SEAFDEC/AQD Southeast Asian Fisheries Development Center | Aquaculture Department
By Development Communication Section
SEAFDEC/AQD scientist Dr. Edgar Amar bagged this year’s prestigious Dr. Elvira O. Tan Memorial Award for his paper “Induction of Immunity and Resistance to White Spot Syndrome Virus (WSSV) in Shrimp Penaeus monodon (Fabricius) by Synthetic Oligodeoxynucleotide and Bacterial DNA.” His paper, which he coauthored with Mr. Joseph Faisan, Jr., won the first place under the category Best Published Paper in Aquaculture and Inland Fisheries.
Their study investigated the effect of oligodeoxynucleotides or ODN’s in strengthening the immunity of black tiger shrimp as a preventive strategy against white spot syndrome virus (WSSV) infection. Oligodeoxynucleotides are short single-stranded synthetic DNA molecules that represent a new set of compounds that heighten the activity of the defense mechanisms of the immune system. The study also tested the ability of whole bacterial genomic DNA from Vibrio harveyi to elicit a stimulatory response in the shrimp in view of the possible use of bacteria as ODN source instead of the commercially available but more expensive synthetic ODNs. The results of the present study show increases in all the immune activities in the shrimp after injection of commercial ODNs or bacterial genomic DNA. The injected shrimps also had significantly lower mortalities after being challenged with a WSSV infection. Thus, strengthening shrimp immunity by the use of immunostimulatory nucleotides and bacterial genomic DNA could be a feasible preventive approach in the management of WSSV infections in shrimp. This study is funded by SEAFDEC/AQD and the Regional Fish Disease Project of the Government of Japan Trust Fund.
Under the same category, another SEAFDEC/AQD scientist, Dr Myrna Bautista-Teruel was awarded the second place for her paper “Evaluation of Agar-Bound Microparticulate Diet as Alternative Food in Abalone Hatchery: Effects of Agar Concentrations and Feeding Frequencies.” She shared this award with her coauthors, Ms. Milagros de la Peña and Ms. Analyn Asutilla.
Their study tested the performance of an agar-bound microparticulate diet (A-MPD) as feed for postlarval abalone Haliotis asinina, focusing on the effects of agar concentrations and feeding frequencies. Larval abalone were fed 1,200 mg A-MPD bound with either 5.0 mg/mL agar solution, 7.5 mg/mL agar solution, 10.0 mg/mL agar solution, and 12.5 mg/mL agar solution, or a natural diet consisting of diatoms at different feeding frequencies: daily, every other day, or every 2 days, starting at day 5. Their results show that postlarval settlement and survival were not significantly different in diets bound with higher agar concentrations when tested in the 3 feeding frequencies. At lower levels of agar incorporation in diets, however, settlement and survival counts became significantly higher on daily feeding. Postlarval settlement and survival were significantly highest with abalone fed a diet bound with 7.5 mg/mL agar solution on a daily feeding frequency. Stability tests and analyses of the feed were also done and the average percent weight loss in the feed was higher with lower levels of agar incorporation. Average particle size of both A-MPD and diatoms was 4 – 5 microns. Crude protein content of A-MPD was 42.7%; that of diatoms was 14.9%. The present study shows that A-MPD may be used as alternative food in abalone hatcheries with the incorporation of 7.5 mg/mL agar solution fed daily to abalone. This study is wholly funded by SEAFDEC/AQD.
