Morphometric Characteristics, Length-Weight Relationships, and Condition Factors of Five Indigenous Fish Species from the River Ganga in Bihar, India

Morphometric characteristics, length-weight relationships (LWRs), and condition factors (K) were studied for five indigenous fish species belonging to five different families (Barilius barila Hamilton, Cirrhinus reba Hamilton, Chanda nama Hamilton, Mystus bleekeri Day, and Clupisoma garua Hamilton), from the River Ganga in Bihar, India. A total of 557 fish individuals were collected seasonally from September 2021 to August 2022 using a monofilament drift gill net and a conical trap net Khairel jal. In morphometric analysis, the highest degree of correlation was observed between the total length and the standard length for all species (except C. garua). The estimated exponent value b varies from 2.920 to 3.214, where the slopes of regression lines among the species have significant differences ( p < 0.0001 ). The b value indicated that three species (B. barila, C. nama, and C. garua) follow positive allometric growth, whereas M. bleekeri shows isometric growth and C. reba exhibits negative allometric growth. The condition factor value for these fishes ranged from 0.67 to 0.98, which indicated that the population of C. reba was robust compared to all other species ( p < 0.0001 ). A new maximum length (146.8 mm) was obtained for B. barila from India. The present study gives baseline biological information on five commercially important indigenous fish species found in the River Ganga, Bihar. As the population of these species has been dwindling in recent times, these data will be important for the conservation and sustainable utilization of these important species in the long run.