Development of the genital papilla of a female Notopterus notopterus, seen in various photographs at high magnification. (a) The emergence of genital papilla, juvenile, stage 35, total length (TL) 52 mm, day 83; note the pair of ventral fins; (b) genital papilla of a stage 36 juvenile with TL 100 mm, 5 months; (c) stage 36, TL=124 mm, 8 months; (d) stage 36 TL= 136 mm, 12 months; (e) stage 37, TL=145 mm, 18 months old specimen; (f) Mature genital papilla obviously longer than the pelvic fins, TL= 230 mm, 24 months old adult female; significant growth of the genital papilla (white arrowhead) in between the ventral fins (arrow) and anal fin. Scale bar= 2 mm (a, c, e); 5 mm (b, d, f)