The Presence of Tetraodontidae Species in the Central Mediterranean: an Update from the Southern Adriatic Sea
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ISSN: 0001-5113 ACTA ADRIAT., ORIGINAL SCIENTIFIC PAPER AADRAY 58(2): 325 - 338, 2017 The presence of Tetraodontidae species in the Central Mediterranean: an update from the southern Adriatic Sea Pierluigi CARBONARA1*, Jerina KOLITARI2, Mirko ĐUROVIĆ3, Palma GAUDIO1, Zdravko IKICA3, Guliem KROQI2, Nicoletta MILONE4 and Maria Teresa SPEDICATO1 1 COISPA Tecnologia & Ricerca, Stazione Sperimentale per lo Studio delle Risorse del Mare, via dei Trulli 18-20, 70126 Bari, Italy 2 Agriculture University of Tirana Aquaculture & Fishery Laboratory, Dürres, Albania 3. IBM Institute Marine Biology, Kotor, Montenegro 4. FAO AdriaMed Project, Rome, Italy * Corresponding author, e-mail: [email protected] This paper presents the first record of the Lessepsian migrant fish Lagocephalus sceleratus (silver-cheeked toadfish) on the Italian side of the south Adriatic Sea. In addition, four specimens of Sphoeroides pachygaster (blunthead puffer) were analysed. Meristic and morphometric data of the silver-cheeked toadfish and blunthead puffer are in accordance with data from the Mediterranean. The specimen of silver-cheeked toadfish was a female with gonad in resting stage and the specimens of blunthead puffer were adults (male and female) with gonads in maturing, mature/spawner and post-spawning stage. The stomach contents of the specimen of silver-cheeked toadfish were composed by Mollusca Opistobranchia and Crustacea Brachyura. Stomach contents analysis of S. pachygaster confirmed that Mollusca are the preferred prey for this species. However, the presence of Crustacea (shrimps, crabs) and fish in the stomachs indicates that the blunthead puffer has a broad and variable diet in the south Adriatic Sea. The present study suggests the presence of an established population of blunthead puffer on the continental shelf of the southeast Adriatic Sea. Key words: Lagocephalus sceleratus, Sphoeroides pachygaster, morphometry, meristic counts, sexual maturity of the gonads, stomach contents INDRODUCTION The human interference on geographical barriers, combined with climate change and The impact of non-native fish populations on increased seawater temperatures are deeply native species determines several effects such as changing the geographical distributions of plant competition for habitats, predation, hybridiza- and animal species, thus increasing the pole- tion and the transfer of parasites and diseases ward spread and success of these species in (ARTHUR et al., 2010; CANONICO et al., 2005; CAREY new environments. Fish community changes & WAHL, 2010). are mainly evident in the Mediterranean basin 326 ACTA ADRIATICA, 58(2): 325 - 338, 2017 (AZZURRO et al., 2011; BIANCHI, 2007; GALIL et al., a source of food poisoning. For this reason, L. 2007), considered one of the main hotspots of sceleratus received considerable public atten- marine bioinvasion on the planet (QUIGNARD & tion and the European legislation (854/2004/ TOMASINI, 2000). This is partly due to many fish EC) prohibits its marketing. Nevertheless, few species reached the Mediterranean Sea after the cases of human poisoning after the ingestion opening of the Suez Canal in 1865, while other of the fish have been reported for the Mediter- newcomers arrived through the Gibraltar Strait. ranean (BENTUR et al., 2008). This Lessepsian Continuous arrival of new species has been migrant species has been considered among the confirmed, although in less quantity, in the Adri- 100 invasive species in the Mediterranean Sea (DRAGIČEVIĆ & DULČIĆ, 2010; DULČIĆ & atic Sea for its rapid expansion (STREFTARIS & ZENE- DRAGIČEVIĆ, 2011). TOS, 2006). Indeed, after the first record in the Among the new fish arrivals in the Mediter- Aegean Turkish coast in Gökova Bay (AKYOL ranean, one of the most emblematic is the case et al., 2005; FELIZ & ER, 2004), L. sceleratus had of species belonging to the Tetraodontidae fam- a rapid expansion in few years throughout the ily, which includes 19 genera and approximately eastern basin, reaching the northernmost parts of 130 species (MATSUURA, 2001; NELSON, 2006). the Aegean Sea and toward south-west until the Puffers are marine fish distributed in tropical southern coast of Tunisia (JRIBI & BRADAI, 2012; and subtropical areas of the Atlantic, Indian and Pacific Ocean, and six species have been KALOGIROU, 2013). The first record of Sphoeroides pachygaster reported in the eastern Mediterranean (GOLANI et al., 2006). off the western coast of south Adriatic Sea The species of Tetraodontidae family have (Mola di Bari) is dated back in 1992 (BELLO, been recorded in the central-northern Adriatic 1993) (Table 1). In the following years, many Sea include the Lagocephalus sceleratus (Gme- others captures of this species were record- lin, 1789), Sphoeroides pachygaster (Müller & ed in the whole Adriatic Sea basin (DULČIĆ, Troschel, 1848) and Lagocephalus lagocepha- 2002; GRUBAČ, 2008; JARDAS & PALLAORO, 1996; lus (Linnaeus, 1758). L. lagocephaelus was JOKSIMOVIĆ & MANDIĆ, 2008; LIPEJ et al., 2013) reported for the first time at Molunat in 2004 (Table 1). (Dulčić & Pallaoro, 2006), while L. sceleratus was Because species of the Tetraodontidae fam- reported in 2012 close to Dubrovnik (ŠPREM et ily have an extremely invasive character and a al. 2014) (Table 1). This species is a Lessepsian potential risk to human health, monitoring these migrant with a potential risk to human health, “alien species” populations is extremely impor- as it contains the most harmful paralytic toxin tant for assessing their impact on ecosystems known (i.e. the tetrodotoxin (TTX)) that may be and fisheries (NADER et al., 2012). Table 1. Records of S. pachygaster and L. sceleratus in the Adriatic Sea CARBONARA et. al.: Seasonal abundance, vertical distribution and life history traits of Mediterranean... 327 The objective of this work was thus to add new records of species belonging to the Tetraodontidae family in the south Adriatic sea, reporting for the first time the capture of Lago- cephalus sceleratus along the Italian coast of Adriatic Sea. MATERIALS AND METHODS The samples of Lagocephalus sceleratus (Silver-cheeked toadfish) and SphoeroidesA B pachygaster (blunthead puffer) were taken from commercial landings and discard monitoring Fig. 1. Study area: red points represent the hauls of the (Data Collection Framework - DCF; EU Reg. MEDITS trawl survey, yellow star the sites of capture 199/2008) coasts and from the MEDITS inter- of S. pachygaster during the MEDITS survey, the blue national trawl survey (AA.VV., 2016) (Fig. 1; points the sites of capture of S. pachygaster during the Table 3). The specimen of Silver-cheeked toad- commercial fishing activity, the green point the site of fish was captured along the Italian coast of south capture of L. sceleratus Adriatic Sea, off Trani at 40 m depth (Fig. 1). measurements (nearest 1 mm) and meristic The analyzed specimens of S. pachygaster were counts were carried out (Fig. 2), following the captured off the coast of Albania and Montene- previous descriptions of species belonging to gro (Fig. 1; Table 3) at a depth range between the Tetraodontidae family (GOLANI, et al. 2002; 75 and 125 m. PSOMADAKIS et al., 2006; RAGONESE et al., 1997; The specimen of L. sceleratus was caught by TORTONESE, 1986). commercial trawler in the 2014 along the Italian The following morphometric measurements coast of south Adriatic Sea (Fig. 1). Among the and meristic counts were taken (Fig. 2): Total 4 S. pachygaster specimens, two were caught length (TL), Standard length (SL), Preanal during the MEDITS survey (2012 - Albanian length (PL), Head length (HL), Snout length coast; 2014 - Montenegrin coast) and the others (SnL), Opercular length (OL), Head height two were caught by a commercial trawler (2014 (HH); Body height (BH); Anal height (AH); – Montenegrin coast) and a longline vessel Caudal peduncle height (CH), Opercular height targeting European Hake (2015 – Montenegrin (OH), Interorbital space (IS), Head width (HW), coast) (Fig. 1). Body width (BW), Anal width (AW), Caudal In total, 5 specimens (1 L. sceleratus and peduncle width (CW), Eye horizontal diameter 4 S. pachygaster) were analysed. Morphology (EH), Eye vertical diameter (EV), Total weight, and color analysis, as well as morphometric Liver weight, Gonad weight, Gutted weight, Table 2. Maturity scale used in the present study (from Number of dorsal fin rays, Number of anal fin MEDITS Handbook, AA.VV., 2016) rays, Number of pectoral fin rays, Number of caudal fin rays. STAGE CODE DESCRIPTION Sex and sexual maturity were determined 1 VIRGIN macroscopically based on the MEDITS maturity 2A VIRGIN DEVELOPING scale (AA.VV., 2016) (Table 2).Gonad weights 2B RECOVERING (GW) were recorded to the nearest 0.1 g. 2C MATURING Stomachs and its contents were carefully 3 MATURE/SPAWNER removed. Identification of prey items was gener- ally limited to the higher taxonomic level, since 4A SPENT the beak-like jaws of puffer fish crush food items 4B RESTING to the extent that prey could rarely be identified 328 ACTA ADRIATICA, 58(2): 325 - 338, 2017 Fig. 2. Schematic representation of the morphometric measurements. Lateral view up (S. pachygaster) and dorsal view down (L. sceleratus) to the species level. Dietary estimations were trally. The livery is characterized by a laterally limited to number (N), percent number (%N), wide silver bands extended from the mouth to occurrence (O) and percent occurrence (%O) for the caudal fin and by a dorsal area grey-brown- each prey. Quantitative measurements of prey ish with black spots regularly distributed.