Euplotes dragescoi, Wilbert & Song, 2008

Wilbert, Norbert & Song, Weibo, 2008, A further study on littoral ciliates (Protozoa, Ciliophora) near King George Island, Antarctica, with description of a new genus and seven new species, Journal of Natural History 42 (13 - 14), pp. 979-1012 : 1003-1010

publication ID

https://doi.org/ 10.1080/00222930701877540

persistent identifier

https://treatment.plazi.org/id/03B587B3-FF9A-C46E-FDF7-6235FDE6FD31

treatment provided by

Felipe

scientific name

Euplotes dragescoi
status

sp. nov.

Euplotes dragescoi View in CoL nov. spec.

( Figures 7A–C View Figure 7 , 10H–K View Figure 10 ; Table 5)

Diagnosis

Medium-sized, marine Euplotes , 86–109×56–69 Mm after protargol impregnation; buccal area about 2/3 of cell length with ca. 37 membranelles; always nine frontoventral, five transverse, and two caudal cirri; two marginal cirri uniquely differentiated: the second one extremely fine and reduced. None to 11 dorsal kineties with about 21 dikinetids in mid-dorsal rows. Macronucleus curved bar- or C-shaped.

Type locality

Rockpools and the littoral zone on the sea coast near Bellinghausen Station, King George Island (62 ° 139S, 58 ° 589W).

Dedication

We dedicate this species to our French colleague, Professor Jean Dragesco, in recognition of his great contributions to ciliatology.

Description

Body shape as shown in Figures 7A and C View Figure 7 , generally slender oval, sometimes asymmetric with straight right margin ( Figure 10J View Figure 10 ). Mostly about 100×60 Mm in size. Buccal field medium–wide, about two-thirds of cell length. Macronucleus typically C-shaped ( Figures 7B, C View Figure 7 ). No micronucleus detected. Ridges on dorsal side inconspicuous, along ciliary rows ( Figure 10I View Figure 10 ), while on ventral side typically as seen in most other congeners ( Figure 10J View Figure 10 ).

Adoral zone evenly curved, bases of membranelles relative short when compared with those of other congeners ( Figures 7A, C View Figure 7 ). Paroral region medium in size, near the proximal end of adoral zone ( Figures 7A View Figure 7 , 10J View Figure 10 , double-arrowheads). Ciliary pattern consistent, most cirri rather strong (except the posterior marginal one), with cilia about 20 Mm long ( Figure 7C View Figure 7 ). Always nine frontoventral (FVC) and five strong transversal cirri arranged in normal pattern. Two left marginal cirri (MC, Figure 7A View Figure 7 ) highly differentiated: the posterior cirrus ( Figures 7A View Figure 7 , 10K View Figure 10 , arrow) extremely fine (hence easily overlooked!), far away from the low-positioned anterior one ( Figure 10J View Figure 10 , arrow; 10K, arrowhead). Cilia in the second cirrus only about 10 Mm long. Consistently two strong caudal cirri (CC) in the normal position ( Figure 7A View Figure 7 ).

Dorsolateral rows mostly 10, the left-most one of which is shortened at the anterior end; usually about two rows on the ventral side ( Figures 7A View Figure 7 , 10J View Figure 10 ). All kineties conspicuously densely ciliated ( Figures 7B View Figure 7 , 10J View Figure 10 ); mid-rows on dorsal side with about 20 dikinetids. Silverline system not revealed.

Remarks

Up to now, over 80 nominal Euplotes (s. l.) have been reported, and among them no species have been described possessing different-sized marginal cirri ( Kahl 1932; Curds 1975; Dragesco and Dragesco-Kernéis 1986; Valbonesi and Luporini 1990; Song and Wilbert 1997). Hence the phenomenon found in E. dragescoi is unique in that one marginal cirrus is extremely ‘‘reduced’’.

This new species is identified from protargol-impregnated specimens and, unfortunately, no silverline system could be revealed. However, it can be unambiguously identified by the combination of the following features: unique dimorphic marginal cirri, appearance of adoral zone, the size, nine frontoventral cirri, the number of dorsolateral rows with densely arranged kinetosomes and, probably, the Antarctic habitat.

Kingdom

Chromista

Phylum

Ciliophora

Class

Hypotrichea

Order

Euplotida

Family

Euplotidae

Genus

Euplotes

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