Dietary Analysis of Sardinella maderensis (Lowe, 1938) in the Marine Waters off the Latakia Coast (Syria), Eastern Mediterranean: A Two-Year Seasonal Study

Abstract

Dietary studies play a vital role in understanding the balance of marine ecosystems and sustainable fishery practices. This research examines the feeding habits of Sardinella maderensis, a commercially important Clupeidae species, in the marine waters off Latakia, eastern Mediterranean. 1,200 specimens were collected using gillnets and chinchilla nets, following local fishing practices, between October 20, 2021, and September 14, 2023. The sampled individuals displayed a standard-length range of 9.32–23.18 cm (mean 14.67±4.2 cm) and a weight range of 12.41–116.1 g (mean 44.28±28.37 g), with a maximum body height averaging 3.49±1.26 cm. Dietary analysis indicated that S.maderensis is a planktivorous species, feeding on 15 planktonic species categorized into seven major groups: Crustaceans ranked first, with a relative importance of 46.95%, a frequency of 45.67%, and a total of 7832.50 points. This group included various types, such as copepods (e.g., Calanoidea and Cyclopidae) and malacostracans, including Euphausiacea, Mysidacea, and Decapoda (Penaeus and Crab megalopae). Detritus ranked second, with a relative importance of 19.60%, a frequency of 17.77%, and 2243.50 points. Phytoplankton followed, ranking third with a relative importance of 15.23%, a frequency of 13.55%, and 4158.88 points. Fish ranked fourth, with a relative importance of 8.95%, a frequency of 12.75%, and 2513 points. This group consisted of three species: Anguilliformes, Ophidion rochei, Trachurus trachurus, and partially digested fish remains. Polychaete worms showed a low contribution, with a relative importance of 0.75%, a frequency of 2.18%, and 255 points. Foraminifera contributed 0.32%, with a frequency of 1.02% and 71 points. Mollusks, represented by a single Octopoda individual, had the lowest contribution, with a relative importance of 0.01%, a frequency of 0.15%, and 20 points. These findings provide essential ecological data on S.maderensis feeding behavior, contributing to improved fisheries management and marine conservation efforts in the coastal waters of Latakia.