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.

Identification and expression analysis of the g-type and c-type lysozymes in grass carp Ctenopharyngodon idellus

Abstract: Lysozyme is an important molecule of innate immune system for the defense against bacterial infections. We identified two genes encoding g-type and c-type lysozymes from grass carp Ctenopharyngodon idellus by the RACE method. The deduced amino acids of both lysozymes possessed typical structural residues and conserved catalytic sites similar to their counterparts across the species. In contrast, there was only 8.6% similarity of amino acid sequence between these two lysozymes. Phylogenetic analyses revealed that these two genes evolved at different rate. C-type lysozyme of grass carp was diverged early in the evolutionary history. Moreover, the expression patterns of these two genes differed. The mRNA levels of both genes were increased after bacterial infection, but the up-regulation of g-type lysozyme was much stronger than that of c-type lysozyme. We also showed that the c-type and g-type recombinant lysozymes possessed different lytic activities against fish bacterial pathogens. These results confirmed that both lysozymes play important roles in the defense of grass carp against bacterial infections. The g-type lysozyme may be induced for the defense against bacterial infections, while c-type lysozyme might be the main molecule for the house-keeping defense under normal conditions. These two types of lysozymes likely use different mechanisms to regulate their expressions.

A revisit to fishmeal usage and associated consequences in Chinese aquaculture

Abstract: China has dominated global aquaculture production for more than two decades. Aquaculture production in China increased from 24.6 million metric tons (mmt) in 2000 to 47.5 mmt in 2014, an increment of 93.1%. Along with the fast-growing aquaculture industry, aquafeed production in China increased from 5.1 mmt in 2000 to 19.0 mmt in 2014, an increment of 272.5%. However, despite the rapid increase in aquafeed production, the fishmeal usage in aquafeeds in China has remained stable over the years. Fishmeal imports into China remained relatively steady at 1.0–1.5 mmt per annum from 2000 to 2014. An often unacknowledged fact is that China contributes more than 60% to the world aquaculture production at a cost of only 25–30% of the world fishmeal output. This review attempts to explain why the fishmeal usage has not increased proportionately with the increasing aquafeed production in China from several angles: (i) the current status of fishmeal usage in Chinese aquaculture; (ii) the relationship between the decreasing dietary inclusions of fishmeal and improved feed techniques, especially the use of alternative protein sources for fishmeal; (iii) the dominance of Chinese aquaculture by low trophic level species of plants, filter feeders, herbivores and omnivores and consequent low demands for fishmeal; and (iv) the increasing price of fishmeal and the management of exploitation of wild fisheries in the main fishmeal exporting countries to China. The trends and prospects of fishmeal usage in the future in Chinese aquaculture and the associated consequences are also addressed. Like other countries, China is now actively developing both resource conservation-based capture fisheries and environment-friendly freshwater and marine aquaculture systems. Aquaculture will be the main source of aquatic food in the future and will also indirectly contribute to save the world wild fisheries, and China will be main player that will continue to contribute towards this end.