Parco Naturale del Fiume Sile

The reproduction of the eel has been a mystery for centuries, since also the biggest male specimens seemed lacking of reproductive organs. Therefore, since ancient times, fanciful hypotheses have been formulated: among them, the theory according to which the animal could develop from the scales produced by adult eels rubbing themselves against stones. Only between the late 18th century and the mid-19th century it was discovered that the animal sexually reproduced, but there were still doubts on the mating place and the place where the eggs hatched, while many people still believed Aristotle's theory, according to which eels were born from small worms forming in the rainwater ponds.