Effect of Maggot Flour (Hermetia illucens larvae) on Histopathology of Koi carp (Cyprinus carpio) Muscles and Gills Infected with Edwarsiella tarda

Highlight Research • Feeding of maggot flour formulations to koi carp infected with tarda • Active compounds contained in maggot • Clinical symptoms of koi carp infected with tarda • Damage to the muscle and gill tissue of koi carp infected with E. tarda Abstract The problem that fishes farmers often face is disease. Maggot contains a high protein which ranges from 41-42%. Besides that, maggot also has a good effect on increasing the body resistance of fish. While the maggot provision fulfills nutritional need, it's also expected to boost immunity against bacterial disease. One of which is Edwardsiella tarda, known to infect koi carp (Cyprinus carpio). Feeding of maggot flour at different doses, namely A (25%), B (50%), C (75%), and D (100%) was carried out to determine its effect on the histopathology of the muscles and gills of C. carpio infected with E. tarda. Water quality during the study obtained an average value, namely the temperature ranging from 26-27.5℃, pH 6.5-8.1, and DO 5.2-8 mg/L. Fish infected with E. tarda showed several clinical symptoms, including rapid operculum movement, irregular and slow swimming, and bleeding on the skin. The results of the histopathological analysis showed that in muscle and gill tissue, treatment C (75%) showed the lowest damage value among other treatments with an average score of necrosis 0.93, hyaline degeneration 1.33, and Edema 1.27. Average score of gill tissue damage was 0.9 fusion, 1.3 congestion, 0.9 hyperplasia. Based on this, the provision of maggot flour can be used to prevent infection of E. tarda against C. carpio.