초록
<P>Research was conducted on the growth performance and nutritional quality of Chinese mitten crabs (<I>Eriocheir sinensis</I>) during a 62-day growing period in a symbiotic coculture comprising rice and crab. Culture experiments were conducted in three rice fields of equal size (996 m<SUP>2</SUP>). On days 0 (July 15, D0), 15 (July 30, D15), 31 (August 15, D31), 46 (August 30, D46), and 62 (September 2, D62), tissue samples of 50 female <I>E. sinensis</I> were collected randomly from each rice field. The results showed that the serum growth hormone (GH) content and muscle ecdysone receptor (<I>EcR</I>) mRNA expression levels were higher in the D31 and D46 groups; the content of serum 20-hydroxyecdysone (20-HE) and the mRNA expression levels of retinoid X receptor (<I>RXR</I>), insulin-like growth factor 2 (<I>IGF2</I>), and chitinase (<I>CHI</I>) reached the maximum in the D31 group. Muscle crude protein content gradually increased; hepatopancreas crude protein and crude lipid content began to decrease after reaching the maximum value in the D0 and D15 groups, respectively; the contents of crude protein and crude lipid in the ovary significantly increased in the D46 and D62 groups (<I>P</I> < 0.05). The content of muscle essential amino acids (EAA) reached the maximum in the D46 group; the hepatopancreas EAA content began to decrease significantly in the D31 group (<I>P</I> < 0.05); and the EAA content of the ovary decreased significantly after reaching the maximum value in the D46 group (<I>P</I> < 0.05). The muscle contents of eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), docosahexaenoic acid (DHA), polyunsaturated fatty acids (PUFA), and n-3 polyunsaturated fatty acids (n-3PUFA) and the ratio of n-3 polyunsaturated fatty acids/n-6 polyunsaturated fatty acids (n3/n6) decreased significantly in the D31 group (<I>P</I> < 0.05); the hepatopancreas contents of EPA, PUFA, n-3PUFA, and n-6 polyunsaturated fatty acids (n-6PUFA) and the ratio of n3/n6 began to decrease after reaching the maximum value in the D31 group, ethyl behenate (21:0), tetracosanoic acid (24:0), DPA, and DHA contents were detected for the first time in the D31 group; the ovary PUFA, n-3PUFA contents, and n3/n6 ratio of the D46 and D62 groups were significantly lower than those of the D31 group (<I>P</I> < 0.05). During the experimental conditions described here, female <I>E. sinensis</I> raised in rice fields reached rapid growth from August 15 to August 30. Additionally, the nutritional quality of the female <I>E. sinensis</I> edible tissues (muscle, hepatopancreas, and ovary) began to decline after August 15, when sufficient nutrients such as protein, lipid, EAA, and PUFA should be provided to the female <I>E. sinensis</I>.</P>