Inter-population ovarian fluid variation differentially modulates sperm motility in Atlantic cod Gadus morhua.
This study tested the hypothesis that the effects of Atlantic cod Gadus morhua ovarian fluid on sperm motility variables are population specific. Sperm from a northern G. morhua population were activated in the presence of ovarian fluid from either northern or southern G. morhua at different concentrations. Ovarian fluid acted as a filter, in some cases reducing sperm swimming performance compared with seawater. Fluid from females foreign in population (southern) to the males (northern) had a greater inhibiting effect than those from the native population. Follow-up analysis indicated that the ovarian fluids had lower Ca(2+) concentration in northern than southern G. morhua, which could be the causative mechanism. If widespread, such cryptic female choice could reduce the incidence of intraspecific hybridization among diverged populations and contribute to reproductive isolation.
Fish Evolutionary Ecology Research Group, Departments of Biology and Ocean Sciences, Memorial University of Newfoundland, St John's, NL, A1C 5S7, Canada.
J
J
Beirão
Fish Evolutionary Ecology Research Group, Departments of Biology and Ocean Sciences, Memorial University of Newfoundland, St John's, NL, A1C 5S7, Canada.
C F
CF
Purchase
Fish Evolutionary Ecology Research Group, Departments of Biology and Ocean Sciences, Memorial University of Newfoundland, St John's, NL, A1C 5S7, Canada.
B F
BF
Wringe
Fish Evolutionary Ecology Research Group, Departments of Biology and Ocean Sciences, Memorial University of Newfoundland, St John's, NL, A1C 5S7, Canada.
I A
IA
Fleming
D000818:Animals; D001826:Body Fluids / Q000737:chemistry*; D005260:Female; D048389:Gadus morhua / Q000502:physiology*; D008297:Male; D010053:Ovary / Q000502:physiology*; D060047:Reproductive Isolation; D013081:Sperm Motility
Ca2+ concentration; cryptic female choice; local adaptation; reproductive isolation