Proceedings of the International Workshop on Resource Enhancement and Sustainable Aquaculture Practices in Southeast Asia 2014 (RESA)
http://hdl.handle.net/20.500.12066/3973
2024-03-28T09:26:27ZResource enhancement and sustainable aquaculture practices in Southeast Asia: challenges in responsible production of aquatic species : proceedings of the international workshop on resource enhancement and sustainable aquaculture practices in Southeast Asia 2014 (RESA)
http://hdl.handle.net/20.500.12066/3974
Resource enhancement and sustainable aquaculture practices in Southeast Asia: challenges in responsible production of aquatic species : proceedings of the international workshop on resource enhancement and sustainable aquaculture practices in Southeast Asia 2014 (RESA)
Romana-Eguia, Maria Rowena R.; Parado-Estepa, Fe D.; Salayo, Nerissa D.; Lebata-Ramos, Ma. Junemie Hazel
The conference was held in order to promote and augment regional initiatives on resource enhancement and sustainable aquaculture practices, and to contribute to poverty alleviation, livelihood and food security in Southeast Asia. The contributions of the selected participants during the conference which are contained in this volume are cited individually.
2015-08-01T00:00:00ZShrimp metabolism: The roles of lactate dehydrogenase (c31), glycogen phosphorylase (c34) and protein kinase (PK) as revealed by RNA interference
http://hdl.handle.net/20.500.12066/4029
Shrimp metabolism: The roles of lactate dehydrogenase (c31), glycogen phosphorylase (c34) and protein kinase (PK) as revealed by RNA interference
Tare, Maria Violeta R.; Kondo, Hidehiro; Hirono, Ikuo; Maningas, Mary Beth B.
Romana-Eguia, Maria Rowena R.; Parado-Estepa, Fe D.; Salayo, Nerissa D.; Lebata-Ramos, Ma. Junemie Hazel
Energy metabolism is well-studied in vertebrate systems, providing insights on the genes and mechanisms involved in different pathways necessary for the survival of an organism. Yet, such studies are still lacking in invertebrate systems much more in shrimp. An earlier study has showed several contigs from the black tiger shrimp to be homologous to white spot syndrome virus (WSSV), a devastating pathogen in shrimp, including contig 31-WSSVORF82 (c31) and contig 34-WSSVORF21 (c34). This study aims to unveil the roles of three genes: c31, c34 and protein kinase (PK) in the shrimp system and its possible role in WSSV-infection. Rapid amplification of cDNA ends-polymerase chain reaction or RACE-PCR was used to obtain the full-length sequence of c31 and c34, followed by in vivo gene silencing using RNAi technology, and intramuscularly injecting dsRNA to WSSVchallenged Macrobrachium rosenbergii and Penaeus (Marsupenaeus) japonicus. Gene expression followed for healthy shrimps and dsRNA-treated shrimps.
Mrc31 was revealed to be the enzyme lactase dehydrogenase (LDH), commonly released during tissue damage and is a marker for disease. The most parsimonious tree pictured Mrc31 to be sister clades to LDH of other shrimp species, Penaeus monodon and P. vannamei, supported with 100% and 72% bootstrap values, respectively. Mrc34 was highly homologous to the glycogen phosphorylase (GP) enzymes of other organisms including that of another shrimp, M. japonicus, bearing a bootstrap value of 99%. For PK, phylogenetic analysis revealed that the three open reading frames (ORFs) from P. monodon, M. rosenbergii and P. japonicus have 30% homology to WSSV-PK supported by a 98% bootstrap value. Mortality data from dsRNA-treated and WSSV-infected shrimps showed that treatment with dsRNA-LDH, GP and PK had significantly higher survival rates compared to that of the controls, Phosphate Buffered Saline (PBS) and Green Fluorescent Protein (GFP). Silencing the three genes in the shrimp has rendered some protective effect against the virus. Gene expression showed that all three genes are present in immune-related organs such as the gills, hepatopancreas and hemocyte. This study is the first to report the possible identities and functions of contigs 31, 34 and PK providing valuable data on the shrimp's genome.
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2015-01-01T00:00:00ZReproductive biology of christian crabs (Charybdis feriatus, Linnaeus, 1758) in San Miguel Bay, Philippines
http://hdl.handle.net/20.500.12066/4028
Reproductive biology of christian crabs (Charybdis feriatus, Linnaeus, 1758) in San Miguel Bay, Philippines
Nieves, Plutomeo M.; Olfindo, Nelson R.; Macale, Aldrin Mel
Romana-Eguia, Maria Rowena R.; Parado-Estepa, Fe D.; Salayo, Nerissa D.; Lebata-Ramos, Ma. Junemie Hazel
The reproductive biology of Charybdis feriatus was investigated from April 2012 to March 2013 to determine gonad maturity, gonado-somatic index (GSI), fecundity, breeding cycle and size at first maturity. Every month, samples of 30 specimens were randomly collected. Gravimetric and volumetric methods were used to estimate fecundity. Results showed that Charybdis feriatus breeds continuously with a distinct period of reproductive activity during the northeast monsoon. Spawning peaks in January where higher values of GSI, mature, and berried female crabs were observed. Female gonad (ovary) weights range from 0.5 to 18.1 grams while mean GSI of female and male were 7.35% and 6.27%, respectively. Berried females were present year round, the highest occurring in December (50%). Fecundity ranged from 1,513,660 to 6,357,133 eggs. The smallest reproductively active female was 8.3 cm. Fecundity was highly correlated with size (r2=0.92).
In view of these observations, the following options are recommended for crab fishery resource management: (1) to set a closed season for crab fisheries, (2) to regulate catches by not taking egg-bearing swimming crabs, and (3) to allow egg-bearing crabs to release its eggs and the larvae in fishing grounds and/or marine protected areas.
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2015-01-01T00:00:00ZFirst record of Laem-Singh virus in black tiger shrimp (Penaeus monodon) in the Philippines
http://hdl.handle.net/20.500.12066/4027
First record of Laem-Singh virus in black tiger shrimp (Penaeus monodon) in the Philippines
Cruz, Christian Albert M.; dela Cruz, Precious C.; Alcala, Paul Christian D.; Tagle, Florenz Giovanni M.; Santos, Erickson S.; Santos, Mudjekeewis D.; Maningas, Mary Beth B.
Romana-Eguia, Maria Rowena R.; Parado-Estepa, Fe D.; Salayo, Nerissa D.; Lebata-Ramos, Ma. Junemie Hazel
Laem-Singh Virus (LSNV), a single-stranded RNA virus that causes growth retardation in Penaeus monodon, is also known as Monodon Slow-Growth Syndrome (MSGS) virus. Black Tiger shrimps afflicted with this virus exhibit unusual dark color, a weight gain of less than 0.1 g in 1 to 2 weeks, unusual yellow markings, bamboo-shaped abdominal markings and brittle antennae. It was first detected in Thailand and the virus quickly spread to neighboring Asian countries such as Malaysia and Singapore. The shrimp economy of countries where infections have occurred experienced losses in the export of live shrimps and broodstocks. An earlier study in 2009 reported that LSNV was not present in the Philippines. However, since no follow-up researches were done in the succeeding years, this study was conducted to detect the presence of virus in selected sites of Luzon. Results based on biased sampling method and RT-PCR data indicated that LSNV is indeed present in the country. This is further supported by DNA sequence data, showing 100% identity with LSNV India isolate. Phylogenetic analysis showed that the Philippine isolate clustered closely with other LSNV isolates. The outcome of this study might have implications in the current practices in the Philippine shrimp aquaculture industry.
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2015-01-01T00:00:00Z