| Eriocheir sinensis,commomly known as river crabs or hairy crabs,belong to the genus Eriocheir of Crustacea and crab shell.which is an economic species with migratory habits,The Yangtze River estuary is its main feeding and breeding ground.In the 1960s,due to the overfishing of aquatic organisms in the Yangtze River Estuary,the establishment of sluices in Yangtze River Estuary and the discharge of a large number of pollutants,the natural crab resources declineed sharply,and the problem of resource protection gradually attracted people's attention.The breeding period is an important life cycle stage for the continuation of the race.The animals in the breeding period have a high demand for energy.Only when the body can the egg be held successfully.Therefore,it is very important to understand the energy metabolism regulation mechanism before and after the animal breeding to restore the population resources.The purpose of this study is to revealthe regulation mechanism of energy metabolism and provide basis for population resource protection in the breeding period basic information and reference basis.1. Changes of energy metabolizing enzymes the non-ovigerous crab and ovigerous crab of Eriocheir sinensisThe changes of key energy metabolizing enerzymes[hexose kinase?HK??phosphofructokinase?PFK?,pyruvate kinase?PK?,succinate dehydrogenase?SDH?,malic dehydrogenase?MDH?,arginine kinase?AK?]in different tissues of Wild-caught and pond-reared female Eriocheir sinensis were studied by physiological analysis.The results showed that the activity of HK in hepatopancreas of non-ovigerous female crabs was significantly higher than ovigerous crabs?P<0.05?;there was no significant difference of PFK activity in hepatopancreas and muscle of Eriocheir sinensis of non-ovigerous and ovigerous crabs?P>0.05?;The activity of PK in hepatopancreas of non-ovigerous crab was significantly higher than ovigerous crabs?P<0.05?,while the activity of PK in muscle of non-ovigerous crabs was significantly lower than ovigerous crabs?P<0.05?.The activity of SDH in hepatopancreas of non-ovigerous female crab was higher than ovigerous crabs,but there was no significant difference between them?P>0.05?,the activity of SDH in the muscle tissue of the non-ovigerous female crab was significantly higher than the ovigerous crab?P<0.05?;The activity of MDH in hepatopancreas tissue of the non-ovigerous female crab was significantly higher than that of the ovigerous crab?P<0.05?,while the activity of MDH in muscle tissue of the ovigerous crab was significantly higher than that of non-ovigerous female crab?P<0.05?.The activity of AK in hepatopancreas of the non-ovigerous female crab was significantly higher than that of ovigerous crab?P<0.05?,while the activity of AK in muscle tissue of the ovigerous crab was significantly higher than the non-ovigerous crab?P<0.05?.The results showed that the energy of hepatopancreas was used to lay eggs for the two populations of the non-ovigerous crab,while two populations of ovigerous crab use the energy intheir muscles for embryo hatching.In order to regulate the osmotic balance of the body,the two populations of the non-ovigerous crabs increased the utilization of glucose and energy consumption.In addition,the activities of HK,PFK,PK,SDH,MDH and PK of the two populations showed the difference in tissues.2. Changes of basal metabolism the non-ovigerous crab and ovigerous crab of Eriocheir sinensisstudying the changes of standard metabolism of wild animals in different life cycle stages is not only to understand their metabolic characteristics,but also to reveal their life cycle adaptation strategies.In this study,the sexual maturity of E.sinensis in the Yangtze River Estuary was used as the experimental object.The metabolic characteristics and asphyxiation point of the non-ovigerous female crab and ovigerous crabs of E.sinensis in the Yangtze River Estuary were studied by the method of bioenergy analysis.The asphyxiation point of the non-ovigerous female crab was?2.591±0.652 mg/L?,which was significantly higher than that of ovigerous crab,which was?1.101+0.310 mg/L??P<0.05?.The oxygen consumption rate and oxygen consumption of non-ovigerous female crab and ovigerous crabs decreased with the decrease of dissolved oxygen content,in the experiment 2 h,the oxygen consumption value of non-ovigerous female crab and ovigerous crabs reached the maximum,which were 0.066 mg/?g·h??0.089 mg/?g·h??3.050 mg/L and 5.992mg/L respectively;in the experiment 6 h,the oxygen consumption rate and oxygen consumption of non-ovigerous female crab and ovigerous crabs reached the minimum value,which was 0.003 mg/?g·h??0.004 mg/?g·h??0.159 mg/L and 0.285 mg/L respectively.The ammonia excretion rate and ammonia excretion amount of non-ovigerous female crab and ovigerous crabs decreased to an increasing trend with the decrease of dissolved oxygen content,in the experiment 2 h,the ammonia excretion rate of non-ovigerous female crab and ovigerous crabs reached the maximum value,which was 0.027 mg/?g·h?and 0.020 mg/?g·h?respectively,in the experiment 6 h,the ammonia excretion rate of the non-ovigerous female crab and ovigerous crabs reached the minimum value,which was 0.002 mg/?g·h?and 0.001mg/?g·h?.In addition,The ratio of oxygen to nitrogen and energy consumption rate decreased with the decrease of dissolved oxygen content.After 4 hours,with the decrease of dissolved oxygen concentration,both the ratio of oxygen to nitrogen and energy consumption rate of non-ovigerous crab and ovigerous crab showed a downward trend,which indicated that hypoxia reduced their metabolic level;there was no significant change in their metabolic rate per unit weight of the non-ovigerous female crab and ovigerous crab;under low dissolved oxygen conditions,the proportion of protein as energy-providing substances was increased.3. Changes of biochemical composition the non-ovigerous crab and ovigerous crab of Eriocheir sinensisIn order to study the changes of biochemical composition of the female crab non-ovigerous and ovigerous crab.The fatty acid and amino acids in different tisses of crabs were compared and analyzed.The results showed that?1?the hepatancreas index of non-ovigerous female crabs??7.31±0.73??was significantly higher than that ovigerous crabs?5.59±0.82??P<0.05?.?2?In muscle and hepatopancras,the percentage of saturated fatty acids and momounsaturated fatty acids in female crabs were significantly higher than that in female crabs?P<0.05?.In addition to the percentage of EPA and DHA in hepatopancreas and muscle of ovigerous crabs was significantly higher than non-ovigerous female crab?P<0.05?,the other polyunsaturated fatty acids in the two tissues of ovigerous crab were lower than non-ovigerous crab,and there was non significant difference the non-ovigerous crab and ovigeous crab?P>0.05?.?3?Compared with the female non-ovigerous crab,the content of total essental amino acids and non essential amino acids in hepatopancreas and muscle of crabs increased by 45.26 mg·g-1and 41.67 mg·g-1?67.13 mg·g-1and 127.58 mg·g-1,respectively.The content of hepatopancreas?23.09±1.5?mg·g-1and muscle?18.68±0.7?mg·g-1 of ovigerous crab was the highest.The results showed that there were differences in hepatopaancreas index,fatty acids and amino acids between the two populations,and fat was the main metabolic substrate in the early stage of reproduction. |
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