These sharks live near the sea floor between 90 and 600 m deep, but may move closer to the surface at night to take advantage of prey there.

Monogeneans of the genus Protocotyle (family Hexabothriidae) have been found only on the gills of species of Hexanchus.

[3] The species Protocotyle euzetmaillardi Justine, 2011 was recently described from the gills of Hexanchus nakamurai off New Caledonia, South Pacific Ocean.

Based on the few stomach examinations of these sharks, they are thought to feed mainly on small to moderately sized bony fish and bottom dwelling crustaceans.

Based on what little is known of the species, these sharks are not suffering major declines to their population, but pressure is growing from deepwater fisheries.