变温对刺参幼参生长、呼吸代谢及生化组成的影响

Effects of cyclic fluctuating temperature treatments on growth,oxygen consumption rate and biochemical composition of young sea cucumber, Aposticchopus japonicus

为研究刺参对温度周期性波动的响应,本实验测定了在12,15,18,21,24 ℃ 5个恒温处理组和15±2 ℃,18±2 ℃,21±2 ℃ 3个变温处理下刺参幼参的生长、呼吸代谢和生化组成.结果表明,在恒温条件下,随着温度的升高,刺参生长逐渐加快,在18 ℃生长最快,然后随温度增加,生长逐渐降低.在15～21 ℃恒温条件下,幼参呼吸代谢无显著差异.在不同恒温处理组中,幼参脂肪含量随体重增加而增加.与恒温对照组相比,变温对幼参生长有显著性影响(P <0.05).与相应的恒温相比,平均温度低于最适温度的变温(15±2 ℃,18±2 ℃)可促进刺参的生长,而平均温度高于最适温度时的变温(21±2 ℃)会抑制刺参生长.变温使幼参耗氧率有增加的趋势,但未达到显著水平.变温造成刺参脂肪含量降低,可能与变温条件下呼吸代谢增加有关.

Growth performance, oxygen consumption rate and biochemical composition of young sea cucumbers were studied at constant and fluctuating temperatures. Groups of young sea cucumber, Aposticchopus japonicus, were reared at fluctuating temperatures of 15±2, 18±2 , 21±2℃ and others were reared at constant temperatures of 12, 15, 18, 21 and 24℃ as controls. Specific growth rates （SGR） were measured under different treatments. Results showed that temperature had significant effects on the growth of sea cucumber. At constant temperatures, growth of young sea cucumbers increased with the increasing of temperature from 12 to 18℃. The subsequent increase of temperature led to the comparative deceleration of the growth rate. Therefore, the appropriate temperature for the growth of sea cucumber was from 12 ℃ to 21℃, and the thermal optimum for growth was about 18℃. Within the ecological tolerance range for the species, the growth rate in fluctuating temperature groups increased compared to the growth rate in the control groups with a constant temperature equal to the average oscillating one. SGR significantly decreased when the temperature fluctuating occured around 21℃. Analysis of covariance （ANCOVA） was used to test the relationship between temperature and body composition of young sea cucumber. The effects of different temperature treatments on body contents of crude protein, crude lipid and energy of sea cucumber were significant. The contents of crude lipid of young sea cucumber reared at fluctuating temperatures decreased compared to those reared at constant temperatures. Among three constant temperature groups, oxygen consumption rates of sea cucumbers increased along with the increasing of temperature treatments. However, there were no significant differences among oxygen consumption rates of sea cucumbers under three constant temperature treatments （ P 〉 0.05 ）. In three fluctuating temperature groups, oxygen consumption rates also increased along with the increasing of temperature treatments. The oxygen consumption rate of sea cucumber in 21＋2℃ was significantly higher than that in 15±20℃（ P 〈 0.05）. Temperature fluctuation enhanced the oxygen consumption of sea cucumbers in the 18±20℃ and 21±2℃ when compared to rates of animals subjected to constant temperattLre. However, the differences of oxygen consumption rates between fluctuating temperature treatments and constant temperattLre treatlnents were not significant （ P 〉 0.05）. Temperature in the sea cucumber culttLre pond can be controlled in the range of 15-18℃, and with a fluctuating amplitude of ＋2℃. By this kind of temperature control mode, growth of young sea cucumber will he accelerated.