PERENDAMAN BERBAGAI DOSIS EKSTRAK DAUN BAKAU (Rhizophora apiculata) UNTUK PENGOBATAN KEPITING BAKAU (Scylla serrata) YANG DIINFEKSI BAKTERI Vibrio harveyi

Abstract

Budidaya kepiting bakau (Scylla serrata) sering terkendala karena serangan penyakit bakterial Vibrio harveyi. Penggunaan antibiotik dalam jangka panjang dapat menimbulkan resistensi dan mencemari lingkungan. Penggunaan bahan alami untuk pengobatan infeksi bakteri sedang digalakkan, salah satunya adalah ekstrak daun bakau (Rhizophora apiculata). Penelitian ini bertujuan untuk mengetahui pengaruh perendaman ekstrak daun bakau terhadap kelulushidupan, laju pertumbuhan spesifik, dan histopatologi hepatopankreas kepiting serta mengetahui dosis terbaik untuk mengobati kepiting yang diinfeksi bakteri V. harveyi. Kepiting bakau yang digunakan berjumlah 48 ekor dengan berat tubuh antara 40.11±2.53 gram, yang kemudian disuntik bakteri V. harveyi dengan kepadatan 10⁶ CFU/ml secara intramuskular. Perendaman ekstrak daun bakau dilakukan 60 – 90 menit pasca penyuntikan setelah muncul gejala klinis seperti merenggangnya kaki renang dan kaki jalan, karapas menghitam, terdapat bintik putih, dan munculnya bercak merah. Perendaman ekstrak daun bakau berpengaruh sangat nyata (P<0.05) dan P(<0.01) terhadap kelulushidupan kepiting yang diinfeksi bakteri V. harveyi. Nilai rerata kelulushidupan tertinggi hingga terendah berturut-turut yaitu 100% (perlakuan D), 66.67% (perlakuan C), 58.33% (perlakuan B), dan 41.67% (perlakuan A). Sebaliknya, perendaman ekstrak daun bakau tidak memberikan pengaruh nyata (P>0.05) dan P(>0.01) terhadap pertumbuhan kepiting bakau. Hasil pengamatan histopatologi diperoleh adanya kerusakan berupa nekrosis dan vakuolisasi pada organ hepatopankreas. Pada penelitian ini, dosis 900 ppm merupakan dosis terbaik dalam mengobati kepiting bakau yang diinfeksi V. harveyi yang mampu memberikan efek penyembuhan terhadap kepiting bakau.

Mud crab (Scylla serrata) culture often found obstacle due to bacterial infection Vibrio harveyi. Long-term use of antibiotics cause bacterial resistante and contaminated the environment. Natural ingredients has been for treatment of diseased crab, one of which was mangrove leaf extract (Rhizophora apiculata). This research was aimed to observe the effect of immersion mangrove leaf extract to the survival rate, specific growth rate, and histopathological picture of hepatopancreas mud crab and to know the best dose to treat mud crab that was infected by bacteria V. harveyi. Mud crab used in this research was 48 animals  with body weight between 40.11±2.53 grams, then injected by bacteria V. harveyi with a density of 10⁶ CFU/ml intramuscularly. Dipping in mangrove leaf extract was conducted for 60 – 90 minutes after injection with the appearance of clinical signs such as wide apart swimming and walking legs, blackened carapace, white spots, and red spots. Dipping of mangrove leaf extract significantly effect (P<0.05) and P(<0.01) on the survival of mud crab that was infected by bacteria V. harveyi. The average value of highest to the lowest survival 100% (treatment D), 66.67% (treatment C), 58.33% (treatment B), and 41.67% (treatment A) respectively. The other way, the submersion with mangrove leaf extract showed not giving significant different (P>0.05) and P(>0.01) on growth of mud crab. Histopathological observations obtained were necrosis and vakuolisation in hepatopancreas organ. In this research, dose of 900 ppm give the best treatment to mud crab (S. serrata) were infected V. harveyi. Therefore, immersion mangrove (R. apiculata) leaf extract was able to provides a healing effect on mud crab infected bacteria V. harveyi.