Bio-ecological characteristics of European eel (Anguilla anguilla L.) population in Sariçay basin (Milas, Muğla)

In this study, the bioecological characteristics of the European eel population in the Sarıçay basin (Milas, Muğla) were investigated. A total of 241 eels were captured only from brackish water. Despite the inactive operation of the fish weir in the region, there was observed fishing pressure on the population. Analyses of population characteristics were carried out by calculating the eye index (%5.30±2.26), fin index (%4.45±0.81), gonadosomatic index (%0.83±0.82), and gastrosomatic index (%3.53±1.31), and the distribution of silver and yellow eels in the population was determined. It was found that 7% of the population was undifferentiated, 70% was in the yellow stage and 23% was in the silver stage. While the sex ratio (F:M) of the population was calculated as 14.5:1, this ratio was determined as 10.5:1 for silver individuals. The length-weight relationship (W=0.0023.L2.9498, R²=0.9299) and condition factor (K=0.229±0.047) of the population were calculated. The average length and weight of the population were found to be 531.98±152.36 mm and 353.48±277.80 gr, respectively. The catch of silver eel has been statistically higher between November and January than in all other months which indicates the spawning migration period (p<0.05). The youngest individuals in the sample were determined to be 1 year old and the oldest individuals were 8 years old. It was found that individuals evaluated as silver were 3+ years old and silvers were 5+ years old in the migration period.