Department of Organismal Biology, Ecology & Zoo Science, West Liberty University, West Liberty, WV, United States of America.
PLoS One. 2022 Oct 14;17(10):e0273540. doi: 10.1371/journal.pone.0273540. eCollection 2022.
Opposed to most crayfish species that inhabit permanent bodies of water, a unique burrowing lifestyle has evolved several times throughout the crayfish phylogeny. Burrowing crayfish are considered to be semi-terrestrial, as they burrow to the groundwater-creating complex burrows that occasionally reach 3 m in depth. Because burrowing crayfishes spend most of their lives within their burrow, we lack a basic understanding of the behavior and natural history of these species. However, recent work suggests that burrowing crayfishes may exhibit a higher level of surface activity than previously thought. In the current study, we conducted a behavioral study of the Little Brown Mudbug, Lacunicambarus thomai using video surveillance to determine their degree of surface activity and behavioral patterns. Throughout 664 hrs of footage, we observed a surprisingly high amount of activity at the surface of their burrows-both during the day and night. The percentage of time that individual crayfish was observed at the surface ranged from 21% to 69% per individual, with an average of 42.48% of the time spent at the surface across all crayfish. Additionally, we created an ethogram based on six observed behaviors and found that each behavior had a strong circadian effect. For example, we only observed a single observation of foraging on vegetation during the day, whereas 270 observations of this behavior were documented at night. Overall, our results suggest that burrowing crayfishes may exhibit higher levels of surface activity than previously thought. To increase our understanding of burrowing crayfish behaviors ecology, we encourage the continued use of video-recorded observations in the field and the laboratory.
与栖息在永久性水体中的大多数淡水小龙虾物种相反，掘穴生活方式在小龙虾的进化历程中已经多次独立进化。掘穴小龙虾被认为是半陆生的，因为它们会挖掘到地下水层，形成复杂的洞穴，这些洞穴偶尔会深达 3 米。由于掘穴小龙虾大部分时间都在洞穴中度过，我们对这些物种的行为和自然历史缺乏基本的了解。然而，最近的研究表明，掘穴小龙虾的表面活动可能比之前认为的要高。在当前的研究中，我们使用视频监控对小褐泥虾（Lacunicambarus thomai）进行了行为研究，以确定它们的表面活动程度和行为模式。在 664 小时的录像中，我们观察到它们在洞穴表面的活动量非常高——无论是白天还是晚上。个体小龙虾在洞穴表面的活动时间百分比范围为每个个体的 21%到 69%，所有小龙虾的平均表面活动时间为 42.48%。此外，我们根据六种观察到的行为创建了一个行为谱，并发现每种行为都有强烈的昼夜节律效应。例如，我们只在白天观察到一次在植被上觅食的行为，而在夜间记录到了 270 次这种行为。总的来说，我们的研究结果表明，掘穴小龙虾的表面活动水平可能比之前认为的要高。为了增加我们对掘穴小龙虾行为生态学的理解，我们鼓励在野外和实验室继续使用视频记录观察。
