Fish length and weight data. This dataset is not publicly accessible because: Data is the property of Isfahan University of Technology, Isfahan, Iran. It can be accessed through the following means: Contact Isfahan University of Technology, Isfahan, Iran. Format: The dataset consists of fish length and weight data. This dataset is associated with the following publication: Zare-Shahraki, M., Y. Keivany, E. Ebrahimi, A. Bruder, J. Flotemersch, and K. Blocksom. Length-weight relationships of seven fish species from the Karun River system, southwestern Iran. Iranian Journal of Ichthyology. Iranian Society of Ichthyology, Isfahan, IRAN, 7(4): 352–355, (2020).