I observed exceptionally variable TL at age for both Black Crappies Pomoxis nigromaculatus and White Crappies P. annularis in several small impoundments in northern Missouri. I used linear mixed models to assess the relative influences of sex, juvenile growth (back‐calculated lengths at age 1 [L1] and age 2 [L2]), and age in explaining variation in TL of age‐3 and older crappies. I also examined the potential effects of TL, age, and sex on body condition (relative weight W_r) and TL, age, and W_r on reproductive investment (gonadosomatic index [GSI]) of females. Models with various combinations of explanatory variables were compared with Akaike’s information criterion. The most supported model explained over 60% of the variation in TL at age of age‐3 and older fish and included age, L2, and sex for both species. For White Crappies, the L2‐only model explained more variation in TL than the age‐only model, but the opposite was true for Black Crappies. Logistic regression using TL and L2 as independent variables revealed that crappies of both species had less than a 50% probability of reaching 229 mm TL—a common minimum TL limit—by age 5 if L2 did not exceed 150 mm, indicating the importance of juvenile growth in determining adult size. The best model for W_r included TL, age, and sex for both species but explained less than 19% of the variation in this variable. Likewise, the best models for GSI explained less than 10% of the variation and included TL and W_r for Black Crappies and TL, W_r, and age for White Crappies. Because of the importance of juvenile growth in determining sizes of adult crappies, future studies should focus on processes that influence growth rates during the juvenile phase.

中文翻译：

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密苏里州小蓄水池中黑色胡扯和白色胡扯的年龄在长度上可变

我在密苏里州北部的几个小水库中观察到黑胡扯Pomoxis nigromaculatus和白胡扯P. ringis的TL在年龄上异常不同。我使用线性混合模型来评估性别，青少年成长（1岁[ L 1]和2岁[ L 2]岁时的反算长度）和年龄的相对影响，以解释3岁和较老的cr腿TL的变化。我还研究了TL，年龄和性别对身体状况（相对体重W _r）和TL，年龄和W _r的潜在影响。对女性的生殖投资（性腺机体指数[GSI]）。将具有各种解释变量组合的模型与Akaike的信息准则进行了比较。最受支持的模型解释了在3岁及以上年龄的鱼类中TL的60％以上的变化，并包括了这两个物种的年龄，L 2和性别。对于白胡扯，仅L 2的模型比仅年龄的模型解释了TL的更多变化，但对于黑胡扯，则相反。使用TL和Logistic回归大号2作为自变量揭示这两个物种的该crappies具有小于达到的50％的概率229毫米TL-一个共同的最低TL限制-5年龄如果大号2未超过150毫米，表明青少年成长对确定成年人的大小很重要。W _r的最佳模型包括两个物种的TL，年龄和性别，但解释了该变量变异的不到19％。同样，GSI的最佳模型解释了不足10％的变化，其中包括黑色胡扯的TL和W _r以及白色胡扯的TL，W _r和年龄。由于幼年生长在确定成年幼仔大小方面的重要性，因此未来的研究应集中在影响幼年阶段生长速度的过程上。