Magnetic particles in chum salmon (<i>Oncorhynchus keta</i>): extraction and transmission electron microscopy

Abstract

Magnetic material was extracted from the head and an area covering the lateral line of chum salmon. Although magnetic material was distributed widely in the head, it was more often extracted from the posterior part of the skull. The material was black in coloration. Crystalline particles were observed with a transmission electron microscope. These particles were covered by a thin film and ranged in diameter from 15 to 196 nm. The major element of these particles was iron, and we conclude that they are biogenic magnetite.