Heterochely and handedness in the orange mud crab Scylla olivacea : implication for future culture practice optimisation

PeerJ

article

Rusydi Rozaimi¹  Alexander Chong Shu-Chien²  Youji Wang⁴  Sutikno Sutikno⁵  Mhd Ikhwanuddin¹  Xi Shi⁷  Ghazali Azmie¹  Hanafiah Fazhan¹  Khor Waiho¹ 

[1] Higher Institution Centre of Excellence ,(HICoE), Institute of Tropical Aquaculture and Fisheries, Universiti Malaysia Terengganu;Centre for Chemical Biology, Universiti Sains Malaysia;School of Biological Sciences, Universiti Sains Malaysia;International Research Center for Marine Biosciences, Ministry of Science and Technology, Shanghai Ocean University;Research Center for Applied Zoology, National Research and Innovation Agency;STU-UMT Joint Shellfish Research Laboratory, Shantou University;Engineering Technology Research Center of Henan Province for Aquatic Animal Cultivation, College of Fisheries, Henan Normal University

关键词: Heterochely;    Handedness;    Portunid;    Orange mud crab;    Scylla olivacea;   

DOI  :  10.7717/peerj.15143

学科分类：社会科学、人文和艺术（综合）

来源: Inra

【 摘 要 】

Asymmetric body traits in bilateral organisms are common and serve a range of different functions. In crustaceans, specifically among brachyuran crabs, heterochely and handedness in some species are known to aid in behavioural responses such as food acquisition, and sexual and territorial displays. However, the heterochely of the intertidal mud crab genus Scylla is still poorly understood. This study investigated the cheliped morphometric characteristics of orange mud crab Scylla olivacea and the relation of heterochely and handedness to sex. Scylla olivacea is heterochelous, with predominant right-handed (70.2%). Three morphometric variables, i.e., propodus length (PL), propodus depth (PD), and propodus width (PW) were significantly larger in the right cheliped and the estimated handedness based on these three variables were consistent with the presence of molariform teeth. The effect of sex had no influence on the occurrence of heterochely or handedness. The frequency of left-handedness increased with size, especially in males. We postulate that handedness reversal, a phenomenon seen in other crab species when the dominant hand is lost, also occurs in S. olivacea, thereby resulting in a change in left-handedness frequency. The use of chelipeds by males in mate and territorial defenses might provide an explanation for the higher risk of losing a dominant cheliped and thus, higher left-handedness frequency compared to females. Future behavioural research could shed light on the selective forces that affect the handedness distribution in mud crabs. Knowledge on heterochely and handedness of mud crabs could be useful for future development of less aggressive crab populations by claw reversal and the optimisation of limb autotomy techniques.

【 授权许可】

CC BY