About Fistularia commersonii Rüppell, 1838
Bluespotted cornetfish, known by the scientific name Fistularia commersonii Rüppell, 1838, has a maximum recorded length of 1.6 m (5.2 ft), with an average length of around 1 m (3 ft 3 in). This species has a distinctively long and extremely slender body shape. It features a tubular snout, large eyes, and a long tail filament that is lined with sensory pores; these pores may help the fish detect prey. Its base body coloration ranges from blue-grey to greenish-grey, with two thin blue stripes or lines of dots running along its back, and a lighter color on the front portion of its body. To achieve camouflage, the fish’s body pattern changes to a broad-banded pattern at night. This species is widespread in the tropical and subtropical waters of the Indo-Pacific. Its range extends north as far as Japan, east to the west coasts of the Americas, and it is also found in the Red Sea, including the waters of Panama and Mexico’s Sea of Cortez. Its presence in the Mediterranean Sea off Israel was first reported in 2000. Over the 20 years following this first report, this species experienced a population explosion in the Levantine Sea and spread rapidly westward. By 2007, it had reached the westernmost sectors of the Mediterranean and extended as far north as the Gulf of Lions. Today, it has been recorded in all Mediterranean sub-basins and is very common in the eastern portion of the sea. F. commersonii is now classified as an invasive species in the Mediterranean Sea. This status stems from its rapid development to reproductive maturity, as well as its detrimental impact on native fish populations. Its colonization of the Mediterranean is an example of Lessepsian migration, a process where species (typically fish from the Red Sea) migrate into the Mediterranean Sea via the Suez Canal. All Mediterranean populations of this species are descended from a small number of founding ancestors, likely from a single invasion event. As a result, Mediterranean individuals have lower genetic variability than conspecifics from the Red Sea.
