Performance of WSSV-infected and WSSV-negative Penaeus monodon postlarvae in culture ponds

Abstract

In a survey of 27 Penaeus monodon culture ponds stocked with postlarvae (~PL10) at medium density (~40 shrimp m -2 ), single-step nested white spot syndrome virus (WSSV) PCR was used to measure the WSSV infection rates in the shrimp populations within 1 mo after stocking. Seven ponds were initially WSSV-free, and the shrimp in 5 of these were harvested successfully. In the ponds (n = 6) where detection rates were higher than 50%, mass mortality occurred during the growth period, and none of these ponds was harvested successfully. In a subsequent study, P. monodon brooders were classified into 3 groups according to their WSSV infection status before and after spawning: brooders that were WSSV-positive before spawning were assigned to group A; spawners that became WSSV-positive only after spawning were assigned to group B; and group C consisted of brooders that were still WSSV-negative after spawning. WSSV screening showed that 75, 44 and 14%, respectively, of group A, B and C brooders produced nauplii that were WSSV-positive. Most (57%; 16/28) of the brooders in group A produced nauplii in which the WSSV prevalence was high (> 50%).When a pond was stocked with high-prevalence nauplii from 1 of these group A brooders, an outbreak of white spot syndrome occurred within 3 wk and only ~20% of the initial population survived through to harvest (after 174 d). By contrast, 2 other ponds stocked with low-prevalence and WSSV-negative nauplii (derived respectively from 2 brooders in group B), both had much higher survival rates (70 to 80%) and yielded much larger (~3 × by weight) total harvests. We conclude that testing the nauplii is an effective and practical screening strategy for commercially cultured P. monodon.

Shrimp Viral Diseases, Import Risk Assessment and International Trade

“…It is possible that aquaculture systems provided the environment in which WSSV outbreaks could be triggered. Molecular studies have confirmed that even in aquaculture systems, it is possible to find WSSV positive shrimp growing normally [25,26] and outbreaks are related to environmental stresses [16].…”

PENGARUH PERBEDAAN WAKTU APLIKASI PROBIOTIK TERHADAP KUALITAS AIR DAN SINTASAN PASCA LARVA UDANG WINDU (Penaeus monodon)

“…Kasus penyakit pada budidaya udang beberapa tahun terakhir ini, melanda Indonesi a dan n egara-n egara l ain sep ert i Thailand (Pasharawipas et al, 1998;Ruangpan et al, 1998;Sukhumsirichart et al, 1998), Taiwan (Peng et al, 2001), Filipina (Albaladejo et al, 1998;Loh et al, 1998), India , Australia (Spann et al, 1995), Jepang (Kono et al, 2004), dan Amerika (Dhar et al, 2001), kini sedikit demi sedikit mulai dapat teratasi. Hal ini bukan karena penyakit virus sebagai penyebab utamanya yang dapat diatasi, akan tetapi terutama karena subtitusi dari udang windu ke vaname, meskipun pada kenyataannya bahwa udang vaname juga tidak terlepas dari serangan penyakit terutama WSSV (Rodriguez et al, 2003;SanchezMartinez et al, 2007).…”

BEBERAPA METODE STRESSING UNTUK MENGINDUKSI PERKEMBANGAN WHITE SPOT SYNDROME VIRUS (WSSV) PADA BENUR UDANG WINDU (Penaeus monodon)

“…Karena induk yang terinfeksi WSSV akan diturunkan secara vertikal kepada larva/keturunannya. Menurut Peng et al (2001), induk udang yang terinfeksi WSSV sebelum memijah, 75% nauplii yang dihasilkannya akan terinfeksi WSSV. Dengan demikian kualitas induk yang digunakan sangat mempengaruhi kualitas nauplii dan tentunya akan berlanjut ke post larva yang diproduksi, dan juga hasil pentokolan di tambak.…”