Several species of ciscoes Coregonus, subgenus Leucichthys that are native to the Laurentian Great Lakes are rare or extirpated. The restoration of Coregonus fishes is being actively pursued through stocking, and success may depend on the availability of unoccupied niche space. We described the spring–summer habitat occupancy and diets of three native cisco species (Bloater Coregonus hoyi, Cisco C. artedi, and Kiyi C. Kiyi) and invasive Rainbow Smelt Osmerus mordax in Lake Superior and measured niche overlap among these species for both small and large sizes. The potential habitat area was highest for Cisco and Kiyi, followed by Bloater and Rainbow Smelt. The probability of overlap in habitat occupation, as measured by bathymetric depth, fish capture depth, distance from shore, and fish capture water temperature was highest for small Rainbow Smelt and Cisco. Trophic overlap, as measured by stomach contents and stable isotopes, was highest between small Bloater and Cisco and between large Bloater and Kiyi. All of the species showed significant ontogenetic change in both habitat occupation and diet. The overall niche overlap in spring–summer habitat and diet was greatest between small Cisco and Rainbow Smelt and between large Bloater and Kiyi; however, differences in individual niche dimensions likely limit competition for both species pairs. Synthesizing the diet and habitat niche data revealed nuanced niches that allow these seemingly similar planktivorous species to coexist. Kiyi had the least niche overlap with other cisco species and Rainbow Smelt, so from an available niche perspective Kiyi would be a strong candidate for reintroduction into lakes from which they were extirpated.

中文翻译：

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苏必利尔湖原生思科和非原生彩虹熔炼之间的生态位划分

劳伦山脉五大湖中原产的几种粘皮类Coregonus属Leucichthys属罕见或已灭绝。目前正通过放养积极地恢复金刚鱼的繁殖，而成功的成败可能取决于空置利基空间的可用性。我们描述的春夏季栖息地占用和三个本地Cisco种（熏鱼饮食霍氏白鲑，思科C. artedi，并Kiyi C. Kiyi）和入侵彩虹胡瓜Osmerus mordax在苏必利尔湖中，无论大小，这些物种之间的测量生态位重叠都相同。思科和Kiyi的潜在栖息地面积最高，其次是Bloater和Rainbow Smelt。对于较小的Rainbow Smelt和Cisco，通过测深，鱼类捕获深度，距海岸的距离以及鱼类捕获水温来衡量，栖息地占用重叠的概率最高。通过胃内容物和稳定同位素测得的营养重叠在小Bloater和Cisco之间以及大Bloater和Kiyi之间最高。所有物种在生境占用和饮食方面均显示出显着的个体发育变化。小型思科和彩虹熔炼厂之间以及大型Bloater和Kiyi之间，春夏季生境和饮食中的整体生态位重叠最大。然而，各个生态位维度的差异可能会限制两个物种对的竞争。综合饮食和生境的利基数据，可以发现细微差别的生态位，这些生态位使这些看似相似的浮游物种得以共存。Kiyi与其他cisco物种和Rainbow Smelt的生态位重叠最少，因此从可用生态位的角度来看，Kiyi是重新引入到被淘汰的湖泊中的强力候选者。