Jiqiu Li

Use of RAPD to detect DNA damage induced by nitrofurazone in marine ciliate, Euplotes vannus (Protozoa, Ciliophora)

The random amplified polymorphic DNA (RAPD) assay was evaluated as a potential tool to detect the ecotoxicity induced by nitrofurazone in marine ciliate, Euplotes vannus. The data revealed a reduction in viability of the test ciliates with increasing nitrofurazone concentration in the range of 0-24 mgl(-1) and time of exposure from 24 to 96 h. The nitrofurazone treated ciliates were subjected to DNA damage analysis by RAPD assay. Among the 33 test RAPD primers used in this study, 11 primers with 60-70% GC content produced unique polymorphic band patterns. A total of 213 bands of 155-3317 bp in molecular size range were observed in the untreated cells. In comparison with the control ciliates, the nitrofurazone treated groups showed differences in RAPD profiles with respect to the band intensity, disappearance of bands and appearance of new bands of amplified DNA. The variation of RAPD profiles showed both the time- and concentration-dependent relationships. The data suggested significant genomic template instability, which corresponds well with the viability of the test ciliates. Thus the results demonstrated the potential of the RAPD assay for application as a powerful tool for detecting genotoxicity induced by fishy drugs in aquatic environment.

Novistrombidium sinicum n. sp. and Novistrombidium orientale n. sp. (Protozoa: Ciliophora): Two New Oligotrich Ciliates from a Mangrove Wetland, South China

ABSTRACT. The morphology and infraciliature of two new marine oligotrich ciliates, Novistrombidium sinicum n. sp. and Novistrombidium orientale n. sp., isolated from a mangrove wetland near Guangzhou, southern China, were studied from live and protargol‐stained specimens. Novistrombidium sinicum is different from its congeners by the combination of the following characters: three posteriorly directed thigmotactic membranelles, one ellipsoidal macronucleus, the extrusomes equidistantly arranged, and the ventral kinety commencing below the right end of the girdle kinety. The small‐sized N. orientale can be separated from its congeners by two posteriorly directed thigmotactic membranelles, one ellipsoidal macronucleus, the extrusomes equidistantly arranged, and the ventral kinety commencing below the right end of the girdle kinety.

Morphology and Molecular Phylogeny of Three Cyrtophorid Ciliates (Protozoa, Ciliophora) from China, Including Two New Species, Chilodonella parauncinata sp. n. and Chlamydonella irregularis sp. n.

This study investigated the morphology and molecular characteristics of three interesting free‐living cyrtophorid ciliates, including two new species, isolated from China: Chilodonella parauncinata sp. n. can be identified by its elongated body shape, with a sharp protrusion in the left anterior part, cell size ca. 60 × 25 μm in vivo, five right and 6–7 left kineties with kinetosomes densely arranged, and a curved cyrtos. Chlamydonella irregularis sp. n. differs from its congeners by the oval body shape, cell size 50–60 × 25–40 μm in vivo, irregular shape of macronucleus, 30–40 club‐shaped ventral protuberances, and 17 somatic kineties. Two isolates of Chlamydonella derouxi Song, 2003, collected from an intertidal area in Shandong and a mangrove wetland in Guangdong respectively, correspond well with two previous descriptions, but differ in comprising more basal bodies in left and right equatorial fragments and in having more finger‐like protuberances on the ventral side. Phylogenetic analyses based on the small subunit rRNA gene sequences showed that C. parauncinata sp. n. clustered with Chilodonella uncinata, but was a well‐outlined species of the genus, and C. irregularis sp. n. and C. derouxi grouped in the family Lynchellidae with their congeners to form the monophyletic genus Chlamydonella.

Molecules or morphogenesis: how to determine the phylogenetic assignment of Paratetrahymena (Protista, Ciliophora, Oligohymenophorea)?

Li, J., Lin, X., Yi, Z., Clamp, J. C., Liu, W. & Al‐Rasheid, K. A. S. (2010). Molecules or morphogenesis: how to determine the phylogenetic assignment of Paratetrahymena (Protista, Ciliophora, Oligohymenophorea)? —Zoologica Scripta, 39, 499–510.

Two New Genera of Planktonic Ciliates and Insights into the Evolution of the Family Strombidiidae (Protista, Ciliophora, Oligotrichia)

Oligotrich ciliates are common marine microplankters, but their biodiversity and evolutionary relationships have not been well-documented. Morphological descriptions and small subunit rRNA gene sequences of two new species representing two new strombidiid genera, Sinistrostrombidium cupiformum gen. nov., sp. nov. and Antestrombidium agathae gen. nov., sp. nov. are presented, and their taxonomy and molecular phylogeny are analyzed. Sinistrostrombidium gen. nov. is characterized by a sinistrally spiraled girdle kinety and a longitudinal ventral kinety. Antestrombidium gen. nov. is distinguished by tripartite somatic kineties (circular and ventral kineties plus dextrally spiraled girdle kinety). Sinistrostrombidium and Antestrombidium branched separately from one another in phylogenetic trees, clustering with different clades of strombidiids. The new genera added to the diversities of ciliary patterns and small subunit rRNA gene sequences in strombidiids leads to presentation of a new hypothesis about evolution of the 12 known strombidiid genera, based on ciliary pattern and partly supported by molecular evidence. In addition, our new morphological and molecular analyses support establishment of a new order Lynnellida ord. nov., characterized by an open adoral zone of membranelles without differentiation of anterior and ventral membranelles, for Lynnella, but we remain unable to assign the genus to a subclass with confidence.

Taxonomic studies on seven species of Dysteria (Ciliophora, Cyrtophoria), including a description of Dysteria paraprocera sp. n.

The living morphology and infraciliature of seven Dysteria species isolated from the seas around China were investigated by observation of both living cells and specimens after protargol impregnation. Dysteria paraprocera sp. n. is characterized as follows: cell size 110-150×30-40μm in vivo; body elongate rectangular and slender; a yellow-brown to dark red coloured pigment spot located at anterior end of body; three right kineties, with rightmost two extending apically to dorsal margin and innermost one starting at level of cytostome; eight or nine short left kineties at equatorial area. Dysteria nabia, D. proraefrons, D. brasiliensis, D. cristata, D. derouxi and D. crassipes basically correspond well with previous studies and therefore only brief descriptions are presented. Discussions of these species are helpful, however, in understanding the circumscription of Dysteria morphotypes. After careful comparison, Dysteria procera sensu Liu et al. (2008, Acta Hydrobiol. Sin. 32 (suppl.), 84-89 (in Chinese with English abstract)) was verified as a new species, D. subtropica sp. n., mainly because the innermost right kinety starts at mid-body. Small-subunit (SSU) rRNA genes were sequenced for four species of Dysteria, namely, D. paraprocera sp. n., D. subtropica sp. n., D. proraefrons and D. nabia. Sequence comparisons and phylogenetic analyses indicate that these species are well outlined and cluster with their congeners.

Morphological and molecular characterization of Aspidisca hongkongensis spec. nov. (Ciliophora, Euplotida) from the South China Sea

The morphology and infraciliature of a new ciliate, Aspidisca hongkongensis spec. nov., a large marine form isolated from the coastal waters near Hong Kong, were investigated. It differs from the congeners by the combination of cell size (about 90 x 60 microm in vivo), 9-11 conspicuous dorsal ridges, one fine and seven strong frontoventral cirri, six membranelles in anterior portion of adoral zone, and 17-23 membranelles in posterior portion of adoral zone. The comparison with similar congeners clearly supports the distinction of this new species based on morphological and small subunit (SSU) rRNA gene sequence studies. The SSU rRNA gene sequence similarity within the genus is about 75.3-92.1% which indicates that this is a distinct form. Phylogenetic trees based on SSU rRNA gene information show that A. hongkongensis groups with A. leptaspis.

Biodiversity of marine scuticociliates (Protozoa, Ciliophora) from China: Description of seven morphotypes including a new species, Philaster sinensis spec. nov.

Seven marine scuticociliates, Philaster sinensis spec. nov., Pseudocohnilembus hargisi Evans and Thompson, 1964. J. Protozool. 11, 344, Parauronema virginianum Thompson, 1967. J. Protozool. 14, 731, Uronemella filificum (Kahl, 1931. Tierwelt. Dtl. 21, 181) Song and Wilbert, 2002. Zool. Anz. 241, 317, Cohnilembus verminus Kahl, 1931, Parauronema longum Song, 1995. J. Ocean Univ. China. 25, 461 and Glauconema trihymene Thompson, 1966. J. Protozool. 13, 393, collected from Chinese coastal waters, were investigated using live observations, silver impregnation methods, and, in the case of the new species, SSU rDNA sequencing. Philaster sinensis spec. nov. can be recognized by the combination of the following characters: body cylindrical, approximately 130-150 × 35-55 μm in vivo; apical end slightly to distinctly pointed, posterior generally rounded; 19-22 somatic kineties; M1 triangular, consisting of 13 or 14 transverse rows of kinetosomes; M2 comprising 10-12 longitudinal rows; CVP positioned at end of SK1; marine habitat. We also provide improved diagnoses for Pseudocohnilembus hargisi, Parauronema virginianum, Uronemella filificum and Parauronema longum based on their original descriptions as well as the present work. Phylogenetic analyses support the monophyly of the genus Philaster.

The Morphology of Three Loxophyllum Species (Ciliophora, Pleurostomatida) from Southern China, L. lembum sp. n., L. vesiculosum sp. n. and L. perihoplophorum Buddenbrock, 1920, with Notes on the Molecular Phylogeny of Loxophyllum

Two new pleurostomatid ciliates, Loxophyllum lembum sp. n., L. vesiculosum sp. n., and the poorly known L. perihoplophorum Buddenbrock, 1920, isolated from brackish waters in coastal regions of southern China, are described following observations of live cells and protargol‐impregnated specimens. Loxophyllum lembum sp. n. is distinguished by a combination of characters including two macronuclear nodules, 6–9 contractile vacuoles along the ventral margin, 11–14 right and 6–8 left kineties and the presence of cortical granules. Loxophyllum vesiculosum sp. n. differs from its congeners mainly by the unique distribution of contractile vacuoles, several of which lie along the dorsal margin and one on the ventral margin, and 15–21 right and 6–8 left kineties. Loxophyllum perihoplophorum is characterized by its large cell size (350–450 μm long in vivo), 3–5 contractile vacuoles along the dorsal margin in the posterior region of the body, and 19–23 right and 7–9 left kineties. An improved diagnosis of L. perihoplophorum is provided. The SSU rDNA sequence of L. perihoplophorum is reported for the first time and its molecular phylogeny is analyzed. Maximum likelihood and Bayesian inference analyses of SSU rDNA sequence data recover the monophyly both of the order Pleurostomatida and of the genus Loxophyllum.

A Morphogenetic Description of Thigmokeronopsis stoecki Shao et al., 2008 (Ciliophora, Hypotricha) and a Comparison with Members of the Family Pseudokeronopsidae

The urostylid family Pseudokeronopsidae Borror and Wicklow, 1983 was considered to be a well-outlined taxon. Nevertheless, recent evidence, including morphological, ontogenetic, and molecular information, has consistently revealed the polyphyly of this family. In the present work, a new population of Thigmokeronopsis stoecki Shao et al., 2008 was found and its binary divisional process was described for the first time. In addition, the morphogenetic features of Thigmokeronopsis species and all the other pseudokeronopsids, for which detailed ontogenetic data are available, were rechecked and compared. This reveals that: (1) the ontogenetic process of T. stoecki corresponds well with its congeners T. jahodai and T. rubra except for the macronuclear behavior; (2) Apokeronopsis and Thigmokeronopsis share a similar ontogenetic mode despite of the differences in the number and origin of their buccal cirri; (3) most pseudokeronopsids share the same pattern in the origins of their oral primordia and fronto-ventral-transverse cirral anlagen, except for Pseudokeronopsis similis, which may not be a valid member of the family Pseudokeronopsidae.