【摘要】 夏眠是刺参最重要的生理特征;水温升高是其夏眠的主要诱发因子,而夏眠的临界温度与刺参体重密切相关。为揭示刺参夏眠对其能量利用对策的影响,测定了2种体重规格(134.0±13.5)g和(73.6±2.2)g刺参在10、15、20、25℃和30℃5个温度梯度下的能量收支。结果表明,温度和体重及其交互作用对刺参能量的摄入均有显著影响;而温度是影响其摄食能分配的主要因素。研究发现,刺参在非夏眠期、夏眠临界期和完全夏眠期的能量利用对策有所不同:在非夏眠期,刺参摄食能支出的最大组分是粪便能,占摄食能的比例超过50%,其次为呼吸耗能,占19.8%～39.4%,而生长能和排泄能占的比例较小,分别为5.7%～10.7%和2.9%～3.7%;在夏眠临界温度下,呼吸和排泄耗能占摄食能的比例均显著增大(分别为88.3%和13.6%),而生长能所占比例降为负值(-55.3%),刺参表现为负生长;而在夏眠期,刺参的摄食能和排粪能为零,为维持其基本生理活动,不得不动用以往贮存于体内的能量,消耗于呼吸和排泄等生理过程,供维持生命之用。总之,从能量生物学的角度看,夏眠的主要生态学意义在于刺参长时间处于相对高温环境,进而导致摄食受阻条件下的一种能量节约方式。更多还原

【Abstract】 Aestivation is defined as a period of dormancy or inactivity allowing animals to survive during an extremely hot and/or dry season.This phenomenon has been observed from various animals including earthworms,snails,bivalves,sea cucumbers,lungfishes and amphibians.Apostichopus japonicus is a temperate sea cucumber and known to aestivate when water temperature rises over 20 ℃ to 24.5 ℃.We measured effects of aestivation on energy utilization(i.e.,energy distribution in growth,feces,respiration and excretion)of A.japonicus with two different body sizes(large(134.0±3.5)g and small(73.6±2.2)g)at water temperatures between 10 ℃ to 30 ℃ with 5 ℃ intervals.The data indicated that water temperature,body size and/or their interaction exerted significant effects on energy ingestion.In particular,water temperature was the main factor influencing energy allocation of A.japonicus.Noticeable variation in the energy utilization of sea cucumber was also observed in this study.During non-aestivation period,energy deposition in growth was lower and the energy loss through feces accounted for the majority of the ingested energy.Under threshold temperature,the energy intake became reduced and energy deposited in growth became negative.During aestivation,sea cucumber discontinued energy intake,resulting in weight loss.Our study suggested that the ecological implication of aestivation in this species could be a mode of energy saving during long-term hot period.更多还原