[3] During the rainy season, males become very colourful; the sides are metallic bluish-green, the tail is orange-red and there are about seven dark, saddle-shaped markings on the back.

Females are grey or brown with dark saddle markings, a pale belly and a black and white band at the base of the tail.

They are translucent at this stage and remain at sea for somewhere between 133 and 256 days before getting the urge to migrate back into fresh water.

They have already developed suction discs, but now they undergo metamorphosis, their mouths move from the tip of the snout to the underneath of the head, they begin to develop pigment, the pectoral fins transform, the tail loses its fork, they grow teeth on the premaxillae bone, changes occur in the cranium and changes in osmoregulation take place.

After two days in the estuary, the juvenile fish move upstream, overcoming small waterfalls with the aid of their suction discs, and after about three or four weeks of migration start to take up territories in the fast-flowing streams where they will breed.