Sex‐Related Foraging Behavior in Sequentially Hermaphroditic Hogfishes (Bodianus Spp.)
1983
Hoffman, Steven G.
I develop Schoener's proposal that the amount of activity time allocated to foraging can be sex related; males more often than females should minimize foraging time, and females should often be foraging—time maximizers. Sexual differences in foraging—time allocation may be small when male mating success is limited by available energy for maximizing sperm production. The foraging—time patterns of the sexes were examined in three sequentially hermaphroditic (protogynous) hogfishes in the genus Bodianus (Family Labridae). The daily social and mating activities of males in each of these marine reef fishes are distinctly different: single males defend permanent, all—purpose territories that contain a harem of females (B. rufus; San Blas Islands, Panama), males defend temporary reproductive territories (B. diplotaenia; Gulf of California, Mexico), or males are not territorial and spawn together in groups (B. eclancheri; Galapagos Archipelago, Ecuador). Female hogfishes in all three species mate daily and spend relatively little time on social and mating activities. Fertilization is external, and parental care of young is absent in these species. Time budget analyses indicated that B. rufus males allocated a much smaller proportion of their time (39.7%) to foraging than did conspecific females (76.8%). Protogyny in B. rufus provided a unique opportunity to test the effect of sex on an individual's time budget experimentally. Sex change by the dominant female was initiated in the field by removing the dominant, territorial male from his harem group. All (N = 9) individuals tested decreased the amount of time spent foraging and increased time allocated to social and mating activities, after they became reproductively functioning males. Sequential removals within harems indicated that the reduction in time spent foraging decreased with the number of female mates remaining in the group. Bodianus diplotaenia males also spent less time foraging (45.9%) than did conspecific females (76.5%). Bodianus eclancheri males spent most (70.2%) of their time foraging, as did conspecific females (77.3%). It appears that males minimize foraging time when their reproductive success depends more upon time spent in social and mating activities than upon net energy gains, as in B. rufus and B. diplotaenia. The reproductive success of female hogfishes, and males that compete for mates by maximizing sperm production (B. eclancheri), appears to be limited primarily by energy available for gamete production and growth; these individuals spend relatively little time engaged in social and mating activities and spend most of their time foraging.
Mostrar más [+] Menos [-]Palabras clave de AGROVOC
Información bibliográfica
Este registro bibliográfico ha sido proporcionado por National Agricultural Library