For how long do visible juvenile Wolf Eels drift in the upper water column?

For up to two years.

The Wolf Eel exhibits a significant ecological shift as it matures, which is reflected in its life stage behavior and habitat preference. The brightly colored juveniles are not immediately benthic dwellers; instead, they spend a considerable period of their early life drifting as planktonic organisms in the water column. This pelagic phase is estimated to last for a duration extending up to two years. Following this period of drifting and relative visibility, the fish undergoes a dramatic transformation in coloration and behavior, settling down to adopt the sedentary, den-based lifestyle typical of the drab, larger adults in rocky reef areas. This commitment to benthic life is usually finalized around the time they reach sexual maturity, which is estimated to occur near seven years of age.