1699

• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Canada; Northwest Territories; Yukon; Nunivak; Alaska
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.210.9161; http://www.biol.ttu.edu/faculty/nmcintyre/Research/CanJZool73_1995.pdf

Abstract: References to Cyclops strenuus in the North American literature are reviewed. Male and female specimens of C. strenuus sensu lato from 20 sites in Alaska, Yukon, Northwest Territories, and Saskatchewan were measured and compared using several morphological parameters. Two or more phenotypes may be present among the 20 populations. The specimens examined differ sharply from Cyclops canadensis Einsle, 1988, especially in the length of the caudal ramus, length of the antennules, width of prosomites 4 and 5, and length of the lateralmost and medialmost terminal caudal setae. Thus, Einsle's conclusion that previous records of C. strenuus in North America are likely referable to C. canadensis may be premature. New records of C. strenuus away from northern coastal areas of Alaska and Canada include Saint Matthew and Nunivak islands, two interior Alaska locations, Galena and Chatanika, and four locations in central and southern Saskatchewan. Passive dispersal via migrating waterfowl may account for the presence of C strenuus in Saskatchewan. To date, only a very few individuals of C. strenuus s.l. from a very large area in North America have been examined. Final decisions about relationships among Nearctic C. strenuus and their relationships to Palearctic congeners must await the examination of many more animals and investigations using biochemical or chromosomal techniques in conjunction with morphology.