This study presents age-based life history information on three small-bodied species targeted in the American Samoan fishery: Chlorurus japanensis palecheek parrotfish/fuga-alosama, Lethrinus rubrioperculatus spotcheek emperor/fiola pa`o`omumu, and Naso lituratus orangespine unicornfish/ili`ilia. Age and reproductive information were derived from sagittal otoliths and gonads. Maximum observed ages were 7 years for C. japanensis, 10 years for L. rubrioperculatus, and 25 years for N. lituratus. Due to a limited numbers of immature samples, a proxy for size at 50% maturity (L50) was derived from the relationship between asymptotic fork length (L∞) and L50 based on data published for species from similar geographic regions and respective families. L50 was estimated at 20.9 cm for C. japanensis, 20.4 cm for L. rubrioperculatus, and 17.5 cm for N. lituratus. Derived estimates were within 1 % of the L50 calculated for C. japanensis and N. lituratus from the limited number of immature samples collected in this study, indicating that for regions where sampling ability is limited, derived relationships between L∞ and L50 can be used to calculate an appropriate proxy. Naso lituratus demonstrated a biphasic mortality schedule with a higher than expected total mortality rate in the first 7 years of life. The age-based demographic information presented here can be used for future stock assessments and ecosystem models, which should facilitate improved management.

中文翻译：

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美属萨摩亚三种具有重要商业价值的珊瑚礁物种的生长和成熟

本研究提供了以美国萨摩亚渔业为目标的三种小体型物种的年龄生活史信息：Chlorurus japanensispalecheek parrotfish/fuga-alosama、Lethrinus rubrioperculatus spotcheekEmperor/fiola pa`o`omumu 和 Naso lituratus orangespine unicornfish/ili伊利亚。年龄和生殖信息来自矢状耳石和性腺。C. japanensis 的最大观察年龄为 7 年，L. rubrioperculatus 为 10 年，N. lituratus 为 25 年。由于未成熟样本的数量有限，50% 成熟度 (L50) 的大小代表来自渐近叉长度 (L∞) 和 L50 之间的关系，该关系基于为来自相似地理区域和各自科的物种发布的数据。C. japanensis 的 L50 估计为 20.9 cm，L. rubrioperculatus 为 20.4 cm，N 为 17.5 cm。文学。从本研究收集的有限数量的未成熟样本中计算出的 C. japanensis 和 N. lituratus 的 L50 的推导估计值在 1% 以内，表明对于采样能力有限的地区，可以使用 L∞ 和 L50 之间的推导关系计算适当的代理。Naso lituratus 表现出双相死亡率，在生命的前 7 年中总死亡率高于预期。此处提供的基于年龄的人口统计信息可用于未来的种群评估和生态系统模型，这将有助于改进管理。L∞ 和 L50 之间的衍生关系可用于计算适当的代理。Naso lituratus 表现出双相死亡率，在生命的前 7 年中总死亡率高于预期。此处提供的基于年龄的人口统计信息可用于未来的种群评估和生态系统模型，这将有助于改进管理。L∞ 和 L50 之间的衍生关系可用于计算适当的代理。Naso lituratus 表现出双相死亡率，在生命的前 7 年中总死亡率高于预期。此处提供的基于年龄的人口统计信息可用于未来的种群评估和生态系统模型，这将有助于改进管理。