Salmon backbones with rich, fatty, flavorful meat are boiled in just salt and water until the bones are soft. 
Kyokuyo's "Salmon Backbone Boiled in Water 140g" is a canned product made by slowly boiling the backbone of domestic salmon until it becomes very tender, providing a rich source of calcium. The simple boiling seasoning is salt alone, making the most of the salmon's natural flavor and fattiness. There is a moderate amount of meat attached to the backbone, and the bone can be eaten, making it suitable for calcium supplementation, such as preventing osteoporosis.

Kyokuyo Salmon Bone Boiled in Water 140g [Canned Fish and Shellfish] Product Specifications