Laophonte ceter, Jankowski, 1981

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 : 383

Limnoricus ceter Jankowski, 1981

( Figs. 6 b–c)

Diagnosis. Marine loricate suctorian. Cell body and lorica sharply flattened laterally. Cell body attached to the margin of lorica aperture that is surrounded by collar-like borders. Contractile, clavate tentacles arranged in apical rows. Long straight stalk (pseudostyle) present. Macronucleus ellipsoidal. Reproduction generally by regular exogemmic, semicircumvaginative, budding.

Morphological description. Laterally flattened marine loricate ciliate. The cell of the body fills two-thirds of lorica that measured 34–60 µm in length and 12–56 µm in width ( Figs. 6 b and 6c). Cell body from 13 to 42 µm in length and from 9 to 37 µm width. Rows of contractile, clavate tentacles arranged in the apical aperture. Ellipsoidal macronucleus was observed in the middle of the cell body ( Fig. 6 c). Micronuclei not observed. Long, straight and enlarged stalk attached the lorica base of the suctorian to the host. Stalk length varied from 6 to 46 µm and thickness from 1 to 4 µm ( Fig. 6 b). The swarmer was not observed.

Remarks. The observed specimens of L. ceter differed from earlier observations in body size and host specificity. Indeed, they were smaller than those earlier reported ( Jankowski 1981): their lorica length and width were two third than those originally described, and the stalk one a fourth of the total stalk length (see Dovgal et al. 2008b).

Furthermore, the holotype specimen was reported from marine isopods ( Jankowski 1981), whereas the specimens documented in this study were found on a harpacticoid copepod and for the first time on a nematode of the genus Desmodora de Man, 1889 .

Host specificity and locality information. L. ceter was first described by Jankowski (1981), attached to marine isopods from the Sakhalin and Kunashyr Islands , and then also from halacarid mites from Barents Sea ( Jankowski 1981). The present specimens were found at S2 and S4 stations of the Suvadiva atoll lagoon at a depth of 62 and 63 m, respectively. The S 2 sediments were characterized by 56% of sand, 0.3 of gravel and 45% of mud, while they were represented by 83% of sand, 14% of gravel and 3% of mud at S4.

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.