Piracema is not name of the fish, its the name given to the period of the year when fish reproduce within the Paraguay River. The season of reproduction started from October till March, during this period the fish swim upstream to lay their eggs and reproduce. Thus the season is critical for the maintenance of fish populations in the waters of the rivers and lakes. Brazilian states prohibit fishing during this period in order to maintain fish population in the river.
Astronomers have always assumed that Uranus must have been knocked onto its side by a collision. Now a new idea suggests that the planet's remarkable tilt could have another explanation.
