Food Composition of the Whiting, Merlangius merlangus in the South-eastern Coast of the Black Sea

Abstract

In this study, the food composition of whiting, Merlangius merlangus, from the South-eastern coasts of the Black Sea was seasonally investigated. With this aim, stomach contents of 762 specimens, the total length of 12.7-18.6 cm, and the body weight of 17-56.5 g, collected between September 2016 and August 2017 were analyzed. It was determined that 75.7% (577 stomachs) of the stomachs examined were empty. The percentage of empty stomachs didn’t show seasonal variation with maximal occurrence in autumn (76.9%) and minimal in winter (74.5%). The prey items identified macroscopically in the stomachs were horse mackerel, Trachurus mediterraneus, anchovy, Engraulis encrasicolus, whiting, Merlangius merlangus, sprat, Sprattus sprattus, goby, Gobius sp. from fish species and Gastrapod from Mollusca. Horse mackerel was the most important ingested prey (IRI%=43.2), followed by anchovy (IRI%=32.0) and whiting (IRI%=19.3). In the diet of the whiting, the sprat and the goby were less important than other fish species. The most important food was horse mackerel in the spring and summer seasons, while it was anchovy in the autumn and winter seasons. Cannibalism was the highest (F%=25) in the spring period and followed by summer (F%=23.8), autumn (F%=21.6) and winter (F%=16.2), respectively. It was determined that whiting consumed individuals of their species as food, up to 37.6% of their length and 11.2% of their weight.