Individual Laterality in Ghost Crabs (Ocypode saratan) Influences Burrowing Behavior

Reuven Yosef,Michal Daraby,Jakub Z Kosicki,Alexei Semionovikh

doi:10.3390/sym13081512

Abstract

Behavioral handedness is known to enhance an individual’s handling capabilities. However, the ecological advantages in brachyuran crustaceans remain unclear, despite the Ocypode species having been studied extensively. Thus, in this study, we analyzed the laterality of the endemic Red Sea ghost crab on one beach in Eilat, Israel. We successfully documented the laterality of the large cheliped in 125 crabs; in 60 (48.0%), the right cheliped was larger, and in 64 (51.2%), the left. We also observed temporal segregation between the right- and left-clawed crabs. The right-handed crabs start activity just after sunrise, while left-handed crabs appear ca. 40 min after it. Similarly, temporal segregations were also observed in the evening. The right-clawed crab activity peaked ca. 20 min before sunset, while the left-clawed crabs were active uniformly. Additionally, burrow entrances corresponded to the larger cheliped of the resident individual and is probably a self-defense-related behavior. We conclude that cheliped laterality in O. saratan populations should be considered as a bimodal trait, where left- and right-handedness is not under natural selection pressure.

Highlights

Laterality is one of the most visible behavioral–physiological features of organisms, observed in many systematic groups, i.e., both invertebrates and vertebrates
In five of the ca. 102 studied species of Thalasucca spp., the large claw was predominantly on the right [21], while another study showed that the large claw was likely to be either on the left or the right side in most species [22]
M. [23] found that 92% of O. ryderi in Somalia were right-handed

Summary

Introduction

Laterality is one of the most visible behavioral–physiological features of organisms, observed in many systematic groups, i.e., both invertebrates and vertebrates. The painted ghost crabs (Ocypode gaudichaudii) in Costa Rica were found to be predominantly left-handed [24]. There has been no direct research on this aspect, but it is suggested that one larger cheliped is linked to behaviors such as feeding, courtship, territorial defense, or burrow usurpation [25,26,27,28].

Results

Conclusion