Shuyan Chi

Guangdong Ocean University, China

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Publications (5)2.84 Total impact

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    ABSTRACT: The synchronous effects of aqueous Na/K and dietary potassium (K+) on growth and physiological characters was studied on the Pacific white shrimp (Litopenaeus vannamei) reared in low-salinity well water (4 ppt) for 8 weeks with initial weight of 0.28 ± 0.01 g. Three practical diets were formulated with supplement of 0, 0.3%, 0.6% K+ which contained 1.29 g/100 g, 1.60 g/100 g, 1.93 g/100 g K+ respectively. The supplement of K+ to the low-salinity well water was 10, 20, 40 mg L−1 which formed Na:K ratios of 42:1, 33:1, 23:1 respectively. Results showed that when the aqueous Na:K ratio was 42 and dietary K+ was 1.93 g/100 g K+, the WGR and PER of L. vannamei were the highest and the FCR was lower than that of others (P < 0.01). Supplement of K+ into well water and diets did not showed significant effects on haemolymph ammonia-N, uric acid, urea content (P > 0.05), but had a extremely significant effect on arginase activity and Cl− concentration (P < 0.01). Moreover, similar results were observed in alkaline phosphatase (ALP), bacteriolytic activity (LSZ) and respiratory burst activity (O2−) (P < 0.05). These results suggested that aqueous Na/K in the low-salt well water and dietary K had significant synergistic effect on the growth, osmoregulation and immunity of L. vannamei. Concluded from the growth performance, nitrogen metabolism, osmoregulation and immunity, as the Na/K in the low-salinity well water descended from 42 to 23, the requirement of dietary K+ was also decreased.
    Aquaculture Research 06/2014; · 1.42 Impact Factor
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    ABSTRACT: An 8 weeks feeding experiment was conducted to determine the effect of dietary potassium on the growth and physiological acclimation of Pacific white shrimp (Litopenaeus vannamei) reared in diluted seawater (salinity 4). Six semi-purified practical diets containing 0.59, 0.96, 1.26, 1.48, 1.74, and 2.17 g potassium K+ per 100 g diet were formulated, respectively. The survival and feed conversion rate did not show significant difference among groups of shrimps given these diets (P>0.05). The shrimps fed the diets containing 0.96–1.48 g K+ per 100 g diet gained the highest weight, specific growth rate, and protein efficiency ratio. Their ammonium-N excretion rate as well as hemolymph concentration of Na+ and Cl− were significantly lower than those of the control (P<0.05), but a reverse trend was observed for their gill Na+/K+-ATPase. Moreover, the shrimps fed with 1.48 g K+ per 100 g diet were the highest in hemolymph urea level, and the phenoloxidase and lysozyme activities were significantly higher than those of the control (P<0.05). The growth and physiological response of the test shrimps suggested that diet containing 1.48 g K+ per 100 g diet improved the growth of L. vannamei in low-salinity seawater, and enhanced the physiological acclimation of the organism.
    Journal of Ocean University of China 04/2014; 13(2).
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    ABSTRACT: Apparent digestibility coefficients of dry matter (DM), crude protein, crude lipid, gross energy, phosphorus and amino acids in Peruvian fish meal (FM), fermented soybean meal, extruded soybean meal, soybean meal, peanut meal, wheat gluten meal, corn gluten meal, shrimp byproduct meal, meat and bone meal (MBM), poultry meat meal and plasma protein meal (PPM) were determined for white shrimp (Litopenaeus vannamei). A reference diet (RF) and test diets (consisting of 70% RF diet and 30% of the feedstuff) were used with 0.5% chromic oxide as an external indicator. A total of 1440 shrimp (initial mean body weight 1.05 ± 0.01 g) were randomly stocked into thirty-six 500-L fibreglass tanks with 40 shrimp per tank and three tanks per diet. Faeces were collected from triplicate groups of shrimp by a faecal collection vessel attached to the shrimp-rearing tank. The shrimp were fed to apparent satiation four times a day and the feeding experiment lasted for 6 weeks. Statistics indicate that apparent DM digestibilities for white shrimp (L. vannamei) were the highest for FM, ranged 52.83–71.23% for other animal products and 69.98–77.10% for plant products. The protein and lipid from plant and animal sources were well digested by white shrimp. Apparent protein and lipid digestibility were in the range 87.89–93.18% and 91.57–95.28%, respectively, in plant products, and 75.00–92.34% and 83.72–92.79%, respectively, for animal products. The white shrimp demonstrated a high capacity to utilize phosphorus in the ingredients. The apparent phosphorus digestibility ranges of animal feedstuffs and plant feedstuffs were 58.90–71.61% and 75.77–82.30% respectively. Amino acid availability reflected protein digestibility, except that in MBM, for which the availability of some amino acid was lower, possibly due to protein damage during processing. Digestibility information could promote the use of ingredient substitution in least-cost formulated diets for white shrimp.
    Aquaculture Research 07/2009; 41(1):78 - 86. · 1.42 Impact Factor
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    ABSTRACT: This feeding trial was conducted to evaluate the potential of poultry by-product meal (PBM) as a protein source in the culture of Litopenaeus vannamei. Seven isonitrogenous and isoenergetic diets were formulated to near to commercial diet with about 40% protein and 7.5% lipid. Fish meal was replaced by 0, 30%, 40%, 50%, 60%, 70% and 100% of PBM (diets 1–7). The diet with 100% fish meal was used as a control (diet 1). Post-larvae were reared in an indoor semi-closed re-circulating system. Each dietary treatment was tested in 4 replicate tanks (260 L) of 40 shrimp, arranged in a completely randomized design. The shrimps were hand-fed for three times a day to near-satiation (0700, 1200 and 1800) for 60 d. Percentage weight gain, survival, feed conversion ratio (FCR), protein efficiency ratio (PER) and body composition of shrimps were measured. There were no significant differences (P>0.05) in growth performance among shrimps fed diets 1–5 (0–60% fish meal replacement). However, shrimps fed diet 7 (100% fish meal replacement) had significantly lower (P<0.05) growth than those fed diets 1–5 (0–60% fish meal replacement). Shrimp fed diets 2–4 (30%–50% fish meal replacement) showed significantly higher growth than those fed diets 6 and 7 (70% and 100% fish meal replacement, respectively). Survival ranged from 94.7% to 100.0% and did not differ significantly (P>0.05) among different experimental diets. No differences in body composition were found among shrimps fed different diets. These results showed that up to 70% of fish meal protein can be replaced by PBM without adversely affecting the growth, survival, FCR, PER and body composition of Litopenaeus vannamei.
    Journal of Ocean University of China 8(4):399-403.
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    ABSTRACT: The Pacific white shrimp, Litopenaeus vannamei, is a euryhaline crustacean capable of tolerating a wide range of ambient salinity (0.5–40 psu). To investigate the effect of long-term low salinity stress on gene expression in the hepatopancreas in shrimp, we performed suppression subtractive hybridization (SSH) in juvenile L. vannamei exposed to long-term low salinity. The shrimp (initial body weight, 0.27 ± 0.01 g) were cultured at salinity 2 psu and salinity 30 psu for 56 days. We then constructed forward and reverse subtractive cDNA libraries. We used bioinformatics tools and vector screening to select a total of 200 (80 from forward, 120 from reverse) randomly selected clones over 100 nucleotides in length for further analysis. Nineteen contigs and 54 singletons were generated from a total of 73 consensuses. The consensuses, upon a sequence homology search using BLASTX (NCBI), revealed that 24.66% (18/73) of them had no significant match to reported sequences in the database, suggesting that they had not previously been found and that they were probably associated with stress-regulated functions. The remaining 75.34% (55/73) of the consensuses encoded proteins were matched to a wide range of functions including immune-related functions, metabolism, ribosomal activity, transfer activity, and apoptosis. The most common group in these SSH libraries was immune-related proteins and enzymes (11/17). Quantitative RT-PCR results confirmed that the relative expression of 5 differentially expressed genes encoding hemocyanin, chitinase, ecdysteroid-regulated protein, trypsin and chymotrypsin 1 was decreased 2-, 1.45-, 11.11-, 1.33- and 1.54-fold, respectively, in the reverse library. This subtractive cDNA library provides a basis for the study of the genetic response of shrimp to environmental stress.
    Aquaculture. s 364–365:186–191.