The Mysterious Eel.
Eel is a very valuable fish and all over the world it is considered a delicacy. At the same time it is a rapidly disappearing species. Due to its risk of rapid extinction the eel is protected, in many countries eel fishing is restricted or even forbidden.
Until now the riddle of eels’ reproduction has not been solved completely. It is believed, that regardless of where they live, eels go to lay eggs in the Sargasso Sea that is in the Atlantic Ocean. They must travel as far as 5000–6000 km.
Eels lay eggs deep in the Sargasso Sea, in the depth of approximately 600 m, that is why nobody has succeeded in recording this process so far. Having fulfilled their mission – laying their eggs – eels die, and their little larvae are carried by the Gulf Stream for an entire year. When finally after a year they reach the shores of Europe, they already look like little glassy eels. They are called glassy because of their transparent bodies.
At the shores of Europe the little glassy eels get into the streams of rivers. Interestingly, most of the come back where their parents used to live.
As they swim upstream, young eels grow and from glassy turn yellow. They go through several stages of maturity until they reach the final destination. Eels take a long time to mature, about 6 – 20 years, depending on their sex. Only fully mature eels are ready to go back to lay eggs to where they have come from – back to the same Sargasso Sea, where they end their life cycle after they lay the eggs.
Scientists are not able to breed it in captivity.
The eel is so mysterious, that until this day scientists are not able to breed it in captivity. However, the Japanese have already discovered the formula for breeding the Japanese eel. Perhaps, in time, it will be adapted to preserve the European eel.
As it is still impossible to breed eels in captivity, young glass eels are brought to fish farms, where they are grown in conditions reminiscent of their natural habitat and fed with high quality feed and with the possibility of natural dangers eliminated. Because of the improved conditions they grow faster than in the nature. Also, a bigger number of eels survive, and this is an advantage for a species that is on the verge of extinction.