Introduction
The number of alien species in the Mediterranean Sea is steadily increasing, and the pace seems to accelerate since the turn of the last century (Galil et al., Reference Galil, Boero, Campbell, Carlton, Cook, Fraschetti, Gollasch, Hewitt, Jelmert, Macpherson, Marchini, McKenzie, Minchin, Occhipinti-Ambrogi, Ojaveer, Olenin, Piraino and Ruiz2014) primarily due to the opening of the Suez Canal (Katsanevakis et al., Reference Katsanevakis, Wallentinus, Zenetos, Leppäkoski, Çinar, Oztürk, Grabowski, Golani and Cardoso2014). The total number of confirmed Lessepsian migrant fish species in the entire Mediterranean is currently 104 (Golani, Reference Golani2021). Their introduction rate and detection seem to have increased continuously ever since.
Golani et al., (Reference Golani, Orsi-Relini, Massuti, Quignard, Dulčić and Azzurro2002, Reference Golani, Askarov and Dashevsky2015) recorded six non-indigenous species of genus Epinephelus Bloch, 1793 in the Mediterranean Sea: Epinephelus areolatus (Forsskål, 1775), E. coioides (Hamilton, 1822), E. fasciatus (Forsskål, 1775), E. geoffroyi (Klunzinger, 1870), E. malabaricus (Bloch and Schneider, 1801), and E. merra (Bloch, 1793).
Many of these species are economically important for Mariculture. The areolate grouper, E. areolatus, has an Indo-Pacific origin, with a distribution extending from the Red Sea and eastern coast of Africa to southern Japan (Froese and Pauly, Reference Froese and Pauly2021).
In its native range, E. areolatus is common in coastal waters, on seagrass beds and on soft bottoms close to hard substrates such as rocky reefs or dead corals, where it feeds on fish and benthic invertebrates (Parrish, Reference Parrish, Polovina and Ralston1987; Randall and Heemstra, Reference Randall and Heemstra1991; Heemstra and Randall, Reference Heemstra and Randall1993).
This species was first recorded in the Mediterranean Sea in 2015 on the Palestine coast, where one specimen was caught (Rothman et al., Reference Rothman, Stern and Goren2016). More recently, two further specimens were collected in Lebanese waters in 2019 (Bariche and Edde, Reference Bariche and Edde2020).
In the present paper, we report the first validated record of E. areolatus from the Syrian coast and detail its morphological characteristics in order to add this observation together with comprehensive morphologic data to the list of Syrian fish fauna.
Materials and methods
On 29 September 2021, a specimen of E. areolatus was caught for the first time on Syrian coast. Morphometric and meristic details were reported. The specimen was photographed, preserved in 7% formaldehyde, and placed at the Biological Laboratory of the General Authority of Fisheries and Aquatic Organisms: Coastal Area Branch, Tartous, Syria as a reference sample.
Results and discussion
Here, we report the first validated record of E. areolatus (Forsskål, 1775) from the Syrian coast. During recurrent ichthyological surveys to detect Lessepsian aliens in the Syrian marine waters, a single specimen of E. areolatous (Figure 1) was found on the 29 September 2021 in a rocky habitat. This specimen was caught with trammel nets from the coast of Tartuos City near Arwad Island at 15–20 m depth, at the mid-easternmost side of the Mediterranean (34°51’51.8” N-35°50’54.8” E) (Figure 2) (Alchikh Ahmad, Reference Alchikh Ahmad2022). This represents the first scientifically validated record of this species for the Syrian waters and the fourth for the Mediterranean Sea. Indeed, this specimen represents a new record of a Lessepsian fish species, as E. areolatous is not cultured in Syria.
Epinephelus areolatous specimen caught on 29/9/2021 in a rocky habitat from Tartuos coast near Arwad Island.
Specimen collecting locality (Tartous, Syrian coast, Eastern Mediterranean).
Recently, AL mabruk et al., (Reference AL mabruk, Giovos and Tiralongo2021), a Libyan researcher, declared the first record of E. areolatus in Syrian waters. Nevertheless, this record was based on a photo posted by a Syrian fisherman on the Facebook®group on 11th May 2020, of a specimen declared as caught on 29 May 2019. Yet, no complete information about the exact location where this specimen was caught, or its meristic characteristics and morphometric measurements were presented.
Our specimen of E. areolatous caught from the Syrian coast had a total length (TL) of 20.5 cm, a standard length (SL) of 17 cm, and a weight of 185 g. It has emarginate caudal fin, 84 series of scales along the body, rear margin of preopercle serrate, with small spines at its lower angle (Figure 1). The first dorsal spine is above the origin of the upper pectoral ray. The pelvic fin begins below a vertical line from the origin of the lowest pectoral ray. Morphometric measurements and meristic counts are presented in Table 1.
Morphometric measurements and meristic counts of Epinephelus areolatus specimen caught on Syrian coast
The body is reticulated with a whitish background and brown spots that gradually become smaller and orange on the head and belly. The spots become darker towards the rear part of body, caudal fin, and soft part of dorsal fin. The posterior edge of caudal fin and upper edge of soft part of dorsal fin have white margins (Figure 1).
Morphometric and meristic data are similar to that previously recorded for this species (Heemstra and Randall, Reference Heemstra, Randall, Carpenter and Niem1999; Allen and Erdmann, Reference Allen and Erdmann2012).
Further studies are necessary to better understand the expansion dynamics of this species in the temperate Eastern Mediterranean, where its abundance is still probably low, a situation that may evolve due to ongoing climate change.
This record of E. areolatous is considered as a recent addition to the fast-expanding list of non-indigenous species off the Syrian coast. More long-term studies are needed to establish a comprehensive picture of these species in the Mediterranean Sea and of their impact on native ones, especially on the Syrian coast.
Conclusion
E. areolatous is a Lessepsian species recorded for the first time in Syrian marine waters. This record fills the gap with species distribution along the Eastern Mediterranean and provides further evidence that the environmental alterations due to human activities and climate changes, made the Mediterranean waters more suitable for tropical species, possibly at the expense of some native ones (Zenetos et al., Reference Zenetos, Albano, López Garcia, Stern, Tsiamis and Galanidi2022).
Acknowledgements
The authors thank Tishreen University, the High Institute of Marine Research, and the General Commission of Fisheries Resources: Coastal Area Branch, Tartous-Syria, for supporting this work. They are grateful to Sophie Arnaud-Haond for her critical reading.
Author contributions
This work was carried out in collaboration between the two authors. Both authors read and approved the final manuscript.
Financial support
This research received no specific grant from any funding agency, commercial or not-for-profit sectors.
Competing interests
The author (s) declare none.
Ethical standards
All research pertaining to this article did not require any research permit.
Data availability statement
Data availability is not applicable to this article as no new data were created or analysed in this study.
