The Effects of Age‐0 Body Size on the Predictive Ability of a Largemouth Bass Bioenergetics Model

• Published in: Transactions of the American Fisheries Society (1900) 2004-03, Vol.133 (2), p.279-291
• Main Authors: Slaughter, Joe E., Wright, Russell A., DeVries, Dennis R.
• Format: Article
• Language: English
• Subjects: Freshwater; Micropterus salmoides; Micropterus salmoides floridanus; Micropterus salmoides salmoides
• ISSN: 0002-8487; 1548-8659
• DOI: 10.1577/02-062

Bioenergetics models for largemouth bass Micropterus salmoides have provided scientists with a valuable tool for estimating growth and consumption based on temperature and the size of individuals. These models were developed for a wide range of fish sizes from various geographic origins and have been used to generate predictions for fish across the entire size and geographic ranges of largemouth bass. Although previous studies have shown general validity in model predictions, no validation has been achieved for smaller‐bodied largemouth bass from differing geographic populations. To test the accuracy of a commonly used model at predicting the growth of small largemouth bass, we ran a series of six 14‐d aquarium experiments that included controlled feeding rates over the range of average daily water temperature regimes in central Alabama. Age‐0 largemouth bass from one population in Wisconsin (northern largemouth bass M. s. salmoides) and two populations in Alabama (Florida largemouth bass M. s. floridanus and northern largemouth bass) were fed at two ration levels, and the actual amount consumed over the 14 d was used to predict growth, which was compared with observed growth. Survival was similar among populations and decreased at higher temperatures. The bioenergetics model inaccurately predicted the growth of age‐0 largemouth bass for all three populations. The bias associated with model predictions increased with temperature. Additionally, model predictions were more accurate for the Florida subspecies than for the northern subspecies throughout the temperature ranges covered in our experiments. These results suggest that differences in body size and source population may influence the relative accuracy of growth predictions by the current model. Refinement of bioenergetics model parameters to more accurately represent the physiology of smaller individuals across the broad latitudinal range of largemouth bass is necessary to allow better predictive ability of growth in age‐0 largemouth bass populations.