Strombidinopsis jeokjo n. sp (Ciliophora : Choreotrichida) from the coastal waters off Western Korea: Morphology and small subunit ribosomal DNA gene sequence

Abstract

The planktonic ciliate Strombidinopsis jeokjo n. sp. is described from Quantitative Protargol-Stained (QPS) preparations, and the sequence of the small subunit rDNA (SSU rDNA) from cultured cells is reported. This species is ovoid and bluntly tapered towards the posterior. The ranges (and mean standard deviation, n = 31) of cell length, cell width, and oral diameter of the QPS-stained specimens were 100-190 mum (149 +/- 25), 60-105 mum (79 +/- 13), and 55-80 mum (64 +/- 5), respectively. Fifteen to seventeen external oral polykinetids had oral membranelle cilia 20-35 mum long. Twenty-six to twenty-eight somatic kinetics were equally spaced around the cell body and extended from the oral to the posterior regions with 23-44 dikinetids per kinety. Both kinetosomes of each kinetid bore cilia 3-7 mum long. Strombidinopsis jeokjo had two ovoid macronuclei of 25-38 mum x 12-15 mum. When properly aligned, the sequence of the SSU rDNA of S. jeokjo (GenBank Accession No. AJ628250) was approximately 2% different from that of an unidentified Strombidinopsis species (GenBank Accession No. AF399132-AF399135), the closest species in the SSU rDNA sequence.