50 CFR § 14.55 - Exceptions to clearance requirements.
Except for wildlife requiring a permit pursuant to part 17 or 23 of this subchapter B, clearance is not required for the importation of the following wildlife:
(a) Shellfish and fishery products imported for purposes of human or animal consumption or taken in waters under the jurisdiction of the United States or on the high seas for recreational purposes;
(b) Marine mammals lawfully taken on the high seas by United States residents and imported directly into the United States; and
(c) Certain antique articles as specified in § 14.22 which have been released from custody by Customs officers under 19 U.S.C. 1499.
(d) 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. Except: That this exception will not apply to any specimens or parts thereof taken as a result of sport hunting.