Juvenile toothfish (40–80 cm in length) are mainly found on the southern Ross Sea shelf and around the Balleny Islands, at depths of 750 m or less. Sub-adult and maturing (80–130 cm) toothfish have been found at more than 750 m in deeper parts of the shelf and along the continental slope. The largest toothfish (>130 cm) are typically found in deeper parts of the slope and on banks, ridges and seamounts in the north. Sex ratios at birth are approximately 50:50. Catches of adults on the slope are approximately 60% female, while catches in the north are approximately 70% male.