Separation and relationship of ten marine scuticociliates (Protozoa, Ciliophora) using RAPD fingerprinting method

On the basis of the random amplified polymorphic DNA-fingerprinting (RAPD) method, 10 morphospecies of scuticociliates from 7genera, including 15 clones of 13 strains, Uronema rnarinum, Uronema cf marinum, Parauronerna virginianum, P. longurn, Metanophrys similis, M. sinensis, Paralembus digitiformis, Mesanophrys carcini, Paranophrys magna and Cohnilembus verminus were analysed using 8 oligonucleotide primers. The genetic similarity among the clones of the same strain measured by a band-sharing index is 0.97~0.98,while 0.40~0.52 among strains. This value measured is 0.39~0.46 among congeners of the same genus, whereas 0.16~0.47 between different genera. A distance tree was constructed based on 8-primer analysis, in which the scuticociliates investigated were separated into two clusters:one consists of 2 genera, Uronema and Parauronema, and the other was composed of five, Metanophrys, Mesanophrys,Paranophrys, Paralembus and Cohnilembus. It is demonstrated also that the morphospecies Parauronema virginianum may be a species-complex, i. e., it contains different genospecies.