Guangxi Institute of Oceanology

Beihai, China

Guangxi Institute of Oceanology

Beihai, China
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Peng Y.,Guangxi Institute of Oceanology | Liu X.,Guangxi Institute of Oceanology | Huang G.,Guangxi Institute of Oceanology | Wei L.,Ocean University of China | Zhang X.,Ocean University of China
Journal of Ocean University of China | Year: 2017

We investigated the effects of low temperature (8.5°C) on the growth and feeding rates and feed conversion efficiency of juvenile P. olivaceus with an average initial weight of 3.87 ± 0.06 g (mean ± SE). Fish were exposed to 8.5°C for 0 (control), 1, 2, 3 and 4 weeks, and then to 20°C for 10, 9, 8, 7 and 6 weeks, respectively. Low temperature clearly led to growth depression. The weight of fish exposed to low temperature for 1 week was restored to that of control, while that of fish exposed to low temperature longer was significantly decreased (P < 0.05). During the entire low-temperature period, specific growth rate, feeding rate and feed conversion efficiency of the fish were significantly lower (P < 0.05) than those of control, while in the whole recovery period, specific growth and average feeding rate were markedly higher (P < 0.05) than those of control. At the end of experiment, only the feeding rate of the fish exposed to low temperature for 1 week was not significantly different from that of control (P > 0.05). Feeding rate and feed conversion efficiency were reduced at low temperature in juvenile P. olivaceus. The compensatory growth of juvenile P. olivaceus may therefore be attributed to the improvement of feeding rate. Our results suggested that growth depression occurs when juvenile P. olivaceus are exposed to low temperature for more than one week. © 2017, Science Press, Ocean University of China and Springer-Verlag Berlin Heidelberg.


Cai X.,Guangdong Ocean University | Wang B.,Guangdong Ocean University | Peng Y.,Guangxi Institute of Oceanology | Li Y.,Guangdong Ocean University | And 4 more authors.
Fish and Shellfish Immunology | Year: 2017

Streptococcus agalactiae is a Gram-positive pathogen that can survive inside professional phagocytes and nonphagocytic cells to cause septicemia and meningoencephalitis in freshwater and marine fish. However, vaccines based on extracellular products (ECP) and formalin-killed whole S. agalactiae cells, as well as subunit vaccine are unable to protect fish from infection by variant serotypes S. agalactiae. The search for live attenuated vaccine with highly conserved and virulent-related genes is essential for producing a vaccine to help understand and control streptococcosis In this study, the phoB gene was cloned from pathogenic S. agalactiae TOS01 strain and the mutant strain SAΔphoB was constructed via allelic exchange mutagenesis. The results showed that the deduced amino acid of S. agalactiae TOS01 shares high similarities with other Streptococcus spp. and has high conserved response regulator receiver domain (REC) and DNA-binding effector domain of two-component system response regulators (Trans_reg_C). Cell adherence and invasion assays, challenge experiments and histopathological changes post-vaccination were performed and observed, the results showed that the mutant strain SAΔphoB has a lower adherence and invasion rate and less virulent than the wild type strain in golden pompano, and it doesn't induce clinical symptoms and obvious pathological changes in golden pompano, thereby indicating that the deletion of phoB affects the virulence and infectious capacity of S. agalactiae. Golden pompano vaccinated via intraperitoneal injection SAΔphoB had the relative percent survival value of 93.1% after challenge with TOS01, demonstrating its high potential as an effective attenuated live vaccine candidate. Real-time PCR assays showed that the SAΔphoB was able to enhance the expression of immune-related genes, including MHC-I, MyD88, IL-22 and IL-10 after vaccination, indicating that the SAΔphoB is able to induce humoral and cell-mediated immune response in golden pompano over a long period of time. © 2016


Liu X.,CAS Qingdao Institute of Oceanology | Liu X.,Guangxi Institute of Oceanology | Zhou Y.,CAS Qingdao Institute of Oceanology | Yang H.,CAS Qingdao Institute of Oceanology | Ru S.,Ocean University of China
PLoS ONE | Year: 2013

Eelgrass ecosystems have a wide variety of ecological functions in which living tissues and detritus may be a food source for many marine animals. In this study, we conducted a laboratory simulating experiment to understand the trophic relationship between the eelgrass Zostera marina L and the sea cucumber Apostichopus japonicus. A mixture of decaying eelgrass debris and seafloor surface muddy sediments was used as food to feed A. japonicus, and then specific growth rates (SGR) and fecal production rates (FPR) were measured. According to the proportion of eelgrass debris, we designed five treatment diets, i.e., ES0, ES10, ES20, ES40, and ES100, with eelgrass debris accounting for 0%, 10%, 20%, 40%, and 100% in dry weight, respectively. Results showed that diet composition had a great influence on the growth of A. japonicus. Sea cucumbers could use decaying eelgrass debris as their food source; and when the organic content of a mixture of eelgrass debris and sediment was 19.6% (ES40), a relatively high SGR (1.54%·d-1) and FPR (1.31 g·ind.-1 d-1) of A. japonicus were obtained. It is suggested that eelgrass beds can not only provide habitat for the sea cucumber A. japonicus but can also provide an indirect food source for the deposit feeder. This means that the restoration and reconstruction of eelgrass beds, especially in coastal waters of China, would be a potential and effective measure for sea-cucumber fisheries, in respect to both resource restoration and aquaculture of this valuable species. © 2013 Liu et al.


PubMed | Guangxi Institute of Oceanology and Guangdong Ocean University
Type: | Journal: Fish & shellfish immunology | Year: 2016

Streptococcus agalactiae is a Gram-positive pathogen that can survive inside professional phagocytes and nonphagocytic cells to cause septicemia and meningoencephalitis in freshwater and marine fish. However, vaccines based on extracellular products (ECP) and formalin-killed whole S. agalactiae cells, as well as subunit vaccine are unable to protect fish from infection by variant serotypes S. agalactiae. The search for live attenuated vaccine with highly conserved and virulent-related genes is essential for producing a vaccine to help understand and control streptococcosis In this study, the phoB gene was cloned from pathogenic S. agalactiae TOS01 strain and the mutant strain SAphoB was constructed via allelic exchange mutagenesis. The results showed that the deduced amino acid of S. agalactiae TOS01 shares high similarities with other Streptococcus spp. and has high conserved response regulator receiver domain (REC) and DNA-binding effector domain of two-component system response regulators (Trans_reg_C). Cell adherence and invasion assays, challenge experiments and histopathological changes post-vaccination were performed and observed, the results showed that the mutant strain SAphoB has a lower adherence and invasion rate and less virulent than the wild type strain in golden pompano, and it doesnt induce clinical symptoms and obvious pathological changes in golden pompano, thereby indicating that the deletion of phoB affects the virulence and infectious capacity of S. agalactiae. Golden pompano vaccinated via intraperitoneal injection SAphoB had the relative percent survival value of 93.1% after challenge with TOS01, demonstrating its high potential as an effective attenuated live vaccine candidate. Real-time PCR assays showed that the SAphoB was able to enhance the expression of immune-related genes, including MHC-I, MyD88, IL-22 and IL-10 after vaccination, indicating that the SAphoB is able to induce humoral and cell-mediated immune response in golden pompano over a long period of time.


Yu H.-R.,Weifang University | Zhang Q.,Guangxi Institute of Oceanology | Cao H.,Weifang University | Wang X.-Z.,Weifang University | And 6 more authors.
Aquaculture Nutrition | Year: 2013

Apparent digestibility coefficients (ADCs) of dry matter, crude protein, crude lipid, gross energy, phosphorus and amino acids in Peruvian fish meal, poultry by-product meal, meat and bone meal, spray-dried blood meal, hydrolysed feather meal, corn gluten meal, soybean meal, peanut meal, cottonseed meal and rapeseed meal were determined for juvenile snakehead (Ophiocephalus argus) with initial mean body weight of 78.1 g. A reference diet and test diets that consisted of a 70 : 30 mixture of the reference diet to test ingredient were used with 5 g kg-1 Cr2O3 as an external indicator. Fish meal, poultry by-product meal and corn gluten meal had higher ADCs of dry matter, crude protein, and gross energy among ingredients tested. Dry matter ADCs ranged 61.9-81.5% for animal ingredients and corn gluten meal and ranged 52.2-68.0% for soybean meal, peanut meal, cottonseed meal and rapeseed meal. Energy ADCs of ingredients followed similar trends to differences in dry matter digestibility. Protein ADCs of animal and plant ingredients ranged 73.6-92.8% and 75.3-85.6%, respectively. Amino acid ADCs generally reflected protein digestibility. Lipid ADCs were relatively high for the ingredients tested. Phosphorus ADCs of animal and plant ingredients ranged 39.5-65.2% and 38.7-57.1%, respectively. © 2012 Blackwell Publishing Ltd.


Zhang Q.,Guangxi Institute of Oceanology | Yu H.,Weifang University | Tong T.,Guangxi Institute of Oceanology | Tong W.,Guangxi Institute of Oceanology | And 3 more authors.
Fish and Shellfish Immunology | Year: 2014

A feeding trial was conducted to investigate the effects of dietary administration of probiotic Bacillus subtilis and prebiotic fructooligosaccharide (FOS) on growth performance, immune responses and disease resistance of juvenile ovate pompano, Trachinotus ovatus. One thousand six hundred and twenty individuals (initial body weight: 10.32±0.46g, mean±S.E) were fed nine practical diets according to a 3×3 factorial design: the basal diet as the control diet supplemented with three levels of B.subtilis (0, 1.05×107 or 5.62×107CFUg-1 diet), crossed with 0, 0.2% or 0.4% FOS. After an 8-week feeding experimental period, six fish per cage were sampled for immunity determination. Then 18 fish of each cage left were challenged by Vibrio vulnificus. The results showed that fish fed with 5.62×107CFU B.subtilis g-1 in combination with 0.2% FOS produced the highest specific growth rate, and were significantly higher than the groups fed with 0 and 0.2% FOS without B.subtilis supplementation (P<0.05). Feed efficiency ratio significantly increased with the increasing doses of dietary FOS without B.subtilis added (P<0.05). The immune assay showed that fish fed with the control diet produced the lowest respiratory burst activity and was significantly different from the groups fed the diets containing 0.2% FOS at each B.subtilis level and containing 0.4% FOS single (P<0.05). Phagocytic activity was significantly decreased with the increasing doses of dietary B.subtilis at 0.4% FOS level (P<0.05). Alternative complement pathway activity of the fish fed with 0.2% FOS single was significantly lower than those fed with 5.62×107CFU B.subtilis g-1 diet supplemented at each FOS level (P<0.05). Fish fed with the control diet had the lowest lysozyme activity, and were significantly different from those fed with 0.2 or 0.4% FOS at 1.05 and 5.62×107CFU B.subtilis g-1 diet level. Moreover, fish fed with diets supplemented with 0.2% and 0.4% FOS at each B.subtilis level had notably lower cumulative mortality after 10 days following V.vulnificus infection (P<0.05). Under the experimental conditions, dietary B.subtilis and FOS had a significant interaction on enhancing the immune responses and disease resistance of juvenile ovate pompano (P<0.05). © 2014 Elsevier Ltd.


Cheng B.,CAS Guangzhou Institute of Geochemistry | Du J.,CAS Guangzhou Institute of Geochemistry | Du J.,Guangxi Institute of Oceanology | Tian Y.,CAS Guangzhou Institute of Geochemistry | And 3 more authors.
Energy and Fuels | Year: 2016

Organic compounds could be adsorbed and even occluded within the macromolecular structures of kerogen. Studies concerning thermal evolution of adsorbed/occluded hydrocarbons inside kerogens will be helpful in understanding its structural characteristics and evolution features and estimating the effectiveness of adsorbed and occluded fractions. In this work, adsorbed and occluded hydrocarbons have been released from a low-matured kerogen from the upper Permian Lucaogou formation of Santanghu Basin, northwest China, and from its pyrolysis residues by solvent extraction and oxidative treatment, respectively. The results showed that some n-alkanes, terpanes, and steranes were detected from both adsorbed and occluded fractions. Series of even-carbon-numbered n-alk-(1)-enes were also determined from the occluded components. The early stage of thermal evolution showed similarities in biomarker features for both adsorbed and occluded hydrocarbons; however, variations were noted in biomarker compositions with increasing thermal levels. The obvious changes of C21-22 pregnane/C27-29 sterane ratios from adsorbed to occluded fractions at high thermal evolution suggested that high concentrations of pregnane (containing homopregnane) in soluble components in highly or overly mature stage may be mainly derived from the corresponding components covalently bound within kerogen. Occluded components exhibited stronger thermal stability than adsorbed components. This study showed that evaluation of the thermal evolution characteristics of kerogens/source rocks based on biomarkers compositions from the adsorbed components at highly to overly matured stages was difficult, while we hope this kind of assessment of kerogens/source rocks can be achieved from occluded components. © 2016 American Chemical Society.


Sun X.-P.,Ocean University of China | Sun X.-P.,Guangxi Institute of Oceanology | Cao F.,Ocean University of China | Shao C.-L.,Ocean University of China | And 4 more authors.
Steroids | Year: 2015

Twelve new 9,10-secosteroids designated as subergorgiaols A-L (1-12), along with four known analogues (13-16), were isolated from the gorgonian Subergorgia rubra collected from the South China Sea. Their planar structures and the relative configurations were elucidated by comprehensive spectroscopic methods including NOESY spectra. The absolute configuration of 1 was established by a dimolybdenum tetraacetate [Mo2(AcO)4] induced circular dichroism (ICD) procedure and the modified Mosher's method. Compounds 1-12 represent the first series of 9,10-secosteroids characterized with a hydroxy group at C-8, which are 8-OH derivatives of astrogorgiadiols/calicoferols. Compound 4 exhibited cytotoxicity against the cervical carcinoma cell line (CaSki) with an IC50 value of 2.4 μM, and 6 showed toxicity toward brine shrimp Artemia salina with an LC50 value of 2.0 μM. © 2014 Elsevier Ltd. All rights reserved.


Liu X.-J.,Guangxi Institute of Oceanology | Peng Y.-H.,Guangxi Institute of Oceanology | Huang G.-Q.,Guangxi Institute of Oceanology
Chinese Journal of Ecology | Year: 2016

Sipunculus nudus is a special species distributed in the Beihai Gulf, and it is also a kind of precious sea food. In order to exploit its economic value, the content of amino acids of S. nudus was measured. Nutritional values of amino acids were evaluated according to amino acids grade standard mode of FAO/WHO. The investigation was conducted in February, May, August and November 2013 in five sea areas including Shankou, Beimu, Yingpan, Daguansha and Zhulin. Then the amino acids content and composition were analyzed. The result showed that the average content of amino acids of S. nudus in Beimu was highest, being 68.02%±0.50%. The contents of amino acids, essential amino acids and non-essential amino acids presented a trend of increase first and decrease later over seasons in the five sea areas. 16 kinds of amino acids were detected in S. nudus, and the content of glutamic acid was highest, which could reach 17.34%± 0.61%. The ratio of essential amino acids to total amino acids and the ratio of essential amino acids to non-essential amino acids approached the FAO/WHO standard. Our results provided theoretical basis and technical support for the development of S. nudus with high edible and medicinal values. © 2016, Editorial Board of Chinese Journal of Ecology. All rights reserved.


PubMed | Guangxi Institute of Oceanology and Ocean University of China
Type: Journal Article | Journal: Fish physiology and biochemistry | Year: 2016

In the present study, the full-length cDNA sequences of leptin (LEP) and its receptor (LEPR) from turbot Scophthalmus maximus were cloned. The cDNA of tLEP was 1126bp in length encoding 157 amino acids. The amino acid sequence shared low identity with human LEP (18.8%), but the three-dimensional structures of these two LEPs were strongly conserved. The deduced 1173-amino acid sequence of tLEPR was 28% identical to human LEPR, and 82% too range-spotted grouper LEPR, containing all functionally important domains conserved in vertebrate LEPR. Tissue distribution analysis showed that tLEP was abundantly expressed in brain, eyes and liver. The highest level of tLEPR mRNA was found in liver and kidney. After a 9-week feeding trial using diets with different ratios of carbohydrate-lipid (1:6, 1:2, 2:1 and 14:1), it was found that the increase in dietary carbohydrate-to-lipid ratios from 1:6 to 2:1 did not significantly influence tLEP and tLEPR expression in turbot liver (P>0.05). The hepatic tLEP expression was significantly elevated in treatment with 14:1 dietary carbohydrate-to-lipid ratio (P<0.05). The hepatic tLEPR mRNA level in group with 14:1 dietary carbohydrate-to-lipid ratio was significantly lower than that in 1:6 group (P<0.05), but had no significant difference with the other two groups (P>0.05). These results revealed the important relationship between dietary carbohydrate-to-lipid ratio and LEP expression in turbot.

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