Distributions and range expansions of rare or invasive species of planktonic calanoid copepods (Copepoda: Calanoida) within lakes and reservoirs in the continental United States

A survey of lakes and reservoirs during the spring and summer of 2012 found that five species of calanoid copepods are invasive in the continental United States: Arctodiaptomus dorsalis (Marsh, 1907), Skistodiaptomus pallidus (Herrick, 1879), Eurytemora affinis (Poppe, 1880), Pseudodiaptomus forbesi (Poppe & Richard, 1890), and Sinocalanus doerri (Brehm, 1909). Two species are listed on the IUCN Red List of Threatened Species: Skistodiaptomus carolinensis (Yeatman, 1986) and S. sinuatus (Kincaid, 1953). Sample locations for the five invasive and two rare species are reported and compared to historical distributions. Results corroborate previous reports of range expansion for the five invasive species, indicating that these species have likely become well-established in regions into which they have recently expanded. New localities for the two rare taxa suggest a possible range expansion within the USA.