The eggs hatch within a week of deposition in the Sargasso Sea. Fertilization is external, the adult eels are presumed to die after spawning. The leptocephalus is the larval form, a stage strikingly different from the adult form the eels will grow into. They are transparent with a small pointed head and large teeth. The laterally compressed larvae are passively transported to the coastal waters, by the surface currents of the Gulf Stream system. As they enter the continental shelf, leptocephali metamorphose into glass eels, they are transparent and possess the typical elongate and serpentine eel shape. Young eels use selective tidal stream transport to move up. As they enter coastal waters, the animals essentially transform. Out of the Sargasso Sea... Glass eels become progressively pigmented as they approach the shore; these eels are termed elvers. The melanic pigmentation process occurs in coastal waters. At this phase of the life cycle, the eel is still s**ually undifferentiated. The Yellow eels is the s**ually immature adult stage of eel. They begin to develop a yellow color and a creamy or yellowish belly. s**ual differentiation occurs during the yellow stage. As the maturation process proceeds, the yellow eel metamorphoses into a silver eel. The silvering metamorphosis results in morphological and physiological modifications that prepare the animal to migrate back to the Sargasso Sea. Вack to the Sargasso Sea...