Habitat-specific diet analysis of Sacramento Pikeminnow (Ptychocheilus grandis) and striped bass (Morone saxatilis) in the Sacramento River

This study examined the diets of two predatory fish species, the native Sacramento Pikeminnow (Ptychocheilus grandis) and the introduced Striped Bass (Morone saxitilis), within the Sacramento River, CA, USA. Sampling occurred between March and December 2017 and was comprised of two primary components. The northern survey component was done via hook and line sampling, on a 35 kilometer reach near Chico, CA, and the southern survey component was done via seven fyke traps located near Sacramento, CA. Stomach contents were collected via non-lethal gastric lavage and were later processed using visual, gravimetric, and genetic techniques. Relative abundance of Sacramento Pikeminnow was significantly higher at man-made structure sites and Striped Bass relative abundance was positively correlated with water temperature. Diets of Sacramento Pikeminnow and Striped Bass captured near Chico, CA were not different, and Striped Bass captured near Chico, CA had significantly different diets to those captured near Sacramento, CA as determined by PERMANOVA analysis.