The roles of male size and female eavesdropping in divorce in the monogamous convict cichlid (Archocentrus nigrofasciatus, Cichlidae)

Abstract

In this experiment we examined the roles of male size and female eavesdropping in divorce using the serially monogamous convict cichlid (Archocentrus nigrofasciatus) by testing predictions based upon the better option hypothesis of divorce. We tested the role of male size by exposing females to males that were 20-25% larger than their current mate or males that were similar size to their current mate. Female convict cichlids prefer larger males, therefore we predicted that the frequency of divorce would be higher when the alternate mate was larger than the current mate. We also examined the role of eavesdropping as a mechanism of female assessment of relative male quality. Females were either permitted to eavesdrop (males physically interacted) or females were unable to eavesdrop (males prevented from interacting). We predicted that female eavesdropping would result in greater frequency of divorce. We found that females chose divorce most often (50% ending in divorce) in the treatment where the alternate male was larger than the current mate and eavesdropping was permitted, whereas females never chose divorce in the treatment where the alternate male was similar in size to the current mate and the female was not permitted to eavesdrop. Although it had a mild effect, male size difference alone did not significantly increase divorce. When size difference was coupled with eavesdropping, however, females did significantly increase their divorce rates.

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

“…Allowing females visual access to their current mate in competition with an alternate male who is larger leads to high levels of mate switching although independently, neither male size differences nor observing competition between size-matched individuals led to pair-bond instability (van Breukelen and Draud 2005). Our results support previous research, as although females had visual access to any male-male competition occurring in our experiments, all males were sized matched.…”

“…In addition, pair stability can breakdown if offspring are removed, and pairs re-form when offspring are returned (Lamprecht and Rebhan 1997). In the prespawning stage of the reproductive cycle, however, pair stability breaks down when females choose a new mate (van Breukelen and Draud 2005). The treatments differed in the number of available breeding sites given to groups of fish and were zero, one, or two.…”

Mate choice in female convict cichlids (Amatitlania nigrofasciata) and the relationship between male size and dominance

“…Logically, when females do not choose dominant males, their preferences should be for traits unrelated to male dominance (e.g., Peterson et al 1999;Stapley 2008; also see Forsgren 1997). In convict cichlids, van Breukelen and Draud (2005) observed that females are more likely to ''divorce'' (i.e., switch mates after establishing a pair bond) after seeing their mate physically interact with a larger male. However, male size in the absence of this brief interaction did not influence divorce rate, suggesting that size as a cue alone is not enough for a female to judge competitive ability.…”

Does being paired give male and female convict cichlids (Amatitlania nigrofasciata) an advantage when competing against same-sex individuals?

“…Another possible reason for this unexpected result is that restraining the female caused the paired male to see the female as being no longer available for pair formation while the single male saw her as a potential mate. Previous studies have shown that females are continuously assessing their mate until spawning (Santangelo and Itzkowitz 2004;van Breukelen and Draud 2005) making the dissolution of the bond possible whenever a new male appears (Triefenbach and Itzkowitz 1998).…”