Describing the diet of a generalist feeder: the striped searobin ( Prionotus evolans ) from Narragansett Bay, Rhode Island (USA)

The warm-water species, striped searobin ( Prionotus evolans ), has colonized Narragansett Bay (Rhode Island, USA) in recent decades. To clarify the high variability of past investigations, the aim of this study was to characterize the diet of striped searobins. Stomach contents from searobins collected throughout Narragansett Bay in 2019 were identified and analyzed. Diet varied ontogenetically, seasonally, and regionally. The ontogenetic changes in diet reflected an expansion of searobin niche breadth: all searobins ate a diet with sand shrimp; however, smaller searobins ate primarily sand shrimp, while larger searobins also consumed crustaceans and finfish. Searobin diet varied by month, but diet composition did not exhibit a singular trend. Regional variation was illustrated by a dominance of mysid shrimp in Upper-Bay searobin samples, while the Mid- and Lower-Bay samples contained larger proportions of other crustacea and sand shrimp. Their flexible diet provides strong evidence that striped searobins are adaptable generalist feeders. Searobin stomachs included nine prey species of economic importance; such predation could become more common as continued increase of habitat use of searobins in Narragansett Bay may result in greater overlap with the occurrence of vulnerable juvenile stages of economically valuable species (e.g., winter flounder). The results of this work contribute to our understanding of the evolving role of the striped searobin in food webs, particularly those in Southern New England (USA).