Open AccessMacrobrachium rosenbergii (DE MAN) CULTURE IN POLYNESIA: OBSERVATIONS ON THE WATER CHEMODYNAMISM IN AN INTENSIVE LARVAL REARING
Author(s) -
Aquacop
Publication year - 1977
Publication title -
proceedings of the annual meeting ‐ world mariculture society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.655
H-Index - 60
eISSN - 1749-7345
pISSN - 0164-0399
DOI - 10.1111/j.1749-7345.1977.tb00126.x
Subject(s) - nitrite , ammonia , larva , macrobrachium rosenbergii , zoology , biology , water quality , chemistry , ecology , biochemistry , nitrate , prawn
In order to specify the limits of the high density larval rearing method (80–100 larvae per liter) in clear water with daily total exchange and to control the water quality evolution, the nitrite and total ammonia were measured. Nitrite concentrations in antibiotic treated tanks stayed low (5μg NO 2 ‐N/1) but can reached 40μg NO 2 ‐N/1 after 41 days in untreated tanks, in spite of daily water exchange. Maximum concentrations of total ammonia were 1.70 ppm N during a 24‐hour cycle. In the rearing conditions (pH 7.85 to 8.20, temperature 25 to 28 C) the un‐ionized ammonia concentrations were 0.07 to 0.18 ppm N. At those levels, no specific larval stress was noted. The interaction of variations in ammonia and nitrite concentration versus, antibiotics, temperature, light intensity, larval stages, diseases, was studied. Ammonia variations, resulting from the larval metabolism, could be a useful indicator for detecting the beginning of bacterial diseases.