Mate choice and sexual selection in domino damselfish, Dascyllus albisella

Domino damselfish (Dascyllus albisella) are reported to exhibit the mutually exclusive patterns of (1) promiscuous mating and (2) female mate choice based on the acoustic characteristics of courting males. This study was conducted to resolve this conflict and to determine the correlates of male mating success. In particular, this study assessed a suite of male characteristics that may determine mate choice, especially focusing on the role of acoustic signaling. D. albisella provides a test case that helps explain female choice in benthic-brooding fishes where males provide all the parental care.;One prerequisite for mate choice is differential mating success, which is not expected if mating is promiscuous. A population of D. albisella was tagged and daily surveys conducted to determine mating success (number of clutches received per (ca. 6-day) breeding cycle). Variation in male mating success (0.00--1.34 clutches-per-cycle) showed a significant (X2 test, p < 0.001) departure from expected success for promiscuous mating.;Behavioral observations of feeding and territoriality suggest that the cost of nest defense is higher than previously assumed for benthic-brooding damselfishes in terms of reduced feeding and more interspecific aggression. However, females were occasionally found to help males defend eggs when the number of intruders exceeded the ability of the mate to defend the eggs. These unexpected results may alter the sexual selection pressure operating in this (and similar) species by changing the relative costs of reproduction for males and females.;Potential mate choice cues (male phenotypic, territorial, behavioral, and acoustic traits) were measured throughout the study. Most traits (age, size, territorial quality, behavior, and acoustic call structure) were unrelated to male success. Only one component of male quality, calling rate, was significantly (p < 0.05) correlated with mating success (Spearman-Rank correlation r 2 = 0.40).;This is one of the first field studies of fish to assess the correlates of male mating success that includes acoustics in a broad survey of male traits. Other studies have examined the role of courtship rate, or acoustic structure, but not both together. This study demonstrated that D. albisella mating is a non-random process that includes female mate choice based on the acoustic-signaling rate (but not acoustic call structure) of males.