An update to the critical checklist of the marine fishes of Malta and surrounding waters

Abstract

The critical checklist of the marine fishes of Malta and surrounding waters published by the present authors in 2023 provided the first evidence-based assessment of the marine ichthyofauna of the Maltese Islands. Since then, new faunistic, fisheries-related, and molecular data have become available, justifying an update. The present work critically reviews the scientific and selected popular literature published up to April 2026, applying the same study area and authentication criteria adopted in the 2023 checklist. The update affects 22 species: six are newly reported from Maltese waters, of which two still require confirmation; nine species previously treated as unconfirmed and three species originally excluded are here confirmed; two species formerly known only from historical records are also confirmed; and two species are excluded on the basis of revised taxonomic or biogeographical knowledge. Consequently, the number of confirmed species increases from 412 to 426, the number of unconfirmed species decreases from 53 to 45, and the number of excluded species decreases from 78 to 77. Within the confirmed fauna, native species increase from 370 to 379, non-established alien species from 17 to 19, and non-established Atlantic immigrants from 3 to 6, whereas the numbers of established aliens, established Atlantic immigrants, and cryptogenic species remain unchanged. The changes documented here reflect improved sampling, especially of deep-water species, the resolution of taxonomic uncertainty through molecular analyses, and the continued arrival of newcomer species. This updated checklist provides a more accurate and current baseline for future faunistic, biogeographical, ecological, conservation, and fisheries-related studies on the marine fishes of Maltese waters.