Serial monogamy benefits both sexes in the biparental convict cichlid

Abstract

Monogamy can be either long-term or serial, with new pairs formed with each breeding bout. Costs and benefits are associated with each strategy. Because biparental convict cichlids (Amatitlania nigrofasciata) typically switch mates, exhibiting serial monogamy, we tested for the costs associated with forcing individuals to remain with the same mate. Convict cichlids were observed over two successive breeding bouts, either with the same or a new, equally experienced, mate. Parental behavior did not differ between breeding bouts, nor did brood size. Surprisingly, fish that remained with their original partner for a second bout took significantly longer to produce a brood compared to fish that paired with new partners. New partners were also more likely to successfully produce a second brood than re-mated partners. This is in contrast to the majority of bird studies that show many benefits to staying with the same partner for multiple broods. In convict cichlids, there seems to be no benefit associated with remaining with the same partner and switching mates reduces duration between broods for both males and females, potentially increasing overall reproductive success.

Keywords: Biparental; Brood success; Cichlids; Parental aggression; Parental care; Reproductive success; Retrieval; Sex differences.

Figure 1. Difference in brood size and days until spawning between first and second breeding bout.

(A) Mean ± SE difference between breeding bouts in brood size and (B) Mean ± SE difference between breeding bouts in days to spawning for male (blue) and female (red) convict cichlids that remained together or mated with new partners.

Figure 2. Direct and Indirect parental behaviors exhibited by convict cichlids with the same or new partners across two breeding bouts.

Mean +/− SEM (A) proportion of time spent in the nest (B) number of wriggler retrievals (C) proportion of time spent engaged in aggression with an intruder and (D) rate of aggression by male (blue) and female (red) parents with the same or new partners across two breeding bouts.