Fecundity of fish is influenced by several factors, including body length, condition, population density, and environmental conditions. It follows that fecundity of fish populations can exhibit spatiotemporal variability; thus, periodic quantification of length–fecundity relationships is important for management. We hypothesized that average fecundity of Cisco Coregonus artedi in the upper Laurentian Great Lakes would be lower in Lake Superior than in Lakes Huron and Michigan. The trophic status of these lakes recently converged, but Lakes Huron and Michigan currently support lower Cisco densities; thus, we expected that they would reach larger sizes and have greater fecundity owing to lower intraspecific competition. Ovaries were collected from prespawn Cisco during 2008–2010 to test this hypothesis. We also compared length–fecundity relationships for 2008–2010 to those of precollapse (1930s–1950s) populations to explore how relationships have changed. Average fecundity of Cisco during 2008–2010 was lower in Lake Superior compared to Lakes Huron and Michigan; length–fecundity relationships in the latter two lakes did not vary significantly, so they were combined. Body condition was highest in Lakes Huron and Michigan. We used otoliths to determine age and found that body condition was domed shaped with respect to age in Lakes Huron and Superior. There were no females older than age 5 in our samples from Lake Michigan because that population was just beginning to recover from very low levels. Females of intermediate age had the highest fecundities in both Lake Huron (ages 7–13) and Lake Superior (ages 8–18). We hypothesize that differences in body morphometry may also influence fecundity, with deeper‐bodied C. artedi albus, the predominant form in Lakes Michigan and Huron, having greater fecundity than shallower‐bodied C. artedi artedi in Lake Superior. Moreover, varying Cisco diets and seasonal movement patterns across lakes may have also contributed to differences. Females in Lakes Superior and Michigan are currently more fecund than their precollapse counterparts.

中文翻译：

---

思科的产地在上大湖中变化吗？

鱼的繁殖力受多种因素影响，包括体长，状况，种群密度和环境条件。由此可见，鱼类种群的繁殖力可能表现出时空变异性。因此，定期确定长度与生殖力之间的关系对于管理很重要。我们假设Cisco Coregonus artedi的平均生育能力苏必利尔湖上游的洛朗山脉五大湖要比休伦湖和密歇根湖低。这些湖泊的营养状况最近趋于一致，但休伦湖和密歇根州目前支持较低的思科密度；因此，我们预期它们会因种内竞争降低而达到更大的规模并具有更大的繁殖力。在2008-2010年期间从产前思科收集了卵巢以检验该假设。我们还比较了2008-2010年的长度与生殖力之间的关系与崩溃前（1930年代至1950年代）人群的关系，以探讨这种关系是如何变化的。与休伦湖和密歇根湖相比，苏必利尔湖地区思科在2008–2010年期间的平均生育力较低。后两个湖泊的长度-生殖力关系没有显着变化，因此将它们合并。休伦湖和密歇根州的身体状况最高。我们使用耳石来确定年龄，发现休伦湖和苏必利尔湖的体况相对于年龄呈圆顶状。在我们从密歇根湖抽取的样本中，没有年龄大于5岁的女性，因为该种群刚刚从非常低的水平开始恢复。在休伦湖（7-13岁）和苏必利尔湖（8-18岁）中，中年女性的繁殖力最高。我们假设，身体形态的差异也可能影响生育力，而身体更深 在休伦湖（7-13岁）和苏必利尔湖（8-18岁）中，中年女性的繁殖力最高。我们假设，身体形态的差异也可能影响生育力，而身体更深 在休伦湖（7-13岁）和苏必利尔湖（8-18岁）中，中年女性的繁殖力最高。我们假设，身体形态的差异也可能影响生育力，而身体更深C. artedi albus是密歇根湖和休伦湖的主要形态，繁殖力强于苏必利尔湖中较浅的C. artedi artedi。此外，不同的思科饮食和跨湖的季节性运动方式也可能导致差异。目前，苏必利尔湖和密歇根州的女性比濒临崩溃的女性要多。