The first record of the marbled spinefoot, Siganus rivulatus Forsskål & Niebuhr, 1775 and further records of the dusky spinefoot, Siganus luridus (Rüppell, 1829) from Malta

Here we report the first record of the Marbeled spinefoot, Siganus rivulatus Forsskål and Niebuhr, 1775 (Acanthuriformes: Siganidae), collected in July 2022 from Maltese coastal waters. The specimen was identified through morphological characters and confirmed genetically through DNA barcoding, given that the family Siganidae is composed of several species belonging to only one genus with similar and overlapping morphological characters. Previous to this report, the closest record of S. rivulatus was off the island of Sicily. Thus, the presence of S. rivulatus in Maltese waters suggests that this species is expanding its distribution within the Mediterranean Sea. Additionally, this study compares this central Mediterranean record of S. rivulatus with genetic data of the Dusky spinefoot, Siganus luridus (Rüppell, 1829), a previously established species. Individual records of Siganus (rabbitfishes) are important to note, as they represent the first warning signs of a possible invasion. Previous work has shown that these species drastically alter the ecosystems of the Mediterranean region through their herbivorous diet and grazing behaviour. Therefore, we need to closely monitor for more individuals and establish mitigation measures against established and expanding populations of these two species.