called the ampullae of Lorenzini, jelly-filled pores in the snouts of many sharks that are able to pick up changes in the electro-magnetic field, for example the muscle contractions of nearby fish. However, these pores can only detect movement only a few inches in front of the shark!

In addition to their rostrum, these sharks poses and amazing ability to protrude their jaws out or their cartilaginous skull by something called slingshot feeding. This is when the jaws are shot forward, extending 8.6-9.4% of the Goblin sharks total body length. However, this fast jaw action also creates a powerful suction-known as a pharyngeal suction-forcing their prey deeper into their mouths.

While many sharks range from greys to blues to browns, this stupendous shark can be a very pale pink! However, this unusual colour is not from a pigment in their skin, but from the thinness of their skin! Their skin has such a great transparency that the oxygenated blood that flows in their capillaries-tiny blood vessels-causes what would be their grey skin, to become pink. This amazing ability might actually been an adaptation for the shark, they live 270m-1300 m deep, red light wavelengths cannot be seen, making the spectacular shark near invisible to both prey and predators!

Their scientific name, Mitsukurina owstoni, comes from the British naturalist Alan Owston who is credited with discovering the shark, and from Kakichi Mitsuriki, the Japanese scientist who identified and described the shark. While the English common name is only from their long rostrum, the direst translation into Japanese is Tengu-zame, base of the Tengu, a Japanese mythological half-man-half-bird who had red skin and a long nose, a comparison more fitting.

Despite their somewhat intimidating appearance, the Goblin shark is not an aggressive species, predating on mainly small bony fish, crustaceans, and cephalopods. Long slender teeth that protrude out from their jaws, appearing almost like blades, are perfect for clutching onto their prey. Nonetheless, the most threat they create towards humans is disrupting our internet as they are known to bite down onto submarine cables!

Like many other shark species, Goblin sharks main threat is by-catch from deep-sea longlining and deep-sea trawling. They are listed by the IUCN as least concern. Unfortunately, being relatively understudied, this may be incorrect as there is a very minimal amount of knowledge about the lives of these sharks. Leaving the question: what else is there to know about the truly incredible Goblin shark?

SCIENTIFIC NAME: Mitsukurina owstoni

FAMILY: Mitsukurinidae

MAXIMUM SIZE: Up to 3.8 meters (12.5 feet) in length

DIET: Feeds primarily on deep-sea fish, but also crustaceans and cephalopods

DISTRIBUTION: Goblin Sharks have a wide but patchy distribution, found in deep waters of the Atlantic, Indian, and Pacific Oceans.

HABITAT: Primarily found in the deep sea, typically between 200 and 1,200 meters (656 and 3,937 feet) in depth. They are occasionally seen at shallower depths, but are typically associated with steep slopes and canyons on the continental shelf and slope.

CONSERVATION STATUS:

Due to their deep-sea habitat and elusive nature, they are rarely encountered and little is known about their population trends. However, they are sometimes caught as bycatch in deepwater fisheries, and there is concern over the potential impacts of deep-sea mining activities on their habitat.

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Images – www.fishesofaustralia.net.au/home/species/3254 | Wikimedia Commons

This month we’re talking about some sharks with unusual names. With names that range from the descriptive to the downright strange. Let’s look at three species with weird and wonderful names!

Tasseled Wobbegong

The Tasseled Wobbegong (Eucrossorhinus dasypogon) is a species of carpet shark found in the shallow coral reefs of the Indo-Pacific. This unique shark gets its name from the tassels that hang from its chin and the sides of its head, making it look like it’s wearing a fancy carpet. The scientific name of the Tasseled Wobbegong, Eucrossorhinus dasypogon, comes from the Greek words “eu” meaning good, “krossoi” meaning fringe, “rhinos” meaning nose, and “dasys” meaning hairy, and “pogon” meaning beard, referring to the shark’s characteristic tassels.

The Tasseled Wobbegong has a broad, flattened head and a body that is covered in small, thorn-like projections. These projections, called dermal denticles, are a common feature of shark skin and help to protect the shark from predators and parasites. The Tasseled Wobbegong’s skin is also covered in a unique pattern of dark spots and stripes that allows it to camouflage itself on the reef floor. With their striking appearance and docile nature, they are a favorite of divers and underwater photographers.

Despite their wild appearance, Tasseled Wobbegongs are relatively docile and are known to be tolerant of human divers. They are primarily nocturnal, spending most of their days hiding in crevices and under overhangs on the reef. At night, they venture out to hunt small fish and crustaceans, using their powerful jaws to crush their prey.

Although the Tasseled Wobbegong is not considered to be a threatened species, it is facing increasing pressure from habitat degradation and overfishing. In 2018, the International Union for Conservation of Nature (IUCN) listed the Tasseled Wobbegong as a species of “Least Concern” on their Red List, which is a positive sign that the population is currently stable.

SCIENTIFIC NAME: Eucrossorhinus dasypogon

FAMILY: Orectolobidae

MAXIMUM SIZE: 122cm

DIET: Bony fish, crustaceans, and cephalopods

DISTRIBUTION: Found in the waters around southern Australia, including Tasmania and the Bass Strait.

HABITAT: Shallow, coastal waters with rocky or coral reefs, as well as seagrass beds and sandy areas.

CONSERVATION STATUS: 

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Crocodile Shark

This unique species (Pseudocarcharias kamoharai) is a small and slender-bodied shark. Which was only disovered in 1985! The genus name, Pseudocarcharias, means “false shark,”. While the species name, kamoharai, honors the Japanese ichthyologist, Kamohara. The English common name “crocodile shark” is derived from its Japanese name mizuwani (水鰐, literally “water crocodile”), which refers to its sharp teeth and habit of snapping vigorously when taken out of the water.

The Crocodile Shark is named for its distinct crocodile-like appearance, with a long snout and sharp teeth. With a maximum length of 1.2 meters. This species is found in deep ocean waters around the globe, from the Atlantic to the Indian Ocean, typically at depths of 200 to 500 meters. However, it has been known to venture as deep as 1,000 meters.

What makes the Crocodile Shark particularly unusual is its opportunistic feeding behavior. This means that it will eat just about anything it comes across. Including small fish, squid, and even other sharks. The Crocodile Shark uses a unique hunting technique to catch its prey. Its slender body and elongated snout allow it to navigate through tight spaces and ambush unsuspecting prey, making it a formidable predator despite its small size.

Since being discovered, we’ve not uncovered much about this elusive species. Not much is known about the biology and behavior of Crocodile Sharks. They are rarely encountered. And in 2019, the Crocodile Shark was listed as “data deficient” on the IUCN Red List. This means that not enough is known about the species to determine its conservation status. This elusive species’ DNA has been analysed and they are determined to be closely related to the Megamouth Shark or sand sharks (Odontaspididae). Alternative research, analysis based on teeth structure, suggests that the closest relatives of the crocodile shark are the thresher sharks.

SCIENTIFIC NAME: Pseudocarcharias kamoharai

FAMILY:  Pseudocarchariidae

MAXIMUM SIZE: 1.2m

DIET: Bony fish and cephalopods

DISTRIBUTION: They are found in tropical and warm temperate waters around the world, including off the coasts of Japan, Australia, South Africa, and Brazil.

HABITAT: Deep offshore waters, typically at depths of 200 to 500 meters, but have been known to come up to shallower depths at night to feed.

CONSERVATION STATUS:

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Viper Dogfish

The Viper Dogfish (Trigonognathus kabeyai) is a species of deep-sea shark found in the North Pacific Ocean. This unique shark gets its name from its distinctive appearance, which resembles that of a viper snake, due to the long, fang-like teeth protruding from its jaws. The scientific name comes from the Greek words “trigonos” meaning triangular, “gnathos” meaning jaw, and “kabeya” in honor of the late Japanese ichthyologist, Toshiji Kabeya, who made significant contributions to the study of deep-sea sharks.

The Viper Dogfish is a relatively small species of shark, growing up to just 40 centimeters in length. Its body is slim and elongated, with a dark brown or black coloration that allows it to blend in seamlessly with its deep-sea environment. They’re typically found at depths of between 365 and 1,200 meters, where they feed on a variety of prey including small fish, squid, and crustaceans. Their long, fang-like teeth allow them to easily catch and hold onto their prey, despite their small size.

Despite being a relatively unknown species, the Viper Dogfish has been listed as a species of “Least Concern” on the International Union for Conservation of Nature (IUCN) Red List.

SCIENTIFIC NAME: Trigonognathus kabeyai

FAMILY: Etmopteridae

MAXIMUM SIZE: 40cm

DIET: Small fishes and invertebrates

DISTRIBUTION: Northwest and central Pacific: Japan, Taiwan and Hawaiian Islands.

HABITAT: Deep waters, between 250 – 1000m. Possibly oceanic as some have been caught at 150m over water as deep as 1500m.

CONSERVATION STATUS: 

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Banner Image – © Frogfish Photography

Wobbegong – © Andy Murch

Crocodile Shark – © Dianne J. Bray, 2011, Crocodile Shark, Pseudocarcharias kamoharai, in Fishes of Australia, accessed 11 May 2014, http://www.fishesofaustralia.net.au/home/species/3001 | Wikimedia Commons

Viper Dogfish – © Stephen M Kajiura | Wikimedia Commons