Redescription of the halophile ciliate, Blepharisma halophilum Ruinen, 1938 (Ciliophora, Heterotrichea, Heterotrichida) shows that the genus Blepharisma is non-monophyletic

Abstract

We collected a heterotrich ciliate from hypersaline waters on the Cape Verde island Sal. After living observation and protargol-staining, it closely matched Blepharisma halophilum Ruinen, 1938. However, because (i) Ruinen most likely described several different species as B. halophilum, and (ii) he provided only very scarce diagnostic features, we redescribe this species with state-of-the-art methods according to modern standards. This will facilitate an accurate identification of this ciliate species, globally distributed in hypersaline water bodies: halophile Blepharisma, about 100–250μm in vivo; 32–42 adoral membranelles; 13–17 somatic kineties, including 2–4 anterior kinety fragments; single elongated macronucleus; cortical granules colourless. Its SSU rRNA gene sequence is very similar (99.7%) to an uncultured organism (environmental sequence) obtained from the hypersaline Lake Tyrrell in Australia. In phylogenetic analyses, these two sequences form a cluster, which with nearly full support (ML/BI, 99/1.00) branches as sister to the Fabreidae, showing for the first time that Blepharisma is yet another non-monophyletic ciliate genus.