First occurrence of Erugosquilla massavensis (Kossmann, 1880) in Italian waters (Ionian Sea)

The Red Sea stomatopod Erugosquilla massavensis was detected for the first time in Italian waters, along the eastern coast of Sicily, in the western Ionian Sea. This finding suggests that a further population expansion, from the Tunisian coasts to a wider area within the central Mediterranean, of one of the most successful Lessepsian migrants is ongoing.


Introduction
The native range of the stomatopod Erugosquilla massavensis (Kossmann, 1880) (Crustacea: Squillidae) includes the Red Sea and the Persian Gulf (Froglia and Manning 1989). Introduced during the 1930s, it was the first Red Sea stomatopod species entering the Mediterranean Sea via the Suez Canal (Steuer 1936(Steuer , 1938, followed by Clorida albolitura Ahyong andNaiyanetr, 2000 (Ahyong andGalil 2006). Successively, the species colonized the eastern and south-central Mediterranean coasts and E. massavensis is now widely distributed along the Levantine coasts; the south, eastern and western Aegean Sea; the Marmara Sea; westwards toward Egypt; and the central Mediterranean. The species more recently was recorded from the eastern region of the Libyan coast and then from Tunisian waters (Shakman and Kinzelbach 2007;Abdelsalam 2014;Ounifi Ben Amor et al. 2015; ELNAIS 2017) ( Figure 1).
The Red Sea mantis shrimp is currently the dominant stomatopod species in the eastern Levantine, abundant at depths ranging between 20 m and 40 m (Gökoğlu et al. 2008), although it can be found up to 150-200 m of depth (Özcan et al. 2008). The species prefers soft bottoms in coastal areas, but tolerates also open waters and sheltered brackish areas (Ounifi Ben Amor et al. 2015.
In this work, the first record of E. massavensis in Italian waters is reported from a coastal region off the island of Sicily, in the western Ionian Sea, and considerations on the possible enlargement of its colonization area are briefly discussed.
The specimen was immediately photographed by the fishing crew but, by mistake, it was placed in with the S. mantis shrimps caught in the same trawl and sold at the Catania fish market.
Identification of the specimen was based on Lewinsohn and Manning (1980) and .

Results and discussion
Erugosquilla massavensis reaches a maximum total length (TL) of 200 mm . The specimen in this study was 145 mm TL ( Figure 2) and within the size range of individuals measured in other Mediterranean areas (Lewinsohn and Manning 1980;Katağan et al. 2004;Ounifi Ben Amor et al. 2015). The species is easily distinguished from Squilla mantis due to the lack of the paired dark spots on the dorsal part of the telson (Figure 2, detail). The colour of fresh individual was: light grey-orange dotted with very small dark spots; the rostral plate margins, abdominal crests and margins were reddish ( Figure 2); tubercles on telson reddish shaded of blue, with whitish tips; uropod dark blue; and basal prolongation of uropod bright orange (Figure 2, detail). The raptorial claw was whitish; and the merus, propodus yellowish.
The present finding suggests the Red Sea E. massavensis shares the same habitat and depth range as the native Squilla mantis. This has also been observed in many cases within Mediterranean waters colonised by this new arrival; but, it appears that the native S. mantis has been displaced to deeper waters by E. massavensis along the Levantine coast of Turkey and off the Israeli coast (Por 1978;Özcan et al. 2008 and references therein).
At this preliminary stage, nothing is known about the state of establishment of the species off the coast of Sicily, and further monitoring of benthic fishing catches and landings is required. Nevertheless, interviews with local fishermen indicate that they have Nevertheless, besides a passive increase in its distribution range, shipping as a vector of introduction cannot be completely discounted, especially given the intense maritime traffic involving ports and harbours in the region, including that of Catania (Deidun et al. 2016). The importance of the shipping introduction pathway has also been underscored in the case of the recently recorded Lessepsian crustacean T. palaestinensis (Insacco et al. 2017).