Mayflies (Ephemeroptera) of the Yukon
Abstract. Thirty taxa of mayflies are reported from the Yukon Territory. Four zoogeographical elements are recognized: 1) widespread Cordilleran and western coastal species, the largest group of species: Acentrella insignificans, Caenis youngi, Callibaetis ferrugineus hageni, Cinygmula spp., Drunell...
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| Format: | Text |
| Language: | English |
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1997
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| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.1045.3260 http://www.ephemeroptera-galactica.com/pubs/pub_h/pubharperp1997p151.pdf |
| Summary: | Abstract. Thirty taxa of mayflies are reported from the Yukon Territory. Four zoogeographical elements are recognized: 1) widespread Cordilleran and western coastal species, the largest group of species: Acentrella insignificans, Caenis youngi, Callibaetis ferrugineus hageni, Cinygmula spp., Drunella spp., Epeorus longimanus, Rhithrogena futilis, Siphlonurus occidentalis, and S. phyllis; 2) five Holarctic species: Baetis bicaudatus, B. bundyae, Ephemerella mucronata, Metretopus borealis, and Siphlonurus alternatus; 3) four species of transcontinental distribution: Baetis tricaudatus, Leptophlebia nebulosa, Paraleptophlebia debilis and Procloeon ingens, and 4) the westernmost extension of the northeastern Nearctic fauna: Heptagenia pulla and Siphloplecton prob. interlineatum. There is no endemic element. This fauna is very similar in diversity and composition to that of Alaska, but much poorer than that of the adjacent Mackenzie Valley in the Northwest Territories. It appears to be composed largely of the hardiest species of the western boreal fauna, with some eastern elements, but with few truly arctic components. Such a depauperate fauna may be due to particularly harsh climatic and ecological conditions and/or zoogeographical barriers, but it is not possible at the present time to rule out insufficient collecting as an important factor. Il n'y a pas d'élément endémique. Cette faune est très semblable en composition et en diversité à celle de l'Alaska, mais elle est beaucoup moins riche que celle de la région adjacente de la vallée du Mackenzie, dans les Territoires du Nord-Ouest. Elle paraît se composer principalement des espèces les plus robustes de la faune boréale occidentale avec l'addition de quelques éléments d'origine orientale et peu d'éléments vraiment arctiques. Cette faune appauvrie pourrait s'expliquer par les conditions climatiques et écologiques particulièrement rigoureuses qui forment des barrières zoogéographiques, mais il est aussi possible qu'un inventaire plus systématique révèle une faune ... |
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