Culture practices and status of the giant freshwater prawn, Macrobrachium rosenbergii, in Taiwan

Abstract

The giant freshwater prawn, Macrobrachium rosenbergii, was first introduced into Taiwan in 1970. However, it was only in the 80s when farming of this species became popular and reached a larger commercial scale. To date, there are more than 200 M. rosenbergii hatcheries, some of which had only recently shifted from hatchery production of marine prawn species. Spawners are obtained mainly from selected breeders harvested from commercial ponds. Hatchery output for 1989 is expected to be more than 1.5 billion juveniles. Most of the ponds were specially built for M. rosenbergii and a small number of ponds were adapted from freshwater fish or marine prawn culture. All in all, these ponds currently cover 3,500 ha. Most have been patterned after the segmental system, where the prawns are caught in nets periodically and transferred to different ponds according to size. After a number of harvestings, prawn which are over 25 g in body weight are sold live in local markets. When farms are effectively and efficiently managed, monoculture of this species may achieve an annual production of 4,000-5,000 kg/ha with 1 to 1.5 crops produced in a one-year period starting from March. Total production reached 4,500 tonnes (t) in 1988. The features and culture status of M. rosenbergii in Taiwan are discussed in this paper, along with other related topics, such as current problems and prospects.