Appendix II, about 21,000 species, are species that are not necessarily threatened with extinction, but may become so unless trade in specimens of such species is subject to strict regulation in order to avoid utilization incompatible with the survival of the species in the wild. In addition, Appendix II can include species similar in appearance to species already listed in the Appendices. International trade in specimens of Appendix II species may be authorized by the granting of an export permit or re-export certificate. In practice, many hundreds of thousands of Appendix II animals are traded annually. No import permit is necessary for these species under CITES, although some Parties do require import permits as part of their stricter domestic measures. A non-detriment finding and export permit are required by the exporting Party.