Title

Feeding Ecology of Dolphinfish in the Western Gulf of Mexico

Document Type

Article

Publication Date

6-24-2016

Digital Object Identifier (DOI)

https://doi.org/10.1080/00028487.2016.1159614

Abstract

Dolphinfish Coryphaena hippurus support important commercial and recreational fisheries in the Gulf of Mexico. Understanding the feeding ecology of this economically important pelagic fish is key to its sustainable management; however, dietary data from this region are sparse. We conducted a comprehensive diet study to develop new trophic baselines and investigate potential ontogenetic and sex-related shifts in Dolphinfish feeding ecology. The stomach contents of 357 Dolphinfish (27.6–148.5 cm TL) were visually examined from fishery-dependent sources off Port Aransas, Texas. Our analyses revealed a highly piscivorous diet with Actinopterygii comprising 70.44% of the stomach contents by number. The most commonly observed taxa were carangid (12.45%N) and tetraodontiform (12.08%N; families Balistidae, Monacanthidae, and Tetraodontidae) fishes. Malacostracans were also common (24.83%N), mostly in the form of pelagic megalopae. Other prey categories included squid and the critically endangered Kemp’s Ridley sea turtles Lepidochelys kempii. Although increasingly commom in larger fish, Sargassum spp. was found across a range of sizes in Dolphinfish, indicating that these fish feed from this drifting macroalgae throughout ontogeny. An ontogenetic shift from primary consumption of carangids and brachyurans in smaller size-classes to tetraodontids, monocanthids, and squid in larger size-classes was also observed. No sex-related difference in diet was observed. The overall infection rate for gastric parasites was 54%, an order of magnitude increase from that previously reported in the region, but consistent with recent studies from other areas. Trematode parasites in the genus Dinurus were found in 55% of stomachs and nematode parasites of the family Raphidascarididae in 16% of stomachs. Overall, Dolphinfish in the western Gulf of Mexico are highly opportunistic carnivores with a gastrointestinal parasite burden consistent with that reported in other ocean basins. These data will be important for sustainable management of this economically important species.

Was this content written or created while at USF?

No

Citation / Publisher Attribution

Transactions of the American Fisheries Society, v. 145, issue 4, p. 839-853

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