- Name of species:
Macrobrachium rosenbergii (Crustacea: Palaemonidae).
- Primary potential:
The primary potential is for aquaculture for cash income.
- Attributes for aquaculture/stock enhancement :
· Larval cycle is uncomplicated and up to 20 days duration
· Hatchery technology for mass seed production is standardised and well established
· Juveniles are hardy and easily transported
· In countries like Australia, annual mass migrations of juveniles occur and these could be used to conduct pilot grow-out trials, thereby reducing the initial risk of building an expensive hatchery· Neither juveniles nor adults are prone to diseases under culture conditions
· Diet is less demanding than for marine prawns
· Grow-out period is 6 months, allowing 2 crops per year. Selective harvesting could be done after 4 months of culture on bi-weekly basis
· In some countries, Macrobrachium spp fetches a higher price than marine prawns; it is best sold live or fresh chilled
- Culture methods :
· Both clear and green water larval culture systems could be used for juvenile production; both low technology backyard and commercial hatcheries have been operating successfully for a number of decades
· Grow-out production is pond-based with pond sizes of 0.1-1 ha suitable for production
· The grow-out system is simple and the integration of prawn and animal production has been successfully applied in many Asian countries. Such low-technology and low-cost production systems could be readily adopted by the Pacific countries
· For commercial farming, marine prawn production systems have been successfully modified for intensive macrobrachium culture, with production of 2-5 tonnes/ha/year achievable
· The farming system generally has low impacts on the environment. Integrated prawn-and-animal farming could be environmentally benign. More intensive systems will have greater impacts on the aquatic system, but the fresh water could be re-used for watering terrestrial crops, and prawn waste accumulated in the bottom of ponds could be removed for fertilising land crops
· Both hatchery and grow-out operations could involve women and family units
- Current production status :
· Both hatchery and grow-out production systems are very well developed
· Extensive, intensive and integrated farming on the species is conducted in many countries in the Southeast Asian region
· 1999 world aquaculture production probably exceeds 130,000 tonnes, and is growing. The production from China alone was 79,000 tonnes in 1999 and 97,000 tonnes in 2000
- Marketing :
· Frozen shrimp are easier to transport but this product is still not well accepted by many Asian countries (for example, dead shrimp fetch only 50-70% of the price for live product of the same size in Thailand and China). The best practical option for many Pacific islands is to sell it fresh chilled, blanched if needed
· The opportunity for export of processed shrimp is low because of the higher head/tail ratio than marine prawns and the loose meat texture resulting from autolysis (enzymatic self-digestion) of body tissues.
· The shrimp is specially suited for cuisines where lots of spices are used in cooking; many from Europe love the shrimp as it cooks extremely well with a variety of wines
· Freshly grilled shrimp are popular in Southeast Asia and among tourists. Despite its freshwater origin, it is displayed in seafood restaurants in aerated aquaria and sold at US$10/kg. There are some 'shrimp-fishing' restaurants in Southeast Asia
· The opportunity for local value-adding is limited
- Comparative advantages/disadvantages (risks) of producing the species in the Pacific:
· The species is established in the Indo-Pacific region and where successful introductions have taken place, the shrimp has proved to be benign and has been well received by the local communities
· It is a good aquaculture species suitable for culture in smaller ponds, which is an advantage as many of the Pacific countries have small land masses
· Hatchery and seed production techniques relatively are easy, established and could be low-tech.
· The species is suitable for extensive and intensive farming; it is a very successful species suitable for polyculture - for example, rice and prawn farming
· Well developed market for the product and the meat has an established niche market
Some Pacific nations need to translocate the broodstock from their neighbours. Macrobrachium rosenbergii is not endemic to the countries in the Pacific, although other species of Macrobrachium are. However, it is believed that M. rosenbergii has been introduced into Guam, Fiji, French Polynesia, Micronesia, New Caledonia, New Zealand, Palau, the Solomon Islands, Vanuatu and Samoa during the past thirty years. No negative impacts have been reported in these translocations. Being a freshwater species it may spread throughout the river systems within an island but there is little threat of it spreading between islands.