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Effects of frequency and amplitude of salinity fluctuation on the growth and energy budget of juvenile Litopenaeus vannamei (Boone)
Author(s) -
Feng Cuimei,
Tian Xiangli,
Dong Shuanglin,
Su Yuepeng,
Wang Fang,
Ma Shen
Publication year - 2008
Publication title -
aquaculture research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.646
H-Index - 89
eISSN - 1365-2109
pISSN - 1355-557X
DOI - 10.1111/j.1365-2109.2008.02037.x
Subject(s) - salinity , litopenaeus , biology , zoology , shrimp , growth rate , juvenile , amplitude , energy budget , temperature salinity diagrams , fishery , ecology , physics , mathematics , quantum mechanics , geometry
The effects of salinity fluctuation on the growth, intermoult period and energy budget of juvenile Litopenaeus vannamei were investigated. Salinity fluctuation regimes were set in different frequencies of 2, 4 and 8 days and different amplitudes of ±2, ±5 and ±10 g L −1 from a control salinity of 20 g L −1 . After a 48‐day feeding trial, the intermoult period of shrimp became shorter with increasing amplitude and frequency of salinity fluctuation ( P <0.05). Both the frequency and the amplitude of salinity fluctuation had a significant effect on the growth rate of L. vannamei juveniles ( P <0.05). At the frequency of 4 days, the highest growth rates occurred at amplitudes of 5–10 g L −1 , whereas the growth rate was the lowest at 10 g L −1 when the frequency was reduced to 2 days. Feed intake (FI) and assimilation efficiency (AE) of shrimp were also significantly affected by the salinity fluctuation ( P <0.05) and matched the growth rate response. The energy expenditures for growth ( G ), respiration ( R ), excretion ( U ) and exuviae ( E ) to the energy consumed as food ( C ) were not affected by salinity fluctuation. However, salinity fluctuation significantly affected the percentage of C as faeces ( F ), with the lowest value occurring at salinity amplitudes of 5–10 g L −1 and frequencies of 4–8 days. Therefore, salinity fluctuations (every 4 days by ±5–10 g L −1 ) result in higher growth rates than constant salinity conditions (20 g L −1 ) through greater FI, enhanced feed assimilation and reduced faecal energy loss.