Isozyme characterization of three Antarctic species of the hypotrich ciliateEuplotes

Abstract

Wild strains of Euplotes euryhalinus, E. focardii, and E. nobilii, three Antarctic species originally described on morphological grounds, were analyzed for five enzyme systems (i.e., amylases, acid phosphatases, tetrazolium oxydases, malic dehydrogenases, and malic enzyme) of proven diagnostic value for the systematics of Euplotes species. The electrophoretic patterns were all effective for discriminating strains of one species from those of another; in particular those of amylases, acid phospatases, and tetrazolium oxidases showed sharp inter-species differences and no appreciable intraspecies variations. These results provided further evidence of the species status of Euplotes euryhalinus, E. focardii, and E. nobilii.

E uplotes (Dorsoventrally Flattened Ciliates)

“…Exceptionally, the interpartner exchange of a gamete-nucleus fails with the two gamete-nuclei from the same partner that fuse together in cytogamy. This is the case in E. focardii, a psychrophilic (cold-loving) species strictly endemic to Antarctica (Valbonesi and Luporini, 1993). Soon during the 10 days that E. focardii takes to complete its conjugal pairing, one partner systematically starts shrinking and being partially reabsorbed by the other.…”