A South Africa court has sentenced a Thai national to 40 years in prison for selling rhino horns.  The magistrate handed down the sentence down Friday to Chumlong Lemtongthai who had pleaded guilty to 59 charges on Monday.  The South African Revenue Service says Lemtongthai was arrested in 2010 with five other suspects. Lemtongthai pleaded guilty to paying prostitutes who posed as hunters to harvest rhino horns, which were then sold on Asia’s traditional medicine market, according to the South African Press Association.South Africa is home to some 20,000 rhinos. Growing Asian demand for rhino horn is believed to be behind a poaching spike.  At least 458 of South Africa’s endangered rhinos have been illegally killed this year.