Diet composition and feeding strategy of John Dory, Zeus faber, in the coastal waters of Korea

Abstract

Background: Most fish undergo prey switch from juvenile to adult. It is thought that slightly different feeding habits occur among adult fishes due to growth, spawning, habitat change, and so on. Therefore, the diet of the John Dory Zeus faber (≥ 24 cm TL) was studied in the coastal waters of Korea by analysis of stomach contents, with comparison by season and size class of diet composition and prey diversity. Monthly samples were taken from February 2017 to January 2018. Results: The results showed that the John Dory was a piscivorous predator, and pisces had occupied 82.3% of IRI%. Trichiurus lepturus and Trachurus japonicus were important preys in all size classes and seasons. Diet composition differed among the size classes and seasons (Chi-square test, P < 0.05). As body size of Z. faber increased, the occurrence of benthic fish (Glyptocephalus stelleri) tended to increase. The seasonal prey composition also changed depending on the abundant species of each season. Conclusions: Z. faber is a piscivorous predator. The consumption habits of Z. faber appear to different results by their size and seasons. This study suggests that Z. faber could be considered an opportunistic predator.

First record of the benthopelagic fish John dory Zeus faber (Linnaeus, 1758) in the Black Sea coasts of Türkiye

“…The sample's stomach was fully empty, so we cannot infer its feeding behavior at the sampling site. John dory is an opportunistic piscivorous predator that takes advantage of abundant and diverse prey items, from cephalopods to Pisces (Choi et al, 2011;İşmen et al, 2013;Kim et al, 2020). John dory is capable of stalking enough to consume selected prey fish in a group or school (Ressell, 1983).…”

“…John dory is capable of stalking enough to consume selected prey fish in a group or school (Ressell, 1983). Prey items cover the entire water column, and their diet varies by region, habitat, and size (Ressell, 1983;Stergiou & Fourtouni, 1991;Kim et al, 2020). The Black Sea is very rich in Pisces, such as whiting, sardines, horse mackerel, anchovy, picarel, bogue, and gobies (Aydın & Karadurmuş, 2012;Gücü et al, 2017;Karadurmuş et al, 2021a), which are the main prey of John dory.…”

“…The Black Sea is very rich in Pisces, such as whiting, sardines, horse mackerel, anchovy, picarel, bogue, and gobies (Aydın & Karadurmuş, 2012;Gücü et al, 2017;Karadurmuş et al, 2021a), which are the main prey of John dory. (Silva, 1999;Kim et al, 2020). The variety and abundance of preys in the Black Sea can provide a vital feeding opportunity for the species.…”

“…This species' maximum size and age are 90 cm (Iwamoto, 2015) and 18 years (İşmen et al, 2013), respectively. It is usually caught by bottom trawl net, long line, or trammel net close to the bottom in the fisheries areas (Jardas, 1996) but is mainly considered a valuable by-catch (Dunn, 2001;İşmen et al, 2013;Kim et al, 2020). This species is used in commercial fisheries for human consumption, fish meal, and oil (Iwamoto, 2015).…”

The genome sequence of the John Dory, Zeus faber Linnaeus, 1758

“…Recently, it has been recorded for the first time in the Black Sea ( Aydın & Karadurmuş, 2023 ). John Dory has a large, highly protrusible mouth allowing it to predate on relatively large fish which they target using well-developed eyes ( Kim et al , 2020 ; Stergiou & Fourtouni, 1991 ).…”