Wild Siamese-twins in black tip sea catfish, Arius dussumieri (Valencienes, 1840) from Gulf of Oman.

Abstract

point) of the upper fish (Figure 4) had lost its poste-rior part and appeared compressed between the 7th and 9th vertebrae. Compressed, 11th & 12th vertebrae (counting from the dividing region of the lower fish (Figure 4) but not otherwise deformed were obser-ved with their neural and haemal spines not defor-med. Minor abnormalities including non-aligned and wavy neural and haemal spines of both fish from different body regions were also noted (Figures 2-4). The fin rays of the common anal fin were deformed and their connection to the underlying pterygiopho-res were lost. The last four fin rays of the dorsal fin of the upper fish was reduced in size while the re-maining two appeared normal, but fused together. The dorsal fin rays of the lower fish were normal (Figu-