the end I gave stronger than expected, and what began as a strong cold running accompanied by the entire body. Overall a real pain in the ass than it seems I've recovered enough now not to say everything.
On Sunday I wanted to do a completely normal life, go out, take the stitching, walking ... so any day. I walked in the scope ORT an artificial lake that exists in curiously shared Logroño and tour with the French Way to Santiago. I often is a stunning natural setting, well connected that started years ago the government of the community and worth. magnificent work of entertainment.
As you travel through one of his many trips the lake, you see posters advertising the features of the environment and river life is inside him. I never noticed a 'description of one of the inhabitants of these waters and yesterday "d 
escubrí" first and sure many of you already know.
is the mysterious and strange life of eels. Amazing what I read there and totally up-front summary. Upon arriving home, I need to continue reading the incredible vicissitudes along life of this unknown and mysterious inhabitant of our fresh water even though I have seen child fishing boat, once clean Ebro River
colloquial way as narrated, I read that ...
Eels are a few things that have fascinated naturalists of all time, beginning with Aristotle, the number of puzzles it presents its biology. Even today are still full of unsolved mysteries. For example, remains a mystery how they are targeted at sea. It remains a mystery where are the eels at sea. There are only documented five sacks and five near the coast.
Eels live most of his life in the rivers, the males in the lower and upper females. Salinity influences the sex of eels. For example, in the Baltic Sea, low salinity, all eels are females. Those that remain in the brackish waters of estuaries become males.
reaches sexual maturity in males between 4 and 8 years old and females between 7 and 12 and at that time in the fall, prepare to spend the HONEY MOON IN THE Caribbean in the Sargasso Sea, RIGHT IN THE BERMUDA TRIANGLE. This is where they mate, lay eggs and larvae on a long voyage into rivers of origin. After two and a half of travel, when measured 75 mm and are about to become elvers appear on European shores. In Spain, between December and February.
To learn more about the life of eels, in the form of questions raised related issues.
Why make a journey of 5,000 km to mate?
The final answer, sure, we do not. But we do know is that 140 million years ago the current Sargasso Sea was a swamp between America and Europe that were stuck. It is assumed that Eels went there to play. It is not uncommon that certain animals have special breeding sites. Probably the males were in the brackish and females in the headwaters of rivers. Females mate and lay down to eggs. All quite normal. But little by little, the continents were separating, and that wetland area was moving away and becoming deeper. Farther and farther and deeper. Eels were adapted slowly to the new situation. We think they have spent 140 million years.
How can withstand 5,000 kilometers without eating?
Before embarking on the journey of migration stop eating, its color darkens over the back and becomes silvery on the belly, it will enlarge the eyes, digestive tract and wasting huge amount of fat accumulates, it becomes 25% of its weight. Eels have been four years in salt water without eating and have resisted well, not only alive but active. That is, the fat that accumulates before your trip perfectly resist the two-year journey.
How old are they when they are called elvers?
are the size that we see in the fish stalls and age is three and a half years.
How old can live up to an eel?
We have said that undertake the autumn migration of males between 4 and 8 years and females between 7 and 12. When they reach the Sargasso Sea to spawn and die. That in normal circumstances, but if not then migrate leaves can reach 50.
"At that age will be huge?
female eels reach up to over a meter in length.
Eels are found in lakes that have no connection with rivers that come from the sea. How can you get there?
eels are able to glide like snakes and wet for several miles, and that's what they do out of the lake and go crawling up the river that lead to the sea and there the Caribbean.
"And how do they breathe?
with many blood vessels and oxygen from the air they breathe through it.
Aristotle had the eels in the lakes appear dry after rain, is it true?
When a lake dries, eels burrow into the mud and encyst being able to survive several years in that state. So when it rains appear "suddenly", such as Aristotle noted. Rather, in a similar way, as Aristotle said that appearing in the mud, not preserved in the mud. So Aristotle is a great observation, the eels come out when it rains on a dry lake that takes a long time, and an error: not born from the bowels of the earth as he thought.
European and American eels, are the same species?
No. And to think the opposite has been one of the great blunders of the twentieth century biology. In 1959 an American researcher, named Tucker, successfully defended the European eel could not make the trip of 5,000 miles without food they had to die. He argued that only the larvae of the American put, which are much closer to the Sargasso Sea. And then some others emigrated to America and Europe. His ideas were widely accepted, until the arrival of modern genetic testing have proven without a doubt that they are two different species. In 2000 a group of German researchers from the Institute of Biodiversity Research, University of Rostock, published a study on mitochondrial DNA of eight species of eels, there are 16 - and study it appeared that the more similar were the European and Americans, but there was no doubt that they were two different species.
Moreover, recently it has been found that eels American spawn in a different place than European. The two in the Sargasso Sea, but not exactly in the same place, but a few hundred miles apart.
How Americans know that the larvae must go to America and Europe should go to Europe?
Here is a beautiful enigma. Science is so, does not have answers for everything and is good to have issues without research to some people are able to solve.
seems, according to another source you consult, the trip is done once in his life and after mating and spawning, they die.
0 comments:
Post a Comment