Naturalized rainbow trout (Oncorhynchus mykiss) populations are an important recreational fishing resource in the Araucanian lakes of southern Chile, but few reproductive studies have been undertaken to assess their sustainability. It is important to address this issue, since this analysis may provide information for improving management activities. In this study we carried out a biometric and reproductive analysis of naturalized rainbow trout breeders to describe their performance and to explore the variables that could determine fecundity, fertilization in addition to egg survival and size. We collected naturalized rainbow trout breeders from six tributaries of Calafquén Lake, during 2006, 2007 and 2012 to record their biometric and reproductive traits. Spawning and incubation were performed under controlled conditions in a hatchery facility to improve the recording process. In each spawning season, total fecundity (TF, No. of eggs/female), relative fecundity (RF, No. of eggs/kg female), fertilization rate (FR, %), egg diameter (ED, mm) and eyed egg survival (EES, %) were modeled as a function of biometric and reproductive parameters, using general linear mixed models. We used this statistical tool to explore the relationships between these reproductive traits and other breeder traits in order to identify all the potential combinations that could be linked to TF, RF, FR, ED and EES. The spawning period ranged from September to November (i.e., spring spawning season), with a clear spawning peak in October in all reproductive seasons. Mean TF (from 2275.9 to 3438.7) and RF (from 1730.5 to 1909.8) fell within the range of, or were close to, data reported for other Araucanian lakes, respectively. Mean values of FR and EES were relatively high, ranging from 88.8% to 93.3% and between 83.4% and 88.8%, respectively. Models indicated that TF is significantly affected by the interaction between female body weight and egg weight, while RF is affected by the combination of female body length and egg weight. In addition, a positive correlation was observed between female body weight and total fecundity, while an inverse association was recorded between relative fecundity and female body length. This trend is in accordance with the trade-off pattern between egg number and fish size described for naturalized populations of rainbow trout from the Northern Hemisphere. However, regression equations output suggests that the reproductive performance of the Calafquén Lake population has a more depleted fecundity in comparison either with naturalized populations from the Northern Hemisphere, or with cultured stocks of this species. Models for ED revealed that this variable is affected by egg weight and also by body length or body weight, all with positive correlations. This result concurs with observations reported for other naturalized populations of rainbow trout from North America, further supporting evidence that larger females of this species produce larger eggs than smaller females. Models for EES revealed the significant positive effect of fertilization rate and relative fecundity, being the latter an unexpected result, given that insignificant correlations between these variables have been found in cultured stocks of this species. Overall, the population analyzed exhibited a regular spawning period, and an optimal reproductive performance in terms of egg survival. To promote the sustainability of the naturalized rainbow trout of Calafquén Lake, we recommend the use of hatchery propagation of wild adults to support the production of fry to be used in subsequent restocking activities. This management effort can benefit because the broodstocks have a short spawning period during their spring run.

归化虹鳟鱼 ( Oncorhynchus mykiss) 种群是智利南部阿劳卡尼亚湖泊中重要的休闲渔业资源，但很少进行生殖研究来评估其可持续性。解决这个问题很重要，因为这种分析可以为改进管理活动提供信息。在这项研究中，我们对归化的虹鳟鱼育种者进行了生物特征和繁殖分析，以描述它们的表现，并探索除了卵存活率和大小之外可以确定繁殖力、受精情况的变量。我们在 2006 年、2007 年和 2012 年期间从 Calafquén 湖的六个支流中收集了归化的虹鳟鱼繁殖者，以记录它们的生物特征和繁殖特征。产卵和孵化在孵化场设施的受控条件下进行，以改进记录过程。在每个产卵季节，总繁殖力（TF，卵数/雌性）、相对繁殖力（RF，卵数/公斤雌性）、受精率（FR，%）、卵直径（ED，mm）和有眼卵存活率 (EES, %) 被建模为生物特征和生殖参数的函数，使用一般线性混合模型。我们使用此统计工具来探索这些繁殖性状与其他育种性状之间的关系，以识别可能与 TF、RF、FR、ED 和 EES 相关的所有潜在组合。产卵期为9～11月（即春季产卵期），各繁殖季节均以10月为明显的产卵高峰。平均 TF（从 2275.9 到 3438.7）和 RF（从 1730.5 到 1909.8）分别落入或接近其他阿劳卡尼亚湖泊报告的数据范围。FR 和 EES 的平均值相对较高，分别在 88.8% 至 93.3% 和 83.4% 至 88.8% 之间。模型表明，TF 受雌性体重和蛋重之间相互作用的显着影响，而 RF 受雌性体长和蛋重组合的影响。此外，在雌性体重和总生育力之间观察到正相关，而在相对生育力和雌性体长之间记录到负相关。这种趋势与针对北半球虹鳟鱼归化种群所描述的卵数和鱼大小之间的权衡模式一致。然而，回归方程输出表明，与来自北半球的归化种群或该物种的养殖种群相比，Calafquén 湖种群的繁殖性能具有更加枯竭的繁殖力。ED 模型显示该变量受蛋重以及体长或体重的影响，所有这些都呈正相关。这一结果与对来自北美的其他归化虹鳟鱼种群的观察结果一致，进一步支持了该物种较大的雌性比较小的雌性产卵更大的证据。EES 模型揭示了受精率和相对繁殖力的显着正效应，后者是一个意想不到的结果，鉴于在该物种的养殖种群中发现这些变量之间的相关性不显着。总体而言，分析的种群表现出规律的产卵期，以及在卵存活方面的最佳繁殖性能。为促进 Calafquén 湖归化虹鳟鱼的可持续性，我们建议使用野生成鱼的孵化场繁殖，以支持用于后续放养活动的鱼苗生产。这种管理工作可以受益，因为亲鱼在春季运行期间的产卵期很短。我们建议使用野生成虫的孵化场繁殖来支持用于后续放养活动的鱼苗生产。这种管理工作可以受益，因为亲鱼在春季运行期间的产卵期很短。我们建议使用野生成虫的孵化场繁殖来支持用于后续放养活动的鱼苗生产。这种管理工作可以受益，因为亲鱼在春季运行期间的产卵期很短。