What are the consequences of being left-clawed in a predominantly right-clawed fiddler crab?

Abstract

Male fiddler crabs (genus Uca) have an enlarged major claw that is used during fights. In most species, 50% of males have a major claw on the left and 50% on the right. In Uca vocans vomeris, however, less than 1.4% of males are left-clawed. Fights between opponents with claws on the same or opposite side result in different physical alignment of claws, which affects fighting tactics. Left-clawed males mainly fight opposite-clawed opponents, so we predicted that they would be better fighters due to their relatively greater experience in fighting opposite-clawed opponents. We found, however, that (i) a left-clawed male retains a burrow for a significantly shorter period than a size-matched right-clawed male, (ii) when experimentally displaced from their burrow, there is no difference in the tactics used by left- and right-clawed males to obtain a new burrow; however, right-clawed males are significantly more likely to initiate fights with resident males, and (iii) right-clawed residents engage in significantly more fights than left-clawed residents. It appears that left-clawed males are actually less likely to fight, and when they do fight they are less likely to win, than right-clawed males. The low-level persistence of left-clawed males is therefore unlikely to involve a frequency-dependent advantage associated with fighting experience.

Lateralisation of aggressive displays in a tephritid fly

“…not significant (χ 2 test, α=0.05) boxing were performed preferentially with left body parts (wing and foreleg, respectively). Aggressive behaviour also appears to be left-biased in intraspecific aggressive behaviours performed by some other invertebrates, such as spiders (Ades and Ramires 2002, see also Heuts and Lambrechts 1999), while contrasting results have been reported for fiddler crabs (Backwell et al 2007). A noteworthy contrast to the leftbiased population level lateralisation of aggressive displays we found in medflies is the recent work of Rogers et al (2013b), showing that honeybees have strong lateral preference to use the right antenna in social interactions.…”

“…Good examples include cichlids (Arnott et al 2011), zebra fishes (Ariyomo and Watt 2013), Siamese fighting fishes (Cantalupo et al 1996;Takeuchi et al 2010) and other teleosts (Bisazza and De Santi 2003), lizards (Hews and Worthington 2001;Hews et al 2004), fallow deer (Jennings 2012(Jennings , 2014 and horses Rogers 2012, 2014). On the other hand, lateralisation of aggressive behaviour has been investigated in very few invertebrates (Frasnelli et al 2012), mainly spiders (Ades and Ramires 2002), fiddler crabs (Backwell et al 2007) and honeybees (Rogers et al 2013b).…”

First report of behavioural lateralisation in mosquitoes: right-biased kicking behaviour against males in females of the Asian tiger mosquito, Aedes albopictus

“…As regards to other arthropods, a left bias in intraspecific was reported for aggression in spiders (Ades and Ramires 2002), while contrasting results were obtained for fiddler crabs [Uca vocans (L.)] (Backwell et al 2007). Also, a number of vertebrate species direct more aggressive responses to conspecifics from their left side than from the right side (Vallortigara and Rogers 2005;Ariyomo and Watt 2013;Austin and Rogers 2014).…”

“…Recently, evidence has also documented the phenomenon in invertebrates, highlighting that lateralisation of the nervous system may be a feature of simpler brains as well (Frasnelli et al 2012). Behavioural asymmetries during aggression have been studied in many vertebrates such as cichlids (Arnott et al 2011), Siamese fighting fishes (Takeuchi et al 2010), zebra fishes (Ariyomo and Watt 2013), lizards (Hews et al 2004), deer (Jennings 2014) and horses (Austin and Rogers 2014); however, very little information is available for invertebrates (Ades and Ramires 2002;Backwell et al 2007;Rogers et al 2013b;Benelli et al 2015a).…”

A linear-encoding model explains the variability of the target morphology in regeneration

“…Interface 11: 20130918 used for aggressive and courtship displays, and the minor (cutter) used for prey capture and grooming [101,102]. Like many crustaceans, fiddler crabs can sever their own limbs (autotomy reflex), after which they can regenerate a new appendage [103].…”