Skeletal deformities widely occur in both marine and freshwater fishes. Various types of deformities have been reported in different fish species, these include lordosis, kyphosis, scoliosis, mandibular deformities, semi-opened operculum, stump body, pug-head, double fins, fin fusion and cross bits. Skeletal deformities occurred due to many causes; chemical, physical and biological. The biological causes include viral, bacterial and parasitic infections. Also nutritional causes as phosphorus and vitamin C deficiency, high levels of vitamin A and finally genetic causes. Deformities can be...