A Preliminary Study on The Determination of Reproductive Biology of European Pilchard, Sardina pilchardus (Walbaum, 1792) Distributed in The Aegean Sea

Abstract

Sardina pilchardus is a multiple spawning fish, i.e., the species that spawns periodically during the spawning period. In order to examine the reproduction biology of the species, the specimens were obtained in the known spawning period indicated by the current literature obtained from fishers who were commercially fishing in December 2018 and January-February 2019. After the fork length and total length together with their weight measurements, the specimens were dissected in the laboratory. The adult females‘ gonads were then fixed in 4% formalin solution for fecundity. A total of 170 individuals was examined and the values of their fork length, total length and weight were computed as 9.7-13.4 cm (mean: 11.16±0.81), 10.5-15 cm (mean: 12.3±0.89), 8.06-23.7 g (mean: 12.7±2.93), respectively. 44 of the supplied specimens were male (25.9%), 122 female (71.8%) and 4 (2.3%) uncertain, thus, the female: male ratio was determined as 2.77:1. According to χ2 test results, a statistically significant difference was observed among individuals. For the specimens examined, the fork length-weight relationship was calculated as W = 0.0098FL2.96, while total length-weight relationship was W = 0.0071TL2.97. In order to calculate the fecundity, sub-samples were taken from the anterior, median and posterior parts of 15 ovaries in the ration of 2 - 5% of the ovary weight and the mature oocytes were counted. As a result, the species‘ fecundity was found to be between 4,600-9,800 (6,110±1,755). The relationship between total length and fecundity was computed as W= 1,640.7 TL-13,907 and a linear relationship was determined.