Otolith chemistry of Champsodon nudivittis (Ogilby, 1895) and Nemipterus randalli (Russell, 1986) in Iskenderun Bay, Turkey

The study objective was to investigate the chemical composition of otoliths of two Lessepsian fish migrants, namely, Champsodon nudivittis and Nemipterus randalli, which thrive in the Iskenderun Bay, Turkey. The study specifically investigated the age structure and explored differences in chemical otolith composition in relation to age. Samples were collected using a traditional Mediterranean bottom trawl (mesh size 44mm) at depths of 45 to 90m. A total of 78 Champsodon nudivittis (size range, 6.0 to 14.0cm) and 60 Nemipterus randalli (size range, 6.1 to 17cm) were captured in May 2012. Age readings were carried out (sectioning technique). Additionally, the concentrations of Na, K, Li, and Ca were determined using flame photospectrometry. The results revealed that the concentrations of Na (5.70mg/g) and K (4.45mg/g) in otoliths of Nemipterus randalli were predominant elements after Ca (128.71mg/g). The concentration of Li in otoliths was also statistically different in the two species. This study contributes to the knowledge of the otolith chemistry in the two Lessepsian fish species now living in the same (but new) geographical region.