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- Assessment of length and age at maturity for California halibut (Paralichthys californicus), including a histologically-based description of the reproductive cycle
- Estimates of length-And age-At-maturity for California halibut (Paralichthys californicus) have been reported for southern California, but not central California. To provide new estimates of length-And age-At-maturity for central California halibut, we macroscopically examined gonads from 635 fish caught between 2012 and 2014 and additionally examined ovaries histologically. We developed a detailed description of the reproductive phases and spawning states for California halibut, and assigned sex-specific length-And age-At-maturity to each individual. Males (n=333) ranged from 19.1 to 95.9 cm fork length (FL) and 1 to 16 yr of age and females (n=302) ranged from 18.6 to 111.0 cm FL and 1 to 19 yr of age. Males matured at younger ages and shorter lengths than females. The smallest mature male was measured at 25.7 cm (1 yr), 50% of males were mature by 27.0 cm (1.1 yr), and 100% were mature by 29.0 cm (3 yr). The smallest mature female was measured at 46.6 cm (2 yr), 50% of females were mature by 47.3 cm (2.6 yr), and 100% were mature by 51.3 cm (4 yr), according to histological criteria. Therefore, all California halibut examined were mature before reaching the commercial and recreational minimum legal size limit of 55.9 cm (22 in). When comparing central California maturity data with information from southern California, we found that central California halibut matured at larger sizes (both sexes) and older ages (females only) than southern California halibut, according to macroscopic criteria., Article
- Lesyna, Barnes
- Growth, mortality, and reproductive seasonality of California Halibut (Paralichthys californicus): A biogeographic approach
- Differences in key biological processes, such as growth and reproduction, can greatly influence localized population dynamics. Thus, it is important to characterize spatial variation in life history traits of harvested species to develop management plans that maximize fishery sustainability. We estimated sex- and region-specific growth, total mortality, and reproductive seasonality to assess biogeographic differences in California Halibut life history. We found that central California Halibut grew faster but attained smaller maximum sizes than those from southern California. Catch curve analysis illustrated no difference in total mortality by sex or region, though females live longer than males. Year-class frequency distributions suggested greater recruitment variability in central California, where abiotic factors (e.g., upwelling strength, sea surface temperature) are likely drivers. Reproductive data indicated that summer spawning seasons peak earliest in Mexico, followed by southern and central California. These results demonstrate a need to assess and manage California Halibut at the regional scale.
- Barnes, Starr, Reilly