Ancient Crocodiles Once Feasted on Giant Tortoises on This Island – via Herp Digest

New York Times, 1/23/18 by Nicholas S. Fleur

An Aldabran giant tortoise from the Aldabra Atoll in the Indian Ocean, feeding on algae. A new study suggests these giant tortoises might once have been hunted by giant, prehistoric crocodiles.

Credit

Dennis Hansen/University of Zurich, Switzerland

Today, Aldabra Atoll, an island in the Indian Ocean near Madagascar and Tanzania, is a predator-free paradise for more than 100,000 giant tortoises. Gone are the seafarers who over-hunted them to near extinction in the 18th and 19th centuries. Gone too are the large crocodiles that may have preyed upon them in prehistoric times, as a new study suggests.

Dennis Hansen, an ecologist from the University of Zurich, was exploring the coral atoll and its azure lagoon, part of the Seychelles, when he came across fossils that intrigued him. They included parts of a giant tortoise shell with circular bite marks and the jaw of an ancient crocodylian. From the finds, he and a colleague concluded that some 90,000 to 125,000 years ago, the ancient crocodiles may have feasted upon the giant tortoises of Aldabra.

The finding, which was published Tuesday in the journal Royal Society Open Science, may offer new insights into the ancient past of the world’s most numerous giant tortoise and the threats it once faced from predators

Measuring more than 3 feet long and 550 pounds on average, the Aldabra giant tortoise is behind only the Galapagos tortoise in size. It has a thick, domed shell which protects its soft body. It also has a long neck and stout legs covered in scales.

Dr. Hansen found about 180 fossils near a pond on the atoll. One was a jawbone of an ancient crocodile that he first thought was a tortoise longbone. But when he turned it over he saw it had holes where teeth could fit. He sent some of the fossils to his colleague Torsten Scheyer, a paleontologist also at the University of Zurich, for further examination.

“It was pretty clear from the start that these were crocodylian remains and something distinctly larger than what was found previously on the atoll,” Dr. Scheyer said.

A crocodylian jawbone fossil found by Dr. Hansen in Aldabra.

Credit

University of Zurich, Switzerland

Although smaller crocodile fossils had been found on the island, the remains that Dr. Hansen found suggested they belonged to beasts that were about 11 and a half feet long, larger than today’s West African crocodiles but not as big as Nile crocodiles or saltwater crocodiles.

Dr. Hansen also found a fragment of a giant tortoise fossil belonging to the part of the shell that would have protected the reptile’s neck. The bite mark on the plate, he said, offered two possible scenarios for what might have occurred.

The first, is that the tortoise was ambushed as it drank.

“Maybe the crocodile, in classic crocodile fashion, jumped out of the water and grabbed it in the only place where it could grab it,” said Dr. Hansen.

Tortoises huddled in the shade near the empty carapace of another. Researchers aren’t sure yet if the crocodiles scavenged on recently dead tortoises or hunted them.

Credit

Dennis Hansen/University of Zurich, Switzerland

The second, is that the tortoise died near the pond from starvation or heat stroke in the arid environment and a nearby crocodile scavenged its rotting carapace.

Stephanie K. Drumheller-Horton, a paleontologist at the University of Tennessee, Knoxville, said the findings were supported by other examples of crocodile bite marks in the fossil record.

“Aldabra giant tortoises would have been tough nuts to crack, even for crocodiles, who can generate incredibly high bite forces,” Dr. Drumheller-Horton said. “It makes sense that you would see bite marks around the edges of the turtle shells, where the crocodiles could more easily get at exposed limbs.”

Alexander Hastings, the assistant curator of paleontology at the Virginia Museum of Natural History, said the authors showed that it was possible that large crocodiles feasted on giant tortoises. But, he added, they would need to find evidence of tortoises with healed wounds in order to show explicitly that the crocodiles were actively hunting and killing the giant tortoises.

“It was thought something that big and that well-armored would be pretty safe from predation, especially on such an isolated island,” Dr. Hastings said. “This study raises at least the possibility that they may have not been so safe.”

Sea Turtle Poachers Attack Sea Shepherd Volunteers, Police, on the French island of Mayotte in the Indian Ocean – via Herp Digest

By The Maritime Executive, 07-13, 2017

Sea Shepherd volunteers and local police have had rocks thrown at them during efforts to save turtles. Less than two weeks after publishing images of poached sea turtles on the French island of Mayotte in the Indian Ocean, Sea Shepherd volunteers interrupted a poaching operation on the night of July 7. 

The island in the Indian Ocean between Madagascar and Mozambique is home to a 68,381km² protected marine reserve, rich in ocean wildlife. Yet the sea turtles are often killed by poachers who sell the meat on the black market.

When the volunteers arrived at the beach known as Moya 1, one of the most popular tourist beaches on the Petit Terre island, they spotted a 4x4 vehicle, its lights switched off as it waited to pick up poached turtle meat. The guards, who should have been there to protect the turtles who come to lay their eggs, were nowhere to be seen.

Down on the beach, the volunteers found two turtles ripped open with their eggs scattered in the sand. Sea Shepherd alerted the local gendarmes. The poachers, who had run to hide on a hill overlooking the beach, began throwing rocks at the volunteers and police from above. No one was hurt, however the poachers also set the Sea Shepherd volunteers’ car on fire.

Despite the intervention of three police officers, who helped seize some of the turtle meat which was left behind by the fleeing poachers, no arrests could be made because the security on the beach that night was grossly insufficient compared to the scale of the threat, says Sea Shepherd.

“France seems to remain blind and deaf concerning the social and ecological crisis which is raging in Mayotte,” said President of Sea Shepherd France, Lamya Essemlali. “France is letting its overseas department perish, a place which is home to one of the world’s largest lagoons, rich in local biodiversity. The only law which seems to prevail on this island is the law of the jungle. This condition has caused social and environmental chaos which is hard to imagine in continental France.”

Sea Shepherd launched Operation Nyamba in June 2017 at the request of locals and work with them to fight the poaching with direct action. “Even though the circumstances on the ground turned out to be worse and more dramatic than we expected, the situation has only reinforced our determination,” says Essemlali. “We will not give up on Mayotte.”

Sea Shepherd has released video footage of the incident on YouTube at http://bit.ly/2v0kHAD

Data on blue whales off California helps protect their distant relatives

Research identifies blue whale habitat in the Northern Indian Ocean

Date: February 8, 2017

Source: NOAA Fisheries West Coast Region

Scientists know a great deal about blue whales off California, where the endangered species has been studied for decades.

But they know far less about blue whales in the Northern Indian Ocean, where ships strike and kill some of the largest animals on Earth.

Now a research team has found a way to translate their knowledge of blue whales off California and in the eastern tropical Pacific Ocean to the other side of the world, revealing those areas of the Northern Indian Ocean where whales are likely to be encountered. The team of scientists from NOAA Fisheries and the Sri Lankan Blue Whale Project published the findings in the journal Diversity and Distributions.

The Scientific Committee of the International Whaling Commission included the results of the study when assessing a shift in busy shipping lanes off the south coast of Sri Lanka that will reduce the danger to whales in an important feeding area.

"Small changes in shipping routes can be a very effective way to address a serious conservation issue with minimal inconvenience to the shipping industry, but rely on a good understanding of the relationship between whale distribution and habitat," said Russell Leaper, a member of the Scientific Committee. "This study makes an important contribution towards that understanding."

Read more 

New marine life found in deep sea vents

By Helen Briggs BBC News

Six new animal species have been identified at deep-sea vents beneath the Indian Ocean.

The remote area is home to life not seen elsewhere in the world's oceans, yet has been earmarked for future mineral exploration.

Hydrothermal vents form at locations where seawater meets magma. They are surrounded by a large number of organisms that are new to science.

The latest finds include worms, snails and a crab.

UK researchers explored an area of the Southwest Indian Ridge, which bisects the ocean between Africa and Antarctica, in 2011.

Scientists at Southampton University revealed they had found many new creatures using a remote-operated underwater robot.

Species spotted at deep-sea vent

They have now analysed samples from the site, known as Longqi, or "Dragon's Breath", and compared them with known species based on the animals' genetic make-up.

The study, published in the journal Scientific Reports, shows six animals new to science.
 

The six new species
a "Hoff" crab
a "giant peltospirid" snail
a whelk-like snail
a limpet
a scaleworm
a polychaete worm 

 

Continued 

Fig-Dwelling Worm Is a Mighty Mouth-Morpher

by Mindy Weisberger, Senior Writer | January 15, 2016 02:02pm ET

On La Réunion Island in the Indian Ocean, microscopic worms that inhabit wild figs can develop five different mouths.

No, not all at the same time. But depending on the worm's exposure to different environmental conditions and the availability of different food sources, it can grow a specialized maw that's best suited to its living situation. The structure of these mouths varies so widely that the scientists who found the worm, Pristionchus borbonicus, initially thought that worms with different mouths were actually different species.

And P. borbonicus wasn't the only worm they turned up that boasted a mouth-morphing superpower. The scientists discovered two more species in the Pristionchus genus — Pristionchus sycomori andPristionchus racemosae — that were also capable of developing five different mouth shapes.All of the worms were found in figs that grow in Vietnam, South Africa and La Réunion Island; and each of the mouthy worm species parasitizes a separate wasp species that pollinates the figs.

Continued ...

Joe Strummer has deep sea snail named after him

Alviniconcha strummeri live beneath the surface of the ocean and apparently ‘look like punk rockers in the 70s and 80s’

Sean Michaels

Tuesday 16 December 2014 08.00 GMT

A species of deep sea snail with the bold, spiky aesthetic of early Clash fans has been named after Joe Strummer. Alviniconcha strummeri are golf ball-sized invertebrates that live around 2,000 metres beneath the surface of the ocean.

The Strummer-indebted snails are one of five new species identified in a paper that was published in the journal Systematics and Biodiversity. “Because they look like punk rockers in the 70s and 80s and have purple blood and live in such an extreme environment, we decided to name one new species after a punk rock icon,” Shannon Johnson, a researcher at California’s Monterey Bay Aquarium Research Institute, told the Santa Cruz Sentinel (via Exclaim).

Only strummeri have been named after a musician: the other alviniconcha species get their monikers from things like research facilities and gastropod experts. “The name highlights the ‘hardcore’ nature of alviniconcha snails, that inhabit the hottest, most acidic and most sulphidic microhabitats at Indo-Pacific hydrothermal vents,” researchers wrote. “The name also recognises the surface of Alviniconcha shells: the spiky periostracum resembles the fashion of punk rock bands.”

Continued ...

Five New Species of Spiky Sea Snails Discovered, One Named after Joe Strummer

A group of marine biologists headed by Dr Robert Vrijenhoek from the Monterey Bay Aquarium Research Institute has described five new species of deep water Alviniconcha snails from the Western Pacific and the Indian Ocean.

Alviniconcha strummeri, a new species of deep-sea snail named after Joe Strummer of The Clash. Image credit: Shannon B. Johnson et al.

Snails in the genus Alviniconcha belong to the family Provannidae.

These deep-sea animals live in the hottest and most acidic waters near hydrothermal vents.

Because these snails live in these extreme conditions, they have severely degraded shells (size varies between 2.5-10 cm) covered in spikes or have no shells at all.

Continued ...

Satellite tagged green turtles reveal shortcomings in marine protection areas

Unique research by scientists from Deakin University in Victoria, Australia, has been using satellite tracking to monitor tagged green turtles in the Indian Ocean.

The findings indicate that even the largest Marine Protection Areas (MPAs) – some covering hundreds of thousands of square kilometres of sea – may need to be buttressed with smaller networks of protected areas.

It has been discovered that the turtles travel much further from their breeding grounds than previously suspected to forage for food.

The international team from Deakin, Swansea University in Wales and the Seychelles located green turtles nesting ashore at night and fitted them with satellite tags.

They then used satellites to monitor their movements in the Chagos Archipelago in the Indian Ocean, one of the largest protected marine parks in the world, covering 640,000 sq km, and renowned for its pristine coral reefs and schools of endangered species.

“Over the last few years, governments around the world have declared some massive marine parks, typically around ocean islands,” said Prof Graeme Hays, Deakin Chair of Marine Science. “How well these protect marine life has been heavily debated.”

Continued

Gigantea vs. Elephantina Isn't a Monster Movie—It's a Slow-Moving War of Words-A 200-Year-Old Spat Over Tortoise Name Has a Winner - via Herp Digest

By  Gautum Naik, Wall Street Journal 4/1/2001

In 1812, the giant tortoise of the Indian Ocean atoll of Aldabra was given a scientific Latin name: Testudo gigantea.

Then, for more than two centuries, researchers sparred over what to call the 600-pound creature.

In recent months, the slow-moving debate quickened. Rival biologists published more than 100 pages of lengthy, academic arguments for why the animal should retain the gigantea name or take on another scientific moniker. Elephantina was held out as one possibility; dussumieri another.

The scientists extended the name-calling to each other as well, with some tartly dismissing others as "unschooled." The Seychelles government, which claims the tortoise as a native, also weighed in on the matter.

It has been "a very charged issue," says Ellinor Michel, executive secretary of the International Commission of Zoological Nomenclature, or ICZN. "Scientists are pretty good at saying that the other person is an idiot."

The tortoise spat is one of about 60 cases presented each year to the ICZN, a little-known group that functions as the world's arbiter for animals' scientific names. Acrimonious battles have raged for years over the correct monikers for certain shrimp, snails, fruit flies, butterflies and dinosaurs.

It is a big job: every year, researchers identify about 20,000 new animal species. Each must be given a scientifically valid name, usually in Latin or in Greek, that will endure. Otherwise, the animal kingdom might fall into chaos. The task is likely to become even tougher: due to drastic budget cuts, the ICZN's own future existence is now severely threatened.

When enacting laws for species conservation, for example, "you have to know what animal you're talking about or you're going to be in trouble," says David Attenborough, the British naturalist. He once spent several days among the Aldabra tortoises. "There are a great number of these extraordinary creatures lumbering around the place," he recalls, adding that one of them stole his shoes from outside the tent.

The world's roughly 1.4 million known animal species typically go by two or more names in scientific literature—a source of confusion to many. Several have 20 names. One species of honey bee has 70. Some critters are described by two or three different names in the same research paper.

The clash over the Aldabra tortoise ranks as one of the most murky and bitter in the ICZN's 118-year history.

In the late 1800s, Charles Darwin argued for the protection of the tortoise, which can grow three feet high and live for two centuries. But the animal has been given up to 40 names. The recent fight has been principally about two of them.

In 1812, a German botanist named August Friedrich Schweigger studied tortoise specimens at the natural history museum in Paris. One, a giant, he named Testudo gigantea. That stuffed specimen later was misplaced for 200 years.

About two decades later, two French biologists described two species of giant tortoises. One they called T. elephantina. They other they referred to as gigantea.

A scientist at London's Natural History Museum concluded that gigantea and elephantina were the same creature. For the next century or so, the Aldabra tortoise was routinely described as gigantea.

In 1982, a French scientist named Roger Bour of the Paris Natural History Museum concluded that the Schweigger specimen didn't originate from Aldabra, after all. He argued that gigantea should be renamed elephantina, the name chosen by his French compatriots in the 1800s.

That proposal muddied the waters. Scientists began to refer to the same tortoise using different names.

An American biologist, Jack Frazier, wanted to eliminate the confusion. In 2006, he designated a tortoise specimen at the Smithsonian museum as the new type specimen for the Aldabra tortoise, which he continued to call gigantea.

That same year, Dr. Bour was rooting around the Paris museum specimens and came across a two-foot-long specimen smelling faintly of the varnish that once had been used to polish it for display. It was Schweigger's gigantea, missing for two centuries.

Dr. Bour quickly concluded that the specimen came from Brazil, not Aldabra, and that gigantea was therefore no longer a valid name. He proposed yet another moniker—dussumieri—named after another Frenchman and referring to a tortoise specimen stored in a Dutch museum, which had been obtained from Aldabra in the late 1800s.

Meanwhile, Dr. Frazier kept lobbying for gigantea, which has wide usage. In 2009, he filed a petition to the ICZN to set the record straight. He also asked colleagues to send written comments in support of the cause.

The quarrel over the Aldabra tortoise, known as case 3463, landed on the desk of Svetlana Nikolaeva, an ICZN zoologist. She and her colleagues work out of a single room at the London natural history museum. Nearby, locked cabinets hold thousands of specimens, from insects and birds to dinosaurs.

ICZN trolls through decades of research to assess the validity of competing names, while fielding calls, letters and emails from rival scientists who passionately argue for one name or another.

"We are pedantry central and we relish that," says Dr. Michel. "But sometimes I'd rather be in a lake scuba-diving."

In any naming issue, ICZN publishes petitions in a research journal it runs, the Bulletin of Zoological Nomenclature. Responses are published, too. ICZN's 26 commissioners then vote on a name for posterity.

Over four years, the bulletin has published more than 80 comments on the Aldabra tortoise. "Usually we publish two or three," says Dr. Nikolaeva.

In September 2009, a published comment from the Seychelles minister of environment pointed out that gigantea "is the name that appears in our legislation, in the legislation of other countries, in international treaties and a host of other official documents." Gigantea should be kept, he said.

One comment, which appeared in June 2009, was from Dr. Bour and a colleague. "In this case the issue was initiated by non-taxonomists apparently unschooled in the rules of zoological nomenclature," the pair wrote. They added that the Aldabra case was a minefield "complete with brave soldiers and cowardly ones."

To call fellow-scientists "unschooled is the height of arrogance," says Dr. Frazier.

For his part, Dr. Bour says that Dr. Frazier cheapened a serious academic debate by lobbying for supportive comments for the name gigantea, many of which got published. "It's not fair play," says Dr. Bour.

On Sunday, ICZN's expert panel published the results of a vote in its bulletin: The slow-moving tortoise need not budge on its name: Gigantea it will be.

Scientists Using Holiday Snaps to Identify Whale Sharks

Feb. 8, 2013 — Holidaymakers' photos could help scientists track the movements of giant endangered sharks living in the waters of the Indian Ocean. A new study, led by a researcher from Imperial College London, is the first to show that these publically sourced photographs are suitable for use in conservation work.

Tourists scuba diving and snorkelling in the Maldives frequently take underwater pictures of the spectacular and docile whale shark, often called the world's largest fish. Conservationists have long hoped to use this photographic resource to help them trace the sharks' life history, relationships and geographic distribution, although the value of these amateur snapshots has never been properly measured.

Tim Davies of Imperial's Department of Life Sciences is the lead author on a study published in Wildlife Research, the first to examine how reliable photographs sourced from the public actually are. He and his team did this by comparing results using tourist images with results based on surveys by marine researchers specifically aiming to track the sharks.

In order for a shark to be clearly identified, any photograph must capture the distinctive pattern of spots located directly behind the gills. This unique marking serves as a 'fingerprint', which can then be scanned with a computer programme to tell the animals apart.

Continued:  http://www.sciencedaily.com/releases/2013/02/130208124629.htm

Sea Lights Help Seals Hunt in the Dark

The glow that certain fish give off may help the world's largest seals hunt them down.

Southern elephant seals spend about 10 months in the southern Indian Ocean, coming ashore only to breed and molt. They forage over broad distances, during which time they dive continuously, sometimes deeper than 4,900 feet (1,500 meters).

The deep, dark ocean is a challenging place to find prey. Whales use echolocation — the biological equivalent of sonar — to scan for potential food, while penguins rely on scent. However, it remained uncertain how southern elephant seals foraged in the deep sea. Scientists now have a better idea after attaching electronic devices to some of them.

Read on:  http://www.livescience.com/22811-elephant-seals-bioluminescent-fish.html

Fishing Expedition Finds Weird Deep-Sea Sharks

A two-month fishing expedition to the Indian Ocean has turned up hundreds of strange deep-sea sharks, and several are likely new to science.

At least eight new species could be among the fishy haul, said Paul Clerkin, a shark ecology graduate student at California's Moss Landing Marine Laboratories.

Clerkin joined the commercial fishing venture in March and April of this year, in hopes that the vessel's massive trawling nets might pluck sharks from the deep sea. He was not disappointed.

"I tell people I have a ton of sharks, and they keep thinking I’m joking," Clerkin said. "It was an actual ton. I brought back 350 sharks." 

The sharks were caught as bycatch from depths of approximately 6,500 feet (2,000 meters) from a region of undersea mountains, or seamounts, about a week's journey south of the island of Mauritius.

Read on:  http://www.livescience.com/22363-shark-deep-sea-new-species.html

The world's most threatened and healthiest sea turtle populations revealed

Turtles under serious threat in Indian Ocean - Nearly half of the world's most endangered turtles found in northern Indian Ocean

September 2011: Almost half - 45 per cent - of the world's most threatened sea turtle populations are found in the northern Indian Ocean, according to a new study.

The team of top turtle experts also determined that the most significant threats across all of the threatened populations of sea turtles are fisheries bycatch, accidental catches of sea turtles by fishermen targeting other species, and the direct harvest of turtles or their eggs for food or turtle shell material for commercial use.

The recent report, produced by IUCN (International Union for Conservation of Nature) Marine Turtle Specialist Group (MTSG) and supported by Conservation International (CI) and the National Fish and Wildlife Foundation (NFWF), is the first comprehensive status assessment of global sea turtle populations. The study evaluated the state of individual populations of sea turtles and determined the 11 most threatened populations, as well as the 12 healthiest ones.

Read on...

New species of large squid found

Has light-producing organs to lure prey

November 2010: A new species of squid has been discovered in the southern Indian ocean.

The new species, 70cm long, is a large member of the chiroteuthid family - squids from this group are long and slender with light-producing organs, which act as lures to attract prey. So far, more than 70 species of squid have been identified from the IUCN-led Seamounts cruise, representing more than 20 per cent of the global squid biodiversity.

‘For ten days now 21 scientists armed with microscopes have been working through intimidating rows of jars containing fishes, squids, zooplankton and other interesting creatures,' says Alex Rogers, Principal Scientist and Marine Biologist at the Zoological Society of London. ‘Many specimens look similar to each other and we have to use elaborate morphological features such as muscle orientation and gut length to differentiate between them.'

The recent discoveries are part of an IUCN-led Seamounts Project, which started a year ago when a team of the world's leading marine experts ventured into a six-week research expedition above seamounts in the high seas of the Indian Ocean. The aim of the cruise was to unveil the mysteries of seamounts in the southern Indian Ocean and to help improve conservation and management of marine resources in the area.

‘The new discoveries will not only satiate the appetite of scientists working in the field, but will help improve conservation and management of Indian Ocean resources and future management of deep-sea ecosystems in the high seas globally,' says Carl Gustaf Lundin, head of the IUCN Global Marine Programme.

http://www.wildlifeextra.com/go/news/new-species-squid.html