Differences in macronutrient content of common aquatic macroinvertebrates available as prey for young-of-the-yearScaphirhynchussturgeons in the lower Missouri River

Abstract

Nutrient availability in prey items can have important consequences for the growth, reproduction, survival, and recruitment into adulthood of juvenile fish. For young of the year sturgeon, which are highly dependent on macroinvertebrates as prey, knowing the nutritional content across various prey items within their habitats can help managers during habitat restoration. The objective of this study was to test for differences in the macronutrient composition of major invertebrate groups commonly consumed by young of the year sturgeon in the lower Missouri River in the summer, when sturgeon habitat assessments occur. Potential prey vary considerably in size. In addition, there were significant differences in the concentrations of nutrients. The lowest concentration of lipid was found in Odonata (2.36 ± 1.83 mg 100 mg À1 ; mean-± pooled variance standard error) and the highest was in Diptera (14.49 ± 3.30 mg 100 mg À1). The lowest concentration of protein was found in Ephemeroptera (58.98 ± 1.90 mg 100 mg À1) and the highest concentration was in Trichoptera (70.07 ± 3.26 mg 100 mg À1). Some spatial differences were found in energy derived from protein in Ephemeroptera in the lower Missouri River, but not in energy derived from lipid. Our findings provide useful information that can contribute to adaptive management efforts for sturgeons in the lower Missouri River.

Factors affecting interannual variation in diet and body lipid content of age‐0 Scaphirhynchus sturgeon in the lower Missouri River, USA

“…Furthermore, empty stomachs were rare and limited to small (<2.0 cm FL) sturgeon near the size at which exogenous feeding is initiated (Snyder, 2002), which is consistent with previous studies (Civiello et al, 2018;Gosch et al, 2016;Sechler et al, 2013). Interestingly, the high incidence of Ephemeroptera in sturgeon ≤5.0 cm in 2017 and 2018 were novel compared to previous years; however, this did not appear to translate into differences in overall lipid content, which is consistent with prior findings that lipid-derived energy is similar among these prey types (González, Barnes, Wilder, & Long, 2020).…”

Multi-elemental consumer-driven nutrient cycling when predators feed on different prey

“…For instance, caterpillars are holometabolous insects, which feed on C-rich plant tissue during their larval stage and require high energy stores, which are high in C, to fuel metamorphosis. Alternatively, crickets are hemimetabolous, and feed on food sources that consist of higher concentrations of N (e.g., dog food that was provided ad libitum) (Fagan et al 2002, Wilder et al 2013, González et al 2020, Reeves et al 2021). Additionally, cockroaches can store excess N as uric acid in their bodies, which can result in higher N% compared to other prey (Sabree et al 2009).…”