Laterality of aggressive responses in Anolis

Abstract

This experiment examined whether or not aggression in the lizard Anolis (suborder Lacertilia, family Iguanidae) is lateralized. Five pair of adult Anolis were subjected to several 20 min behavioral trials, during which one animal was placed in the cage of the other. Behaviors were captured on video and coded according t o eye preference, motor activity, posture, and color. Analysis of the data found that the most aggressive behaviors, including biting, threatened biting, and aggressive movements, were done under the guidance of the left eye. Both left and right eyes were used with equal frequency during non-aggressive movements. Most of these aggressive episodes were done while the animals were "lightly" colored, Because of a n almost complete crossingover of the optic tract in Anolis, along with the absence of a corpus callosum, it is likely that most,if not all, of the information in the left eye was processed by the right hemisphere. These results suggest that the lizard Anolis, like humans, rats, and chicks, may mediate aggressive responses predominantly through right-hemispheric brain mechanisms, o 1996 Wiley-Liss, Inc.

The costs of hemispheric specialization in a fish

“…Toads, for example, are more likely to strike at a prey moving in their right lateral field of vision while agonistic responses are delivered preferentially to a conspecific seen on their left side (Vallortigara et al 1998). Similar differences have been found in birds and reptiles (Deckel 1995;Dharmaretnam & Rogers 2005). Even in species with frontally placed eyes, such as humans, hemispheric dominance can sometimes hinder performance when strict cooperation between the two halves of the brain is required.…”

“…For example, toads, chicks and dunnarts differ in their promptness to react to a predator depending on the visual hemifield in which it appears (Lippolis et al 2002(Lippolis et al , 2005Dharmaretnam & Rogers 2005), and mosquitofish make closer cooperative predator inspection when predator and shoalmates are seen with the correspondingly preferred eye (De Santi et al 2001). Gelada baboons and Anolis lizards are more likely to attack a conspecific on one side than the other (Deckel 1995;Casperd & Dunbar 1996), and side biases are shown by toads, chicks and pigeons in food detection (Vallortigara et al 1998;Diekamp et al 2005). Investigating whether individuals with greater left -right differences pay larger costs even in these cases will help us to assess the generality of our findings and expand our understanding of the selective mechanisms maintaining individual differences in lateralization.…”

Dominance and stress signalling of carotenoid pigmentation in Arctic charr (Salvelinus alpinus): Lateralization effects?

“…For instance, several species direct more aggressive responses towards visual input from their left side including primates [46,47], lizards [48], and teleost fish [49]. However, in some teleost fish the aggression is lateralized into the right visual field [25,26].…”

Population variation in lateralized eye use in the poeciliid Brachyraphis episcopi

“…Preferential eye use is ubiquitous among birds, reptiles, amphibians and fish (Deckel 1995;McKenzie et al 1998;Sovrano et al 1999;Dadda et al 2003;see Andrew 2002 for a review). Current theories suggest that lateralization initially arose in response to the development of laterally placed eyes with little binocular overlap in the visual field and complete decussation at the optic chiasma.…”