Thecacineta urceolata Liao & Dovgal, 2015

Ansari, Kapuli Gani Mohamed Thameemul, Guidi, Loretta, Dovgal, Igor, Balsamo, Maria & Semprucci, Federica, 2017, Some epibiont suctorian ciliates from meiofaunal organisms of Maldivian archipelago with description of a new ciliate species, Zootaxa 4258 (4), pp. 375-387 : 381

Thecacineta urceolata Liao & Dovgal, 2015

( Fig. 6 a)

Diagnosis. Marine suctorian ciliate. Cell body attached at the bottom of the lorica. Narrow apical end protruding from lorica aperture. Smooth lorica ridged at its aperture. A bundle of capitate tentacles placed apically. Macronucleous spherical. Long and curved stalk with apical widening. Reproduction by vermigemmic budding.

Morphological description. Marine loricate suctorian. Cell body narrowed towards the apical end. Body 70 µm in length and 19 µm in width. Smooth lorica larger than the cell body, about 84 µm in length and 42 µm in width with a ratio of ca. 2:1. Annular ridge, not well pronounced, in the lorica aperture that narrowed from body to apical end with its specific urceolate structure clearly visible ( Fig. 6 a). A bundle of tentacles in the apical part of body, about 10–15 µm in length and 1 µm in thickness. Macronucleus spherical almost equal in length and width and located just above the base of the body ( Fig. 6 a). Long, thin and curved stalk 75 µm in length and 7 µm in thickness. Reproduction usually by vermigemmic budding with formation of laterally vermiform protomit, but swarmer not observed in the present samples.

Remarks. The observed specimen of T. urceolata Liao & Dovgal, 2015 differs from those earlier observed by the lorica and stalk size. It showed a larger lorica size as well as a stalk twice in length compared to the earlier report (holotype—Liao & Dovgal, 2015). Moreover, the observed specimen had no cuticular transverse ribs as the morphologically close species Praethecacineta halacari Schulz, 1933 that was reported on Copidognathus sp. from He-Ping-Dao ( Dovgal et al. 2009b). P. halacari Schulz, 1933 is characterized by the semi-circumvaginative exogemmic budding with formation of lateral ciliate protomit, which differs from the vermigemmic budding of T. urceolata .

Host specificity and locality information. T. urceolata was first described from Ludao , ( Taiwan seagrass bed of Thalassia hemprichii (Ehrenberg) Ascherson, 1871 ) on the marine nematode species Desmodora pontica Filipjev, 1922 . Also in the present study T. urceolata was observed on a Desmodora species, but this specimen was found in carbonate sediments of the Suvadiva lagoon bottom at a water depth of 63 m. The sediments were mainly represented by sand (83%), gravel (14%) and mud (3%).

Figures

FIGURE 6. Bright field microscopy images of a) Thecacineta urceolata Liao and Dovgal, 2015 adhering to the nematode Desmodora sp.; b – c) Limnoricus ceter Jankowski, 1981, adhering to the nematode Desmodora sp. and on a harpacticoid copepod, respectively.