FIGURE 4 in Three new cryptic species of the freshwater zooplankton genus Holopedium (Crustacea: Branchiopoda: Ctenopoda), revealed by genetic methods

FIGURE 4. Putative geographic distribution of Holopedium species. Dots indicate populations where species assignments were confirmed by genetic analyses. Dark shaded areas represent the hypothesized range of each species based on results from this study and from distribution data from 1,827 localities inhabited by Holopedium, obtained from literature reports or by sampling (see Rowe 2000). Since several species are morphologically cryptic while the species complexes can be readily distinguished, the areas between or adjacent to genetic localities are tentatively marked as that same species, provided that there are Holopedium records there belonging to the same complex. Pending further evidence, all South American localities are here shaded as H. amazonicum and most Eurasian localities as H. gibberum s.s., but further cryptic species may be detected in the future. Definitive species assignments for populations in Greenland and India, which are currently described as separate species, require genetic evidence (see text), but morphological traits indicate that they do belong to the H. gibberum complex. Their distributions are shown along with H. gibberum s.s. (inset map in part b). a) H. glacialis n.sp., b) H. gibberum s.s., c) H. atlanticum n.sp., d) H. acidophilum n.sp., and e) H. amazonicum s.s.