Morphology and phylogeny of two Phialina species (Ciliophora, Haptoria) from northern China

Abstract

The morphology and infraciliature of two haptorian ciliates, Phialina clampi nov. spec. and P. caudata (Kahl, 1933) nov. comb. (original combination: Lacrymaria caudataKahl, 1933), isolated from sandy sediments of an estuary in Yantai, northern China, were investigated using live observations and protargol preparations. Phialina clampi nov. spec. is distinguished from its congeners by the following traits: extended cells about 80–300 × 18–50 μm in vivo; a single oval-shaped macronucleus; caudally located contractile vacuole; two types of extrusomes: type I about 20–35 × 1–4 μm in size, type II 1.5–3.0 × 0.7–1.0 μm in size and attached to somatic cortex; 27–31 somatic kineties. Phialina caudata is characterized as follows: extended cells about 80–170 × 20–45 μm in vivo; body radish-shaped, with a sharp posterior end; a single globular to oval macronucleus and micronucleus; subterminal contractile vacuole; 20–24 somatic kineties. Phylogenetic analyses based on SSU rRNA gene sequences indicate that P. caudata clusters with an unidentified Phialina before grouping with Phialina clampi, which form a basal clade of the family Lacrymariidae.