Growth and Reproductive Capacity of the Endemic Fish Species Egirdira nigra (Teleostei: Leuciscidae)
Fahrettin Küçük, Salim Serkan Güçlü, Ufuk Gürkan Yıldırım, Ergi Bahrioğlu, Gözde ŞavranObjective: In this study, various characteristics of the Eğirdir minnow, an endemic species of Anatolia that inhabits specific/narrow areas, were determined from 142 individuals sampled between 2021 and 2022. These characteristics include length-weight relationship, Von Bertalanffy growth equation, condition factors, spawning season, first spawning size, and fecundity attributes.
Materials and Methods: A monthly sampling of 142 specimens of Egirdira nigra was conducted using multi-mesh gill nets between March 2021 and April 2022.
Results: The sampled E. nigra population consists of individuals aged II-V, with 57.75% female and 42.25% male. The length-weight relationships were as follows: W = 0.0059 L3.5445, R² = 0.9312 (female + male), W = 0.009 L3.3077, R² = 0.9353 (male), and W = 0.0058 L3.5679, R² = 0.9233 (female). The condition factors were calculated as 1.67 (male) and 1.87 (female). The gonadosomatic index was highest in March (13.95) and lowest in August (0.5073). The population’s mean fecundity was calculated as 4787 individuals/egg.
Conclusion: Although the population exhibits a wide age range and positive growth values, it is believed to be under significant threat from invasive/exotic species sharing the same environment, such as Atherina boyeri, Gambusia holbrooki, Pseudorasbora parva, and Carassius gibelio. Therefore, the conservation of species and their habitats is of paramount importance.