Transmission of White Spot Syndrome Virus and Possible Use of Physical Barrier as Preventive Measure (Transmisi White Spot Syndrome Virus dan Penggunaan Barier Fisik Sebagai Upaya Pencegahan)

Abstract

Penyakit bercak putih viral hingga saat ini masih menjadi masalah dalam budidaya udang. Munculnya penyakit tersebut diikuti kematian massal, sehingga menimbulkan kerugian besar. Penyakit yang disebabkan white spots syndrome virus (WSSV) menular cepat dari satu petakan tambak ke petakan lain. Penelitian bertujuan melakukan uji kuantitas WSSV pada transmisi virus baik melalui air dan kohabitasi. Metode penelitian adalah bioassay dilakukan skala laboratorium. Penularan melalui air disimulasi pada akuarium disekat dengan 3 jenis kasa berukuran pori berbeda, yaitu 300μ, 700μ dan 2 mm. Kohabitasi dilakukan dengan memelihara udang terinfeksi WSSV secara buatan dengan udang dan moluska sehat. Hasil penelitian didapatkan bahwa WSSV menimbulkan infeksi pada udang sehat yang ditempatkan terpisah dari udang sakit menggunakan sekat kasa. Virus bercak putih juga menular secara kohabitasi udang sakit dengan udang sehat baik dari udang windu ke udang windu (sejenis) maupun udang windu ke udang vannamei (berlainan jenis). Hasi penelitian menunjukkan bahwa trisipan bukan karier WSSV, karena tidak menularkan. Analisis LT-₅₀ (lethal time 50%) didapatkan bahwa udang yang diuji tantang WSSV melalui inkubasi dengan air mengandung ekstrak WSSV didapatkan konsentrasi 2,75x102 WSSV copy.mL^-1 menyebabkan kematian 50% dalam waktu 108 jam atau hampir lima hari. Penggunaan kasa putih meskipun tidak sepenuhnya menahan, dapat menghambat sebagian transmisi WSSV. Hasil kajian memberikan gambaran tentang kecepatan penyebaran WSSV di lingkungan budidaya udang serta memberikan panduan bagaimana mengendalikan WSSV.

Kata kunci: penyakit, transmisi WSSV, udang, kohabitasi, trisipan

White spot viral disease has devastated shrimp industry in Indonesia. The emergence of this disease is always followed by massive death causing huge losses. Disease is caused by a virus namely White spots syndrome virus (WSSV) is rapidly transmitted from one pond to other ponds. This study aims to quantify WSSV upon transmission process at different route of transmission either through water, the cohabitation ant to cerithidae. A model has developed to fascilitate transmission through water. Aquarium capacity of 60 liter use in this research, each made into two compartment with separation by 3 different screen with pore sizes, 300μ, 700μ and 2 mm. Healthy tiger shrimp Penaeus monodon, reared in one compartment and artifitially diseased shrimp in another compartment. Cohabitation was done by rearing healthy shrimp of tiger shrimp and vannamei shrimp together with artifially infected shrimp with WSSV. For transmission through snails, snail fed with infected shrimp and reared together with infected live shrimp. Transmission also done through bathing healthy shrimp into water contained WSSV extract. The result showed that WSSV is able to cause infection in healthy shrimp eventhough are spaced apart from diseased shrimp using different mesh size screen. White spot virus can also be transmitted by cohabitation from diseased tiger shrimp either to tiger shrimp (same species) or to vannamei shrimp (different species). The result showed that snail is not a career for WSSV. LT-50 of challenge of shrimp with WSSV through incubation with water contained of WSSV extract found that innocula at concentration 2,75 x 105 WSSV copy.μl^-1 causing mortality at 50% within 108 hours. White screen, eventhough not fully efective, but still can retarded WSSV transmission. Result of study provide a greater understanding of how the virus be transmitted in the shrimp farm, and as guidance strategy in controlling in shrimp aquaculture.

Keywords: disease, transmission of WSSV, cohabitation, shrimp, snail