35 research outputs found
Achieving high production of micropropagated seaweed through optimization of the culture protocol
No full textKappaphycus and Eucheuma are the two carrageenanproducing red algae extensively cultured and farmed in tropical and subtropical waters. Seaweed production accounted for 5.4 percent of the world’s aquaculture production in 2019, which was over USD 15 billion in value. With this value share, the production of seaweed farming was higher than other aquatic commodities, such as tilapia, carp, shrimps, and others (Cai et al., 2021). The red algae production of the Philippines started in the 1960s (Ronquillo & Gabral-Llana, 1989), and by the early 2000s, the country had become the world’s top supplier of seaweed, particularly Kappaphycus sp., until 2007, when Indonesia outperformed it.
Problems and challenges in seaweed farming, including climate change, pests and diseases, and biosecurity issues, caused the continuous decline of the seaweed production yield (Faisan, Sollesta-Pitogo, & de la Peña, 2022). Furthermore, the deterioration of seaweed quality caused by the repetitive use of vegetative cutting methods has also become one of the most pressing concerns in seaweed farming. Unfortunately, this procedure of growing plantlets for farming is one of the most common methods many seaweed farms used in the Philippines and other countries.
Research in SEAFDEC Aquaculture Department (AQD) looks into breaking from the conventional method of farming seaweed plantlets and optimizing laboratorybased production. With this, it hopes to create a more sustainable source of propagules, better growth and survival in grow-out, and a higher carrageenan quality in cultured Kappaphycus alvarezii
Induction of immunity and resistance to white spot syndrome virus (WSSV) in shrimp Penaeus monodon (Fabricius) by synthetic oligodeoxynucleotide and bacterial DNA
No full textShrimps like all invertebrates are believed to lack true adaptive immunity but recent evidence indicate that they can be protected against pathogenic organisms by priming their immune system with immunostimulatory substances. Here, we describe results of investigation aimed to strengthen shrimp immunity as a preventive strategy against white spot syndrome virus (WSSV) infection. Oligodeoxynucleotides (ODNs) with and without Cytosine-Guanine (CpG) motifs, and Vibrio harveyi genomic DNA (VHD) were administered by intramuscular injection and shrimp responses were assessed by ex vivo assays and experimental infection trials. Results showed that CpG ODN significantly increased ex-vivo immunity indices such as total hemocyte count (THC), plasma agglutination titer (PAT) and hemocyte lysate agglutination titer (HLAT). VHD significantly increased immune indices such as THC, plasma total protein (PTP) and HLAT. Reverse (GpC) motifs increased THC only. At a lower viral challenge dose, both CpG and GpC motifs, and VHD, were able to reduce shrimp mortality significantly but only CpG and VHD did so at a higher challenge dose. 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 was supported by research funds from SEAFDEC AQD and the Regional Fish Disease Project of the Government of Japan Trust Fund Phase 4 under Study Code 8001-T-FD-FH1204
Efficacy of an inactivated vaccine and nutritional additives against white spot syndrome virus (WSSV) in shrimp (Penaeus monodon)
No full textAlthough the immune system of shrimps is not comparable to that of vertebrates, shrimps can acquire protection against pathogenic challenge by building up immunity. In this study, formalin-inactivated virus (FIV) was administered by injection, bath-immersion, or orally to determine levels of vaccination-mediated protection against the pathogenic white spot syndrome virus (WSSV). Diets supplemented with alfalfa, methyl sulfonyl methane (MSM), or wheat grass were provided with or without FIV. Shrimp injected with FIV and challenged 3, 15, or 30 days after vaccination had cumulative and relative survivals of 83%, 67%, and 33%, respectively. Survival of shrimp challenged by bath-immersion 3-45 days after vaccination by immersion was significantly higher than in the unvaccinated control. Orally vaccinated shrimp challenged by bath-immersion were partially protected up to 45 days after vaccination (cumulative survival 63.7%, relative 61.7%) but not til 60 days after vaccination (cumulative 8%, relative 3.2%). Survival of unvaccinated shrimp challenged by bath-immersion improved when shrimp were fed a diet supplemented with wheat grass or MSM, but not alfalfa. Survival was further enhanced when FIV was provided together with diets supplemented with wheat grass (cumulative 72.7%, relative 94.8%) or MSM (cumulative 73.3%, relative 96.3%)
Field efficacy evaluation of a formalin-inactivated white spot syndrome virus (WSSV) vaccine for the preventive management of WSSV infection in shrimp grow-out ponds
No full textA shrimp grow-out trial was conducted in four 700 m2 earthen ponds in Dumangas Brackishwater Station of SEAFDEC Aquaculture Department, in Iloilo, Philippines to evaluate the efficacy of a combination of immersion- and orally-administered formalin inactivated vaccine (FIV) as an antiviral strategy against WSSV. Purified virus prepared by sucrose gradient ultracentrifugation was inactivated by overnight incubation in 0.5% buffered formalin. PCR-screened Penaeus monodon postlarvae (PL14) obtained from a commercial hatchery were divided into two groups: 1) immersed in FIV solution for 2 h before stocking in ponds (VAC); and 2) unexposed control (CON). Both groups were stocked at a density of 15 m−2 and grown for 115 d following recommended good practices. Pond water was aerated using two 20-HP electric blowers. Shrimp were given commercial feed following the manufacturer's protocol. They were booster-vaccinated by administering FIV-coated feed every 15 d until the termination of the trial. Shrimp samples were regularly collected to obtain estimates of growth, survival, and feed conversion ratio. In addition, shrimp and extraneous crustacean species were analyzed for the presence of WSSV and IHHNV by PCR. Water quality and bacterial load were monitored regularly. After 115 d of culture (DOC), shrimps grew to 12.93 ± 1.26 g in VAC and 8.54 ± 0.78 g in CON. Likewise, survival and yield was higher in VAC (71.2 ± 3.13% and 1311 ± 70.4 kg ha−1, respectively) compared to CON (52.7 ± 5.05% and 640 ± 3.0 kg ha−1, respectively). PCR analysis showed both shrimp and extraneous crustaceans to be lightly infected with WSSV and IHHNV. A few dead shrimp were noted during routine pond inspection as shrimp biomass increased towards the end of the trial. However, no mass mortalities occurred and shrimp were successfully harvested on 115 DOC. VAC and CON shrimp were also collected on day 70, 90, and 105 and experimentally infected with WSSV in tanks. Significant differences in survival rates (p < 0.05) between the groups were obtained 15 d post-challenge. Further studies in tanks and in ponds on prophylactic oral delivery of antiviral treatments with the use of protein vaccines and vectors/carriers are recommended.This work was fully supported by project funds from SEAFDEC/AQD and the Government of Japan Trust Fund under Study Code 8400-T-RD-FH0210. We wish to thank the management of the Dumangas Brackishwater Station (DBS) for use of the facilities during the field trial. The generous assistance of DBS and Fish Health Section staff are gratefully acknowledged
Surveillance of Emerging Fish Viral Pathogens in Some Southeast Asian Countries
No full textPreventing the transboundary movement of fish viral pathogens in a global environment requires active surveillance. This study examined the presence of three emerging viral pathogens among koi, common, grass, and silver carp in Cambodia, Lao PDR, Myanmar, Philippines, and Vietnam. The stud- ied viruses included koi herpesvirus (KHV), spring viremia of carp virus (SVCV), and grass carp reovirus (GCRV). Detection methods consisted of virus isolation by cell culture, infection assay in naive fish, polymerase chain reaction (PCR), and reverse-transcriptase PCR (RT-PCR). Tissues were collected and pooled from 193 fish samples in Dec. 2004 to Feb. 2005, 406 in Sep. 2005 to Feb. 2006, and 1302 in Oct. 2006 to Feb. 2007. For cell cul- ture, tissue filtrates were prepared from pooled spleens, kidneys, livers, and gills and inoculated onto koi fin (KF-1), grass carp kidney (GCK), and fat head minnow (FHM) cells. For infection assay, tissue filtrates were injected intraperitoneally to healthy, naive common carp. No virus was detected after three cell culture passages and the infection bioassays. One-step and nest- ed-step PCR was used to detect KHV in gills of fish samples. One-step and semi-nested RT-PCR was used to detect SVCV and GCRV in the spleens, kidneys, and livers of fish samples. Samples from all three years from all five countries yielded negative results for all three viruses, indicating that KHV, SVCV, and GCRV were not present in these five countries during the period of the study although KHV outbreaks had been detected in Indonesia, Taiwan, Japan, Thailand, China, and Malaysia
[Le chevalier accompli].
No full textCul-de-lampe allégorique représentant l'aboutissement de la formation du chevalier éclairé par l'amour. Les objets entourant cette image sont ceux des chevaliers (lance, casque, flèches).Eisen inv. (en bas à gauche); E. de Ghendt Sculp. (en bas à droite).Gravure en taille douceTitre factice; Cinquième fascicule d'un recueil factice intitulé Histoires anglaises, tome 2, contenant des versions illustrées (Le Jay 1769, 1770 et 1772) des cinq histoires des Épreuves du sentiment, tome 2.Page 136Dans Sargines l’amour réciproque du héros éponyme et de Sophie fait "germer les vertus et les biens, le développe & les tourne au profit de l’humanité" (p. 135). Sur l’imag, l’amour éclaire de son flambeau Sophie qui est renversée et admire Sargines, car il a non seulement appris à lire et à écrire par amour pour elle, comme l’atteste le livre sous le bras de l’angelot, mais il a aussi remporté le tournois et gagné ainsi l’honneur de partager le "faisan paré" ( p. 124) à la table du roi Philippe-Auguste, son oncle. On aperçoit cet oiseau "mystérieux pour la chevalerie" (note p. 124) à gauche dans le médaillon.
Référence (s) : Monique Moser-Verrey, "L'anecdote historique en texte et en image: d’Arnaud et d’Ussieux", Eighteenth-Century Fiction 23: 4 (2011)
Abdominal segment deformity syndrome (asds) and fused body segment deformity (fbsd) in cultured Penaeus indicus
No full textThe abdominal segment deformity disease (ASDD) is a new shrimp disease reported only in cultured Penaeus vannamei in Thailand. Shrimp with ASDD have deformed abdominal segment, jagged gut line and bumpy surfaces. Similar signs were observed in cultured P. indicus in the Philippines. However, aside from the signs described for ASDD, some P. indicus showing abdominal segment deformity syndrome (ASDS) had more severe deformities up to the extent that the number of body segments was reduced due to fusion. Shrimp with fused body segment deformity (FBSD) had four instead of five pairs of legs. To account the prevalence of the deformities in P. indicus, shrimp were classified into grossly normal shrimp (NS), shrimp with abdominal segment deformity syndrome (ASDS) and shrimp with fused segments (FBSD). Out of the shrimp sampled, 83.4 ± 5.4% was NS, 10.9 ± 6.2% was ASDS and 5.7 ± 3.0% was FBSD. Morphometric characteristics of the shrimp were measured. There was no significant difference in body weight (BW) among male and female NS, ASDS and FBSD. In both sexes, total length (TL) of FBSD was significantly shorter compared to NS and ASDS. Shrimp samples were also screened to be negative for known infectious viral diseases including white spot syndrome virus (WSSV), infectious hypodermal and haematopoietic necrosis virus (IHHNV), infectious myonecrosis virus (IMNV), P. vannamei nodavirus (PvNV), Macrobrachium rosenbergii nodavirus (MrNV) and Taura syndrome virus (TSV). Occurrence of ASDS and FBSD in post-larvae (PL) produced from captive and wild spawners were also determined. Based on a tank experiment, no significant difference was detected between the percentages of ASDS in PL produced from wild or captive spawners but FBSD was only noted in PL produced from the latter. Deformities generally did not affect the size of P. indicus except for the reduced length of shrimp with FBSD which when coupled with missing pleopods could lead to major economic loss for shrimp farmers if not addressed properly.This work was supported by the AQD, SEAFDEC (5310-TTV-C0314T)
Evaluation of cultivation potential and carrageenan properties of Hypnea sp. from Panay Island, Philippines
No full textLink to the electronic supplementary material.Hypnea is a cosmopolitan genus of red seaweeds and an important source of carrageenan worldwide. However, Hypnea species remain largely unutilized in seaweed aquaculture in the Philippines. This study aimed to evaluate the growth performance and carrageenan properties of an indigenous, unexploited Hypnea sp. collected from Panay Island and to compare them with those of the commercially cultivated Kappaphycus striatus. In a field cultivation experiment, Hypnea sp. showed significantly higher biomass (145.1 ± 53.7 g) than K. striatus (92.9 ± 10.3 g) up to day 28 (p < 0.001), while no significant difference was observed at days 36 and 43. The final yields were 181.0 ± 68.4 g for Hypnea sp. and 191.1 ± 33.0 g for K. striatus (p > 0.05). Semi-refined carrageenan extracted from the cultured Hypnea sp. exhibited gel-forming capacity, suggesting the presence of κ-carrageenan. However, both the viscosity and gel strength of Hypnea sp. (9.52 ± 3.53 cP; 148 ± 41.6 g cm⁻2) were significantly lower in K. striatus (70.9 ± 49.4 cP; 456 ± 201 g cm⁻2) (p < 0.001), indicating that Hypnea sp. possesses distinct carrageenan properties from conventional commercial seaweed. Although further development of carrageenan-based products tailored to its unique properties will be required for commercial utilization, these findings highlight the potential of Hypnea sp. as a candidate seaweed for aquaculture in the Philippines.Open Access funding provided by Japan International Research Center for Agricultural Sciences (JIRCAS). This study was supported by the Japan International Research Center for Agricultural Sciences under the 5th Medium to Long-Term Plan and implemented at SEAFDEC/AQD with a Study Code: FS-01-S2023T
Evidence of WSSV transmission from the rotifer (Brachionus plicatilis) to the black tiger shrimp (Penaeus monodon) postlarvae and means to control rotifer resting eggs using industrial disinfectants
No full textRotifers are considered possible vectors of the white spot syndrome virus (WSSV) and have been implicated in its recurrence in pond-cultured shrimp. However, direct evidence of the transmission and the pathogenicity of this virus from rotifers to shrimp has been lacking. In the present study, the pathogenicity of WSSV transmitted from infected rotifers (Brachionus plicatilis) to post larval black tiger shrimp (Penaeus monodon) was investigated. Results show that WSSV transmitted from infected rotifers to post-larval P. monodon caused an 82% cumulative mortality as compared to a 9% mortality in the non-infected control group. We also investigated the possibility of industrial disinfectants (sodium hypochlorite, granulated calcium hypochlorite and formalin) as possible means to inhibit the viability of rotifer resting eggs, considered a biological reservoir of WSSV in earthen ponds. Among the disinfectants that were tested, granulated calcium hypochlorite at 5 mg/L was the most effective. The present study provides direct evidence of the high pathogenicity of WSSV transmitted from rotifers to post larval P. monodon and shows the potential use of granulated calcium hypochlorite in pond disinfection. This treatment could be a promising strategy to inhibit the spread and recurrence of WSSV outbreaks in P. monodon culture
Dietary onion or ginger modulates the stress response and susceptibility to Vibrio harveyi JML1 infection in brown-marbled grouper Epinephelus fuscoguttatus juveniles
No full textOnion Allium cepa and ginger Zingiber officinale have health‐promoting properties that qualify them as functional foods. The effect of repeated acute stressors was examined in juvenile Brown‐marbled Grouper Epinephelus fuscoguttatus that were fed four diets supplemented with onion at 1.8%, ginger at 1.8%, vitamin C at 0.86%, and β‐glucan at 0.8% of the diet. The non‐supplemented diet served as the control. After 12 weeks of feeding, fish were exposed to stressors and were experimentally infected with a fish pathogen, the bacterium Vibrio harveyi JML1. After repeated exposure to hypoxia, cortisol levels rose significantly in the non‐supplemented fish compared to those fed onion, ginger, β‐glucan, or vitamin C. Within groups, postexposure cortisol levels in the onion‐, ginger‐, and vitamin C‐fed fish did not change relative to pre‐stress levels, whereas significant increases in poststress values were observed in the control and β‐glucan groups. The net cortisol increase was also significantly greater in the non‐supplemented group compared to the supplemented groups. The net cortisol increase did not vary among the supplemented groups except that the β‐glucan‐fed group exhibited a higher net increase than the onion‐fed group. Similarly, repeated acute exposure to osmotic stress significantly increased the plasma cortisol level in the non‐supplemented group compared to groups that received supplements; no differences were found in the supplemented groups except the β‐glucan group. Within groups, significant increases in poststress values relative to pre‐stress levels were found only in the control and β‐glucan groups. Repeated acute exposure to hypoxia significantly increased cumulative mortality in the control group compared to the supplemented groups (except the β‐glucan group), whereas repeated exposure to acute osmotic stress significantly increased cumulative mortality only in the control group 10 d after infection with V. harveyi JML1. Based on our collective results, most of the supplemented groups performed better than the control, but the best supplements were onion and ginger in terms of enhancing stress tolerance and increasing survival of Brown‐marbled Grouper upon infection with V. harveyi JML1.This study was supported by the SEAFDEC–AQD under Study Code FH-07-F2004T and by the Institute of Aquaculture, College of Fisheries and Ocean Sciences, University of the Philippines Visayas, under a collaborative agreement
