虾夷扇贝动态能量收支模型参数的测定

The estimation of dynamic energy budget(DEB) model parameters for scallop Patinopecten yessoensis

本研究以虾夷扇贝为实验生物,介绍了动态能量收支(dynamic energy budget,DEB)模型5个关键基本参数的测定及计算方法,分析了方法的利弊及注意事项,为贝类DEB模型参数的准确获取提供参考方法。采用壳长与软体部湿重回归法计算虾夷扇贝的形状系数δm;采用静水法测定不同温度条件下虾夷扇贝的呼吸耗氧率,计算阿伦纽斯温度TA参数;采用饥饿法测定、计算单位时间单位体积维持生命所需的能量[]、形成单位体积结构物质所需的能量[EG]和单位体积最大储存能量[EM]3个参数。室内饥饿实验持续60 d,直至呼吸耗氧率及软体部干重基本保持恒定。结果显示,壳长(SL)与软体部湿重(WW)的回归关系式为WW=0.0118SL3.4511(R2=0.9365),根据公式V=(δm L)3,对软体部湿重的立方根和壳长进行线性回归,所得的斜率即为形状系数δm值(δm=0.32);获得不同规格的虾夷扇贝耗氧率与水温(热力学温度,K)倒数的线性回归关系,线性回归方程斜率的绝对值为阿伦纽斯温度TA,平均为(4160±767)K。饥饿实验结束时,软体部干重和呼吸耗氧率分别降低了56%和81%。虾夷扇贝的耗氧率稳定在0.17 mg/(ind·h),经计算获得[]=25.9 J/(cm^3·d);饥饿持续30天之后,虾夷扇贝软体部干重基本维持在(0.25±0.01)g,经计算获得[EG]=3160 J/cm^3,[EM]=2030 J/cm^3。动态DEB理论是基于能量代谢的物理、化学特性而建立的,体现了生物能量代谢的普遍性规律,能够反映摄食获取能量在不同发育生长阶段的能量分配情况。但是,DEB模型参数的测定及计算比较复杂。基本参数的准确获取将影响其他参数以及模型的准确性。本研究为虾夷扇贝DEB模型的构建奠定基础。

The Dynamic Energy Budget（DEB） theory is a mechanistic theory on metabolism that captures the flows of energy and matter through out the entire life cycle of an organism. A DEB model of an individual organism describes the rates at which the organism assimilates and utilizes energy for maintenance, growth and reproduction, as a function of the state of the organism and of its environment. The DEB model assumes common physiological processes across species and the only difference is in parameter values. It achieves this through a relatively high degree of abstraction, with the pragmatic consequence that the state variables and core parameters are not directly observable. In this paper, both laboratory and field experiments were designed to collect datasets for parameter estimation of scallop Patinopecten yessoensis. 5 basic parameters, such as shape coefficient（δm）,Arrhenius temperature（TA）, volume-specific maintenance costs per unit of time（[ ]）, volume-specific costs for growth（EG） and maximum storage density（EM） were measured and calculated in this paper. And the advantages,disadvantages and precautions of these methods were analyzed. By the method of line regression of shell length and soft tissue wet weight of Patinopecten yessoensis to calculate the shape coefficient; With static method to measure the oxygen consumption rate of scallop at different temperature conditions, and then to calculate the Arrhenius temperature; by starvation meathod to get the parameters of [ ], [EG ] and [EM ]. The lab-based starvation experiment was done over 60 days. Changes in body flesh weight were monitored and the oxygen consumption rate was measured. The experiment was finished when the oxygen consumption rate and the dry weight of the soft tissue remained constant. The results showed：（1） The regression relationship between shell length（SL） and soft part wet weight（WW） is WW=0.0118SL3.4511（R2=0.9365）. According to the formula V=（δm L）3,the soft tissue wet weight of the cube root and shell length linear regression, the slope is the shape coefficient. The various estimates by means of weighted regression were highly significant（R2=0.8776, p〈0.05）. δm value was 0.32,which was in the range of reported results for other species of bivalves.（2） TA was calculated on experiments on oxygen consumption as function of temperature. The mean value of TA was（4160±767） K.（3） Soft tissue DW and oxygen consumption rate decreased by 56% and 81% respectively over the starvation experiment. Ash free dry flesh weight was proportional to the dry flesh weight, with coefficients of 81.4% and 53.0% respectively at the beginning and late stages of the experiment. [ ], [EG] and [EM] were estimated to be 25.9 J cm–3 d–1, 3160 J cm–3and 2030 J cm–3, respectively. These results have laid the foundation for the construction of the DEB model of scallop.