Chinese Academy of Fishery Sciences

About: Chinese Academy of Fishery Sciences is a nonprofit organization based out in Beijing, China. It is known for research contribution in the topics: Population & Gene. The organization has 8107 authors who have published 7929 publications receiving 92095 citations. The organization is also known as: Zhōngguó shuǐchǎn Kēxuéyánjiūyuàn & Chinese Academy of Fishery Sciences.

Characterization of microbial communities in intensive GIFT tilapia (Oreochromis niloticus) pond systems during the peak period of breeding

Abstract: Aquaculture pond is a complex ecosystem where the microorganisms in the sediments, in the animal intestinal tract and in water interact with each other to influence the water quality and health of aquatic animals. In order to understand the spatial distribution and relationship of microbial communities in intensively farmed genetically improved farmed tilapia (GIFT, Oreochromis niloticus), 454 high-throughput pyrosequencing was applied to analyse the 16S rRNA gene of bacteria in intensive GIFT ponds in Wuxi City, Jiangsu Province, China. A total of 72 747 initial sequences were obtained from four depths of pond water, from tilapia large intestines and from pond sediment. The most common phylum in all samples was Proteobacteria, Actinobacteria and Cyanobacteria were the most abundant in water, Fusobacteria and Firmicutes in the large intestine and Chloroflexi in sediment samples. The sediment microbial community structure was comparatively similar to that of the tilapia large intestine. The microbial communities from different water depths were somewhat similar, especially the three most shallow samples, although the abundance of Actinobacteria gradually decreased with increased water depth. This data offer a preliminary exploration of the response mechanisms of the bacterial communities to aquafarming and contributes to the understanding of the status of bacterial communities of tilapia pond systems during the peak period of breeding from the aspect of their spatial distributions.

Bioremediation efficiencies of Gracilaria verrucosa cultivated in an enclosed sea area of Hangzhou Bay, China

Abstract: Due to the discharge of nutrients into the East China Sea, severe eutrophication has appeared in Hangzhou Bay. Therefore, we cultivated Gracilaria verrucosa on a large scale in the Jinshan enclosed sea with an area of 1.72 km2 in the northern part of Hangzhou Bay to perform bioremediation. The Fengxian enclosed sea with an area of 2.3 km2 and 50 km far from Jinshan was used as the control. The results showed that the Hangzhou Bay was severely eutrophicated before G. verrucosa cultivation. During the period of cultivation between August 2006 and July 2007, the annual growth rate of G. verrucosa was 9.42% day−1, and the sea water quality was improved from worse than grade IV to grades II–III, with the concentration of dissolved inorganic nitrogen (DIN) and PO4-P significantly lower than that in the Fengxian enclosed sea (p < 0.01). The concentration of NH4-N, NO3-N, NO2-N, and PO4-P after G. verrucosa cultivation was decreased by 54.12%, 75.54%, 49.81%, and 49.00%, respectively. The density of phytoplankton in the Jinshan enclosed sea with cultivation of G. verrucosa was 6.90 –126.53 × 104 cells m−3, which was significantly lower than that in the Fengxian enclosed sea. In addition, species diversity, richness, and evenness was significantly increased after cultivation of G. verrucosa in the Jinshan enclosed sea compared with that in the Fengxian enclosed sea. The density of Skeletonema costatum, Prorocentrum micans, and Prorocentrum donghaiense, which were the usual species of red tides at the coastal sea of China, in the Jinshan enclosed sea with cultivation of G. verrucosa was significantly lower. Based on these results, if the water quality in the Jinshan enclosed sea were to be maintained at grade I (DIN ≤0.20 mg L−1) or II (DIN ≤0.30 mg L−1), 21.8 t or 18.0 t fresh weight of G. verrucosa need to be cultivated, respectively. These results indicated that large-scale cultivation of G. verrucosa could play a significant role in the bioremediation of Hangzhou Bay.

Molecular Cloning and Expression Analysis of Transformer-2 Gene During Development in Macrobrachium nipponense (de Haan 1849)

Abstract: The transformer-2 gene (tra-2) plays a key role in the sexual differentiation regulatory hierarchy. In this study, tra-2 gene homologs designated as Mntra-2 was cloned and characterized from Macrobrachium nipponense. The full-length cDNA of Mntra-2 consists of 1724 bp with an open reading frame (ORF) encoding 192 amino acids, an 827 bp 5′-untranslated region (UTR) and a 318 bp 3′-UTR. The predicated molecular mass of Mntra-2 was 20.805 kDa with an estimated theoretical isoelectric point of 10.36. The deduced amino acid sequence shares high homology with Penaeus monodon. Real-time quantitative polymerase chain reaction (RT-qPCR) analyses demonstrated that the expression levels of Mntra-2 varied significantly during different developmental stages of embryogenesis, larvae, and post-larvae and in various adult tissues. During embryogenesis, the expression level of Mntra-2 was slightly higher at the cleavage stage than at the blastula stage, and reached the highest level at the nauplius stage. During the larvae, the Mntra-2 expression gradually increased from 1 d larvae post hatch (L1) to L10 and decreased to a lowest level at the end of metamorphosis. During the post-larvae, the Mntra-2 expression was higher level at the 5 d after the metamorphosis (P5). RT-qPCR showed the Mntra-2 mRNA was expressed in ovary, testis, muscle, heart, abdominal ganglion, brain, and intestine with the highest level of expression in muscle and intestine. The results indicate that Mntra-2 is an arthropods tra-2 homolog and probably plays important roles in embryonic development and sex differentiation of M. nipponense.

Depth-dependent target strength of anchovy (Engraulis japonicus) measured in situ

Abstract: Three sets of target strength (TS) data were collected in the southern part of the Yellow Sea using a calibrated, 38 kHz, Simrad EK500 split-beam echosounder. Midwater trawl sampling showed that .97% of the catch by number was anchovy (Engraulis japonicus), with total lengths ranging from 6 to 15 cm, and that the arithmetic-mean length and root-mean-square length were 10.6 and 10.8 cm, respectively. The mean TS of anchovy in the 10– 45-m layer was estimated to be – 50.9 dB, with a 95% confidence interval of ( – 51.0, –50.8) dB. The TS data showed, however, a clear depth-dependence that was very close to and not significantly different from what might be expected according to Boyle’s law. The TS model was estimated to be TS = 20 log L 2 71.6 for the conventional relationship between TS and length, but TS = 20 log L2 (20/3) log (1+z/10) 2 67.6 when the depth (z, m) effect was included according to Boyle’s law. These results may have a significant influence on abundance estimates of anchovy derived from acoustic surveys, both in the Yellow Sea and in other parts of the world.