Sailfish

Photo: Robin Hughes · CC BY-NC-SA

Sailfish are the dominant billfish predator in the Mozambique Channel around Bazaruto, and surface activity — including bill-slapping and dorsal fin breaking — is occasionally visible from dive boats during the October to March period when sardine runs and spawning fusilier aggregations concentrate prey at the surface. Their iconic dorsal sail is normally folded flat during swimming to reduce drag but is raised during cooperative hunting, where groups of sailfish herd baitfish into tight balls near the surface, taking turns charging through the school with sail erect to disorient prey. Encounters during dives are brief and thrilling — sailfish investigate divers with passes at close range before disappearing into blue water at speed.