Tag Archive | "Fish"

Tags: , , , , , , ,

Russian Sturgeon

Posted on 09 January 2013 by RE Team

The Scientific Name : Acipenser gueldenstaedtii

Where is it found?

The Russian is currently found the Caspian Sea and the Black Sea. In the Caspian sea region it spawns in the rivers Ural and Volga, where in the Black Sea spawning occurs in the lower Danube and Rioni rivers. Once it was found in abundance in the Azov Sea basins, which is now considered as extinct as no known native spawning population is there in that region. The species prefers shallow water of the coastal sea and deep regions of large rivers where the current is strong.

 

Russian Sturgeon Range

 

How does it live?

The Russian Sturgeon feeds on a wide variety of benthic molluscs, crustaceans and small fish. Males attain maturity at around 8 years, while females at around 10 years. The females reproduce every 4-6 years while males 2-3 years. This long reproduction cycle is a major threat for the fish. After maturity they migrate from the sea to the fresh water rivers into several hundred kilometers. It usually happens in the Autumn of in the Spring when the temperature rises above 10 deg C. Juveniles mostly spend their years in the sea till they attain maturity.The maximum age ever recorded of a Russian Sturgeon is 48 years.

How does it look?

Russian Sturgeon is a gigantic fish usually reaches a length of 2 meters and weight more than 100 kg. The juveniles look beautiful with white diamond like scales that become grey with age. They grow very fast, 1 ft/year, for initial few years. Body Of the Russian Sturgeon is spindle-shaped and proportionally wide. Dorsal scutes can range from 8 to 18, lateral scutes 24-50 and ventral scutes 6-13. It differs from other species of the Acipenser genera by its short snout with rounded tip, as well as by its lower lip, which is interrupted at its center. Barbells are not fringed, they are short, curved and situated near the top of the snout.

What are the threats?

The Russian Sturgeons are struggling hard to survive. The spawning grounds for the species have been lost to various large river dams created in the Danube, Don and Volga river. It is estimated that the species has lost more than 70% of its spawning grounds since 1950s. Annual catch for the fish has dropped drastically since 1980s from 90 – 100% i n most of the regions. Fishing, which is now strictly banned, is also one of the major threat to the fish currently. The caviar of the Russian sturgeon is one of the most sought after, and the flesh of the fish is also in demand always making poaching of the fish more frequent. High levels of pollution (from oil and industrial waste), in both the Black and Caspian Sea basins have altered hormonal balance, and increased the number of hermaphroditic fish. In 1990, 55,000 sturgeon were found dead on the shore of the Sea of Azov as the result of pollution.

Conservation Efforts

The fishing of Russian Sturgeon is made illegal many years ago in Russia and Iran both. But the enforcement of the law is not happening. The increasing demand is luring the poachers. General conservation measures for the fish is also weak or never applied. Fish lifts and artificial spawning grounds have been introduced to parts of the Caspian region without much success. The pollution level of the Caspian and Black sea have been decreasing in recent years, but the fish is still not out of danger from genetic deformation.

The Russian Sturgeon Conservation

Comments (0)

Tags: , , , , ,

Cracking Arkansas Death Mystery

Posted on 04 January 2011 by RE Team

The new year brought mystery and tragedy to the southern state of United States of America, Arkansas. The land of mountains, valleys, forests and rich wildlife has seen massacre of birds, fishes due to still unknown and mysterious cause.

 

A poor dead black-bird in Arkansas

 

This mysterious event first occurred in the small town of Beebe on the day of New Year. Within an area of just one-mile diameter, birds started falling out of the sky. The tragic event stunned thousands of people in the town. Within few hours the number of falling birds increased to more than thousand.  It was like a doomsday event in movies, the red-winged blackbirds, grackles, and starlings fell all over from the skies filling the roads and walkways. The death fall that started at around 11:30 pm just on the New Year Eve, gave the residents a horrifying experience. The total number of deaths of those poor birds may cross five thousands.

Adding more to it, Arkansas River saw another strange and unexplained event. On a 20-mile stretch between Ozark and Clarksville the river washed up hundreds of thousands of dead drum fish. This new report made the locals of Arkansas crazy and they are horrified at these unnatural incidents.

 

Dead drum fish at Arkansas river

 

Scientists are still not in a position to find the exact cause of these two incidents. This inability of the scientists has compelled common people to think out of the track and consider these events to be the act of supernatural.  Some believe these two incidents are not just coincidence, they have hidden meaning. There are more speculations like alien acts, ghostly affair, or some conspiracy theory etc.

But it may not be a strange event for the scientists. These are definitely two independent accidents happened at the same time in the same area.

The fish death can be explained easily as some disease, similar to what The Arkansas Game and Fish Commission believes. Because the fish are from the same species, it is highly possible that some unknown disease stroked them. The possible cause of any pollutant is ruled out because, it would have killed all the fished but not only one species.

The recent lab result on the birds also says that there is no involvement of poisonous material. It has been discovered that the birds all suffered from blunt force trauma. Authorities have stated that the incident could have possibly been the result of hail, lightning, or even trauma from fireworks. And this is absolutely true and is considered as a regular event in other parts of the world. Jatinga, a small village in North-East India sees this event every year during winter. Any torches or fire, on special weather condition of the region, attracts birds of some specific species. The birds fly down straight from the high sky at night and fall prey to the fire or torch. This was considered as a “Gift of Gods” by the tribal of the region historically. This is well explained in this website already. The Arkansas bird death is pretty much similar to this and can be related.

The Arkansas events are definitely two independent accidents happening at the same time in the same place, creating chaos among people. But in reality, the birds’ deaths can be explained as a known incident similar to Jatinga bird suicide, while the fish deaths can be considered as an act of some deadly disease.  We hope scientists will soon resolve the mystery with firm results.

Comments (0)

MOST CONCERNED ENDANGERED SPECIES

Photos of Nature