Male Mate Choice in the Guppy (Poecilia reticulata): Do Males Prefer Larger Females as Mates?

Abstract

Although females are the choosier sex in most species, male mate choice is expected to occur under certain conditions. Theoretically, males should prefer larger females as mates in species where female fecundity increases with body size. However, any fecundity‐related benefits accruing to a male that has mated with a large female may be offset by an associated fitness cost of shared paternity if large females are more likely to be multiply mated than smaller females in nature. We tested the above hypothesis and assumption using the Trinidadian guppy (Poecilia reticulata) by behaviourally testing for male mate choice in the laboratory and by ascertaining (with the use of microsatellite DNA genotyping) patterns of male paternity in wild‐caught females. We observed significant positive relationships between female body length and fecundity (brood size) and between body length and level of multiple paternity in the broods of females collected in the Quaré River, Trinidad. In laboratory tests, a preference for the larger of two simultaneously‐presented virgin females was clearly expressed only when males were exposed to the full range of natural stimuli from the females, but not when they were limited to visual stimuli alone. However, as suggested by our multiple paternity data, males that choose to mate with large females may incur a larger potential cost of sperm competition and shared paternity compared with males that mate with smaller females on average. Our results thus suggest that male guppies originating from the Quaré River possess mating preferences for relatively large females, but that such preferences are expressed only when males can accurately assess the mating status of encountered females that differ in body size.

The metabolic, locomotor, and sex-dependent effects of elevated temperature on Trinidadian guppies: limited capacity for acclimation

“…Because female guppies are larger than their male counterparts, this result is in line with the above-mentioned findings and suggests that female guppies may be more susceptible to warming temperatures than are males. Moreover, this enhanced sensitivity of females may be problematic for the stability of guppy populations because female fecundity decreases with decreasing body size in guppies (Reznick and Endler, 1982;Herdman et al, 2004). The same may hold true for other ectothermic species that similarly exhibit female-biased sexual size dimorphism.…”

Heterospecific harassment of native endangered fishes by invasive guppies in Mexico

“…Since the species are in different families and cannot hybridize, male P. reticulata are unlikely to gain any benefit from courting/copulating with heterospecific females. They are known to be attracted to large females (Herdman et al 2004), and we suggest that the attention paid to S. bilineata females may be a non-adaptive consequence of heightened responsiveness to ripe (equal to deep bodied) female guppies, as S. bilineata females have deeper bodies than female guppies and may thus represent a supranormal stimulus to males (figure 2). This may explain why, even in the presence of an excess of guppy females, the males persistently attempt to inseminate S. bilineata females.…”

Do unattractive friends make you look better? Context-dependent male mating preferences in the guppy

“…Since pursuing and courting females may result in significant energetic costs [23,24], and males cannot simultaneously court two different females, it can be expected that male guppies exhibit some degree of choosiness. Indeed, males have been shown to prefer receptive [4], larger [25] and unfamiliar females [26] as mates.…”