Rapid Growth, High Feeding Rates, and Early Piscivory in Young-of-the-Year Bluefish (Pomatomus saltatrix)

Abstract

The bluefish (Pomatomus saltatrix) is an offshore-spawning estuarine-dependent fish that is abundant along the east coast of North America. Young-of-the-year bluefish undergo a habitat shift from offshore waters to inshore nursery areas at about 40–70 mm total length which coincides with an increased growth rate and a diet shift from planktivory to piscivory. Here, we measure growth of young-of-the-year bluefish on different diets and estimate consumption rates both in the field and in the laboratory. Growth on a fish diet is significantly higher than that on a zooplanktivorous diet. Bluefish have among the highest evacuation (5–7 h), consumption (20–30% body weight/d), and specific growth rates (1–2 mm/d) reported for temperate fishes and are similar to those for pelagic tropical species. These results suggest that bluefish may exhibit a tropical feeding physiology in temperate estuarine nurseries as a way to achieve rapid growth rates.