Except for wildlife requiring a permit pursuant to parts 16, 17, 18, 21, 22 or 23 of this subchapter, dead, preserved, dried, or embedded scientific specimens or parts thereof, imported or exported by accredited scientists or accredited scientific institutions for taxonomic or systematic research purposes may enter or exit through any U.S. Customs port, or may be shipped through the international mail system. Provided, that this exception will not apply to any specimens or parts thereof taken as a result of sport hunting.