Freshwater prawn research at SEAFDEC/AQD
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Abstract
The Philippines lags behind Thailand and Indonesia as far as research and commercial production of the freshwater prawn, Macrobrachium sp., are concerned. Although studies on Macrobrachium sp. (or ulang as it is locally known), started at the Binangonan Freshwater Station of SEAFDEC/AQD in the mid-1980’s, research efforts were discontinued soon thereafter because of a) inadequate technical skills; b) problems with larval rearing and the domestication of wild stocks; and among others, c) the Macrobrachium sp. being considered in the Philippines as a low priority species in contrast to commercially important freshwater commodities like tilapia and milkfish. This was two decades ago and in retrospect, had researches continued, the freshwater prawn in the Philippines could have been successfully domesticated and current problems concerning limited aquaculture production of genetically depauperate non-indigenous stocks could have been resolved.
With the renewed interest in the culture of alternative species like the freshwater prawn, researchers at the Binangonan Freshwater Station started to conduct some studies on the refinement of breeding, larval rearing and culture of Macrobrachium rosenbergii in late 2003. These studies are briefly described here.
Suggested Citation
Eguia, M. R. R., Aralar, M. L. C., & Laron, M. A. (2007). Freshwater prawn research at SEAFDEC/AQD. In M. R. R. Eguia & M. L. C. Aralar (Comps.), Recent developments in the genetic improvement of the giant freshwater prawn (Macrobrachium sp.) (pp. 63–64). Tigbauan, Iloilo, Philippines: Aquaculture Department, Southeast Asian Fisheries Development Center.
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Book chapterISBN
9789718511848Related items
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Shrimp grow-out culture techniques in the Philippines
(Aquaculture Department, Southeast Asian Fisheries Development Center, 1993)The major commercial shrimp species in the Philippines belong to the genus Penaeus and Metapenaeus. The important penaeid shrimps are: P. monodon (giant tiger shrimp or sugpo); P. japonicus and P. semisulcatus (tiger shrimp and bulik or sugpo); and P. merguiensis and P. indicus (white shrimp and Indian white shrimp or putian). The giant tiger shrimp is the major species cultured in ponds while the others are incidental crops. There are 210,000 ha of potential and existing brackishwater ponds in the Philippines (Fig. 1). Because most of these are underdeveloped, present technologies are aimed at improving production or encouraging the development of new areas. Brackishwater fishfarming in the country is primarily centered on milkfish (Chanos chanos) (Table 1). Shrimp used to be merely an incidental crop when postlarvae from the wild enter the milkfish ponds. In the last decade, many traditional milkfish growers recognize the market of shrimps, primarily the giant tiger shrimp. Polyculture of milkfish and shrimp was practiced, and the fishfarmers shifted to shrimp monoculture when price of shrimp in the international market went up. In the mid-70s, SEAFDEC/AQD developed and extended its shrimp hatchery technology, and hatcheries proliferated throughout the country. Seed supply became abundant, encouraging more people to invest in grow-out culture. However, production remained low and inconsistent since the growout technology remains largely an art. When Taiwanese grow-out technology was introduced in the country and research in shrimp was intensified in the Department of Agriculture, University of the Philippines, and SEAFDEC/AQD, new coastal areas were developed particularly in Negros Island where vast tracts of sugarland and rice land were converted to shrimp ponds. Milkfish ponds were also renovated for shrimp culture. There are four shrimp culture levels in the country, namely: traditional, extensive, semi-intensive, and intensive which vary mainly in pond design, stocking density, feeds and feeding, and water management (Table 2). Only the semi-intensive and intensive culture systems are discussed. -
Growth, molting, food ingestion, and absorption in juvenile Macrobrachium rosebergii in relation to dissolved oxygen
(European Aquaculture Society, 1989)Growth, molting, food ingestion, and absorption in juvenile Macrobrachium rosenbergii were evaluated at 2.5, 3.5, 5.0, and 7.7ppm dissolved oxygen (DO), 29°C, and 0.5°/oo salinity. DO levels were maintained by bubbling nitrogen gas against water flowing down through PVC gas-exchange columns. Prawns (0.58 to 0.60g dry weight) were grown individually in 4 l glass chambers for 40 days and fed in excess twice daily. In a separate experiment, food ingestion and absorption in prawns (0.66 to 1.36g dry weight acclimated to the tour DO levels were determined gravimetrically. Growth rate was significantly reduced only at 2.5ppm DO. The mean growth rates, as percentage dry weight increase per day, were 0.76, 1.56, 1.81, and 1.76% at 2.5, 3.5, 5.0, and 7.7ppm DO, respectively. Molting was not inhibited at the tour DO levels tested. Intermolt periods of all prawns ranged trom 8 to 18 days with a mean of 13.6 days. Food ingestion was reduced at 2.5ppm DO, but apparent absorption of dry matter was independent of oxygen at the tour levels tested. Mean ingestion rates, as percentage of dry body weight were 5.51, 8.85, 8.05, and 10.35%. The mean apparent absorption efficiency of all prawns was 87.95%. This study showed that juvenile M. rosenbergii requires about 3.5ppm DO to grow optimally in the laboratory. Reduction in growth of M. rosenbergii at DO levels below 3.5ppm is due in part to a reduction in food intake and not to changes in absorption efficiency and molting frequency. -
Shrimp hatchery and grow-out operations in Thailand
(Aquaculture Department, Southeast Asian Fisheries Development Center, 1993)Shrimp farming in Thailand has been practiced since more than 50 years ago. This began with the extensive system (traditional method) where shrimp fry are allowed to enter ponds during the high tide, and then harvested after some time. Production then was low and widely fluctuated. After the Department of Fisheries (DOF) successfully spawned and nursed the shrimp (Penaeus, )new techniques were developed and this led to more intensive culture systems. Production of shrimp from aquaculture continuously increased - from 991 t in 1972 to 130,000 t in 1991. The estimated production for 1992 is 150,000 t. The tiger shrimp (Penaeus monodon) is the most desired species due to its rapid growth (commonly grows to 30 g in 4 months in ponds) and its high export value. It is also the major species cultured especially in the intensive system. The other species are banana shrimp (P. merguiensis), white shrimp (P. indicus), and Metapenaeus ensis. These are normally grown in extensive and semi-intensive culture systems.
