Plecospondylic spinal column in the viviparous Cyprinodont Lebistes reticulatus (Peters)

Description of a case of plecospondylic spinal column in the viviparous Cyprinodont Lebistes reticulatus (PETERS), the so-called guppy or millionfish. In this deformity the following phenomena have been observed: displacement of vertebrae, transformation of vertebrae, increase in size of vertebrae, decrease in size of vertebrae, coalescence of vertebrae, disappearance of vertebrae. Inflammatory cells such as lymphocytes, polynuclear granulocytes and cells with club-shaped inclusions (DUTHIE, 1939; STOLK, 1950 a, 1954 a, 1954 b, 1954 c; CATTON, 1951; ARONOWITZ, NIGRELLI and GORDON, 1951) were not found. Consequently inflammatory processes have not played an important part in the origin of this spinal column deformity. The skeleton of the head and the extremities and, moreover, the musculature and the skin showed no deformities. Beside the occurrence of absorption and formation of cartilage the displacement of the vertebrae with respect to each other may undoubtedly have played a role as an etiological factor. Probably an osteomalacia occurred and consequently a growing together of the vertebrae and as a result the successive wave-like curvatures of the spinal column. To what extent this osteomalacia is a result of hereditary factors cannot be determined.