A study on the nonspecific immunity of Litopenaeus vannamei ever inhabiting freshwater and seawater was carried out at different molt stages by comparing their total hemocyte count(THC) and respiratory burst(RB) and a...A study on the nonspecific immunity of Litopenaeus vannamei ever inhabiting freshwater and seawater was carried out at different molt stages by comparing their total hemocyte count(THC) and respiratory burst(RB) and activity of phenol oxidase(PO), nitric oxide synthase(NOS) and lysozyme(LY). Two-way ANOVA showed that salinity and molt stage independently affected THC and RB and the activity of PO, NOS and LY of juvenile L. vannamei significantly(P < 0.05). The THC and RB and the activity of NOS gradually increased from the post-molt stages(A and B) to the pre-molt stages(D0–D3), which were common in shrimps inhabiting freshwater and seawater. The activity of PO peaked at the inter-molt stage(C), and touched the lowest at the post-molt stage in freshwater and pre-molt stage in seawater. The activity of LY was stable over the molt cycle. The RB and the activity of PO, NOS and LY of juvenile L. vannamei were significantly lower in freshwater than in seawater; whereas THC was significantly higher in freshwater than in seawater(P < 0.05). It was concluded that the post-molt stage(especially stage A) was critical to shrimp culture, which should be intensively attended when L. vannamei was cultured in freshwater.展开更多
Litopenaeus vannamei, a euryhaline species, can be cultured at a wide range of salinities. The emergence of freshwater pond-culture ofL. vannamei is an important prelude to the continued development of shrimp culture ...Litopenaeus vannamei, a euryhaline species, can be cultured at a wide range of salinities. The emergence of freshwater pond-culture ofL. vannamei is an important prelude to the continued development of shrimp culture in China. In this study, we com- pared the respiratory metabolism of juvenile L. vannamei cultured in freshwater and saltwater by measuring their oxygen consump-tion rate （OCR）, ammonium-type nitrogen excretion rate （AER） and pyruvate kinase （PK） and lactate dehydrogenase （LDH） activi-ties at different molting stages in order to physiecologically characterize juvenile L. vannamei under freshwater conditions. The re- suits showed that OCR was significantly higher in saltwater than in freshwater at all stages of molting cycle. However, variation of OCR among molting stages in saltwater was similar with that in freshwater, and the highest OCR was observed at post-molting stage. At all stages of molting cycle, AER was significantly higher in freshwater than in saltwater, and the highest was observed at post-molting stage. The activity of PK was significantly higher in saltwater than in freshwater. Conversely, the activity of LDH was higher in freshwater than in saltwater in general. Significant variation of PK and LDH activities in molting cycle was observed in saltwater and freshwater. The results indicated that aerobic metabolism of juvenile L. vannamei was more active in saltwater than in freshwater; while its protein metabolism was more active in freshwater than in saltwater.展开更多
基金supported by a project of The Major State Basic Research of China (2009CB118706)
文摘A study on the nonspecific immunity of Litopenaeus vannamei ever inhabiting freshwater and seawater was carried out at different molt stages by comparing their total hemocyte count(THC) and respiratory burst(RB) and activity of phenol oxidase(PO), nitric oxide synthase(NOS) and lysozyme(LY). Two-way ANOVA showed that salinity and molt stage independently affected THC and RB and the activity of PO, NOS and LY of juvenile L. vannamei significantly(P < 0.05). The THC and RB and the activity of NOS gradually increased from the post-molt stages(A and B) to the pre-molt stages(D0–D3), which were common in shrimps inhabiting freshwater and seawater. The activity of PO peaked at the inter-molt stage(C), and touched the lowest at the post-molt stage in freshwater and pre-molt stage in seawater. The activity of LY was stable over the molt cycle. The RB and the activity of PO, NOS and LY of juvenile L. vannamei were significantly lower in freshwater than in seawater; whereas THC was significantly higher in freshwater than in seawater(P < 0.05). It was concluded that the post-molt stage(especially stage A) was critical to shrimp culture, which should be intensively attended when L. vannamei was cultured in freshwater.
基金supported by National Program on Key Basic Research Project (Grant No.2009CB118706)
文摘Litopenaeus vannamei, a euryhaline species, can be cultured at a wide range of salinities. The emergence of freshwater pond-culture ofL. vannamei is an important prelude to the continued development of shrimp culture in China. In this study, we com- pared the respiratory metabolism of juvenile L. vannamei cultured in freshwater and saltwater by measuring their oxygen consump-tion rate （OCR）, ammonium-type nitrogen excretion rate （AER） and pyruvate kinase （PK） and lactate dehydrogenase （LDH） activi-ties at different molting stages in order to physiecologically characterize juvenile L. vannamei under freshwater conditions. The re- suits showed that OCR was significantly higher in saltwater than in freshwater at all stages of molting cycle. However, variation of OCR among molting stages in saltwater was similar with that in freshwater, and the highest OCR was observed at post-molting stage. At all stages of molting cycle, AER was significantly higher in freshwater than in saltwater, and the highest was observed at post-molting stage. The activity of PK was significantly higher in saltwater than in freshwater. Conversely, the activity of LDH was higher in freshwater than in saltwater in general. Significant variation of PK and LDH activities in molting cycle was observed in saltwater and freshwater. The results indicated that aerobic metabolism of juvenile L. vannamei was more active in saltwater than in freshwater; while its protein metabolism was more active in freshwater than in saltwater.
