Enhancement Glutathione Peroxidase Activity and α2-Macroglobulin Gene Expression of Macrobrachium Rosenbergii Fed with Aqueous Morinda Citrifolia Leaves Extract-Supplemented Diet

Morinda citrifolia, known commercially as noni is often used for enhance immunity, these plant rich of phenolic compound with antioxidant properties. In the present study, Macrobrachium rosenbergii were fed with diets containing of aqueous M. citrifolia leaves extract (AMLE) at 0.6, 4 and 6 g kg-1. Glutathione peroxidase (GPx) activity was conducted to measure immune parameter, these parameter was evaluated before and after 7, 21, 35, 49 and 63 days of feeding trial. Immune gene expression of α2-macroglubulin (α2-M) was evaluated in this study. The results showed that after 63 days of feeding treatment, significantly increased in GPx activity. Gene expressions of α2-macroglubulin was significantly upregulated. These results recommend that administration of AMLE can be used as an immunostimulant and regulated immune response and immune gene expression in M. rosenbergii

Development of freshwater prawn (Macrobrachium rosenbergii) seed production and culture technology in the Mekong Delta Region of Vietnam: A review of the JIRCAS Project at Cantho University.

The Mekong Delta of Vietnam is a region rich in aquatic resources having high potential for aquaculture development. Inland aquaculture in the Mekong Delta has greatly increased since the last decade. Fish culture carried out in combination with other agricultural activities such as animal husbandry and rice cultivation, and intensive aquaculture in ponds and cages have been the dominant forms of fish production. However, the giant freshwater prawn, Macrobrachium rosenbergii, has recently become a species of economic significance and the target of aquaculture activity in the Mekong Delta. M. rosenbergii is cultured throughout the region in the rice fields, ponds, orchard gardens and in pens along river banks. The major constraints in this industry are seed supply and culture techniques, becoming the major obstacles for the further development of the culture of this species. In a collaborative research project implemented between the Japan International Research Center for Agricultural Sciences (JIRCAS) and Cantho University (CTU) since 1994, studies have been carried out on various aspects relating to the establishment of M. rosenbergii seed production and culture technology. The project is now in the middle of its second phase and has generated a great deal of scientific and practical information. This paper presents an overview of the achievements of this project

Genetic diversity in wild stocks of the giant freshwater prawn (Macrobrachium rosenbergii): implications for aquaculture and conservation

The giant freshwater prawn (Macrobrachium rosenbergii) is cultured widely around the world but little is known about the levels and patterns of genetic diversity in either wild or cultured stocks. Studies have suggested that genetic diversity may be relatively low in some cultured stocks due to the history of how they were founded and subsequent exposure to repeated population bottlenecks in hatcheries. In contrast, wild stocks have an extensive distribution that extends from Southern Asia across Southeast (SE) Asia to the Pacific region. Therefore, wild stocks could be an important resource for genetic improvement of culture stocks in the future. Understanding the extent and patterns of genetic diversity in wild giant freshwater prawn stocks will assist decisions about the direction future breeding programs may take. Wild stock genetic diversity was examined using a 472 base-pair segment of the 16S rRNA gene in 18 wild populations collected from across the natural range of the species. Two major clades ("eastern" and "western") were identifi ed either side of Huxley’s line, with a minimum divergence of 6.2 per cent, which implies separation since the Miocene period (5-10 MYA). While divergence estimates within major clades was small (maximum 0.9 per cent), evidence was also found for population structuring at a lower spatial scale. This will be examined more intensively with a faster evolving mtDNA gene in the future

Reviving the Macrobrachium rosenbergii (de Man) fishery in Vembanad Lake, India

In Vembanad Lake and its confluent rivers (Kerala, India), the catches of Macrobrachium rosenbergii (de Man) were reported to have dwindled to a mere 39 t in the 1980s from average landings of 300 t during the 1960s. This decline is due to the impact of a number of human interventions affecting the ecosystem and, hence, the stocks of M. rosenbergii. Monitoring of landings in 1994-1995 and 1995-1996 indicates an improvement in catches. This paper discusses the reasons for the decline and revival in stocks and suggestions for their replenishment

Genetic diversity in wild stocks of the giant freshwater prawn (Macrobrachium rosenbergii): implications for aquaculture and conservation

The giant freshwater prawn (Macrobrachium rosenbergii) is cultured widely around the world but little is known about the levels and patterns of genetic diversity in either wild or cultured stocks. Studies have suggested that genetic diversity may be relatively low in some cultured stocks due to the history of how they were founded and subsequent exposure to repeated population bottlenecks in hatcheries. In contrast, wild stocks have an extensive distribution that extends from Southern Asia across Southeast (SE) Asia to the Pacific region. Therefore, wild stocks could be an important resource for genetic improvement of culture stocks in the future. Understanding the extent and patterns of genetic diversity in wild giant freshwater prawn stocks will assist decisions about the direction future breeding programs may take. Wild stock genetic diversity was examined using a 472 base-pair segment of the 16S rRNA gene in 18 wild populations collected from across the natural range of the species. Two major clades ("eastern" and "western") were identifi ed either side of Huxley’s line, with a minimum divergence of 6.2 per cent, which implies separation since the Miocene period (5-10 MYA). While divergence estimates within major clades was small (maximum 0.9 per cent), evidence was also found for population structuring at a lower spatial scale. This will be examined more intensively with a faster evolving mtDNA gene in the future.Genetic diversity, Stocks, Nature conservation Macrobrachium rosenbergii

Selective breeding program for genetic improvement of Macrobrachium rosenbergii in Thailand.

Although the giant freshwater prawn (Macrobrachium rosenbergii) has been domesticated in Thailand for over decades, appropriate selective breeding program has yet to be achieved. Good quality seeds for the Machrobrachium aquaculture industry is therefore not regularly produced. One of the selective breeding programs on improving growth performance of the domesticated strain have been carried out at the Aquatic Animal Genetics Research and Development Institute (AAGRDI), Department of Fisheries of Thailand. AAGRDI has now developed improved and domesticated stock of Macrobrachium rosenbergii for two generations. Meanwhile, domesticated stocks from private hatcheries have also been acquired. There is, therefore, the need to develop another improved stock of this species basically from these two domesticated stocks together with a wild stock in order to improve the genetic diversity of the base population for further selective breeding program. Macrobrachium wild stock has been domesticated under hatchery conditions at the AAGRDI for one generation. Generally, a good base population for genetic improvement program requires high genetic variation as well as an ideally suitable stock that can be well adapted for each of different local environments. Therefore, all proper crosses of these three stocks need to be cultured in different areas of the country and then evaluated on both performance and genetic variation before selective breeding program takes place

Heterogeneous individual growth of Macrobrachium rosenbergii male morphotypes

In a single cohort of small freshwater prawn, Macrobrachium rosenbergii, the size range of females in the population is rather small. However, among the males, three major morphotypes are found and each has a distinct size category. The differential growth pattern in males, termed "heterogeneous individual growth" (HIG), is a major bottleneck confronting the profitability of farming this species. An attempt is made to understand the cause and impact of HIG on the culture system and methods by which HIG could be minimized in growout in order to maximize the market yield structure of the harvested population