This practical manual offers a detailed guide to the taxonomy of finfish, including essential procedures for sample collection, preservation, and species identification. It covers various fish orders, including Hexanchiformes, Squaliformes, and Perciformes, along with methods for morphometric measurements, meristic counts, and advanced techniques such as DNA barcoding and karyotyping. With comprehensive instructions and methodologies, this manual is designed to support students and researchers in effectively identifying and classifying finfish, enhancing their practical understanding of aquatic taxonomy.'