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 诸多监测研究借助标记技术获取个体扩散相关数据。标记操作可能会对陆生等足类动物（terrestrial isopods）的生命活动产生影响，取食行为即为这类影响的典型表现。本研究旨在评估不同材料用于潮虫（woodlice）体外标记的有效性，以及此类标记对受试动物取食表现的影响。研究选用氰基丙烯酸酯胶（cyanoacrylate glue）+闪光粉（glitter）与指甲油（nail polish）作为两种独立标记材料，对3个物种——光滑球潮虫（Balloniscus glaber）、绘斑底潮虫（Benthana picta）以及普通卷甲虫（Armadillidium vulgare）——开展体外标记。采用卡普兰-迈耶曲线（Kaplan-Meier curves）与对数秩检验（Log-Rank analysis）比较不同标记材料的标记效能。取食性能试验以柱荚黄檀（Machaerium stipitatum）叶碟为食源，通过方差分析（ANOVA，α<0.05）比较各组受试个体的取食速率。结果显示，除观察时长超过15天时的绘斑底潮虫标记组与未标记组间存在显著差异（对数秩检验=8.446，p=0.015）外，各标记材料的标记持久性无统计学差异。研究认为指甲油更适用于取食实验。仅绘斑底潮虫的各标记处理组之间，取食速率存在统计学差异（方差分析，F=7.5440，p=0.0002）。上述结果表明，体外标记不会对受试动物的取食习性产生负面影响，该技术可用于野外条件下陆生等足类动物的扩散监测，有效监测时长约为15天。