Where they actually spawn is uncertain but is believed to be in the South Coral Sea off the coast of North Queensland. Mature females about a metre in length have been found to contain more than 3 million eggs. The eel larvae, known as leptocephali because of their leaf like flat shape, are carried south by the East Australian Current from their spawning grounds until they reach the continental shelf. At around this time they metamorphose into the normal tubular eel shape although devoid of any pigment and so are known as glass eels. When the glass eels begin to migrate into fresh water they may be anywhere from one to three years old.
Migration begins in the autumn in Northern regions reaching Western Victoria by mid spring.
Whilst in the estuarine waters the glass eels quickly develop into fully pigment elvers and adjust to fresh water. Subsequent migrations from the estuaries into fresh water involve both elvers and glass eels and may happen after, during or before the main migration from the sea. Generally these occur at night and may involve as many as four different age classes. Eels can live for a long time and females may reach the age of 35 years before feeling the urge to begin the cycle all over again. Males may live for 25 years.