Late juvenile to the maturation stage in Notopterus notopterus. (a) Stage 36: appearance of ventral fin, black arrowhead, day 92; (b) Stage 37: late stage of juvenile with total length of 145 mm, note the change in color and the emergence of scales, 18 months; (c) Stage 38: adult male with total length 275 mm, captured at age of 30 months; note the ventral fin (arrowhead) longer than the genital papilla. Scale bar = 10 mm (a); 20 mm (b); 30 mm (c).