Tag: ‘Animal’

The bioluminescent tail of Genji

16 Mar 2006

Scientists have succeeded in unraveling the mystery -- at the protein structure level -- of the mechanism at work in the glowing tail of the "Genji firefly" (Luciola cruciata Motschulsky), which is considered to have the highest luminous efficiency of any known source of light. The results of the joint research carried by the Institute of Physical and Chemical Research (RIKEN) and Kyoto University are to be published in the March 16 edition of the British science journal Nature.

Bioluminescence

By tinkering with the chemical composition of luciferase (a bioluminescent enzyme), the research team succeeded in changing the emission color from its normal greenish-yellow to orange and red. Researchers are now attempting to recreate the blue glow of the sea firefly (Vargula hilgendorfii) and firefly squid (Watasenia scintillans) in order to have all three primary colors at their fingertips.

"This might prove useful in applications such as short-term emergency lighting when no source of electricity or combustion is available," says Kyoto University professor Hiroaki Kato. "Light could be created by mixing up a liquid protein solution."

Anytime energy is converted into light, there is some loss due to heat. Luminous efficiency is a measure of the proportion of energy supplied to a light source that is effectively converted into visible light energy (i.e. the amount not lost to heat or infrared radiation). The luminous efficiency of incandescent light bulbs is around 10%, while fluorescent light is around 20% and LED is around 30%. Firefly tails are significantly higher, at 90%. Scientists were aware that the Genji firefly used luciferase in combination with luciferin (a light-emitting substrate) and adenosine triphosphate (ATP) to produce light, but the detailed workings of the mechanism have until now remained a mystery.

[Sources: Jiji, RIKEN press release]

Housecats “tagged” to protect Tsushima leopard cat?

10 Mar 2006
Tsushima Leopard Cat

Environmental advocates have come up with a set of guidelines aimed at preserving the Tsushima leopard cat (Tsushima yamaneko), an endangered and protected species that inhabits Tsushima in Nagasaki prefecture. Measures include mandatory registration of all domestic cats to reduce the number of strays and prevent the Tsushima leopard cat from contracting infectious diseases. The guidelines were decided at the International Workshop for the Preservation of the Tsushima Leopard Cat, which was held in Tsushima in January. Organizers are pressing the relevant national and prefectural organizations to adopt the proposed measures.

The guidelines stipulate that cat owners must register their pets and have them implanted with microchips. In addition, the guidelines call on the government to construct better roads to reduce the number of traffic accidents -- a major cause of death for the Tsushima leopard cat. They also suggest breeding the wildcats in captivity at several facilities to preserve the species.

[Source: Kyodo News]

Zoos grapple with winter blues

25 Feb 2006

As Japan?s harsh winter takes its toll on zoo animals by causing problems from chapped feet to appetite loss, zookeepers do what they can to deal with the cold weather.

At Tama Zoo (Hino, Tokyo), where the temperature is about 3 degrees Celsius (5 degrees Fahrenheit) lower than central Tokyo, zookeepers keep the Bornean orangutans indoors when it is cold. The popular skywalk, built last April to provide a means for the orangutans to exercise their rope-walking skills, remains unused because the orangutans have been unwilling to venture outside since last November. Zoo officials shut down the skywalk in December because the baby orangutans, who usually cross the ropes with vigor, developed chapped feet.

Orangutan at Tama Zoo
Orangutan at Tama Zoo on a warm day

Even the elephants and rhinos, considered relatively resistant to cold weather with their thick skins, have had to move to heated indoor enclosures earlier and more often than usual.

At Ueno Zoo (Taito ward, Tokyo), zookeepers often bring the giraffes and elephants indoors early. ?Prolonged exposure to cold temperatures weakens the physical condition of the animals, so we do what we can to keep them healthy,? says one zookeeper.

At Higashiyama Zoo in Nagoya, a flamingo suffered a leg injury caused by a piece of broken ice in the freezing pond.

At the Japanese Monkey Center (Inuyama, Aichi prefecture), zookeepers apply ointment to the frostbitten feet of South African long-haired spider monkeys. Other monkeys in the zoo hospital are suffering from colds and appetite loss.

It has been a tough winter for us all.

[Source: Asahi Shimbun]

Giant jellyfish wreak havoc on Japanese fishing

20 Jan 2006

Giant jellyfish (Echizen kurage) caused 101,540 cases of damage to fisheries between September and December 2005, including reduced catches and increased labor, according to research conducted by the Fisheries Agency. The results of the research were announced January 19 at a strategy meeting attended by officials from prefectural and city governments.

The research was conducted by local governments over the four month period. Cases of reported damage were broken down as follows: increased labor/time -- 34%, reduced catches -- 23%, reduced seafood prices due to lower quality and freshness -- 22%, interruption/suspension of fishing operations -- 4%, and physical damage such as torn nets -- 4%. Damage to trawl nets and fixed nets was significant for some types of fishing. October saw the most damage, with 37,087 cases reported.

The number of cases was determined based on each type of case that occurred per fishing vessel per day. Actual financial damages are difficult to calculate, so they remain unknown.

Fiscal year 2005 has seen the largest numbers of giant jellyfish in recent history, and the increased numbers have affected fishing in the Japan Sea, as well as in the Pacific Ocean and Sea of Okhostk. The overall numbers are now declining, but the jellyfish are still showing up in large areas of the Japan Sea and on the Sanriku Coast, where they are expected to be seen through February.

Giant jellyfish
Photo via National Geographic

[Source: Mainichi Shimbun]