The methods of juvenile production of Udang Galah (Macrobrachium rosenbergii) have been documented
by several workers (ling, 1969 .. Ling and Costello, 1976 .. Fujimura 7966, 1967, 1968, 1972 .. Fujimura
and okomoto, 1970,. Sandifer etl.1976).
The methods given by these workers involve intensive hatchery management such as frequent water
change and cleaning of larval tanks to ensure good sanitation. Such a technique would involve wastage of
sea water and at the same time is labour intensive.
'to overcome the above mentioned problems a study 'was conducted at the hatchery of the Faculty of
Fisheries and marine Science, Serdang, to produce" Udang Galah" juveniles 'Without water change and by
using «green water' at salinities 6~8°100 and 12-14% 0 respectively. Previous studies by Cohen et al. (1976)
have conclusively shozon that (green water' is an efficient system to remove toxic metabolites such as ammonia
from the culture medium. The 'green water' 'which mainly consists of unicellular algae such as Chlorella is
produced by expos;'lg 'loater of salim'ty 6°(00 'Which contained Sarothcrodon mossambicus to sunlight (Fujimura
