External marking of terrestrial isopods (Isopoda, Oniscidea): efficiency of materials and influence on feeding behavior

Abstract Many monitoring studies use marking techniques to obtain dispersal data on individuals. Marking procedures may influence the vital activities of the terrestrial isopods, such as feeding behavior. The objective of this study was to identify the efficiency of different materials for external marking of woodlice and the influence on their feeding performance. Cyanoacrylate glue + glitter and nail polish were used as separate marking materials on three species: Balloniscus glaber, Benthana picta and Armadillidium vulgare. The material efficiency was compared using Kaplan-Meier curves and Log-Rank analysis. Individuals were fed with leaf discs of Machaerium stipitatum for feeding performance trials, and consumption rates were compared using ANOVA (α<0.05). There was no difference in durability between the materials used for external markings, except between marked and unmarked Benthana specimens when the observation period exceeded 15 days (Log-Rank=8.446, p=0.015). Nail polish was considered more suitable for feeding experiments. Statistical differences in consumption rates were observed only between the marked individual treatments of Benthana (ANOVA, F=7.5440, p=0.0002). These results indicate that external marking does not affect the feeding habits of the animals and suggest that this technique can be used to monitor dispersal of terrestrial isopods in field conditions for approximately 15 days.

摘要 诸多监测研究常借助标记技术获取个体扩散数据。标记操作可能会对陆生等足目动物（terrestrial isopods）的生命活动，如取食行为，产生影响。本研究旨在评估不同材料用于潮虫（woodlice）体外标记的效果，及其对潮虫取食表现的影响。本研究选取氰基丙烯酸酯胶（cyanoacrylate glue）+闪粉与指甲油作为独立标记材料，应用于3个物种：光滑球潮虫（Balloniscus glaber）、彩绘弯趾潮虫（Benthana picta）以及普通卷甲虫（Armadillidium vulgare）。采用Kaplan-Meier生存曲线与Log-Rank检验比较不同标记材料的持久性。以Machaerium stipitatum的叶碟为食物开展取食性能试验，通过单因素方差分析（Analysis of Variance，ANOVA，α<0.05）比较取食速率。结果显示，除观察时长超过15天的彩绘弯趾潮虫标记组与未标记组间存在显著差异外（Log-Rank=8.446，p=0.015），其余各组标记材料的持久性无统计学差异。指甲油被认为更适用于取食实验。仅在彩绘弯趾潮虫的标记个体处理组间观察到取食速率的统计学差异（ANOVA, F=7.5440, p=0.0002）。本研究结果表明，体外标记技术并不会对受试动物的取食习性产生影响，提示该技术可用于野外条件下陆生等足目动物的扩散监测，有效监测时长约为15天。