Behaviour of Two Species of Grapsid Crab During Intraspecific Encounters

Agonistic and mating behavior in relation to chela features in Hemigrapsus takanoi and H. sinensis (Brachyura, Varunidae)

“…In H. sinensis, whose sexual dimorphism in chela is not so prominent, both males and females used chela frequently in agonistic interactions and chelae use in mating behavior is infrequent. Warner (1970) suggested the relation between sexual dimorphism in chela and social behaviors for two grapsoid crabs Aratus pisoni and Goniopsis cruentata: in A. pisoni with prominent sexual dimorphism only males used chela in ritualized agonistic behavior, whereas in G. cruentata with less prominent sexual dimorphism both sexes used chela.…”

Incidence of Limb Loss and Bald Chelipeds in the Japanese Mitten Crab Eriocheir japonica (de Haan) in its Marine Phase

“…Differences in the utilization of each limb in encounters are also an important factor (Smith & Hines 1991) . Among grapsids, touches using the walking legs occur during intraspecific encounters (Warner 1970;Abele et al 1986). On the other hand, chelipeds are raised and extended during defensive or threatening behaviour against predators or competitors (Warner 1970;Jachowski 1974;Abele et al 1986) .…”

“…Among grapsids, touches using the walking legs occur during intraspecific encounters (Warner 1970;Abele et al 1986). On the other hand, chelipeds are raised and extended during defensive or threatening behaviour against predators or competitors (Warner 1970;Jachowski 1974;Abele et al 1986) . Therefore, the lack of site specificity found in grapsids including E, japonica suggests that the risk to limbs in encounters is balanced.…”

Biological associations of color variation in the Indo-Pacific swimming crab Charybdis hellerii

“…This could explain the high values of red color and the low values of blue color for all parts shown in the present study. Crustaceans show several agonistic behaviors related to the social organization, and sometimes have triggers to display these behaviors (Kuris et al 1987, Warner 1970, Innocenti et al 2003. This color variation, with differences mostly between adult males, adult females and the juveniles, The color variation may also be related to the individual size, as described for varunid crabs (Casariego et al 2011).…”