Occurrence of magnetic material in teleosts.

Fishes representing the main groups of teleosts have been investigated for magnetic material by susceptibility measurements. All the investigated species contain magnetic material. Bone samples from the skull and the vertebral column contain magnetic particles which yield a saturation magnetization in the range 10(-4) emu g-1 to 10(-3) emu g-1 in a sample. The localization of the magnetization is diffuse within the tissues connected to the bone. There are no significant differences between the amounts of magnetic material that are found in migrating or more stationary species.