Seasonal variation of the ectoparasite infestation levels of Trachurus picturatusin Bizerte (Tunisia).

• Main Authors: Hamdi, Ilhem, Hermida, Margarida, Zouari Tlig, Sabiha, Benmasour, Bouchra
• Format: Book
• Language: English
• Published: 2023
• Subjects: Trachurus picturatus; seasonal variability; parasitological indices; North East Atlantic
• Online Access: http://hdl.handle.net/1834/42924

The blue jack mackerel, Trachuruspicturatus, is a commercially important resource in the Mediterranean Sea and the North-East Atlantic. The main aim of this work was to assess the infection levels and diversity of the ectoparasites of the blue jack mackerel.Over a one-year period, between March 2017 and February 2018, 126 specimens of T. picturatuswere collected seasonally from the Bizerte coast (Tunisia). The ectoparasite fauna of the examined host was composed ofthe two monogenean species, Pseudaxinetrachuriand Gastrocotyletrachuriand a copepod species,Peniculusfistula fistula. This is the first record of thiscopepod parasite inTunisia. The analysis revealed that the infection levels fluctuated throughout the year. Both monogeneans (P. trachuriand G. trachuri) had high prevalences during the warm season (P%=87.1, P%= 32.3, respectively). Additionally, P. trachurishowed some seasonal variations in mean abundance and mean intensity between summer and the other seasons. Furthermore, there was a highly significant variation in the mean abundance of G. trachuribetween the summer and autumn-winter seasons. The resultsof the current study may be explained by the seasonal variations in environmental conditions, the life cycles of the hosts and parasites, the feeding and migratory patterns of the hosts, the chemicals released by the hosts, and the interspecific competition between the two monogenean species. Published Refereed