Asymmetric Contests for Breeding Sites Between Monogamous Pairs of Convict Cichlids (Archocentrus Nigrofasciatum, Cichlidae): Pair Experience Pays

Abstract

Research on fighting has emphasized contests between individuals, typically males, but pairs also compete. Monogamous pairs of convict cichlids (Archocentrus nigrofasciatum) compete with other pairs for breeding sites in nature. We simulated such contests with competing pairs who differed in one or two of three possible asymmetries: body size, residency, and pair experience. In single-asymmetry experiments, larger pairs defeated smaller pairs, resident pairs defeated intruder pairs, and experienced pairs (those that had been together for 96 hours) defeated novice pairs (those that had been together for 48 hours). Thus, each of the three asymmetries was important in determining the outcome of contests. In further experiments, pairs had two contrasting asymmetries simultaneously. Larger pairs always defeated smaller pairs (15-25% difference in male standard length) even though the larger pair was inferior in one of the other asymmetries. When the two pairs were similar in size (standard length of males differed less than 6%), experienced intruder pairs defeated novice resident pairs nearly half the time. This is the first study to investigate the effects of pair experience on fighting ability. Although we predicted that experience might benefit pairs through improved coordination of their behaviour, behavioral measures such as time spent at the spawning site and pair digging behaviour showed no significant differences among groups. We posit that more experienced pairs fought harder for the breeding site because they were closer to spawning and the expected payoff for winning the breeding site was therefore higher. Finally, when both pairs were of similar size but differed in residence status and experience, there was more escalated fighting than in contests between size-disparate pairs; two possible interpretations of this result are discussed.

Aggressive interactions between the invasive Rio Grande cichlid (Herichthys cyanoguttatus) and native bluegill (Lepomis macrochirus), with notes on redspotted sunfish (Lepomis miniatus)

“…This indicates the perceived value of the territory for resident L. macrochirus, which were willing to risk injury by engaging in costly behavior. The interspecies communication of sequential assessment only seemed to break down at the occasional attempt by H. cyanoguttatus to 'mouth wrestle', which is a common aggressive behavior in cichlids (Draud and Lynch 2002). The native L. macrochirus did not engage in this behavior and turned away from such challenges.…”

Lateralization of lateral displays in convict cichlids

“…Both sexes are highly aggressive and territorial (e.g. [28]), engaging in numerous contests that include intersexual encounters [7], and likely benefit equally from performing lateral display in a coordinated and predictable way [4]. Thus, while they may differ in the frequency with which particular displays (lateral or frontal) are used [17] they may not differ in lateralization of lateral display.…”

Pair-bond formation and breeding-site limitation in the convict cichlid, Archocentrus nigrofasciatus

“…Videotapes were then assessed for pair formation and aggression between paired individuals for 15 min. Fish were considered paired if they were found together in the breeding site, chased other fish in the aquaria as a pair, or spent time within one body length of each other without any aggressive behaviors between each other (Draud and Lynch 2002). Aggressive behaviors quantified were chases and bites performed at another individual.…”

“…In addition, individuals that mate more than once during the breeding season often reuse their initial territories in subsequent breeding bouts (Wisenden 1995). In laboratory studies, pairs that have had prior residence of a breeding site win contests over nonresident pairs unless both members of the intruding pair are substantially larger than their resident counterparts (Itzkowitz et al 1998), and experienced pairs (i.e., those that have been together longer) win a breeding site over less-experienced pairs (Draud and Lynch 2002).…”