ABSTRACT
As mentioned before, secondary metamorphosis, which occurs in juveniles, involves various morphological, physiological and behavioral modifi cations that pre-adapt the animal to life in a new environment. These modifi cations are less drastic than those observed during larval/true/fi rst metamorphosis. This type of metamorphosis in teleosts seems to be related to extreme migration and complex biological cycles, as observed in salmons (smoltifi cation) and eels (silvering).
