The length-weight relationship between fish and their bodies is a crucial tool for describing key biological aspects of fish stock. This includes: measuring lengths of the species to determine the fish\'s weight, as well as estimating its growth rate using the allometric coefficient. Also, analyzing the body condition of the specimens of fish. The knowledge and data gained from the study of the functional relationship between length and weight of fish are crucial for providing fish stock assessments and for developing fish stock condition analyses and strict fisheries monitoring programs.

The present research examines the length-weight relationship using a MATLAB-based software. This allows for the application of linear regression analysis to data sets of length and weight measurements from sprats and anchovy commercial catch sample. The second stage validates the nonlinear length and weight relationship model W(i). Under certain conditions, both linear and nonlinear models can be valid and statistically significant in the present analysis. These are the relevant conclusions and analyses, as well as a comparison of the accuracy and analysis of results obtained using the models discussed above.