Ontogenetic changes in schooling behaviour during larval and early juvenile stages of Pacific bluefin tuna Thunnus orientalis.

Schooling was first observed at 25-27 days after hatching (26. 2-33. 8 mm, total length) in the Pacific bluefin tuna Thunnus orientalis. At this time, the mode of swimming changed from intermittent sprinting to continuous cruising, and this allowed the fish to adjust to an inertial hydrodynamic environment.