Abstract
In tem per ate re gions fresh wa ter prawn, Macrobrachium rosenbergii, ju ve niles are nursed to more ad vanced sizes (≥ 0.3 g) in indoor tanks, then trans ported to ponds for growout. Stress dur ing transport can pro duce im me di ate mor tal ity and un de tected mor tal ity af ter pond stock ing. This study was de signed to eval u ate the ef fect of bio mass den sity dur ing trans port in sealed con tain ers on pre-stock ing prawn sur vival. Nine rep li cate sty ro foam trans port con tain ers were pre pared. Each con tained one dou ble bagged plas tic bag with 10 L of ox y gen-sat u rated 22EC wa ter with an at mo sphere of 10 L pure ox y gen. Ju ve nile prawn weigh ing 0.26±0.02 g (av er age weight ±S.D.) were ran domly stocked into trans port con tain ers at ei ther 10, 25 or 50 g of prawn per li ter of wa ter, then sealed for eight hours (max i mum re gional trans port pe riod). There were three rep li cate trans port con tain ers per den sity. At eight hours post-stock ing, bags were opened, wa ter qual ity de ter mi na tions were con ducted, and live and dead an i mals were sep a rated and counted. To tal am mo nia-ni tro gen and un-ion ized am mo nia-ni tro gen con cen trations were sig nif i cantly higher (P ≤0.05) in con tain ers stocked at 50 g/L than in con tain ers stocked at ei ther 10 or 25 g/L, which were also sig nif icantly dif fer ent (P ≤0.05) from each other. Ni trite-ni tro gen con cen tra tions were sig nif i cantly higher (P ≤0.05) for con tain ers stocked at 50 g/L than in those stocked at 10 g/L. How ever, ni trite con cen tra tions in con tain ers stocked at 25 g/L were not sig nif i cantly dif fer ent (P> 0.05) from con tain ers stocked at other den si ties. Dis solved ox y gen was sig nifi cantly lower (P ≤0.05) in trans port con tain ers stocked at 50 g/L (1.3 mg/L) than those stocked at 25 g/L or 10 g/L (1.6 mg/L and 3.2 mg/L, respec tively), which were also sig nif i cantly dif fer ent (P≤0.05). Sur vival was sig nif i cantly lower (P ≤0.05) in trans port con tain ers stocked at 50 g/L (86.6%) than in con tain ers stocked at 25 g/L (93.0%) and 10 g/L (97.2%), which were also sig nif i cantly dif fer ent (P ≤0.05). These data in di cate that trans port den si ties greater than 10 g/L should be avoided for trans port ≥8 hours in sealed con tain ers.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have