Euplotes balteatus sensu Song & Wilbert, 2002

Pan, Ying, Li, Liqiong, Shao, Chen, Hu, Xiaozhong, Ma, Honggang, Alrasheid, Khaled A. S. & Warren, Alan, 2012, Morphology and Ontogenesis of a Marine Ciliate, Euplotes balteatus (Dujardin, 1841) Kahl, 1932 (Ciliophora, Euplotida) and Definition of Euplotes wilberti nov. spec., Acta Protozoologica 51 (1), pp. 29-38 : 35-37

Syn. Euplotes balteatus sensu Song & Wilbert, 2002

In 2000, a Euplotes species collected from King George Island, Antarctica, was reported as another population of Euplotes balteatus ( Song and Wilbert 2002) . It was diagnosed as follows: 40–70 × 30–50 µm in vivo, 25–33 adoral membranelles, 10 frontoventral, 5 transverse, 2 caudal and two close-set marginal cirri; 8 to 10 dorsal kineties with ca. 11 dikinetids in mid-rows; silverline system double- eurystomus type ( Fig. 4G–K ). However, the Antarctica population differs from E. balteatus in several respects including: 1) the dorsal grooves (distinct vs. inconspicuous in E. balteatus ); 2) marginal cirri (densely ranged vs. widely separated in E. balteatus ); 3) the number of dorsal kineties (9 vs. 8 in E. balteatus ) ( Dujardin 1841, Kahl 1932, Tuffrau 1964, Curds 1975). These are significant differences from which we conclude that the Antarctica population is not E. balteatus . Indeed, it cannot be identified with any known species of Euplotes so we therefore establish a new species for this population, Euplotes wilberti nov. spec.

Diagnosis: Small to medium-sized marine Euplotes about 40–70 × 30–45 µm in vivo, 27–33 membranelles, 10 frontoventral, 5 transverse, 2 caudal and two closely spaced marginal cirri; 8 to 10 dorsal kineties with ca. 11 dikinetids in mid-dorsal rows; double- eurystomus type silverline system.

Type locality: Rock pool and the littoral of Potter Cove, King George Island (62°14′S, 58°40′W), Antarctica .

Type specimen: A protargol slide of the Antarctica population was deposited in the Oberöterreichisches Landesmuseum (LI), A-4040 Linz, Austria ( Song and Wilbert 2002). Unfortunately the slide was not registered so it is not currently possible to declare a type specimen .

Dedication: We dedicate this new species to Dr. Norbert Wilbert, Institut für Zoophysiologie, Universität Bonn, Germany, in recognition of his contributions to the study of ciliates as well as his excellent descriptions of this organism ( Song and Wilbert 2002, Wilbert and Song 2008).

Comparison with other morphologically related forms: To date, there have been reports of 8 smallsized Euplotes with a double- eurystomus type dorsal silverline system, 10 frontoventral and 2 marginal cirri, namely E. balteatus ( Dujardin, 1841) Kahl 1932 , E. parabalteatus Jiang et al., 2010 , E. alatus Kahl ,

. system separated, TC level shaped) silverline. trisulcatus E 40 36 – 25 7 11 Widely the below Curved bar Tuffrau 1960 (

dorsal type ” separated C-shaped et. al eurystomus E. plicatum 55 42 – 25 – 22 10 14 Widely Inverted Valbonesi 1997) (double- “ and a E. magnicirratus 54 ** 52 – 49 8 13 17 – Separated below, level TC the C-shaped Inverted) 1972 (Carter

cirri, 2 marginal in. µm quinquecarinatus – 30 * * 15 – Widely separated C-shaped 1968) Borror (cirri Measurements E. 55 25 9 13 frontoventral cirri. *, below level) (1968 with 10 – transverse alatus . E – 43 36 * 30 ca 8 – 11 10 Separated the TC C-shaped Borror Euplotes species TC macronucleus,. parabalteatus E – 35 30 23 19 – – 6 7 – 8 11 ， Separated below TC the level bar-shaped Curved a) 2010 Jiang (marine similar

,

Ma –

separated work kineties. E balteatus – 30 80 18– 25 8 12 16 – Widely C-shaped Present morphologically – DK dorsal, ranged, TC the level C-shaped Wilbert and. illustrations specimens. of Comparison membranelles E. wilberti 70 – vivo 40 – 27 33 10 – 8 9 14 – Densely above Inverted Song) (2002 from published from impregnated 2. adoral size in AM DK dikinetids Table – AM Character Body No of.. No of of. No in mid-rows Marginal cirri Ma shape Reference * Counted ** Probably

1932, E. magnicirratus Kahl, 1932 , E. quinquecarinatus Gelei, 1950 , E. plicatum Valbonesi, 1997 , E. trisulcatus Kahl, 1932 and E. wilberti nov. spec. Table 2 summarizes the main characters that define these species. From these data it can be seen that E. wilberti nov. spec. is clearly distinguished from its most similar congeners thus justifying its validity as a separate species.

Figures

Fig. 4A–K. Euplotes balteatus and Euplotes wilberti nov. spec. from life (A, G), after protargol (D, J, K) and silver nitrate (B, C, E, F, H, I) impregnation. Arrows point to the marginal cirri. A – ventral view of Euplotes balteatus, to show the ventral ciliature (from Kahl 1932); B, C – ventral and dorsal views of Euplotes balteatus, showing the silverline systerm (from Tuffrau 1964); D – Euplotes balteatus, to show variations in the shape of the macronucleus; E, F – ventral and dorsal views showing the silverline system; G–K – Euplotes wilberti nov. spec., to show the live morphology (G), silverline system (H, I), infraciliature (J, K) and macronucleus (K) (from Song and Wilbert 2002). Scale bar: 30 µm.