Computational and Molecular Population Genetics, Zoological Institute, University of Bern, Baltzerstrasse 6, 3012 Bern, Switzerland.
J Fish Biol. 2009 May;74(7):1594-614. doi: 10.1111/j.1095-8649.2009.02233.x.
The gonad morphology of whitefish Coregonus lavaretus collected in Lake Thun, Switzerland, and two neighbouring lakes was assessed in order to differentiate between 'normal' and 'abnormal' character states of gonad morphology, which had been previously described in C. lavaretus from Lake Thun (constrictions, asymmetries, aplasia, compartmentations, fusions and hermaphroditism). In total, 4668 fish were collected and analysed using two complementary sampling schemes: (1) monthly samples of catches by the commercial fishermen and (2) samples of ripe spawners of all known 33 spawning sites of the three lakes. Considerable variation in gonad morphology in C. lavaretus populations of all lakes was found. Notably, all deviation types were observed in fish of all three lakes. Asymmetries and constrictions were frequent in all three lakes and showed systematic differences in frequency between the two sampling strategies. This indicates that asymmetries and constrictions represent to a large extent natural variation in gonad morphology of C. lavaretus and are also prone to considerable measurement error. In contrast, aplasia, fusions, compartmentations and hermaphroditism occurred predominantly in one C. lavaretus form of Lake Thun and in particular in populations spawning at great depths. This suggests that these deviation types are probably reliable indicators for gonad deformations and supports the interpretation that Lake Thun harbours a unique case of deformed gonads in C. lavaretus of yet unknown origin.
为了区分白鲑（Coregonus lavaretus）性腺形态的“正常”和“异常”特征状态，我们评估了在瑞士图恩湖（Lake Thun）和两个邻近湖泊中采集的白鲑的性腺形态。先前在图恩湖的白鲑（缩窄、不对称、发育不全、分隔、融合和雌雄同体）中已经描述过这些特征状态。总共收集了 4668 条鱼，并使用两种互补的采样方案进行了分析：（1）商业渔民每月的捕捞样本；（2）三个湖泊中所有已知 33 个产卵点的成熟产卵者样本。在所有湖泊的白鲑种群中，性腺形态都存在相当大的变异。值得注意的是，所有三种湖泊的鱼类都观察到了所有偏差类型。不对称和缩窄在所有三个湖泊中都很常见，并且在两种采样策略之间显示出系统的频率差异。这表明不对称和缩窄在很大程度上代表了白鲑性腺形态的自然变异，并且也容易受到相当大的测量误差的影响。相比之下，发育不全、融合、分隔和雌雄同体主要发生在图恩湖的一种白鲑形式中，特别是在深水区产卵的种群中。这表明这些偏差类型可能是性腺畸形的可靠指标，并支持这样的解释，即图恩湖拥有一种未知起源的白鲑畸形性腺的独特情况。
