Abstract
The study was conducted to estimate the growth and production economics of freshwater mud eel (Monopterus cuchia) culture in three districts e.g. Rangamati (S1), Khagrachhari (S2), and Bandarban (S3) of the Chattogram hilltract, Bangladesh, over a 6-month period (March to September 2022). Juvenile eels (initial weight: 50–60 g; length: 25–34 cm) were stocked at 10 individuals/m² and fed a diet of small indigenous species (1.5% of body weight every three days) and live vermi worm (1.5% of body weight daily). The highest weight gain was recorded in S3 (130.85±6.36 g, p < 0.05), which also exhibited superior survival (73.26±1.5%), specific growth rate (0.70±0.02% day⁻¹), and net production (4,724.27±53.54 kg/acre/6 months) compared to S1 and S2. The Cobb–Douglas production function revealed that the cost of seed and live fish had significant negative effects on gross return (p < 0.01 and p < 0.05), with elasticities of -0.03 and -0.30 respectively. The findings indicate that although growth performance of M. cuchia is favorable, profitability is strongly constrained by input costs, particularly seed and feed. Improving the availability of quality seed at affordable prices is therefore essential for the sustainable expansion of cuchia culture in this region.