Nursery culture of tropical anguillid eels in the Philippines

This technical publication focused on nursery production of anguillid eels from glass eels to elver using data gathered from eel farm surveys and rearing trials conducted by SEAFDEC/AQD as part of the JAIF (Japan-ASEAN Integration Fund) project on Enhancing Sustainable Utilization and Management Scheme for Tropical Anguillid Eel Resources in Southeast Asia

Susceptibility of Macrobachium rosenbergii to local white spot syndrome virus isolate using immersion assay

White spot syndrome virus (WSSV) continue to be one of the leading causes of serious epizootic in cultured shrimp. Macrobrachium rosenbergii or giant freshwater prawns are found to be resistant in White spot syndrome virus (WSSV). However, conflicting studies have shown that pathogenicity of WSSV to M.rosenbergii may vary according to the life cycle of prawn, strain of WSSV and the source of the virus during passaging. On this preliminary study, the susceptibility of M. rosenbergii stocks to local strain of WSSV as exposed via immersion assay will be determined. Likewise, the pathogenicity of WSSV will be identified using the median lethal dose (LD50). The confirmation for the presence of WSSV on giant freshwater prawns will be done using nested PCR. The preliminary study will provide valuable data for the succeeding experiments

Phytochemical composition antioxidant and antibacterial activity of the Philippine marine green alga (Ulva pertusa)

The phytochemical constituents, total phenolic and flavonoid contents, antioxidant and antimicrobial activities of the ethanolic extract of the marine green alga Ulva pertusa collected from floating fish net cages off the coast of Guimaras island, Philippines, were investigated. Qualitative phytochemical analysis revealed the presence of bioactive compounds including alkaloids, flavonoids, phenols, saponins, tannins, and terpenoids. Quantitatively, total phenolic and flavonoid contents of the extract were 20.54±2.08 mg gallic acid equivalent (GAE) g-1 and 539.07±6.36 mg rutin equivalent (RE) g-1, respectively. The antioxidant activity of the extract using 1,1-diphenyl-1-picrylhydrazyl (DPPH) assay exhibited a concentration-dependent radical scavenging capacity. Additionally, the ethanolic extract inhibited the growth of Staphylococcus aureus ATCC25923, Escherichia coli ATCC25922, Streptococcus agalactiae, Aeromonas hydrophila, A. sobria, and Vibrio harveyi in a concentration-dependent manner with strong inhibitory activity at 100 mg mL-1 concentration. Taken together, U. pertusa contains bioactive compounds that possess potent antibacterial activity and remarkable antioxidant capacities. These substances are promising candidates that may be utilized in the synthesis of novel drugs.This study was funded by the Government of Japan Trust Fund V through the Regional Disease Project (study code: FH01-F2010-T) and partly by SEAFDEC AQD

Phylogenetic analysis of tilapia lake virus (TiLV) isolates from the Philippines based on partial genome segment 3 sequences

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 (Accession No. LC504279) and six new sequences from cases of infection reported from 2017 to 2020. Phylogenetic analysis of 179 bp fragment of segment 3 showed that the seven TiLV isolates from the Philippines can be divided into three phylogenetic groups. When comparing all sequences, unique nucleotide substitutions and amino acids were noted among these groups. Variation in mortality rates in naturally infected samples was also observed; however, poor environmental conditions during the disease outbreak may also contribute to the mortalities. These suggest the presence of at least three phylogenetic groups of TiLV in the Philippines which has significant implications for the future development of a vaccine, diagnostic kits, and genetic selection programs.This work was funded by SEAFDEC/AQD