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Genomic analysis of Vibrio harveyi strain PH1009, a potential multi-drug resistant pathogen due to acquisition of toxin genes
(Elsevier, 2023-03-25)
In has increasingly been observed that viral and bacterial coinfection frequently occurs among cultured shrimp and this coinfection could exacerbate the disease phenotype. Here, we describe a newly discovered bacterial strain, Vibrio harveyi PH1009 collected from Masbate Island, Philippines that was found to be co-infecting with the White Spot Syndrome virus a sample of black tiger prawn, Penaeus monodon. The genome of V. harveyi PH1009 was sequenced, assembled, and annotated. Average Nucleotide identity calculation with Vibrio harveyi strains confirmed its taxonomic identity. It is a potential multi-drug and multi-heavy metal resistant strain based on the multiple antibiotic and heavy metal resistance determinants annotated on its genome. Two prophage regions were identified in its genome. One contained genes for Zona occludens toxin (Zot) and Accessory cholera toxin (Ace), essential toxins of toxigenic V. cholerae strains apart from CTX toxins. Pan-genome analysis of V. harveyi strains, including PH1009, revealed an “open” pan-genome for V. harveyi and a core genome mainly composed of genes necessary for growth and metabolism. Phylogenetic tree based on the core genome alignment revealed that PH1009 was closest to strains QT520, CAIM 1754, and 823tez1. Published virulence factors present on the strain QT520 suggest similar pathogenicity with PH1009. However, PH1009 Zot was not found on related strains but was present in strains HENC-01 and CAIM 148. Most unique genes found in the PH1009 strain were identified as hypothetical proteins. Further annotation showed that several of these hypothetical proteins were phage transposases, integrases, and transcription regulators, implying the role of bacteriophages in the distinct genomic features of the PH1009 genome. The PH1009 genome will serve as a valuable genomic resource for comparative genomic studies and in understanding the disease mechanism of the Vibrio harveyi species....
Inclusion of live mud polychaete (Marphysa iloiloensis) in the feeding regime improved the hatchery performance of domesticated Indian white shrimp (Penaeus indicus)
(Elsevier, 2023-03-07)
A 60-day feeding trial was conducted to evaluate the effect of inclusion frequency of hatchery-bred mud polychaete, Marphysa iloiloensis, as part of a combination diet on the reproductive performance and larval quality of ...
Effect of size grading on growth of yellow Pacific shortfin eel (Anguilla bicolor pacifica)
(Wiley, 2023-03-22)
Heterogeneous growth, which is common among farmed fish, can be remedied by size grading. This study focused on whether the size grading process, which is commonly practiced in aquaculture, improves the subsequent growth ...
Evaluation of community-based livelihood development initiatives: The sustainable livelihood approach
(University of the Philippines Visayas, 2022)
The sustainable livelihood approach (SLA) is a tool for evaluating livelihood strategies that utilize assets categorized as environmental, human, physical, financial and social assets. In this study, the SLA was applied ...
A technical and economic evaluation of supplemental feeding strategies for Nile tilapia (Oreochromis niloticus L.) reared in lake-based cages
(AquacultureHub Inc., 2022-03)
Tilapia cage farming in eutrophic lakes uses low stocking densities since tilapias can thrive mainly on natural food or minimal supplementary feeding. For semi-intensive Nile tilapia cage culture, feeding strategies to ...
Whole-genome sequencing for identification of bacterial isolates affecting local penaeid shrimp farms: A national survey for the Philippines
(5M Books Ltd, 2022)
The shrimp aquaculture industry is a major economic player in the food and livelihood sectors, both globally and in the Philippines. The development of industrialized shrimp farming methods has led to a rapid increase in ...
Biofloc-based nursery production system: Heeding the call towards a sustainable shrimp culture industry in the Philippines
(International Network for Natural Sciences, 2022)
The increasing global population resulted in intense pressure on the food production sectors to meet the rise in food demand. The aquaculture industry, which is one of the major food production sectors, provides opportunities ...
Effect of background tank color in combination with sand substrate and shelters on survival and growth of Scylla tranquebarica instar
(Elsevier, 2022-05)
Effect of tank color in combination with substrate-shelters on the survival and growth of the instar of purple mud crab, Scylla tranquebarica (initial body weight of 28.7 ± 2 mg) was investigated. Ten treatments were tested ...
Phylogenetic analysis of tilapia lake virus (TiLV) isolates from the Philippines based on partial genome segment 3 sequences
(College of Agriculture and Food Science, University of the Philippines Los Baños, 2022-03)
This study aimed to expand current knowledge on TiLV genetic diversity by sequence analysis of a portion of genome segment 3 of TiLV detected from the Philippines. This includes a recently deposited sequence in GenBank ...
Economic analysis of stake and rack-hanging methods of farming oysters (Crassostrea iredalei) in the Philippines
(Elsevier, 1998)
The cost efficiency of stake and rack-hanging methods of farming oysters are compared. Annual costs and returns data for both methods were obtained from a socioeconomic survey conducted in 1991 at the Aquaculture Department of the Southeast Asian Fisheries Development Center (SEAFDEC/AQD). On average, 14 kg m<sup>−2</sup> (shell-on) and 22 kg m<sup>−2</sup> (shell-on) were produced using the stake and rack-hanging methods, respectively. The translog cost function for 58 oyster farms was estimated using iterative seemingly unrelated regression (SUR). Statistical analysis indicates that the higher production from the rack-hanging method is significantly different (α=0.10) from the production using the stake method. The cost-efficient method varied based on production levels. At output levels less that 9044 kg (shell-on), the rack-hanging method had lower average cost per unit, and for higher production levels the stake method had the lower average costs. Similar conclusions were drawn from the marginal cost analysis. Results imply when production is less than 9044 kg, then the most efficient technology is the rack-hanging method and if production is greater than 9044 kg, the most efficient method is the stake method....