Temporal and Spatial Variation in Fecundity of Yellowtail Rockfish

Abstract

Fecundities of the commercially important yellowtail rockfish Sebastes flavidus were compared to determine interannual variability and geographic variation, which will assist in stock assessment, characterization, and management. Gravimetrically estimated fecundities were compared in 1985–1991 between California, the southern extent of the speciesˈ distribution, and coastal waters of Washington, near the center of the speciesˈ abundance, where yellowtail rockfish are most heavily fished. California yellowtail rockfish were older, smaller in weight and length, and had smaller mesenteric fat deposits and more extensive disease and parasite pathologies than Washington fish. Egg production of this comparatively fecund viviparous fish increased linearly and sigmoidally with body weight and length, and asymptotically with age. Significant interannual differences were found in fecundities of young fish (<age 15) from California while no differences were observed in older California fish (>age 14) or in young or old Washington fish. Washington yellowtail rockfish had higher group fecundities because they were larger at age. Rate‐specific fecundities were significantly higher in young Washington fish. Predictive models of fecundity were highly correlated for young yellowtail rockfish, less so for old fish. Although fecundity of young fish depended on weight, length, and age, that of old fish was age‐independent. Our findings show age‐dependent interannual and geographic differences in reproductive effort, which suggest population‐specific reproductive life histories.

Full Issue Article Volume 25, Issue 3

“…The age of 50% maturity is variable among species but is typically 5-7 years, and may be as late as 20 years in some species (Wyllie Echeverría 1987;Barss 1989;Love et al 1990;O'Connell and Fujioka 1991). Several studies have shown geographical variation in age-at-maturity depending on latitude and depth (Gunderson et al 1980;Pearson and Hightower 1991;Eldridge and Jarvis 1994;Gunderson 1996). Many species have sex-specific growth rates, which can result in differential age-at-maturity and sex-specific natural mortality rates (Love et al 1990; Lenarz and Wyllie Echeverría 1991).…”

North American Journal of Fisheries Management

“…Accurate fecundity estimates are important for understanding dynamics of fish populations, predicting trends in population abundance, and estimating spawning-stock biomass (Eldridge and Jarvis 1995). Reproductive potential influences the ability of a species to respond to abiotic and/or biotic stresses.…”

Reproductive characteristics of Ancherythroculter nigrocauda, an endemic fish in the upper Yangtze River, China

“…Knowledge on the reproductive biology of fishes is critical for understanding a species' life history and devising appropriate management strategies [1,2]. Studies in reproductive biology mainly focus on sex ratio, spawning time, gonad development, length at maturity, and fecundity.…”