Open AccessEffects of Two Densities of Caged Monosex Nile Tilapia, Oreochromis niloticus , on Water Quality, Phytoplankton Populations, and Production When Polycultured with Macrobrachium rosenbergii in Temperate Ponds
Author(s) -
Danaher Jason J.,
Tidwell James H.,
Coyle Shawn D.,
Dasgupta Siddhartha,
Zimba Paul V.
Publication year - 2007
Publication title -
journal of the world aquaculture society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.655
H-Index - 60
eISSN - 1749-7345
pISSN - 0893-8849
DOI - 10.1111/j.1749-7345.2007.00109.x
Subject(s) - polyculture , macrobrachium rosenbergii , biology , tilapia , oreochromis , prawn , nile tilapia , fishery , zoology , monoculture , temperate climate , aquaculture , ecology , fish <actinopterygii>
The effects of different densities of caged Nile tilapia, Oreochromis niloticus , on water quality, phytoplankton populations, prawn, and total pond production were evaluated in freshwater prawn, Macrobrachium rosenbergii , production ponds. The experiment consisted of three treatments with three 0.04‐ha replicates each. All ponds were stocked with graded, nursed juvenile prawn (0.9 ± 0.6 g) at 69,000/ha. Control (CTL) ponds contained only prawns. Low‐density polyculture (LDP) ponds also contained two cages (1 m 3 ; 100 fish/cage) of monosex male tilapia (115.6 ± 22 g), and high‐density polyculture (HDP) ponds had four cages. Total culture period was 106 d for tilapia and 114 d for prawn. Overall mean afternoon pH level was significantly lower ( P ≤ 0.05) in polyculture ponds than in CTL ponds but did not differ ( P > 0.05) between LDP and HDP. Phytoplankton biovolume was reduced in polyculture treatments. Tilapia in the LDP treatment had significantly higher ( P ≤ 0.05) harvest weights than in the HDP treatment. Prawn weights were higher ( P ≤ 0.05) in polyculture than prawn monoculture. These data indicate that a caged tilapia/freshwater prawn polyculture system may provide pH control while maximizing pond resources in temperate areas.