This document provides information on common freshwater fish species found in Kerala, India. It begins with an introduction to fish taxonomy and the importance of fish as a food source in South Asia. The document then describes several important fish species found in Kerala's rivers and lakes, including the Peninsular Hill Trout, Hiffin Carp, Nash's Barb, Malabar Silurus, Boal, and various species of glassfish. It provides details on the physical characteristics, habitats, threats, and conservation status of each species. The document also includes background information on Kerala's geography, rivers and lakes, and key contributors to the study of Kerala's freshwater fish diversity.