A spinal column malformation in the creolefish Paranthias colonus (Osteichthyes: Serranidae).

A creolefish, Paranthias colonus Hildebrand, with deformities in the spinal column, was captured at Isla Espíritu Santo, B.C.S., México (24o35’ N; 110o24’ W). The specimen is in the icthyological collection of the Centro de Investigaciones Biológicas del Noroeste (CIBNOR) in La Paz, B.C.S. (#CIB1300). The spinal column has v-shaped lardosis in two positions (Fig. 1). One starts at the vertebra 18 and the second at the vertebra 20. Secondary effects include a reduction in size of vertebrae 18 and 19, and a bend and thickening of the neural and haemal spines on vertebra 19. We found no reference to this type of malformation in P. colonus. In our judgement, the malformation is a genetic alteration occuring during the ontogenetic development, which did not prevent the fish from reaching full size.