Light and internal body clocks influence movement and balance strategies in young zebrafish

Larval zebrafish exhibit distinct swimming behaviors based on light conditions to maintain balance and posture.

• In darkness, zebrafish swim in long bouts with significant nose-up rotations to counterbalance nose-down drift from inactivity.
• Effective maintenance of posture in the dark requires vestibular sensation from the utricle.
• In light, zebrafish utilize shorter, more frequent swimming bouts that vary in pattern.
• Ambient light significantly influences locomotor strategies, while circadian rhythms also play a role in swim movements.
• The study identifies how both external light and internal biological clocks affect swimming and balance in diurnal fish.

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