On the Occurrence of the Blunthead Puffer, Sphoeroides pachygaster (Osteichthyes: Tetraodontidae), in the Strait of Messina (Central Mediterranean)

The record of Sphoeroides pachygaster reveals the presence of the species in the Strait of Messina (Central Mediterranean Sea). The adult species was captured on 15 march 2012. It measured 280？mm of total length and weighed 461.5？g. Morphometric measurements (mm) and meristic counts were reported in this paper. 1. Introduction The blunthead puffer Sphoeroides pachygaster (Müller & Troschel, 1848) is widely distributed in tropical and temperate waters on both sides of the Atlantic Ocean [1, 2]. The species was reported from New England to Southern Brazil [3], off the Eastern Atlantic in Irish Waters [4], in the Bay of Biscay [5, 6] and off Portugal [7]. S. pachygaster was frequently reported in the south of the Strait of Gibraltar, from Morocco, Senegal [8], to the Gulf of Guinea [1, 9]. The species is known in the Mediterranean [10–12] where the northernmost extension range of the species was the Adriatic Sea [13]. In the Tunisian marine waters, the species was observed by Brada？ [14] and recently by Chérif et al. [15], where a substantial population seems to be at present definitively established. In the Italian Seas S. pachygaster was found in the Southern Tyrrhenian Sea [16], Sicilian Channel [17], Ionian Sea [18], Adriatic Sea, and Northern Tyrrhenian Sea [13, 19]. Information available strongly supports the general opinion which considers S. pachygaster a recent immigrant, probably undergoing a fast diffusion eastwards [16, 17] even though Relini and Orsi Relini [20] speculated on the possibility of a previous presence of the species within the Mediterranean on the basis of old ichthyological illustrations. The aim of this paper is to point out that the species is present in the area. With the present note, the blunthead puffer can now be added to the Strait of Messina fish check-list. 2. Material and Methods On 15 March 2012 in the Strait of Messina (Sicily), one specimen of Sphoeroides pachygaster was caught by a fisherman (Figure 1). The specimen was weighted to the nearest gram and measured to the nearest millimetre. The morphometric measurement and meristic counts were performed according to Ragonese et al. [17]. Figure 1: Area of discovery: Strait of Messina. The specimen was photographed and preserved in the ichthyological collection of the Institute for Marine Coastal Environmental (IAMC) of the National Council of Research (CNR) in Messina (Italy). 3. Results and Discussion The first finding of Sphoeroides pachygaster in the Strait of Messina was an adult male that weighted 461.5？g (Figure 2). The morphometric measurement with percents of