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Marine Life & Conservation Blogs

Creature Feature: Goblin Shark

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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.


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

The Shark Trust is the leading UK-based shark conservation charity. The team works globally to safeguard the future of sharks, and their close cousins, the skates and rays. Engaging with a global network of scientists, policymakers, conservation professionals, businesses and supporters, to further shark conservation. Established in 1997 to provide a voice for UK sharks, the Shark Trust has an ever-growing number of passionate supporters. And together we're creating positive change for sharks around the world. Want to join us and help protect sharks around the world? Click here! www.sharktrust.org

Marine Life & Conservation Blogs

Book Review: Plankton

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Plankton: A Worldwide Guide by Tom Jackson and Jennifer Parker

This is a book that jumps off the shelf at you. The striking front cover demands that you pick it up and delve further, even if you may not have known you wanted to learn more about the most diminutive life in our ocean, plankton!

Small it might be. Much of the imagery in the book has been taken under huge magnification. Revealing stunning beauty and diversity in each scoop of “soup”. There is lots to learn. Initial chapters include interesting facts about the different vertical zones they inhabit, from sunlight to midnight (the darkest and deepest areas). I loved finding out more about the stunning show that divers oft encounter on night dives – bioluminescence.

The black water images are wonderful. So this is a book you can have as a coffee table book to dip in and our of. But, these tiny organisms are also vital to our very survival and that of all the marine life we love. They provide half the oxygen produced on our planet. They are also responsible for regulating the planets climate. And for a shark lover like me – they are food for charismatic sharks and rays like the Basking Shark and Manta Ray, along with a huge number of other species. This book contains great insight into their biology, life cycles, migration, and how the changes in currents and sea temperatures affects them.

This is a book that is both beautiful and packed with information about possibly the most important group of organisms on our planet. Anyone interested in the ocean should have it one their shelves.

What the publisher says:

Plankton are the unsung heroes of planet Earth. Passive drifters through the world’s seas, oceans, and freshwater environments, most are invisible or very small, but some are longer than a whale. They are the global ocean’s foundation food, supporting almost all oceanic life, and they are also vitally important for land-based plants, animals, and other organisms. Plankton provides an incomparable look at these remarkable creatures, opening a window on the elegance and grace of microscopic marine life.

This engaging book reveals the amazing diversity of plankton, how they belong to a wide range of living groups, and how their ecology, lifestyles, and adaptations have evolved to suit an enormous range of conditions. It looks at plankton life cycles, the different ways plankton feed and grow, and the vast range of strategies they use for reproduction. It tracks where, how, and why plankton drift through the water; shares perspectives on migrations and population explosions or “blooms” and why they happen; and discusses the life-sustaining role of plankton in numerous intertwined food webs throughout the world.

Beautifully illustrated, Plankton sheds critical light on how global warming, pollution, diminishing resources, and overexploitation will adversely impact planktonic life, and how these effects will reverberate to every corner of our planet.

About the Authors:

Tom Jackson is a science writer whose many popular books include Strange Animals and Genetics in MinutesJennifer Parker is a zoology and conservation writer and the author of several books. Andrew Hirst is a leading expert on plankton whose research has taken him around the world, from the Antarctic to Greenland and the Great Barrier Reef.

Book Details

Publisher: Princeton University Press

Hardcover

Price: £25

ISBN: 9780691255996

Published: 9th April, 2024

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Marine Life & Conservation Blogs

Creature Feature: Butterfly Rays

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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.

As we’re currently in butterfly season, this month we decided to concentrate on the Butterfly Rays!

Within the family Gymnuridae, there are two genera and 12 species of Butterfly Ray. These species are morphologically different to lots of other rays because of the width of the disc and pectoral fins – in contrast to many other species of Butterfly Ray, their bodies are much wider than they are long, especially considering their very short tail. This gives them the appearance of gliding or flying across the sand.

Gymnura altavela – Spiny Butterfly Ray

Gymnura australis – Australian Butterfly Ray

Gymnura crebripunctata – Longsnout Butterfly Ray

Gymnura japonica – Japanese Butterfly Ray

Gymnura lessae – Lessa’s Butterfly Ray

Gymnura marmorata – California Butterfly Ray

Gymnura micrura – Smooth Butterfly Ray

Gymnura natalensis – Backwater Butterfly Ray

Gymnura peocilura – Longtail Butterfly Ray

Gymnura sereti – Seret’s Butterfly Ray

Gymnura tentaculata – Tentacled Butterfly Ray

Gymnura zonura – Zonetail Butterfly Ray

Spiny Butterfly Ray, Gymnura altavela. Playa La Granadella, Spain, Mediterranean Sea.

Today we’re taking a look at Gymnura altavela, the Spiny Butterfly Ray. Like all Butterfly Rays, the Spiny Butterfly Ray is a demersal species, meaning it spends the majority of its time on the bottom of the seabed. Butterfly Rays are known for their burying behaviour in the sand, a technique they use to camouflage themselves when they are resting during the day. This protects them from predators, in some areas larger sharks. It also aids them in their ambush hunting technique – by hiding themselves under the sand they are able to easily snatch up their dinner – usually crustaceans, molluscs or other small fish – as they swim by unawares. This behaviour can leave tell-tale butterfly-ray shaped imprints in the bottom of the seabed.

Spiny Butterfly Rays can grow up to 260 cm (disc width (wingspan)), although average is around 200 cm. They give birth to live young, and each litter consists of 1-8 pups. This species has also been found to aggregate, likely for mating. One study found that aggregations of primarily females in the coastal regions off Gran Canaria may correlate with the shifting water temperature.

It is estimated that the species has undergone a population reduction of 50-79% over the last 33 years. This is primarily due to fishing pressure – the Spiny Butterfly Ray is targeted and bycaught in both industrial and artisanal fisheries types using a variety of gear types. The species is now Critically Endangered in the Mediterranean and Southwest Atlantic.

Scientific Name: Gymnura altavela

Family: Gymnuridae

Maximum Size: 260 cm (disc width)

Diet: crabs, shrimps, various invertebrates, fishes, small crustaceans, and molluscs.

Distribution: throughout the Atlantic and Mediterranean and Black Seas.

Habitat: muddy and sandy substrates down to 150m.

Conservation status: Critically Endangered in the Mediterranean and Europe, Endangered Globally.

For more great shark information and conservation visit the Shark Trust Website


Banner Image: ©Tomas Willems. Main image: ©Andy Murch

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