Outcome of dyadic conflict in male green swordtail fish, Xiphophorus helleri: Effects of body size and prior dominance

Abstract

Abstract. The relative contribution of prior experience and of size asymmetries to the determination of dyadic dominance between unfamiliar individuals was examined using pairs of green swordtail fish, Xiphophorus helleri. Three experiments were conducted to assess the extent to which superiority in size could override potential handicaps resulting from prior experience. These results indicated that prior experience accounted for dyadic dominance when the size advantage of a previously subordinate over a previously dominant opponent was less than 25 mm 2 . However, as the lateral surface of the subordinate fish increased, neither previous experience nor size differences clearly accounted for the outcome of dyadic conflict. Even when the size advantage of subordinate opponents was in the 126-150 mm 2 range, size differences did not adequately explain the outcome. In conflicts between large previously subordinate and smaller dominant fish, there was evidence for an inverse linear relation between the effects of size and the likelihood of establishing dyadic dominance. In general, males with prior experience as subordinates had to be at least 40% larger than a previously dominant fish to win a significant proportion of conflicts. These results indicate that prior agonistic experience and body size effects can be additive when at the advantage of one opponent. These factors can also cancel each other out when in opposition, at least when size differences are not extreme. The results also confirm the main effect of both factors as well as their interaction in the determination of conflict outcomes for X. helleri.

Eavesdropping on visual cues in green swordtail (Xiphophorus helleri) fights: a case for networking

“…Ribowski & Franck 1993a), and has been studied quite extensively (e.g. Franck & Ribowski 1987Beaugrand et al 1991;Ribowski & Franck 1993b). In addition, swordtails form strict linear dominance hierarchies both in the laboratory and in the ® eld, a social environment that should be conducive to networking effects (Beaugrand et al 1984;Franck & Ribowski 1993;Franck et al 1998;Earley & Dugatkin 2002).…”

The role of recent experience and weight on hen's agonistic behaviour during dyadic conflict resolution

“…Knowledge of some animals' physical attributes or past dominance history enables the human observer to predict the direction of the dominance relation when those animals are put together (Beaugrand et al, 1991. Behavioural acts evident at the onset of an encounter can also help to predict, with a high success rate, which subject will dominate.…”

“…In the Martin et al (1997) study, weight asymmetries were opposed to recent experience asymmetries in the hope of seeing one cancelling or overcoming the other as Beaugrand et al (1991Beaugrand et al ( , 1996 had obtained in green swordtail fish. Martin et al (1997) did not find that weight significantly increased chances of victory, contradicting the conclusions drawn by Murchison (1935) and by Guhl and Allee (1944), who reported that heavier subjects were more likely to adopt aggressive behaviour and to hold a higher position in the social hierarchy.…”

Aggression and dominance in cichlids in resident-intruder tests: the role of environmental enrichment

“…individuals that are familiar with, and have invested in, a territory or environment] have a greater likelihood to dominate intruders or newcomers [i.e. individuals that are unfamiliar with a territory or environment upon meeting the resident] than vice versa (Braddock, 1949;Thinès & Heuts, 1968;Heuts, 1979;Beaugrand et al, 1991Beaugrand et al, , 1996Heuts & Nijman, 1998). It stems from a pay-off asymmetry between residents and intruders.…”