Annual reproductive cycle of a successful Lessepsian immigrant in the Eastern Mediterranean Sea, Pomadasys stridens (Forsskål, 1775) (Family: Haemulidae)

Abstract

ABSTRACT The striped piggy, Pomadasys stridens (Forsskål, 1775), is one of the successfully colonized Lessepsian immigrants entering the Mediterranean through the Suez Canal. This study was carried out to understand to what extent the reproduction strategy adopted by this species had played a role in its successful establishment. The study is based on samples collected during the monthly trawl surveys conducted between January 2017 to November 2020 in the Northeast Mediterranean. The annual gonadal development cycle was estimated by observing the Gonadosomatic Index changes. Seasonal patterns in energy intake and allocation were acquired from Hepatosomatic, Digestosomatic, and Relative Body Condition indices. The results indicated that the species has prolonged gonadal development periods, during which spawning occurs twice, in early summer and at the onset of the winter. A comparison of all indices involved indicated that the species feeds and develops gonads at the same time before summer spawning, feeds heavily and stores energy during the warmest period, and uses the stored energy in the winter spawning. As these features do not differ much from their congenerics inhabiting the geography they originated from, it is suggested that it was not the ecological plasticity of the species that is the basis of their success but the reproductive traits they have fitted well to the Mediterranean Ecosystem.