A transparent goldfish that reveals its inner organs has been developed by a joint research team of Mie University and Nagoya University in Japan.

The aim of the project was to create a transparent fish that makes it possible for researchers to study blood constituents and organ behaviour without having to dissect the animal. Unlike ordinary goldfish variants, this type has therefore been made really big and can weigh up to 1 kg. Up until now, the transparent fish of choice for researchers have been the see-through zebrafish, but this tiny fish only weigh abut 3 grams and is therefore much more difficult to study than the 1 kg goldfish.

The translucent goldfish was developed in just three years by repeatedly letting selected pale goldfish specimens mate with each other.

“Pale-colored goldfish have little commercial value, but their negative value has turned into a positive,” said Mie University Associate Professor Yutaka Tamaru.

The creation of a transparent goldfish was announced Wednesday last week at the annual meeting of the Molecular Biology Society of Japan.

Female scissortail sergants allow potential mates to fertilize a small batch off eggs and then monitor their parenting skills to decide if they are good enough to deserve a full clutch.

When studying filial cannibalism* in scissortail sergeants, ecologist Andrea Manica** of the University of Cambridge noticed that some females approached a male’s nest, deposited a small amount of eggs, and then left.

This aroused his curiosity and he decided to provide the males with ceramic tiles to use as nest sites. Once a female has deposited a small clutch on a ceramic tile, Manica either left the eggs alone or rotated the tiles to move the eggs.

The tiles that were left alone turned out to be popular; two-thirds of the females returned to deposit a full clutch of eggs later. The tiles that had been rotated by Manica were much less desirable and only a quarter of the females returned to lay a new batch.

Overall, this method of testing potential fathers seems to be rather rare in the population researched by Manica. Out of 421 females, only 7.4 percent laid test eggs before depositing a full batch. Manica also noticed that the method was used mainly at the onset of the breeding cycle. Later in the cycle, the amount of eggs already inside a nest seemed to suffice as indicator.

“The female fish probably use these test eggs when they don’t have much to go by. As a strategy, to me it makes lots of sense. There are probably lots of other species that do that,” said Manica.

The Scissortail sergant (Abudefduf sexfasciatus) is a large damselfish native to coral reefs in the Indo-Pacific. Also known as the Striptailed damselfish, it can be recognized on its black striped tail and sides. In this species, the eggs are cared for by the male fish who must not only resist the urge to eat his own offspring but also be brave and skilled enough to protect them from being eaten by other predators.

The study has been published in Animal Behaviour.
http://www.elsevier.com/wps/find/journaldescription.cws_home/622782/description#description

* Filial cannibalism is when an adult eats the young of its own species. In many species of fish, adults won’t hesitate to eat even their own immediate offspring.

** http://www.zoo.cam.ac.uk/zoostaff/manica.html

According to NBC News Channel, someone has placed a shark pup on top of a toilet in a public restroom in Beaufort, South Carolina. When the young shark was discovered by two women who needed to use the facility, it was already dead. The women shot a picture of the shark and alerted the facility manager.

Beaufort is a small city located in a marshy estuary adjacent to the Atlantic Ocean on the coast of South Carolina. The species of shark has not been identified, but it was probably caught nearby.

The rare Gangetic dolphin (Platanista gangetica) has been declared National Aquatic Animal of India. A few days after the formal declaration, which took place at a National Ganga River Basic Authority meeting in New Delhi earlier this week, Bihar chief minister Nitish Kumar announced that he has directed state authorities to put a halt to dolphin hunting in the Ganga.

“A close watch is being kept on the ghats of river Ganga by the magistrates, police officials and block development officers to stop hunting and fishing of the mammals,” senior officials said.

Patna District Magistrate J K Sinha said that instructions from chief minister has been passed
to senior officials, including sub-divisional officers, magistrates, police officers and block development officers to ensure close surveillance and act swiftly to stop hunting of the aquatic animal.

“Schools will take steps to aware the students about the gangetic dolphin which would

boost eco-tourism in the region,” he added.

Although the Wildlife Protection Act of India mandates dolphin conservation as a priority, little has been done at the government level to implement or enforce the law.

Where is Bihar?

Bihar is an Indian state located in the eastern part of the country. It is bordered by Nepal to the north, Jharkhand to the south, Uttar Pradesh to the west, and West Bengal to the east. The state is bisected by the Ganga River which flows through the middle of the state from west to east.

What is Ganga?

Outside India, the Ganga River is more commonly known as the Ganges River.

What is the Gangetic dolphin?

The Gangetic dolphine, also known as Ganges dolphin, Ganges river dolphin, Blind dolphin, and Side-swimming dolphin, is a dolphin endemic to the Ganges-Brahmaputra-Meghna and Karnaphuli-Sangu river systems of Nepal, India, and Bangladesh. Its scientific name is Platanista gangetica and it is listed as Endangered on the IUCN Red List of Threatened Species. The current population consists of 1,200-1,800 individuals, and roughly half of these are found in Bihar and Uttar Pradesh.

It is referred to as the Blind dolphin due to its poor eye-sight which is probably an adaptation to the murky waters of the Ganga River.

Larry, a 3-foot-long Tawny nurse shark (Nebrius ferrugineus) has been moved from his cramped dwellings in a Burbank pet store to the Birch Aquarium, a public aquarium and museum capable of offering him much more spacious accommodations. The Birch Aquarium is a part of the Scripps Institution of Oceanography in La Jolla, which in turn is part of the University of California in San Diego.

Larry’s move to a new home is the result of Burbank resident Stephanie Field spotting Larry at the Scales ‘n’ Tails pet shop in Burbank.

“I swore to him I would get him out of there”, Field said.

After discussing the situation with PETA and an animal shelter, Field went back to the store to talk to the owner Vahe Issaian. She had decided to purchase Larry and set him free in the ocean off the coast of California, but Issaian explained to her that doing so would only serve to kill the shark.

“That’s when I found out Vahe is a really good guy,” Field said.

As it turned out, Issaian had been trying to find a new home for Larry for quite some time but without any success. Issaian had first brought him to his pet store in 2001 when Larry’s owner left for military service and could care for his big fish any longer. In 2002, Larry was purchased by a couple from Valencia with whom he stayed until 2008.

“They had it for five years, and I picked it up in mid-2008 because they were remodelling their home and didn’t have an eight-foot wall for the aquarium,” Issaian said.

Since then, Larry had been living at Issaian’s other Burbank store, Millenium Pets. Trying to find a new home for a shark that can reach a length of 10 feet (3 metre) is not the easiest thing in the world since few people have enough space to devote to such a gigantic pet.

Finally, it was Field’s mother who suggested calling the Australian Consulate and this set the wheels in motion. After talking to the consulate on Wednesday morning, Field received an e-mail that same day telling her that progress had been made and that she could stop making calls.

On Tuesday, assistant curator Fernando Nosratpour picked up Larry from the pet shop and moved him to his new home. Larry will now spend two weeks in quarantine before he’s introduced to the other sharks.

Always research pets before you buy them

Adult Tawny nurse sharks can reach a length of 10 feet (3 metres) and getting a nurse shark for your hobby aquarium is not a good idea unless you have a HUGE tank. Nosratpour says that the Birch Aquarium do receive offers now and then to take nurse sharks that people have bought without first researching how large they will become as adults.

“Most public aquariums can’t take them anymore,” he said. “Pet stores can’t take them, and you can’t ship them back to where they are from. But people still buy them, and that’s a problem.”

The Tawny nurse shark is found in the Indian and Pacific Oceans in a region stretching from the northern coast of Australia and almost all the way to the Red Sea. It is the only now living member of the genus Nebrius and can be distinguished form other nurse sharks by its angular fins. It is listed as “Vulnerable” on the IUCN Red List of Threatened Species.

Two species of Asian mouse-deer have been observed utilizing a very interesting technique to get away from predators; they jump into the water and stay there until its safe to come up. By carefully swimming up to the surface to breathe now and then they can stay submerged for long periods of time.

People living in the Indonesian country side have always claimed that deer hide in the water when chased by their dogs, but it wasn’t until the behaviour was observed by a team of scientists doing a biodiversity survey that it caught the attention of the larger scientific community.

In June 2008, the team visited the northern Central Kalimantan Province in Borneo, Indonesia where they suddenly spotted a mouse-deer swimming in a forest stream. When the deer understood that it was being watched by humans, it went below the surface and remained hidden. Over the next hour, team members could see it come to the surface four or five times. Although it probably went up for air a few more times without being noticed, it could clearly remain submerged for more than five minutes at a time.

Eventually, the researchers caught the animal and photographed it before releasing it back into the wild unharmed. It was a pregnant female deer.

One of the members of the team is the wife of Erik Meijaard, a senior ecologist working with the Nature Conservancy in Balikpapan, Indonesia. When she showed her husband the photograph, he identified it as a Greater mouse-deer (Tragulus napu).

That same years, another group of observers witnessed a Mountain mouse-deer (Moschiola spp) throwing itself into pond and swimming under water to get a way from a hungry mongoose in Sri Lanka. The mongoose followed it into the pond, but eventually retreated as the deer continued to stay submerged.

“It came running again and dived into the water and swam underwater. I photographed this clearly and it became clear to me at this stage that swimming was an established part of its escape repertoire,” says Gehan de Silva Wijeyeratne, who saw the incident.

“Seeing it swim underwater was a shock”, he says. “Many mammals can swim in water. But other than those which are adapted for an aquatic existence, swimming is clumsy. The mouse-deer seemed comfortable, it seemed adapted.”

Both incidents have now been described in the journal “Mammalian Biology”.

“This is the first time that this behaviour has been described for Asian mouse-deer species,” says Meijaard. “I was very excited when I heard the mouse-deer stories because it resolved one of those mysteries that local people had told me about but that had remained hidden to science.”

What is a mouse deer?

Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Artiodactyla
Family: Tragulidae

Mouse deer are small deer-like animals with large upper canine teeth. In male specimens you can even see the teeth project down either side of the lower jaw. Ten different species of mouse-deer have been described by science and all except one live in South-East Asia. The Water Chevrotain (Hyemoschus aquaticus) is the only mouse deer native to the African continent and it is also the largest member of the family.

The Water Chevrotain (Hyemoschus aquaticus) lives in swampy habitats and is known to dash into the nearest river as soon as it is spooked by something. Until recently, this was the only mouse deer in which the habit of swimming under water and staying submerged for long periods of time had been described and all the Asian members of the family Tragulidae were thought to be strictly dry-land animals.

One of the most controversial environmental issues of the past decade now seems to have been solved thanks to the consolidated efforts of one U.S. and one U.K. researcher.

In the late 1980s and early 1990s, researchers started getting reports of numerous deformed wild frogs and toads. Many of them missed a limb partly or completely, while others – even more strikingly – had extra legs or extra arms.

The reason behind the deformities became a hot-potato, with some people suspecting chemical pollution or increased UV-B radiation (brought on by the thinning of the ozone layers), while others leaned towards predators or parasites.

“There was a veritable media firestorm, with millions of dollars of grant money at stake,” says Stanley Sessions, an amphibian specialist and professor of biology at Hartwick College, in Oneonta, New York.
Eventually, professor Sessions and other researchers managed to show that many amphibians with extra limbs were actually infected by small parasitic flatworms called Riberoria trematodes. These nematodes burrow into the hindquarters of tadpoles and rearrange the limb bud cells. This interferes with limb development, and in some cases the result is an extra arm or leg.

While these findings explained the conspicuous presences of additional limbs, it wasn’t enough to solve the mystery of the leg- and armless amphibians.

“Frogs with extra limbs may have been the most dramatic-looking deformities, but they are by far the least common deformities found,” Sessions explains. “The most commonly found deformities are frogs or toads found with missing or truncated limbs, and although parasites occasionally cause limblessness in a frog, these deformities are almost never associated with the trematode species known to cause extra limbs.”

To investigate the conundrum, Sessions teamed up with UK researcher Brandon Ballengee of the University of Plymouth. As a part of a larger research project, the two scientists placed tadpoles in aquariums and added various predators to see if any of them could be responsible for this type of injuries.

As it turned out, three different species of dragonfly nymph happily attacked and nicked of the hind legs of the tadpoles; feasting on the tasty legs without actually killing the tadpoles.

“Once they grab the tadpole, they use their front legs to turn it around, searching for the tender bits, in this case the hind limb buds, which they then snip off with their mandibles,” says Sessions. “Often the tadpole is released […],” says Sessions. “If it survives it metamorphoses into a toad with missing or deformed hind limbs, depending on the developmental stage of the tadpole.”

Eating just a leg instead of trying to kill the entire tadpole is beneficial for the dragonfly, since tadpoles develop poison glands in their skin much earlier than those in their hind legs.

Through surgical experiments, Sessions and Ballengee confirmed that losing a limb at a certain stage of a tadpole’s life can lead to missing or deformed limbs in the adult animal. Really young tadpoles are capable of growing a new limb, but they loose this ability with age.

Sessions stresses that the results of his study doesn’t completely rule out chemicals as the cause of some missing limbs, but says that this type of “selective predation” by dragonfly nymphs is now by far the leading explanation.

“Are parasites sufficient to cause extra limbs?,” he asks. “Yes. Is selective predation by dragonfly nymphs sufficient to cause loss or reduction of limbs. Yes. Are chemical pollutants necessary to understand either of these phenomena? No.”

You can find Sessions and Ballengee’s study in the Journal of Experimental Zoology Part B: Molecular and Developmental Evolution.

A team of U.S. scientists has documented the first transmission of the lethal phocine distemper virus from the Atlantic Ocean to a population of sea otters living along the coast of Alaska.

The presence of phocine distemper virus has been confirmed in nasal swabs take from live otters and through necropsies conducted on dead otters found along the Alaskan coast. The findings also indicate that the virus was passed between seal species across Northern Canada or Arctic Eurasia before reaching the otters in Alaska’s Kachemak Bay.

Prior to this study, PDV had never been identified as the cause of illness or death in the North Pacific Ocean and researchers suggest that diminishing Arctic sea ice may have opened a new migration route for both animals and pathogens.

The study was carried out by researchers from two California universities and the Alaskan branch of the U.S. Fish and Wildlife Service. It has been published in ”Emerging Infectious Diseases”, a journal published by the U.S. Centers for Disease Control and Prevention.

What is phocine distemper virus (PDV)?

Phocine distemper virus (PDV) is a paramyxovirus of the genus Morbillivirus. It is dangerous for pinniped species, especially seals, and is a close relative of the canine distemper virus (CDV).

PDV was first identified in 1988 when it caused the death of approximately 18,000 harbour seals, Phoca vitulina, and 300 grey seals, Halichoerus grypus, in northern Europe. In 2002, the North Sea lost approximately 21,700 harbour seals in new a PDV outbreak – estimated to be over 50% of the total population.

Infected seals normally develop a fever, laboured breathing and nervous symptoms.

“Small fish may have small brains but they still have some surprising cognitive abilities”, says Dr Jeremy Kendal* from Durham University’s Anthropology Department.

Dr Kendal is the lead author of a new study showing that Nine-spined stickleback fish (Pungitius pungitius) can compare the behaviour of other sticklebacks with their own experience and make choices that lead to better food supplies.

“‘Hill-climbing’ strategies are widely seen in human society whereby advances in technology are down to people choosing the best technique through social learning and improving on it, resulting in cumulative culture”, says Dr Kendal. “But our results suggest brain size isn’t everything when it comes to the capacity for social learning.”

Around 270 Nine-spined sticklebacks were caught from Melton Brook in Leicester using dip nets. After being divided into three experimental groups and one control group, the fish were housed in different aquariums and the fish in the experimental groups were subjected to two different learning experiences and two preference tests in a tank with a feeder placed at each end.

1.) The fish were free to investigate both feeders during a number of training trials. One feeder (dubbed “rich feeder”) always handed out more worms than the other one (dubbed “poor feeder”). The fish were then tested to see which feeder they preferred.
2.) In the second training trail, those fish that come to prefer the rich feeder could see other fish feeding. During this stage, the rich and poor feeders were swapped around and the rich feeder either gave even more worms than before or roughly the same or less. During the second test, the fish were once again free to explore the tank and both feeders. Around 75 per cent of the Nine-spined sticklebacks had learned from watching the other fish that the rich feeder, previously experienced first hand themselves as the poor feeder, gave them more worms. In comparison, significantly fewer sticklebacks favoured the feeder that appeared to be rich from watching other sticklebacks if they themselves had experience that the alternative feeder would hand out roughly the same or more worms.

Further testing showed that the sticklebacks were more likely to copy the behaviour of fast feeding fish.

“Lots of animals observe more experienced peers and that way gain foraging skills, develop
food preferences, and learn how to evade predators”, Dr Kendal explained. “But it is not always a recipe for success to simply copy someone. Animals are often better off being selective about when and who they copy. These fish are obviously not at all closely related to humans, yet they have this human ability to only copy when the pay off is better than their own.”

The study, which has been published in the journal Behavioral Ecology, was carried out by scientists from St Andrews and Durham universities and funded by the Biotechnology and Biological Sciences Research Council. The lead author of the study, Dr Kendal, is a Research Council UK Fellow.

A new study funded by the U.S. navy and the Office of Naval Research show that Beaked whales are at higher risk of developing decompression sickness since they live with extremely high levels of nitrogen in their blood and body tissues. This may explain why beaked whales seem to be especially susceptible to naval sonar. If the sonar causes the animals to surface more rapidly than they would normally do, e.g. because they are frightened by the underwater sounds, it may lead to decompression sickness which may in turn explain the strandings associated with naval sonar exercises.

Decompression sickness, commonly referred to as “the bends” among scuba divers, is a consequence of the sudden drop in pressure that occurs when you ascend rapidly from the deep. When mammals dive, nitrogen builds in our bodies. If we ascend slowly the nitrogen isn’t dangerous, but if we ascend too quickly the nitrogen forms bubbles inside the body. Tiny bubbles might not sound like anything to fuzz about, but within the body it can be lethal.

Beaked whales are believed to accumulate large amounts of nitrogen within their bodies since they make repeated dives to such great depths. They can stay submerged without breathing for long periods of time and are capable of descending down to nearly 1,500 metres. Having this inclination for decompression sickness may explain why beaked whales seem to be more vulnerable to naval sonar than other marine mammals.

“It provides more evidence that beaked whales that are being found dead in association with naval sonar activities are likely to be getting decompression sickness,” said Robin Baird, a marine biologist at Cascadia Research Collective and one of the report’s authors.

The study has focused on three species of beaked whale: Cuvier’s beaked whale (Ziphius cavirostris), Blainville’s beaked whale (Mesoplodon densirostris), and the Northern bottlenose whale (Hyperoodon ampullatus). The Northern bottlenose whale was studied off the cost of Nova Scotia, Canada while the two others were observed around Hawaii, U.S.

According to a 2006 report in the Journal of Cetacean Research and Management, 41 known cases of mass strandings of Cuvier’s beaked whales have occurred since 1960. Some of them have happened at the same time as naval sonar exercises in the area, including Greece in 1996, the Bahamas in 2000, and the Canary Islands in 2002. When the beaked whales stranded in Bahamas were autopsied, they turned out to have bleedings around their brains and ears; bleedings which may have been caused by nitrogen bubbles.

The U.S. navy has agreed to adopt certain practises to protect whales, but is resisting more stringent restrictions until more scientific evidence is at hand. The navy has budgeted 26 million US per year over the next five years to fund marine mammal research on how these animals are affected by sound.

If you wish to find out more about the beaked whale study, it is published online this week in the journal Respiratory Physiology and Neurobiology.