Age and growth of recently settled splitnose and redbanded rockfishes in the northern California Current

Abstract

Growth is key to the survival of fishes during their early life and ultimately affects annual recruitment to adult populations. To evaluate early life history traits of two commercially harvested fishes, splitnose (Sebastes diploproa) and redbanded (S. babcocki) rockfishes, we examined the otolith microstructure of juveniles of both species that settled simultaneously in an unusually large settlement pulse. Although overall growth during the dispersal phase was similar for both species, splitnose rockfish were ~2 wks younger and smaller in length at time of sampling, encompassed a narrower age range, and had higher prevalence and earlier occurrence of accessory primordia in their otoliths. Despite almost identical morphological traits of juveniles, our results suggest different pelagic strategies. The otoliths of splitnose rockfish grew faster during a 30-d period, reflecting either faster somatic growth during this period or a different rate of otolith deposition.