Occurrence of Sudis hyalina Rafinesque, 1810 (Paralepididae) in Büyükeceli Coast (Mersin Bay, Northeastern Mediterranean)

In November 2018, an individual belonging to the Sudis hyalina was caught in a trawling operation in the Büyükeceli Coast (Mersin Bay, NE Mediterranean). Morphological and meristic measurements of the specimen were made and recorded with the catalogue number of MEUFC-18-11-102 in the Museum of the Systematic, Faculty of Fisheries, Mersin University. this paper as follows:


Introduction
Sudis hyalina belongs to the Paralepididae family of Aulopiformes.
It is known that S. hyalina, a deep-sea fish, has a very wide distribution area between 200-2000 m depth in the mesopelagic and bathypelagic zone (Post, 1990). However, the reproduction of this species usually occurs in tropical and warm shallow waters (Post, 1990). The maximum length of the species reported in the literature is 100 cm for adult individuals, while the total length of young individuals is generally 40 cm (Bauchot, 1987). Their fins do not contain spines.
Total dorsal soft rays: 12-16, total anal soft rays: 21-24. Their body color is silvery pink. The lower jaw of S. hyalina is markedly curled up, and its teeth are large and the number is greater than the upper jaw. Gill rakes contain tooth-like structures (Whitehead et al., 1986). The structure of the mouth and teeth reflects the diet of the species. They are carnivore predators (Post, 1990).
The records of the species were done from Levantine Basin by Golani (1996), from Taşucu and Iskenderun Bay by Mater and Kaya (1987) and Kaya and Bilecenoğlu (2000), from the shores of Turkey by Bilecenoğlu et al. (2014), from Mersin Bay by Ergüden and Bayhan (2015), from Gökova Bay, Aegean Sea by Türker et al. (2016), from the Lebanese coast by Tortonese (1970) and from the Syrian coast by Ali et al. (2014) in the Eastern Mediterranean; from the middle and western Mediterranean Sea by Psomadakis et al. (2006), D'Onghia et al. (2011), and Mytilineou et al. (2013. The aim of this study is to report the new locality record of S. hyalina from Büyükeceli coast (Mersin Bay) and to determine the current status of this species in the coast of Turkey.

Material and Methods
One individual of S. hyalina Rafinesque, 1810 was caught by a trawl operation at a depth of 365 m on 7 November 2018 in the Büyükeceli Coast (Mersin Bay) (coordinate: 36°05'45.5"N 33°23'20.0"E). This specimen was preserved in 4% formalin and was deposited in the Museum of the Systematic, Faculty of Fisheries, Mersin University, (catalogue number: MEUFC-18-11-102). Morphometric and meristic characters of this specimen are given in Table 1

Results
In this study, a young individual (total size of 38.1 cm) of S. hyalina was caught from the Büyükeceli coast in November 2018. Some morphometric and meristic measurements of this individual were made and presented in Table 1.

Discussion
Morphometric and meristic measurements of the captured individual were compared with the measurements of two individuals of S. hyalina that were caught in the coast of Syria by Ali et al. (2014) ( Table 1).
The measurements of two individuals caught in Syrian waters were found to be compatible with an individual caught from Mersin Bay. This may be because individuals in both studies had similar size. The individuals in both studies were also young. The fact that the young individuals belonging to the species are rarely caught in coastal waters during fishing activities may indicate the existence of a population in the Mediterranean, but also the fact that mature individuals only come to the shallow waters for spawning. The reproduction of this species usually occurs in tropical and warm shallow waters (Post, 1990).
S. hyalina has been reported from all over the Mediterranean (Tortonese, 1970;Mater and Kaya, 1987;Golani, 1996;Kaya and Bilecenoğlu, 2000;Psomadakis et al., 2006;D'Onghia et al., 2011;Mytilineou et al., 2013;Ali et al., 2014;Bilecenoğlu et al., 2014;Ergüden and Bayhan, 2015). However, the number of individuals of the species reported in these records is limited. S. hyalina is a carnivore predator species and has been continually reported in the Mediterranean over the past 50 years; this may be indicating that the species is not under pressure of predator, fishing, or any other non-indigenous species, and maintains its presence in the Mediterranean. It was thought that the capture of a small number of individuals of S. hyalina may be due to the fact that it is a deep sea fish and the adults are present in the bathypelagic zone, except for spawning period.

Conclusion
According to the literature records, S. hyalina is a circumglobal species and has been recorded in the Mediterranean Sea for the last 50 years. Therefore, it can be said that the species is permanently found in the Mediterranean fish species list. The Mediterranean Sea is an ecosystem that dynamically changes species diversity due to the Lessepsian migration. Although the earlier records of the species have been reported, additional records are important biodiversity data in terms of the current status of the species in the region, the state of population formation, the examination of the relations between species.

Conflict of Interest
The authors declare that there is no conflict of interest.