Ref ID : 7513
Michael A. Gates; Cirral Patterns of Cirrotype 9 Euplotes (Hypotrichida, Ciliophora). Protistologica XIV(2):125-132, 1978
Reprint
In File
Notes
Only the quantitative study of variation can confirm the existence of natural groupings of ciliated protozoa. A quantitative analysis of the distribution of cirri in 13 geographically diverse freshwater Euplotes samples having 9 frontoventral cirri reveals a continuum of cirral patterns in which there exist two large, internally coherent groups. These two groups correspond to two basic cirral patterns, whose most obvious difference is the position of the second cirrus in the fourth cirral streak. Many of the classical, typologically-defined species have indistinguishable cirral patterns and similar dargyromes. They correspond to only a few basic morphotypes. All of the freshwater double dargyrome cirrotype 9 forms which lack cirrus 3/IV constitute at most two morphospecies, with the historically confused forms, E. eurystomus and E. patella, united under the binomen of the latter. Similarly, all except one (E. affinis) of the freshwater populations lacking cirrus 2/IV may be considered to belong to the same morphospecies, the common and widely distributed euryhaline form with a multiple dargyrome, E. muscicola.