Simultaneous courtship and parenting in males and sex role reversal in females of the haremic bluebanded goby, Lythrypnus dalli

Abstract

While males typically compete for females, species with female biased sex ratios and/or large male investment in offspring care often exhibit reversed sex roles. Here we investigated, in a haremic fish species, the bluebanded goby,Lythrypnus dalli, the impact of male and female courtship behaviour on male reproductive success, measured as the total number of eggs in the nest and total number of developed eggs. Reproductive success was not associated with rates of male behaviour, such as parenting, approaching and courtship, but was associated with rates of female courtship. Consistent with predictions for a role-reversed reproductive strategy, only males demonstrated nest care and females exhibited high rates of courtship and intrasexual competition, such that alpha females interrupted courtship solicitations by beta females. Overall, these data are consistent with sex role reversal inL. dalliand show that the expression of male courtship behaviour does not interfere with paternal care.

Contextual modulation of social and endocrine correlates of fitness: insights from the life history of a sex changing fish

“…Although the underlying mechanisms are far from simple, we will present some brief examples of direct and indirect fitness effects of two classes of hormones: glucocorticoids and androgens. Reproductive behavior can be energetically costly in terms of courtship displays (Fusani et al, 2014 ), spawning/mating (Watson et al, 1998 ), and parenting (Pradhan et al, 2014c , in press ). For example, nesting male peacock blennies judge whether they can accept another clutch of eggs based on their energetic state (Olsson et al, 2009 ).…”

“…More than one female (and usually all females) lays eggs in the nest of the male, resulting in male reproductive success that is multiple times higher than any individual female in the group (Behrents, 1983 ). Female L. dalli routinely lay eggs and males readily parent in the laboratory (Pradhan et al, in press ). Using sequential digital images of eggs in the nest, we can quantify the number of eggs laid, the number of clutches laid, average clutch size, inter-clutch interval, hatching success, and the number of eggs that hatch (Figure 4 ).…”

“…In stable social groups, the quantity of eggs fertilized by the male is associated with the pattern of agonistic interaction in the group, especially among females (Solomon-Lane et al, 2014 ). More dominant females interrupt courtship solicitation displays by subordinate females and assume solicitation displays themselves (Pradhan et al, in press ). Even though dominant and subordinate females display courtship at similar rates, number of eggs and number of eggs that advance to the “eyed” stage are positively associated with rates of dominant female courtship (Pradhan et al, in press ).…”

“…More dominant females interrupt courtship solicitation displays by subordinate females and assume solicitation displays themselves (Pradhan et al, in press ). Even though dominant and subordinate females display courtship at similar rates, number of eggs and number of eggs that advance to the “eyed” stage are positively associated with rates of dominant female courtship (Pradhan et al, in press ). Therefore, agonistic interactions and social status could be used as one type of behavioral proxy.…”

“…Therefore, agonistic interactions and social status could be used as one type of behavioral proxy. Once eggs are fertilized, males provide sole parental care, and they vary in their hatching success (Solomon-Lane et al, unpublished data), a quantitative measure of parenting efficacy, and in their rates of parenting (Pradhan et al, in press ). In stable social groups, male reproductive success is negatively associated with the frequency of agonistic behavior, approaches and displacements, in the social group (Figure 4C ) (Solomon-Lane et al, 2014 ).…”