Susceptibility of hatchery-reared snubnose pompano Trachinotus blochii to natural betanodavirus infection and their immune responses to the inactivated causative virus
MetadataShow full item record
Cited times in Scopus
Mass mortality of snubnose pompano Trachinotus blochii fry exhibiting dark coloration, anorexia, and abnormal swimming behavior was recently documented at the hatchery of the Aquaculture Department of the Southeast Asian Fisheries Development Center, Philippines. Samples of brain tissues were collected from affected fish and processed for RT-PCR amplification and virus isolation in cell culture. Infected E-11 cells exhibited cytopathic effect characteristic of betanodavirus. Histopathology of moribund fish showed pronounced vacuolations in the brain, spinal cord, and retina. An RT-PCR product of approximately 430 bp was amplified from the culture supernatant of betanodavirus-infected E-11 cells and sequenced. Sequencing of the T4 region of the coat protein gene (RNA 2) revealed clustering of the isolated virus within the red-spotted grouper nervous necrosis virus type. The pathogenicity of the isolated betanodavirus in healthy pompano juveniles and fry was determined via intramuscular injection and immersion challenges, respectively. Higher mortality rates were obtained in challenged fish compared with the controls. An inactivated vaccine was subsequently prepared by treating the clarified betanodavirus with formalin. Pompano juveniles intraperitoneally injected with the inactivated vaccine exhibited neutralizing antibodies from days 15 (mean titer 1:240) to 125 (1:560) with the highest titer noted at day 64 (1:2240) post-vaccination. Additionally, pompano fry bath-vaccinated and consequently bath-challenged with betanodavirus at day 35 post-vaccination showed higher survival rate compared with the control, indicating the potential of the inactivated betanodavirus vaccine against VNN in pompano fry and juveniles.
CitationPakingking Jr., R., Mori, K., Bautista, N. B., de Jesus-Ayson, E. G., & Reyes, O. (2011). Susceptibility of hatchery-reared snubnose pompano Trachinotus blochii to natural betanodavirus infection and their immune responses to the inactivated causative virus.
This study was funded by SEAFDEC/AQD (study code: 5203-T-RD FH0507) and the Government of Japan Trust Fund through the Regional Fish Disease Project (study code: 8001-T-FD-FH0507). We would like to thank Dr. Takuma Sugaya of Fisheries Research Agency, Oita, Japan, for the invaluable help on sequencing and phylogenetic analysis and Dr. Felix Ayson for the critical review of the manuscript.
Showing items related by title, author, creator and subject.
Conference paperK Fukusho - In TU Bagarinao & EEC Flores (Eds.), Towards sustainable aquaculture in Southeast Asia and Japan: Proceedings of the Seminar-Workshop on Aquaculture Development in Southeast Asia, Iloilo City, Philippines, 26-28 July, 1994, 1995 - SEAFDEC Aquaculture DepartmentAquaculture production in Japan in 1993 was 1,351,000 tons, 15.6% of the total fisheries production. About 93.6% came from mariculture and 6.4% from freshwater aquaculture. The per cent contribution of aquaculture to total production has increased in recent years but partly because marine fisheries,especially of sardine and pollack, have decreased. Aquaculture has reached a plateau, and decreased slightly between 1992 and 1993. Diverse marine and freshwater species are cultured in Japan — various fishes, crustaceans, mollusks, seaweeds, sea squirt, sea urchin, and others. Research and development in mariculture focus on finding substitutes for animal protein in feeds, improvement of fish quality, protection of the culture environment, use of offshore floating culture systems, and protection from diseases. Research in freshwater aquaculture has expanded to include recreational fishing, the propagation and preservation of endangered species, and the construction of fish ladders for salmonids and other migratory species.
Conference paperAC Emata - In TU Bagarinao & EEC Flores (Eds.), Towards sustainable aquaculture in Southeast Asia and Japan: Proceedings of the Seminar-Workshop on Aquaculture Development in Southeast Asia, Iloilo City, Philippines, 26-28 July, 1994, 1995 - SEAFDEC Aquaculture DepartmentMost of the fish research at SEAFDEC AQD in 1992-1994 was on milkfish. Studies were conducted on year-round spawning through hormonal or environmental manipulation; optimum lipid and protein levels and ration size for captive broodstock; and the influence of spawner age on reproductive performance. The economics of hatchery operations, alone or integrated with broodstock as a commercial enterprise, was assessed. Mass production of larvae was refined with the use of commercial or SEAFDEC-formulated larval diets. Alternative rearing schemes in large tanks and ponds were tried. Hatcheryproduced and wild-caught larvae were compared in terms of growth and production in experimental nursery and grow-out ponds. Supplemental diets for brackishwater grow-out culture were formulated. Studies on broodstock management of grouper Epinephelus spp. included lipid enrichment of the diet and hormonal induction of sex inversion. Seed production techniques were developed but survival rates were low. Grouper culture was found economically feasible in experimental ponds with 'trash' fish as feed. The mangrove red snapper Lutjanus argentimaculatus was successfully induced to spawn with injection of human chorionic gonadotropin. Initial larval rearing trials were successful but survival rates must be improved. Hormonal manipulation of spawning of the Asian sea bass Lates calcarifer allows seed production during most of the year. Photoperiod manipulation leads to maturation of females, but not males, beyond the natural breeding season (April-November). Nursery rearing of 9 mm juveniles is feasible in floating net cages with night lights that attract food zooplankton. The requirements of sea bass for lipid, protein, carbohydrates, and essential amino acids were determined. In the rabbitfish Siganus guttatus, weekly injections of luteinizing hormone releasing hormone analogue (LHRHa) sustains milt production for three weeks. Thyroid hormones injected into broodstocks improved the growth of larvae to day 7. Induced spawning techniques for the Asian catfish Clarias macrocephalus were refined by determining the seasonal responsiveness to LHRHa and pimozide injections and testing for pheromonal induction of spontaneous spawning. The optimum insemination rate was determined and egg hatchability was enhanced by removal of the adhesive coat before incubation. Several practical diets for catfish during grow-out culture were tested against 'trash' fish. The broodstock management for bighead carp Aristichthys nobilis was studied. Cage-reared juveniles from cage-reared broodstock showed the best growth. To improve the reproductive performance, the broodstock diets were supplemented with vitamins A, C, and E. Research on tilapias focused on genetics and strain selection. Several strain testing procedures for Nile tilapia were evaluated in their efficiency to detect economically important strain differences. Reference lines were developed from two existing red tilapia strains to measure and reduce the effects of uncontrolled nongenetic variables in strain evaluation experiments with Nile tilapia. The tolerance of two Nile tilapia strains to heavy metals was similar when gauged by the 24-hour and 96-hour lethal concentration and by fish growth, survival, and reproductive performance. In a separate study, four strains of red tilapia showed generally higher seed production when reared in tanks than in cages. Improvements in the feed and feeding management for Nile tilapia were also studied. Intensive tilapia farming and feeding have led to oxygen depletion and fish kills in Sampaloc Lake. To rehabilitate the lake, it is imperative to reduce the farming area from 30 to 6 hectares; stop the use of commercial feeds; and remove the water hyacinths and other debris. Fish kills in Laguna de Bay have also become serious in recent years, and a review of the occurrences, losses, and possible causes is currently being conducted. Studies on the epizootic ulcerative syndrome of snakeheads in Laguna de Bay have yet to pinpoint the pathogen. Skin lesions in tilapias in several ponds and lakes in the country were found to be due to bacteria.
Book | Conference publication
Development and use of alternative ingredients or fish meal substitutes in aquaculture feed formulation: Proceedings of the ASEAN Regional Technical Consultation on Development and Use of Alternative Dietary Ingredients or Fish Meal Substitutes in Aquaculture Feed Formulation MR Catacutan, RM Coloso & BO Acosta (Eds.) - 2015 - Aquaculture Department, Southeast Asian Fisheries Development CenterRecognizing the need for a concerted effort to follow-up on this priority issue of the ASEAN on aquaculture feed development and utilization. SEAFDEC (Aquaculture Department and Secretariat) and the Government of Myanmar organized the 'Regional Technical Consultation (RTC) on development and Use of Alternative Dietary Ingredients or Fish Meal Substitutes in Aquaculture Feed Formulation'. The meeting was convened with the main purpose of providing a forum for charting the regional priorities and future directions on feed development, particularly on the use of alternative feed ingredients or protein substitutes. The specific objectives were to: (i) review the ASEAN-SEAFDEC member country status, constraints associated with developing alternative dietary ingredients for aquaculture feed; (ii) identify specific advances being made in the region with respect to the development of alternative aquaculture feed ingredients; and (iii) define approaches or initiatives supporting catch reduction of low-value/trash fish; (iv) formulate relevant policy recommendations (regional and country-specific) for effective development and utilization of aquaculture feeds; and (v) enhance cooperation among member countries and relevant stakeholders on initiatives that support sustainable aquaculture practices, particularly on feeds. This publication presents the outputs of the RTC. The country reports and review papers presented during the conference which are contained in this volume are cited individually.