Deformities consisting of an upward curvature of the spine in the caudal region with varying degrees of reduction of the caudal fin were observed in some fry of a laboratory population of Oreochromis niloticus (L.). This spinal deformity was combined with a reduction of the operculum, exposing some gill lamellae. No deformed fry survived for more than 7 days after completion of yolk sac absorption. Breeding tests demonstrate that the mutant phenotype is controlled by a single autosomal recessive gene.
Mair, G.C. Caudal deformity syndrome (CDS): an autosomal recessive lethal mutation in the tilapia, Oreochromis niloticus (L.). Journal of Fish Diseases (1992) 15 (1) 71-75. [DOI: 10.1111/j.1365-2761.1992.tb00638.x]