Multi-Species Comparison of Paternity in Sebastes Rockfishes from the Northeast Pacific Ocean

Rockfishes of the speciose genus Sebastes provide a rich study system for comparative analyses of paternity. Sebastes species exploit a variety of niches, from shallow nearshore reefs to deep continental slope habitats.  There are 72+ described species in the northeast Pacific Ocean, and 102+ species worldwide (Love et al. 2002).  Sebastes species are all viviparous, with internal fertilization and gestation, making the determination of maternity of larvae relatively straightforward, when sampling gravid females.  Multiple paternity, a reproductive strategy theorized to increase effective population size, has been documented in several species of rockfishes, but its occurrence and prevalence are unknown for most species.  Here, we assess paternity in six Sebastes species—S. auriculatus, S. entomelas, S. flavidus, S. goodei, S. hopkinsi, and S. ovalis—using 6-9 microsatellite DNA markers per species to estimate the number of sires contributing to each brood of larvae.  Genotyping over 6,000 individual larvae, we find evidence for multiple paternity in nearly all species surveyed, with striking interspecific contrasts in the apparent rate of polygamy.  These findings help to elucidate the reproductive biology of this group and have implications for maintenance of genetic diversity and effective population size, potentially informing management and conservation decisions.