UC San Diego

Survival through the larval phase greatly affects the population dynamics of most fishes, and both diet and maternal investment have long been hypothesized as important contributors to interannual recruitment variability. This study examines the feeding ecology of larval Sebastes spp. rockfishes with respect to ontogeny, selectivity, and the respective influences of diet and maternal investment on size and growth. Prey selection was calculated from larval gut contents, maternal investment was estimated using otolith core radii, and recent growth was derived from outer increment widths. Bayesian multilevel models were used to describe independent and interactive effects of diet and core on length and growth. Larval rockfishes were observed to primarily select for Calanoid nauplii and copepodites, modulating feeding with ontogeny and in response to prey availability. Models that accounted for maternal investment and prey specificity more effectively predicted length and growth than models that only accounted for total gut content biomass. Calanoid copepodite gut content carbon biomass was generally more correlated with length and growth than gut content carbon biomass of other taxa, but older and younger larvae experienced different growth rates in association with different prey. Positive relationships between core and both length and age suggest that maternal provisioning increases the likelihood of larval survival. These findings provide evidence of selective feeding throughout larval Sebastidae development, support the notion that maternal investment may positively influence larval survivorship across coastal Sebastes species assemblages, and emphasize the importance of taxonomical prey preference in facilitating growth and survival of larval rockfishes.