Low-effort regression estimation of daily ration in young walleye, Stizostedion vitreum

I used a low-effort regression approach to estimate daily rations of pond-reared age 0 walleye, Stizostedion vitreum (16.0-37.2 mm total length). The regression model predicted average 24-h food mass ((F) over bar(24)) from two or three consecutive point estimates of food mass (F-t) in fish guts taken at a sampling interval of 3 h. Predicted F, values were multiplied by gastric evacuation rates and by 24 h to yield daily ration estimates. Accuracy tests of the low-effort regression model for age 0 walleye based on resampling revealed that 93-100% of predicted (F) over bar(24) values fell within 2 SEs of observed (F) over bar(24) values determined from nine fish collections over 24 h. The age 0 walleye regression model provided estimates of daily ration that were within the 95% confidence intervals around observed daily ration values for conspecifics in an independent test pond (this study) and in other distinct pond systems. The age 0 walleye regression model also provided estimates of daily ration that were within the 95% confidence intervals around five out of seven observed daily ration values for age 0 lake yellow perch, Perca flavescens, also a diurnal feeder like walleye. The model reliably provided estimates of daily ration for fish that were 1.5-4.5 times the mean wet weight of the largest fish included in the model's domain.