First record of two urotsylid ciliates (Protozoa: Ciliophora: Spirotrichea) from Japan expanding the circumscription of species

Abstract

ABSTRACT Two urostylid ciliates, Trichototaxis marina Lu et al., 2014 and Uncinata bradburyae (Gong et al., 2001) Luo et al., 2015, new to Japan, were collected from coastal water in Nagasaki. Both were identified based on live and protargol-stained specimens. Morphologically, two new populations of T. marina correspond well with the type population in the live morphology and ciliature, especially a very flexible body having a long elliptical shape, and reddish cell colour caused by irregularly shaped pigments, multiple left marginal rows and marine habitat. A few morphological features were supplemented for the species. The Japanese population of Uncinata bradburyae presents the diagnostic features, especially the presence of an anterior snout-like procession and the elongated membranelles in the proximal portion of adoral zone, orientation of the anterior portion of the left marginal row, highly developed transverse cirri, and high number of dorsal kineties derived from two unique, de novo formed anlagen. Additionally, greenish pigments were first documented for the species. The new record suggests U. bradburyae might be a eurythermal species. The overall pattern of the divisional events resembles that of the Qingdao population described previously. Part of the reorganisation was also first revealed for U. bradburyae, which corresponds to the divisional processes in the opisthe. The present study corroborates the wide distribution of both species, and contributes to circumscribe the species by expanding the range of some morphometric data.