First record of the oceanic puffer Lagocephalus lagocephalus (Linnaeus, 1758) from the Syrian marine waters (eastern Mediterranean)

Abstract

Background

The puffer fish species (Tetraodontidae) inhabit tropical and subtropical coastal waters around the world, and some species exist in many parts of the Mediterranean Sea. In the Syrian marine waters (eastern Mediterranean), five species are known to exist but Lagocephalus lagocephalus (Linnaeus, 1758) was not recorded there before.

Method

Samples were collected from a depth of 300 m off Banyas coast, Syria, using bottom longline, the morphometric measurements and meristic measurements were recorded.

Results

One specimen of the oceanic puffer Lagocephalus lagocephalus (Linnaeus, 1758) was caught from the marine water of Syria.

Conclusion

This is the first record of Lagocephalus lagocephalus (Linnaeus, 1758) in the Syrian marine waters.

Background

The puffer fishes (Tetraodontidae) comprise 200 species belonging to 29 genera (Froese and Pauly 2019) that inhabit tropical and subtropical coastal waters around the world (Bilecenoglu and Fernández-Álvarez 2013; Teker et al. 2018). There are 11 species known from the Mediterranean and Black Seas (Bearez et al. 2017; Ali 2018). Tetraodontidae has the second most poisonous creature to human on the planet after the Golden Poison Frog. The poisonous nature of this puffer fish is largely due to the tetrodotoxin (TTX) and paralytic saxitoxin contents of their internal organs (liver, ovary, intestine, skin…etc.). Tetrodotoxin is a potent neurotoxin that blocks the voltage-gated sodium channels on the surface of nerve membranes: It is 100 times more potent than cyanide, and one puffer fish may be enough to kill 30 adults (Santhanam 2018; Tamele et al. 2019). In the marine waters of Syria, five Tetraodontid species [Lagocephalus sceleratus (Gmelin, 1789), Lagocephalus spadiceus (Richardson, 1845), Lagocephalus suezensis (Clark & Gohar, 1953), Sphoeroides pachygaster (Müller & Troschel, 1848) and Torquigener flavimaculosus (Hardy & Randall, 1983)] had been previously recorded (Rahman et al. 2014; Galiya et al. 2015; Ali 2018). The oceanic puffer Lagocephalus lagocephalus (Linnaeus, 1758) is a native tetraodontid species that can be found in many Mediterranean coasts (Froese and Pauly 2019), but had not been recorded before in the marine waters of Syria (Ali 2018). Hence, the present study reports that the oceanic puffer L. lagocephalus (Linnaeus, 1758) had been recorded in the Syrian marine waters.

Methods

Samples were collected from a depth of 300 m off Banyas coast, Syria (N: 35°14′35.11“, E: 35°55’12.56”) (Fig. 1), using bottom longline. The fish was identified according to Carpenter and De Angelis (2016), and the morphometric measurements (length to the nearest mm., weight to the nearest gr.) and some meristic measurements were recorded. The fish was then photographed, carefully dissected for sex, maturity and reproduction determinations, preserved in 7% formaldehyde, and placed at the biology laboratory of High Institute of Marine Research -HIMR (Tishreen University - Lattakia, Syria) as a reference sample (unnumbered yet).

Fig. 1

A map showing the collection site of L. lagocephalus specimen

Results

One specimen of the oceanic puffer Lagocephalus lagocephalus (Linnaeus, 1758) was caught on 20-12-2018 from the marine water of Syria (Fig. 2a). It was a live mature male (testis length was 137 mm, gonadosomatic index value was 4.02; Fig. 2b) at spawning stage; the milt was ready for release after slight pressure on the belly. The specimen has the following properties (Fig. 2a): the head was blunt with heavy jaws forming a beak of two, upper and lower, teeth. The dorsal and anal fins were slightly falcate to back, the pelvic fin was absent, the skin had no scales but the ventral side had tiny spinules. The dorsal side of the body was dark green and the belly was white with 18 dark spots. The dorsal, anal, pectoral and caudal fins were dark. The morphometric measurements are shown in Table 1; They were very close to those recoded by Erguden et al. (2017) and Teker et al. (2018) (Table 1) in the Turkish marine water. The diagnostic characters were: Dorsal fin rays (D), 13; Pectoral fin rays (D), 14; Anal fin rays (A), 11; Caudal fin rays (C), II + 15. All the above mentioned features were in full agreement with those of L. lagocephalus species (Smith and Heemstra 1986; Teker et al. 2018). After catching this specimen, two Syrian professional fishermen confirmed that this species had appeared in their catch, on 2017 and 2014; with 3 and 1 individuals respectively.

Fig. 2

a- a male L. lagocephalus specimen caught on 20-12-2018, b-Testis of the specimen

Table 1 Morphometric measurements of L. lagocephalus captured from the marine water of Syria and those recorded by Erguden et al. (2017) and Teker et al. (2018)

Discussion

The oceanic puffer L. lagocephalus exists in tropical and subtropical seas, and spreads from north-west to north-east of the Mediterranean (Papaconstantinou 1988; Dulčić and Pallaoro 2006; Bañón et al. 2010; Bilecenoglu and Fernández-Álvarez 2013; Farrag et al. 2016; Erguden et al. 2017; Teker et al. 2018); It has never been recorded before in the marine waters of Syria (Galiya et al. 2015; Ali 2018). By recording this species, Tetraodontidae would be represented by six species in the checklist of the Syrian marine fish species; four out of these belong to the genus Lagocephalus. The oceanic puffer L.lagocephalus is so far represented by a single confirmed specimen, and thus, its establishment in the area has still to be proven. The advanced testis maturity of this specimen gives a preliminary indication that this species breeds in the area. The survival of this species in the Syrian waters and the recent sea water warming (Vallerga et al. 2003, Aldo Drago et al. 2004, RAC 2009, Ben Haj et al., 2009, Ibrahim et al. 2010, Alshawy et al., 2016, Alshawy et al. 2019) may assist this species to expand its original range and establish itself there. Compared to the other puffer fish species in the Syrian marine water, L.lagocephalus has the highest level of toxicity, especially in the edible parts, where ~ 300 g of flesh are enough to kill a human, (Saoudi et al. 2008; Saoudi et al. 2011; Rahman 2015). Thus, its establishment in the area may have serious consequences on people consuming the flesh, especially that the local people are not always aware of puffer fishes toxicity. In addition, food and space competitions with the other fish species may have a serious consequences on the native fish communities (Aydın 2011). Similarly, puffer fish destroy the traditional habitats of native fish, which reduces fish stocks, and destroy fishing nets and lines which reduce fish catch (Eastmed 2010).

Conclusion

This study reveals that the oceanic puffer Lagocephalus lagocephalus (Linnaeus, 1758) exists in the Syrian marine waters, where it is recorded for the first time. This species may expand its original range and establish itself in the area, which may lead to serious poisonous effect to human health and to serious ecological consequences to other fish populations.