in Potiya, near Chittagong, Bangladesh, is written for those interested is establishing a small-scale inland freshwater prawn hatchery using the clear water method. It is assumed that the reader has some basic knowledge of aquatic biology, but is not necessarily a degree holder in the subject. The method described is based on the use of brine obtained from salt pans. The brine is diluted with well or surface water to make up the rearing water. Such technology is widely used in commercial hatcheries in Thailand. As rifle is not always available, a simple biofilter, for recirculation of the water, is incorporated in the tank design. The biofilter greatly reduces, or eliminates, the need for water changes during the rearing cycle. The hatchery system described consists of larvae rearing tanks, mixing and brine storage tanks, Artemia incubators and supporting mechanical equipment.

Recirculation systems are becoming increasingly popular and have now been shown to give consistent production of quality post-larvae. All the necessary details for setting up such a simple system are included in this manual, which is also profusely illustrated to make what is described in the text clearer.