Small-bodied aquatic animals present a challenge to researchers seeking to uniquely mark individuals for scientific study. Microtransponder tags, such as p-Chips, represent the smallest electronic animal tags available to meet this need. The use of p-Chips to tag freshwater crayfishes, however, has not been explored. The goal of this study, therefore, was to determine the effects of p-Chip tagging on growth and survival of crayfishes in a controlled laboratory environment. We also investigated potential influences from variables such as sex, reproductive form, number of molt events, and crayfish size on mortality. We internally tagged individuals of the woodland crayfish Faxonius hylas (Faxon, 1890) (12.2–26.6 mm carapace length; CL) with either one p-Chip (single-tag) or one p-Chip and one visual implant elastomer tag (double-tagged) and observed the effects over a period of 90 days. Survival probability over time was not statistically different (P > 0.05) among tagging groups, sex, and reproductive form. Survival rates were similar across all tagging groups, with 75% in the control group, 77% in the double-tagged group, and 78% in the single-tag group. A strong correlation, however, was observed between survival and the number of molt events. Additionally, there was a negative correlation between survival and crayfish size (CL), indicating a higher risk of mortality for larger individuals. There were no statistically significant differences in growth in CL (P = 0.30) or mass (P = 0.19) among the tagging groups. We conclude that p-Chips are a viable tagging option for the study of crayfishes given their size, readability, and retention through molting cycles. We recommend that future studies repeat this experiment using smaller individuals to determine the minimum crayfish size compatible with p-Chip tagging. It is also important to test p-Chips with other crayfish species and compare the growth and mortality of crayfish tagged with p-Chips in natural habitats.

中文翻译：

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越小越好吗？首次评估内部带有 p-Chips 标记的小龙虾的生长和死亡率

小型水生动物对寻求对个体进行独特标记以进行科学研究的研究人员提出了挑战。微应答器标签（例如 p-Chips）代表了可满足这一需求的最小电子动物标签。然而，尚未探索使用 p 芯片来标记淡水小龙虾。因此，本研究的目的是确定 p-Chip 标记对受控实验室环境中小龙虾生长和存活的影响。我们还研究了性别、繁殖形式、蜕皮事件数量和小龙虾大小等变量对死亡率的潜在影响。我们使用一个 p-Chip（单标签）或一个 p-Chip 和一个视觉植入弹性体标签（双标记）并观察 90 天的效果。随着时间的推移，标记组、性别和生殖形式之间的生存概率没有统计学差异（P>0.05）。所有标签组的存活率相似，对照组为 75%，双标签组为 77%，单标签组为 78%。然而，在存活率和蜕皮事件的数量之间观察到很强的相关性。此外，存活率和小龙虾尺寸（CL）之间存在负相关，这表明体型较大的个体死亡风险较高。标记组之间 CL (P = 0.30) 或质量 (P = 0.19) 的生长没有统计学上的显着差异。我们得出的结论是，考虑到小龙虾的大小、可读性和蜕皮周期的保留，p-Chips 是研究小龙虾的可行标记选择。我们建议未来的研究使用较小的个体重复此实验，以确定与 p-Chip 标签兼容的最小小龙虾尺寸。将 p-Chips 与其他小龙虾品种进行测试并比较自然栖息地中带有 p-Chips 标记的小龙虾的生长和死亡率也很重要。