Now showing items 1-11 of 11

    • Article

      Abdominal segment deformity syndrome (asds) and fused body segment deformity (fbsd) in cultured Penaeus indicus 

      The 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.
    • Book

      Diseases of penaeid shrimps in the Philippines 

      CR Lavilla-Pitogo, GD Lio-Po, ER Cruz-Lacierda, EV Alapide-Tendencia & LD de la Peña - 2000 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Series: Aquaculture extension manual; No. 16
      The manual provides information on the diseases that affect the 3 major species of shrimps cultured in the Philippines: Penaeus monodon, P. merguiensis and P. indicus. It includes the common name of the disease, causative agent, species affected, stages affected, gross signs, effects on the host and methods of prevention and treatment. This revised edition includes newly discovered diseases. It is hoped that the manual will be of considerable help to shrimp farmers in identifying the disease and lead to prevention or early disease diagnosis and control.
    • Article

      Genetic diversity of wild and cultured Black Tiger Shrimp (Penaeus monodon) in the Philippines using microsatellites 

      Z Xu, JH Primavera, LD de la Peña, P Pettit, J Belak & A Alcivar-Warren - Aquaculture, 2001 - Elsevier
      Six microsatellites were used to study (1) the genetic diversity of wild Penaeus monodon shrimp from four geographic regions (Palawan, Quezon, Capiz and Negros Occidental-W) in the Philippines, and (2) its association with the status of mangroves and intensity of shrimp culture systems in these regions. Two cultured populations (Negros Occidental-C and Antique) were used for comparison. All six microsatellite loci were polymorphic. A total of 184 different alleles were found over all loci. The total number of alleles per locus ranged from 6 to 54, with allele size ranging from 159 base pairs (bp) to 400 bp. The observed heterozygosity of the six loci ranged from 0.47 to 1.00. The number of genotypes per locus ranged from 5 to 70. Fst values showed significant genetic differentiation among the four wild populations. Genetic differences between wild populations were also detected by pairwise comparison based on genotypic and allelic frequencies. Genetic differentiation among wild populations exhibited a positive correlation with mangrove status and intensity of culture systems at P=0.083. The Negros Occidental-W population, which originated from an area with the most severe mangrove loss and the most intensive culture systems, was the most significantly differentiated population. It also showed less genotypes per locus than the other three wild populations, suggesting a decrease in genetic diversity in this population. The population from Capiz, a province with a wide area of extensive culture ponds and few remaining secondary mangroves was the second most differentiated population. The Quezon population, which originated from an area with a few extensive culture ponds and less mangrove destruction, was not genetically different from the Palawan population, which was from a pristine site with mostly primary mangroves and no major aquaculture industry. The cultured populations showed less genetic diversity and were significantly different from the four wild populations based on pairwise Fst values and pairwise comparisons of allelic and genotypic frequencies. The results suggest that (a) there was a significant genetic differentiation among the wild P. monodon populations in the Philippines, and (b) the cultured populations were significantly differentiated from the natural populations. More replicate samples from each of the geographic regions are needed to conclusively determine the possibility of an association between genetic differentiation and the status of mangroves and/or intensity of shrimp culture systems.
    • Book chapter

      Immunological and molecular biology techniques in disease diagnosis 

      LD de la Peña - In GD Lio-Po, CR Lavilla & ER Cruz-Lacierda (Eds.), Health Management in Aquaculture, 2001 - Aquaculture Department, Southeast Asian Fisheries Development Center
      The improvement of existing immunoassay techniques, development of monoclonal antibody technology and the development of new immunoassay approaches are all working together to provide new tools for the detection of disease-causing organisms in fish and crustaceans. Following the introduction of nucleic acid hybridization technique and PCR, it was recognized that the methods offered a sensitive approach to the detection and identification of specific microorganisms as in the case of a bacterial or viral infection in a variety of sample types. Potentially, a characteristic DNA sequence from a single virus particle or cell of a particular organism can be amplified to detectable levels within a short period of time. Conventional diagnostic methods that involve the culture of microorganisms can take days or weeks to complete or very tedious to perform. PCR offers a rapid, very sensitive, very specific and simple alternative. Further developments in immunodiagnostics and emerging technologies such as DNA-based tests will revolutionize the detection and identification of infectious disease agents.
    • Koi herpesvirus-associated mortalities in quarantined koi carp in the Philippines 

      JR Somga, LD de la Peña, CD Sombito, MG Paner, VS Suarnaba, GC Capulos, PI Santa Maria & GL Po - Bulletin of the European Association of Fish Pathologists, 2010 - European Association of Fish Pathologists
      Illegally imported koi carp were confiscated at the Ninoy Aquino International Airport (NAIA), Manila, Philippines by the Fisheries Quarantine and Inspection Service Officers of the Bureau of Fisheries and Aquatic Resources (BFAR). The confiscated fish were turned over to the BFAR Fish Health Laboratory where they were held for observation at a water temperature of 28 degree C. After 5 days, some fish were showing abnormal swimming behavior and some had died. The most prominent disease signs in the freshly dead and moribund fish were body ulcerations and pale gills showing white necrotic patches, consistent with the clinical signs of KHV infection. Gills were dissected and fixed in 95% ethanol. All of the samples tested positive for KHV in a 1-step PCR assay.

      This paper reports the first case of KHV associated mortalities in illegally important koi carp confiscated by the Fisheries Quarantine and Inspection Service Officers of BFAR. This highlights the importance of the quarantine and inspection service s role in preventing the illegal entry of fish into the country and the introduction of exotic aquatic diseases.
    • Article

      Occurrence of luminous bacterial disease of Penaeus monodon larvae in the Philippines 

      CR Lavilla-Pitogo, MCL Baticados, ER Cruz-Lacierda & LD de la Peña - Aquaculture, 1990 - Elsevier
      Larval mortalities associated with luminescence have been observed in epizootic proportions in black tiger prawn (Penaeus monodon) hatcheries in Panay Island, Philippines. Luminescent vibrios, identified as Vibrio harveyi and V. splendidus, were isolated from infected larvae but not from uninfected ones. These bacteria were also recovered readily from seawater samples from nearshore areas, the main source of hatchery rearing water. Thus, it is possible that the nearshore seawater is one major source of infection. Pathogenicity tests resulted in significant mortalities of larvae and postlarvae of P. monodon within 48 h of immersion challenge. Scanning electron microscopic observations show that colonization by the bacteria occurred specifically on the feeding apparatus and oral cavity of the larvae, suggesting an oral route of entry for the initiation of infection.
    • magazineArticle

      Polymerase chain reaction (PCR) in disease diagnosis 

      LD de la Peña - SEAFDEC Asian Aquaculture, 2002 - Aquaculture Department, Southeast Asian Fisheries Development Center
    • Prevalence of viral nervous necrosis (VNN) virus in wild-caught and trash fish in the Philippines 

      LD de la Peña, VS Suarnaba, GC Capulos & MNM Santos - Bulletin of the European Association of Fish Pathologists, 2011 - European Association of Fish Pathologists
      Viral nervous necrosis (VNN) caused by piscine nodavirus is a devastating disease affecting mainly marine finfish. In the Philippines, VNN was first reported in hatchery-reared grouper (Epinephelus coioides) broodstock in 2001. These broodstock are usually fed with trash fish. It is therefore suspected that contaminated trash fish may be the source of VNN transmission to the broodstock. To confirm the source of contamination, periodic monitoring of the VNN prevalence using RT-PCR was done on different species of trash fish available in the Iloilo Fishing Port Complex and on the wild-caught fish in Panay Gulf. Results showed that most of the trash fish and wild-caught fish were sub-clinically infected or carriers of VNN, and that the virus might have already been established in the environment where they were living. These findings provide strong evidence that trash fish could be the main source of viral contamination in broodstock since they are identified as the only major input in the culture systems. To prevent the transmission of VNN to broodstock through contaminated trash fish, a shift to a broodstock pelleted feed is highly recommended.
    • Conference paper

      Qualitative and quantitative comparison of bacterial flora associated with hatchery-reared and wild-caught shrimp postlarvae 

      CR Lavilla-Pitogo, LD de la Peña & MG Paner - In Proceedings of the International Workshop: Antibiotic Resistance in Aquaculture Environments, 24-25 February 2005, Chiang Mai, Thailand, 2005 - ASIARESIST
      Because of high mortality recorded in pond-reared shrimps due to luminescent vibriosis infection, a study was conducted to determine if postlarvae (PLs) could be major sources of luminescent bacteria (LB). Batches of hatchery-reared (PL12 to 18) and wild-caught Penaeus monodon PLs were examined to determine their bacterial load. Results show that although all PLs have associated Vibrio spp., not all of them harbored detectable levels of LB. Fifty eight percent of wild-caught postlarval batches did not have associated LB compared with only 23-44% of hatchery-reared postlarvae. A significant difference in quantitative LB load was noted between hatchery reared and wild-caught PLs with the former harboring up to 3.0 x 105 cfu LB/postlarva. Wildcaught PLs had only up to 3.5 x 102 cfu LB/postlarva. Antimicrobial sensitivity tests using disc diffusion method show significant resistance to Chloramphenicol and Oxytetracycline among isolates from hatchery-reared PLs (33 and 44%) compared with bacteria from wild-caught PLs (3 and 6%) and near shore seawater (0 and 12%). The differences between the quantitative and qualitative bacterial flora of hatchery-reared and wild-caught PLs may have contributed to the occurrence of luminescent vibriosis in grow-out ponds, which generally make use of hatchery-reared postlarvae.
    • Book chapter

      Serological and DNA-based techniques in disease diagnosis 

      LD de la Peña - In GD Lio-Po & Y Inui (Eds.), Health Management in Aquaculture, 2010 - Aquaculture Department, Southeast Asian Fisheries Development Center
      The improvement of existing serological techniques, development of monoclonal antibody technology and the development of new serological approaches are all working together to provide new tools for the detection of disease-causing organisms in fish and crustaceans. Following the introduction of nucleic acid hybridization technique and PCR, it was recognized that the methods offered a sensitive approach to the detection and identification of specific microorganisms as in the case of a bacterial or viral infection in a variety of sample types. Potentially, a characteristic DNA sequence from a single virus particle or cell of a particular organism can be amplified to detectable levels within a short period of time. Conventional diagnostic methods that involve the culture of microorganisms can take days or weeks to complete or very tedious to perform. PCR offers a rapid, very sensitive, very specific and simple alternative. Further developments in immunodiagnostics and emerging technologies such as quantitative PCR, lateral flow assay and loop-mediated isothermal amplification diagnostic tests will revolutionize the detection, identification and quantification of the infectious disease agents. Further, advancements in gene sequencing analyses will enable strain differentiation among closely related viruses.
    • Article

      Susceptibility of fish species cultured in mangrove brackish area to piscine nodavirus 

      Y Maeno, LD de la Peña & ER Cruz-Lacierda - Japan Agricultural Research Quarterly, 2007 - Tropical Agricultural Research Centre
      Susceptibility of orange-spotted grouper Epinephelus coioides, Asian sea bass Lates calcarifer, mangrove red snapper Lutjanus argentimaculatus, milkfish Chanos chanos, and rabbitfish Siganus guttatus to piscine nodavirus from orange-spotted grouper was studied by experimental infection. The fish were intraperitoneally injected with 0.05 mL of the filtrate homogenate of infected organs from diseased grouper at 106.8, 105.8 or 104.8 TCID50/fish, while the control group received 0.05 mL of Hanks’ balanced salt solution. Clinical signs such as lethargy, anorexia and darkened pigmentation were observed in the orange-spotted grouper, Asian sea bass, mangrove red snapper, and milkfish injected with high and medium doses of the homogenate. Although no or little mortality occurred in the experimentallyinfected fish 10 days post-inoculation, viral nervous necrosis specific lesions such as severe necrosis and vacuolation in the brain and retina were produced in these four fish species. The virus was reisolated in SSN-1 cells inoculated with the filtrated tissue homogenate of survivors in all doses for all four fish species. However, in the experimentally infected rabbitfish no histological lesion was observed, and no virus was reisolated. These results indicate that grouper, sea bass, mangrove red snapper, and milkfish are susceptible to the piscine nodavirus isolated from diseased grouper.