摘要：This research evaluated the nonspecific immune responsse, resistance, and growth of Litopenaeus vannamei fed nucleotide diet. Shrimp juveniles (mean weight 5.39±0.56 g) were reared in two groups of glass aquaria, each with three replications. Shrimps in group one and group two were fed nucleotide diet and basal diet each for four weeks. Total haemocyte count (THC) and PO activity were evaluated at the end of feeding while growth was measured at two weeks interval. At the end of feeding trial, the shrimps were intramuscularly injected with Vibrio harveyi 0.1x10 6 cfu.shrimp -1 . THC of shrimp fed nucleotide diet significantly increased (P -1 diet showed positive effect on the enhancement of nonspecific immune responsse, resistance, and growth of L. vannamei . Key words: Litopenaeus vannamei, nucleotide, THC, PO activity, resistance ABSTRAK Penelitian bertujuan untuk mengevaluasi respons imun non-spesifik dan resistensi udang vaname ( Litopenaeus vannamei ) yang diberi pakan nukleotida. Juvenil (5,39±0,56 g) dipelihara dalam dua kelompok akuarium kaca masing-masing dengan 3 ulangan. Udang dalam dalam kelompok pertama diberi pakan nukleotida sedangkan udang dalam kelompok kedua diberi pakan standar selama 4 minggu. Total haemocyte count (THC) dan aktivitas phenoloxidase (PO) diukur pada akhir pemberian pakan sedangkan pertumbuhan udang diukur setiap dua minggu. Pada akhir periode pemberian pakan perlakuan, udang diuji tantang secara injeksi intramuskular dengan bakteri Vibrio harveyi 0,1x10 6 cfu.udang -1 . THC udang yang diberi pakan nukleotida meningkat secara signifikan (P -1 pakan selama 4 minggu memberi pengaruh positif terhadap peningkatan respons imun non-spesifik, resistensi dan pertumbuhan udang vaname. Kata kunci: Litopenaeus vannamei , nukleotida, THC, aktivitas PO, resistensi
