Note: Looks similar to Blue Shark dorsal fin (not CITES listed). The blue dorsal has a shorter free rear tip and lower angular leading edge, with a more brownish coloration.
The Silky Shark Carcharhinus falciformis is listed as Vulnerable on the IUCN Red List of Threatened Species™ and in CITES Appendix II.
Information has been adapted from Abercrombie and Hernandez (2017). Identifying shark fins: implementing and enforcing CITES. Abercrombie & Fish.