Vertebral compression involves alterations of the growth plates, and is but one component of a range of changes with complex aetiology that result in spinal deformity. A striking feature of compressed salmon vertebrae is the coincidence of metaplastic synchondrosis and the shape alterations of the vertebral end plates, raising the possibility that either bone alterations induce the conversion of the notochord tissue or that changes of the notochord induce bone alterations. The current state of knowledge suggests the latter, since the notochord plays an important...