Re-description and molecular phylogeny of the free-swimming peritrichs Hastatella radians Erlanger, 1890 and H. aesculacantha Jarocki & Jakubowska, 1927 (Ciliophora, Peritrichia) from China

Abstract

The present work investigated Hastatella radians Erlanger, 1890 (type species), and H. aesculacantha Jarocki & Jakubowska, 1927, isolated from Chongming Island, Shanghai, China, based on light microscopy observations of live individuals, silver staining and molecular phylogeny methods. Hastatella radians is characterized by its size (about 30-75 μm long, 25-70 μm wide), two girdles of ectoplasmic processes, infundibular polykinety 3 (P3) composed of two rows of unequal length and terminating beyond adstomal end of P2, 8-22 transverse silverlines between peristome and trochal band, and 5-9 between trochal band and scopula. The infraciliature of H. aesculacantha is described for the first time, and we improved its diagnosis: cell size about 25-52 × 20-41 μm in vivo; four girdles of ectoplasmic processes; P3 two-rowed, outer row much shorter than inner one; 5-7 silverlines between peristome and trochal band and four or five between trochal band and scopula. Phylogenetic analyses based on SSU rDNA sequences revealed that Hastatella is monophyletic and has a close relationship to Astylozoon enriquesi.

Keywords: Astylozoidae; Infraciliature; Morphology; SSU rDNA sequences.