Mediterranean Records of the Alien Fishes Paracanthurus hepatus and Heniochus intermedius: Source Reconciliation and New Observations from France and Italy

Conspicuous tropical fishes are readily detected by sea users, but repeated sightings and uncertain identifications can distort occurrence histories. We reviewed source-traceable Mediterranean records of Paracanthurus hepatus and Heniochus intermedius through 1 October 2026 and documented two additional video observations: P. hepatus at Cap Dramont, France, on 10 September 2024, and Heniochus cf. intermedius near Sorrento, Italy, on 23 June 2026. Five P. hepatus observation episodes represent at least four individuals. The French observation was approximately 79 m from the site of a fish removed in July and 0.92 km from another individual last observed five days earlier; it may represent the latter fish after displacement or an additional individual. The reconciled Heniochus chronology contains 27 reported occurrence entries across 11 countries: 14 retained as H. intermedius and 13 as H. cf. intermedius. Aquarium release is the leading hypothesis for P. hepatus, whereas Suez Canal dispersal is plausible for H. intermedius; individual pathways remain unverified. Source reconciliation and conservative identification improve citizen-science contributions to Mediterranean biodiversity monitoring.