This study investigates length-mass relationships for 17 families of freshwater macroinvertebrates collected in the Choghakhor Wetland (Central Iran). Body length, head width, distance between eyes and mass (dry weight and wet weight) were used to estimate biomass with linear, log-linear and exponential models. The results show better performance of the log-linear model (ANOVA, p = 0.03), as compared to the other two (ANOVA, p > 0.05). A cross-validation test demonstrated that all three models performed reasonably well, in terms of both statistics and the accuracy of prediction. However, for more than 60% of the relationships the p value for the log-linear model was greater than for the other two, suggesting that the accuracy of this model is in general superior. Body length was generally demonstrated to be a good indicator to estimate biomass. However, for some taxa, the measurement of sclerotized structures (i.e., the distance between the eyes and the head width) were also found to be suitable biomass indicators. The latter is beneficial for the estimation of biomass with individuals that have been kept for a long time under laboratory conditions and/or those that show damaged parts of their bodies. The present study provides the first set of length-mass relationships for macroinvertebrates in the Middle-East region, and its findings are expected to contribute to the estimation of biomass in aquatic environments that are affected by semi-arid conditions and different degrees of anthropogenic stress.

这项研究调查了Choghakhor湿地（伊朗中部）中收集的17个淡水大型无脊椎动物家族的长度-质量关系。通过线性，对数线性和指数模型，使用体长，头宽，眼睛与质量（干重和湿重）之间的距离估算生物量。结果显示 ，与其他两个模型（ANOVA，p  > 0.05）相比，对数线性模型（ANOVA，p = 0.03）的性能更好。交叉验证测试表明，在统计和预测准确性方面，所有三个模型均表现良好。但是，对于超过60％的关系，p对数线性模型的值大于其他两个模型的值，这表明该模型的精度通常更高。一般证明，体长是估计生物量的良好指标。但是，对于某些分类单元，还发现对硬化结构的测量（即，眼睛之间的距离和头部的宽度）是合适的生物量指标。后者对于评估长期在实验室条件下饲养的个体和/或表现出身体受损部位的个体的生物量估算是有益的。本研究为中东地区大型无脊椎动物提供了第一组长度-质量关系，