Golden Apple Snail (Pomacea canaliculata) and Sea Lettuce (Ulva lactuca) as Fishmeal Replacements in Milkfish (Chanos chanos, Forsskal) Feed

Abstract

The increasing cost and unsustainable sourcing of fish meal, primarily derived from low-value fish, pose ecological concerns and threaten food security by reducing fish available for human consumption. This study was conducted to assess the potential of Golden Apple Snail (Pomacea canaliculata) and Sea Lettuce (Ulva lactuca) as alternative protein sources for the partial or complete replacement of fishmeal in milkfish (Chanos chanos) diets. Six experimental diets were prepared with fishmeal inclusion rates of 50% and 100% using combinations of golden apple snail and sea lettuce. These feeds underwent proximate analysis and were tested in a 90-day feeding trial on milkfish fingerlings to assess growth performance. Results indicated that the 50% fish meal replacement diet achieved the highest crude protein content, body weight gain, and feed conversion efficiency, with the lowest feed conversion ratio. In contrast, the 100% replacement diet resulted in the greatest increase in body length and specific growth rate. Statistical analysis indicated significant differences (p < 0.001) between the control and experimental diets. This study demonstrates the viability of P. canaliculata and U. lactuca as sustainable alternatives to fish meal, offering a novel feed formulation strategy to enhance milkfish aquaculture while reducing reliance on conventional fish-based inputs.