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Here at Arkive, we provide the ultimate multimedia guide to endangered species, and through our blog we’ll keep you up to date with news from the world of wildlife videos, photography and conservation, alongside the latest on our quest to locate imagery of the planet’s most wanted plants and animals.
Jun 8

This year the Society of Biology’s amateur photography competition is inviting budding photographers to think creatively about forests, grasslands, deserts and watery environments, fitting in with the theme ‘Home, Habitat & Shelter’.

Entries can focus on any of the world’s amazing ecosystems, although as today is World Ocean’s Day we thought we would give potential entrants some inspiration from one of nature’s most mysterious and varied environments. Occupying approximately two thirds of the Earth’s surface and containing around 95 percent of the Earth’s water, the world’s oceans provide numerous habitats for a wide range of species. The oceans are divided into five distinct areas: the Pacific, Atlantic, Indian, Southern (Antarctic) and Arctic.

Oceans are divided into five layers, and each layer is designated depending on its depth, physical characteristics and biological conditions, and the richness of life within each zone can vary considerably. Oceanographers categorise the open ocean as the pelagic zone, while the far depths, including the oceanic trenches, are described as hedalpelagic. At depths between 6,000 and 11,000 metres, there is a very low density of marine-life due to the harsh physical and chemical conditions.

But even at great depths and with no direct access to sunlight, creatures have evolved to survive and thrive. The giant tube worm lives around strong flowing hydrothermal vents, which are cracks on the ocean floor from which very hot, mineral-rich water flows into the surrounding ocean water. These vents are usually found near volcanically active places and the surrounding water is heated by the magma beneath the Earth’s surface.

Giant tube worm plume – a deep-sea species

The giant tube worm lives inside thin, tube-like structures made from chitin (a hard, protective material found in the outer skeleton of some invertebrates) and can grow up to two metres long. It has an impressive, haemoglobin-rich, red plume which is extended when it is undisturbed. The highly specialised body is divided into four sections, each of which plays a role in gas exchange, structure and support, and absorption of nutrients. Like other worms, it does not have a digestive tract and relies on a symbiotic relationship with bacteria in its body tissue. The bacteria perform chemosynthesis, a process by which organic molecules are produced for the worm to feed on.

Giant tube worm specimen

The remoteness of the hydrothermal vents prevents scientists from studying the ecology and biology of this species and others that live in these deep-sea areas. So although it is clear to see they have adapted to thrive in harsh oceanic environments, other biological features such as reproduction and feeding habits are relatively unknown.

If you have been inspired to think about a creature that has developed to flourish in a unique environment or you have simply been struck by the beauty of a creature in its natural habitat, why not enter the Society of Biology amateur photography competition. Photographs could focus on biological research which helps to answer the complex question of why and how different organisms survive in diverse environments; or, could simply capture the beauty of an animal in its natural habitat.

Further details on entering the photography competition are available on the Society of Biology website

Jun 7

Atlantic bluefin tuna (Thunnus thynnus)

Species: Atlantic bluefin tuna (Thunnus thynnus)

Status: Endangered (EN)

Interesting Fact: The Atlantic bluefin tuna can swim at speeds of up to 72 kilometres per hour when pursuing its prey.

More information: The enormous Atlantic bluefin tuna can grow to lengths of 4.6 metres and weigh up to 684 kilograms. This fish species has two types of muscle, one for continuous long-distance swimming and the other for short, fast bursts of speed. This amazing adaptation means that individuals of this species are able to swim across the Atlantic Ocean in just 60 days. Although the Atlantic bluefin tuna is generally found swimming in mixed species schools close to the surface of the water, it is capable of diving to depths of up to 1,000 metres when chasing prey. Another fascinating adaptation of the Thunnus genus is the blood exchange system known as the rete mirable which enables individuals to swim in water that is much to cold for other fish. The Atlantic bluefin tuna is a highly migratory species and has a naturally occurring magnetic mineral located in its head that helps with navigation to and from its spawning grounds.

The severe exploitation of the Atlantic bluefin tuna has led to the drastic decline of every known population, particularly in the North Atlantic Ocean. Despite quotas being in place to ensure sustainable numbers are removed from the population, the limits are frequently not respected and unless the legal levels are suitably enforced, it is predicted that some Atlantic bluefin tuna stocks will collapse. The western Atlantic stock may have already collapsed and is now in grave danger of extinction due to overfishing. In the Mediterranean, tuna ranching poses the greatest threat to this species. Individuals are captured alive and taken to a ranch where they are fattened before being sold. Since 1998, catch limits have been in place and in 2006 the International Commission for the Conservation of Atlantic Tunas (ICCAT) established a 15 year recovery plan for the Atlantic bluefin tuna. The plan includes stricter catch limits and closing certain fisheries at specific times of the year to allow the local stocks to recover.

Find out more about Atlantic tuna conservation: International Commission for the Conservation of Atlantic Tunas (ICCAT).

See images and videos of the Atlantic bluefin tuna on ARKive.

Hannah Mulvany, ARKive Content and Outreach Officer.

Jun 5

As you know, back in May we celebrated our 11th birthday, and to mark the occasion we asked our followers to vote for their favourite Arkive highlight from the past year. A huge thank you to everyone who filled out the survey, it has been fantastic to get your feedback on what we have been doing and to find out what you felt was the most important focus for Arkive.

The results are now in and we are thrilled to announce that you chose our work profiling the world’s most endangered species as your winner. This has been a key aim for Arkive since the very beginning, and today we have over 16,000 species profiles in our collection. Of course, this work wouldn’t be possible without the support of the world’s best wildlife filmmakers and photographers, conservationists and scientists, who contribute their imagery and lend their support and advice.

Why not dive in and discover something new today?

Cotton-headed tamarin

The stunning cotton-headed tamarin is one of South America’s most endangered primates

Our 11th birthday also seemed like the ideal opportunity to give the Arkive website a fresh new look and feel, making the most of our amazing imagery. Check out our beautiful new homepage today.

May 31

Lemur leaf frog (Hylomantis lemur)

Species: Lemur leaf frog (Hylomantis lemur)

Status: Critically Endangered (CR)

Interesting Fact: The lemur leaf frog has the remarkable ability to change colour depending on whether it is active or resting.

More information: The lemur leaf frog is a tiny, highly threatened amphibian from Central America. This species is primarily nocturnal, and spends the day well hidden on leaves. During the day, this frog is a vibrant leaf-green colour, changing to red-brown when it is active. At night, the lemur leaf frog walks stealthily among low vegetation in search of its invertebrate prey. This species breeds during the rainy season, and the female lays between 15 and 30 eggs on leaves that hang over water. After the eggs have hatched, the larvae are washed into the watercourse during heavy rain. This Critically Endangered amphibian is currently found in Costa Rica and Panama, and marginally in Colombia. In Costa Rica this frog is only known from three sites.

The lemur leaf frog has undergone a drastic population decline, estimated to be more than 80 percent loss over a 10 year period. While pigments in the skin of the lemur leaf frog are thought to grant it some resistance, the decline of this species is thought to be due to chytridiomycosis, a disease that is responsible for global amphibian population crashes.  This frog is also threatened by deforestation, especially in Costa Rica.

In Panama, this species is known to exist within at least six protected areas, whereas the habitats of the Costa Rican populations remain unprotected. A captive breeding programme began in 2001 at the Atlanta Botanical Garden, which has been highly successful and has since transferred individuals to other zoos to continue the effort. Other breeding programmes exist at the El Valle Amphibian Conservation Center in Panama, and the Manchester Museum in the United Kingdom.

Find out more about the lemur leaf frog and other species of South America

See images of the lemur leaf frog on ARKive

Find out more about amphibian conservation

Ben Hogan, Wildscreen ARKive PIPS Intern

May 29

In a letter to Nature magazine, researchers have expressed their concern over the appearance of a non-native toad species, the Asian common toad, in Madagascar.

The Asian common toad (Duttaphrynus melanostictusi) is a close relative of the cane toad (Rhinella marina), an invasive toad species that rapidly spread across Australia after its introduction in the 1930s, and has devastated many native fauna and flora populations. First seen on Madagascar in March, the Asian common toad has been sighted several times in areas close to Toasmasina, the main port of the island nation. Worryingly, there have also been sightings of the amphibian just 25 kilometres from the Betampona Nature Reserve and short distances from other biodiversity hotspots. The dispersal of this species is not just limited to Madagascar and it is thought that populations may have also become established in other areas. One of the authors of the letter, Jonathan Kolby, of James Cook University in Queensland, Australia, said, ”There is now a high dispersal risk of these toads spreading from Madagascar to other Indian Ocean islands such as the Mascarene Islands, Comoros, and Seychelles.”

It is thought that populations may have also become established on other Indian Ocean islands, such as the Mascarene Islands

It is thought that the Asian common toad could have various negative impacts on the fauna of Madagascar, including spreading diseases such as ranavirus and chytridiomycosis to native amphibians and competing with them for food and breeding areas. This toad species is poisonous and is known to be toxic to animals that ingest it. Snakes are thought to be one of the animal groups most at risk from the invasion and there are over 50 endemic snake species on Madagascar, including the Madagascar ground boa. Other endemic species including fossas, lemurs, and birds will also be put at risk should the population of this harmful amphibian become established. Kolby also said, “It’s worrying because Madagascar has amazing endemic biodiversity – plants, animals, and amphibians that are found nowhere else. And this one species has the propensity to damage that.”

95 percent of the reptiles on Madagascar are endemic to the island, including the Madagascan ground boa

As well as being a threat to the animals of Madagascar, the Asian common toad is also a threat to the human population as it is known to contaminate drinking water and transmit parasites. After the devastation the cane toad has caused in Australia, it is thought that immediate action is required on Madagascar to prevent history from repeating itself. Kolby said, “The question is, can we still eradicate them? Have we caught it soon enough that eradication could be a feasible option? Obviously we all hope the answer is yes.” Suggested methods of eradication include removing adult toads, draining breeding ponds, and installing fences to prevent the toads from reaching water where they would be able to breed. Highlighting the urgency of the situation, Kolby said, ”Time is short, so we are issuing an urgent call to the conservation community and governments to prevent an ecological disaster.”

In Australia, the introduced cane toad is responsible for the declines of many native species, including the Near Threatened brush-tailed phascogale

Read more on this story at Nature – Toxic toads threaten ‘ecological disaster’ for Madagascar.

View images and videos of Madagascan species on ARKive.

Hannah Mulvany, ARKive Content and Outreach Officer

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