Effect of feeding Tubifex worms, mixed zooplankton, and a combination of both, and habitat enrichment on the growth and survival of barred spiny eel ( Macrognathus pancalus , Hamilton, 1822) juveniles

In many parts of the world, rural communities rely heavily on indigenous fish species to meet their nutritional needs, underscoring the need for sustainable farming practices. Diet optimization and effective environmental management are essential to promoting the health and well-being of these fish during domestication. In this study, we evaluated the survival and growth of Macrognathus pancalus, a high-value benthopelagic and overexploited food fish, using various food materials: live tubifex, zooplankton, a combination of zooplankton and tubifex, and an artificial feed as a control. Additionally, we assessed different floor substrates as habitats—sand, mud, a combination of sand and mud, and a control without any substrate. The experiments were conducted in triplicate in reinforced plastic tanks over a 90-day period. The results revealed that fish (0.60 ± 0.08 g) fed with tubifex achieved significant growth of 1.89 ± 0.22 g (p < .05) with the higher survival (81.33 ± 2.31%), followed by those fed with a combination of mixed zooplankton and tubifex (1.38 ± 0.12 g). It was observed that fish (2.40 ± 0.75 g) in a water habitat without any substrate (control) achieved significant growth of 6.86 ± 2.60 g (p < .05), followed by those in a sandy habitat (5.21 ± 0.02 g). These findings suggest that feeding tubifex to fish in tanks without a floor substrate could be the most effective approach for the culture of this fish.