Description of the Halophile Euplotes qatarensis nov. spec. (Ciliophora, Spirotrichea, Euplotida) Isolated from the Hypersaline Khor Al‐Adaid Lagoon in Qatar

Abstract

The morphology, ontogenesis, and phylogenetic relationships of a halophile euplotid ciliates, Euplotes qatarensis nov. spec., isolated from the Khor Al-Adaid Lagoon in Qatar were investigated based on live observation as well as protargol- and silver nitrate-impregnated methods. The new species is characterised by a combination of features: the halophile habitat, a cell size of 50-65 × 33-40 μm, seven dorsal ridges, 10 commonly sized frontoventral cirri, two widely spaced marginal cirri, 10 dorsolateral kineties, and a double silverline pattern. The morphogenesis is similar to that of its congeners: (i) the oral primordium develops hypoapokinetally and the parental oral apparatus is retained; (ii) the frontoventral-transverse field of five streaks gives rise to the frontal, ventral, and transverse cirri, but not to the cirri I/1 and the marginal cirri; (iii) the dorsal somatic ciliature develops by intrakinetal proliferation of basal bodies in two anlagen per kinety that are just anterior and posterior to the future division furrow; (iv) the caudal cirri are formed by the two rightmost dorsolateral kineties. The SSU rDNA sequence of E. qatarensis branches with full support in the Euplotopsis elegans-Euplotes nobilii-Euplotopsis raikovi clade. The closest related publicly available SSU rDNA sequence is the one of E. nobilii, with which E. qatarensis has 93.4% sequence similarity. Euplotes parawoodruffi Song & Bradbury, 1997 is transferred to the genus Euplotoides based on the absence of frontoventral cirrus VI/3.

Biogeography and Character Evolution of the Ciliate Genus Euplotes (Spirotrichea, Euplotia), with Description of Euplotes curdsi sp. nov.

“…Clade A, the most species-rich, includes several non-supported nodes, resulting in not fully resolved relationships among its subclades. A synopsis tree based on supported subclades, and illustrating a consensus of the evolutionary history of the genus Euplotes (see also [26, 36, 49]), is shown in Fig 4. Here, E .…”

“…elegans , the recently characterized E . qatarensis [36] and an undescribed freshwater population [50]. …”

“…qatarensis shares the double- eurystomus dargyrome type of E . curdsi , but has invariably 10 kineties, and an anterior projection on the right side of the body [36]. …”

“…[26–28]), it is generally easy to perform identifications using standardized techniques, and molecular data tend to corroborate the validity of morphologically-defined species [26, 29]. However, with the growing number of novel taxa being reported [30–36], it is increasingly important for descriptions to be accurate and include multiple types of data that are thoroughly compared to all relevant literature. In Euplotes , many molecular marker sequences have been ascribed to morphospecies without providing morphological results supporting the identification, and those sequences are routinely used as barcodes for identification.…”

Morphology, ontogeny and molecular phylogeny of Euplotes aediculatus Pierson, 1943 (Ciliophora, Euplotida)

“…纤毛虫原生动物为单细胞真核生物, 种类繁多, 其自由生活的类群广泛分布于海洋、淡水和土壤等 各种生境, 甚至在苔原、极地和高盐等极端生境中 也有发现, 还有一些类群营寄生或共栖生活 Qu et al, 2015;Dong et al, 2016;Li et al, 2016)。纤毛虫高度分化的细胞器、分司不同功能的 两型核结构以及特有的有性生殖方式(接合生殖), 使其作为重要的模式生物在细胞生物学、遗传学、 生态学以及真核生物的起源和进化等领域具有重 要的研究价值 (Corliss, 1979;Lynn, 2008;宋微波等, 2009)。 游仆类是纤毛虫中进化最为复杂和高等的一 大类群, 其多样性、发生学及系统学一直是国内外 研究的热点 (Carter, 1972;Curds, 1975;Shao et al, 2010;Yi et al, 2012)。经典的系统分类中, 游仆类隶 属于纤毛虫中的腹毛类 (Kahl, 1932;Borror, 1972;Corliss, 1979;Borror & Hill, 1995) (5-AAC CTG GTT GAT CCT GCC AGT-3)和18s-R (5-TGA TCC TTC TGC AGG TTC ACC TAC-3) (Medlin et al, 1988)。PCR扩增后, 产物直接送测序 公司测序 (Yi et al, 2009)。 额腹棘毛数目 Number of frontoventral cirri 9 9 9 9.0 0 0 19 (Pierson, 1943;Tuffrau, 1960;Pierson et al, 1968;Carter, 1972 虫为名的种群, 实际均为小腔游仆虫 (Pierson et al, 1968;Curds, 1975;庞延斌和魏红兵, 1999 Tuffrau, 1960;Carter, 1972;Curds, 1975 来源于独立发生的原基; 左缘棘毛原基独立发生等 (Washburn & Borror, 1972;Ruffolo, 1976;Shao et al, 2010;Fotedar et al, 2016 …”