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1.
Morphological data from life, protargol impregnation, and scanning electron microscopy were combined with genetic data not only to describe the marine plankton ciliates Pelagostrobilidium neptuni (Montagnes and Taylor, 1994) Petz, Song, and Wilbert, 1995 and Strombidium biarmatum nov. spec., but also to elucidate their phylogenetic relationships. Additionally, the ontogenesis of P. neptuni was studied and the diagnosis of the genus Pelagostrobilidium was improved due to further data from the newly affiliated species P. epacrum (Lynn and Montagnes, 1988) nov. comb. (basionym: Strobilidium epacrum Lynn and Montagnes, 1988). The phylogenetic analysis of the small subunit ribosomal RNA genes matched the morphologic and ontogenetic assigning of P. neptuni to the choreotrichid family Strobilidiidae. The considerable genetic distance of d = 0.074 between P. neptuni and Strobilidium caudatum corroborated the morphological differences and thus the maintenance of the genus Pelagostrobilidium. Strombidium biarmatum nov. spec. is a typical member of the genus, except for the two types of extrusomes ("trichites"): ~12 × 0.5 μm, needle-shaped ones attached anterior to the girdle kinety and ~6 × 0.5 μm, rod-shaped ones at the distal end of the intermembranellar ridges. Its flask-shaped resting cysts have several strong spines. In accordance with the morphologic data, S. biarmatum is placed within the order Oligotrichida by gene sequence analysis. The great genetic distances within the oligotrichids support the diversity found in morphologic and ontogenetic studies.  相似文献   

2.
3.
Fifty-six features of halteriid, oligotrichid, and choreotrichid ciliates are cladistically analysed, including an updated hypothesis about the evolution of the somatic ciliary patterns. Based on its morphology, Lynnella clusters with Parastrombidinopsis, Parastrombidium, and Strombidinopsis, while it is basal to the other choreotrichids in the molecular phylogenies. The two clusters of Favella species in small subunit rRNA gene trees are supported by morphological features, justifying a separation at genus and family level. The genus Favella has a smooth lorica surface and a somatic ciliary pattern comprising a left and lateral ciliary field as well as two dorsal kineties and a monokinetidal ventral kinety abutting on the right ciliary field. The new genus Schmidingerella n. gen., established for the second Favella cluster, groups with Metacylis and Rhabdonella in the molecular trees. It differs from Favella in (i) a lorica wall with reticulate surface ridges and minute openings and (ii) a ventral kinety that is distinctly apart from the right ciliary field and composed of a monokinetidal anterior and a dikinetidal posterior portion. The genera Codonaria, Codonella, and Codonellopsis are affiliated with the family Dictyocystidae, whose diagnosis is improved to include the lorica sac.  相似文献   

4.
DNA barcoding of fishes of Laguna de Bay, Philippines   总被引:2,自引:0,他引:2  
Laguna de Bay, the largest lake in the Philippines, is an important part of the country's fisheries industry. It is also home to a number of endemic fishes including Gobiopterus lacustris (Herre 1927) of family Gobiidae, Leiopotherapon plumbeus (Kner 1864) of family Terapontidae, Zenarchopterus philippinus (Peters 1868) of family Hemiramphidae and Arius manillensis Valenciennes 1840 of family Ariidae. Over the years, a steady decline has been observed in the abundance and diversity of native fishes in the lake due to anthropogenic disturbances. In this study, a total of 71 specimens of 18 different species belonging to 18 genera, 16 families, and seven orders were DNA barcoded using the mitochondrial cytochrome c oxidase subunit I (COI) gene. All of the fish species were discriminated by their COI sequences and one endemic species G. lacustris, showing deep genetic divergence, was highlighted for further taxonomic investigation. Average Kimura 2-parameter genetic distances within species, family, and order were 1.33%, 18.91%, and 24.22%, respectively. These values show that COI divergence increases as taxa become less exclusive. All of the COI sequences obtained were grouped together according to their species designation in the Neighbor-joining tree that was constructed. This study demonstrated that DNA barcoding has great potential as a tool for fast and accurate species identification and also for highlighting species that warrant further taxonomic investigation.  相似文献   

5.
We studied the morphology, morphometry, resting, and reproductive cysts, as well as the molecular phylogeny of Bryophrya gemmea n. sp., a colpodid ciliate that was discovered in ephemeral puddles in Idaho, northwest United States. This new species is distinguished from congeners by the irregularly pentagonal adoral organelles, four to five vestibular kineties, the single micronucleus, and one to three rows of brightly refractive protuberant interkinetal cortical granules to the right of the preoral suture. Resting cysts have two distinct membranes and an outer mucous coat. As typical for most colpodids, reproduction occurs in division cysts but details of ontogenesis are unknown. The 18S rRNA gene sequence shows only weak support for the phylogenetic relationship between Bryophrya and the bryophryid genus Notoxoma previously inferred from morphologic characters. Further, our molecular phylogenies classify bryophryids rather basal within the order Colpodida, not supporting ordinal status suggested by morphologists. Based on molecular data and morphologic characters, the colpodid genus Ilsiella is removed from the family Marynidae and placed in a new family, Ilsiellidae. Considering the molecular data, an evolutionary scenario for the formation of colpodid oral structures from a cyrtolophosidid ancestor through a bryophryid intermediate is proposed.  相似文献   

6.
The phylogenetic relationships of nine species of freshwater sponges, representing the families Spongillidae, Lubomirskiidae, and Metaniidae, were inferred from analyses of 18S rDNA, cytochrome oxidase subunit I (COI) mtDNA, and internal transcribed spacer 2 (ITS2) rDNA sequences. These species form a strongly supported monophyletic group within the Demospongiae, with the lithistid Vetulina stalactites as the sister taxon. Within the freshwater sponge clade, the basal taxon is not resolved. Depending upon the method of analysis and sequence, the metaniid species, Corvomeyenia sp., or the spongillid species, Trochospongilla pennsylvanica , emerges as the basal species. Among the remaining freshwater sponge species, the spongillids, Spongilla lacustris and Eunapius fragilis , form a sister group to a clade comprised of the spongillid species, Clypeatula cooperensis , Ephydatia fluviatilis , and Ephydatia muelleri , and the lubomirskiid species, Baikalospongia bacillifera and Lubomisrkia baicalensis . C. cooperensis is the sister taxon of E. fluvialitis , and E. muelleri is the sister taxon of ( B. bacillifera + L. baicalensis ). The family Spongillidae and the genus Ephydatia are thus paraphyletic with respect to the lubomirskiid species; Ephydatia is also paraphyletic to C. cooperensis . We suggest that C. cooperensis be transferred to the genus Ephydatia and that the family Lubomirskiidae be subsumed into the Spongillidae.  相似文献   

7.
Three-spined sticklebacks Gasterosteus aculeatus are frequent paratenic hosts of the nematode parasites Anguillicola crassus and Camallanus lacustris. As paratenic hosts, sticklebacks could spread infection by carrying high numbers of infective stages. In contrast, low infective ability of either parasite for the paratenic host could hinder the spread of infection. In the present study, G. aculeatus was, for the first time, infected under controlled laboratory conditions with defined doses of the parasites. Sticklebacks were exposed to 6, 12, 18 and 24 parasite larvae to determine the infective ability of the 2 nematode species. There were significantly higher infection rates for C. lacustris (18 to 49%) than for A. crassus (4 to 14%) at each exposure dose. In C. lacustris-infected sticklebacks, infection rates tended to be highest after exposure to 12 C. lacustris larvae and lowest after exposure to 24 parasites. In A. crassus-infected sticklebacks, no effect of parasite exposure dose on infection rates was observed. Immunity parameters such as respiratory burst activity and lymphocyte proliferation of head kidney leukocytes recorded 18 wk post exposure were not significantly affected by either parasite or exposure dose. Granulocyte:lymphocyte ratios were elevated only within the stickleback group showing the highest infection intensity of C. lacustris, i.e. to those exposed 18 parasites.  相似文献   

8.
The phylogenetic relationship of the freshwater sponges (Porifera) in Lake Baikal is not well understood. A polyphyletic and/or monophyletic origin have been proposed. The (endemic) Baikalian sponges have been subdivided into two families: endemic Lubomirskiidae and cosmopolitan Spongillidae. In the present study, two new approaches have been made to resolve the phylogenetic relationship of Baikalian sponges; analysis of (1) nucleotide sequences from one mitochondrial gene, the cytochrome oxidase subunit I (COI) and of (2) one selected intron from the tubulin gene. Specimens from the following endemic Baikalian sponge species have been studied; Lubomirskia baicalensis , Baikalospongia intermedia, Baikalospongia recta , Baikalospongia bacillifera and Swartschewskia papyracea . They are all grouped to the family of Lubomirskiidae. Sequence comparisons were performed with the ubiquitously distributed freshwater sponge Spongilla lacustris (family Spongillidae) as well as with one marine sponge, Suberites domuncula . A sequence comparison * * The sequences reported here are being deposited in the EMBL data base. of the mitochondrial COI gene revealed a monophyletic grouping of the endemic Baikalian sponges with S. lacustris as the most related species to the common ancestor. The sequences of the COI gene from B. recta , B. intermedia , B. bacillifera and L. baicalensis were found to be identical and separated from those of S. lacustris and S. papyracea . In a second approach, the exon/intron sequences framing the intron‐2 of the sponge tubulin gene were chosen for the phylogenetic analysis. The intron sequences were aligned and used for construction of a phylogenetic tree. This analysis revealed again a monophyletic grouping with S. lacustris as the closest related species to the common ancestor. It is concluded that the Baikalian sponges, which have been studied here, are of monophyletic origin. Furthermore, the data suggest that the endemic species S. papyracea is the phylogenetically oldest, extant, endemic Baikalian sponge species.  相似文献   

9.
10.
A new genus and species of freshwater sponge, Clypeatula cooperensis , collected from three lakes in the Northern Rocky Mountains of Montana, USA, are described. The sponge grows as a hard, disc-shaped encrustation on the undersides of rocks and logs. It lacks microscleres and has amphioxeal megascleres that often show a slight midregion bulb and are usually covered with short, conical spines except at their tips. The sponge is also non-gemmulating, overwintering in a regressed state in which choanocyte chambers are reduced in number. Phylogenetic analyses of complete 18S rDNA sequences of C. cooperensis , Ephydatia muelleri , Spongilla lacustris and Eunapius fragilis suggest that C. cooperensis is more closely related to Ephydatia muelleri than to Spongilla lacustris or Eunapius fragilis . Our data, nonetheless, do not rule out the possibility that C. cooperensis is more closely related to the non-gemmulating sponges of Lake Baikal (Russia) than it is to Ephydatia muelleri . These phylogenetic analyses support the erection of a new genus, the monophyly of freshwater sponges belonging to the families Spongillidae and Lubomirskiidae, and the monophyly of demosponges.  相似文献   

11.
Evolutionary relationships of taxa within the ciliate subclass Haptoria are poorly understood. In this study, we broaden the taxon sampling by adding 14 small subunit ribosomal RNA gene sequences, 13 large subunit ribosomal RNA gene sequences and 13 ITS1‐5.8S‐ITS2 gene sequences of haptorians. This includes the first molecular data from two genera, Pseudotrachelocerca Song, 1990, and Foissnerides Song & Wilbert, 1989. Phylogenies inferred from the three individual genes and concatenated data sets show that: (i) the subclass Haptoria could be a multiphyletic complex with about up to four main clades while “interrupted” by some intermingled with the related subclasses Rhynchostomatia, Trichostomatia and some incertae sedis; (ii) the genus Pseudotrachelocerca Song, 1990, is clearly separated from Litostomatea and clusters within an assemblage comprising the classes Prostomatea, Colpodea and Plagiopylea; (iii) both morphological evidence and molecular evidence indicate that the genus Foissnerides should be transferred from family Trachelophyllidae to Pseudoholophryidae; (iv) the validity of the order Helicoprorodontida Grain, 1994, and its monophyly is strongly supported; (5) the family Chaeneidae does not belong to the order Lacrymarida but represents a distinct clade in the subclass Haptoria.  相似文献   

12.
Parrotfishes of the genus Sparisoma (Scaridae) are ecologically important tropical reef fishes restricted to the Atlantic Ocean. We investigated phylogenetic relationships among the eight extant species within this genus using mitochondrially encoded 12S and 16S ribosomal genes. Our molecular data support the view that (i) Sparisoma originated approximately 14-35 million years ago (mya), probably in the tropical western Atlantic, off Brazil; (ii) there have been at least four discrete bouts of cladogenesis within the genus, with the most recent one ( approximately 2.8-5.6 mya) involving four events in both the east and the west Atlantic and across the Atlantic; and (iii) the genus invaded the eastern Atlantic on two different occasions, probably by at least two different routes. The data also offer support for Bellwood's ideas concerning the evolutionary changes in adult feeding patterns and habitat use within Scarids. Specifically, they support the evolutionary position of the ecological traits of Sparisoma as intermediate within the family.  相似文献   

13.
ABSTRACT. We discovered a free‐living peritrich ciliate with outstanding features in the River Rhine. Its morphology and 18S rRNA gene sequence were studied with standard methods. Apocarchesium arndti n. sp. has several peculiarities. (i) There are ordinary zooids, macrozooids, and microzooids, which form a hemispherical rosette on a discoidal base, the stalk dish, locking the ~18 μm wide and up to 2 mm long, spirally contracting colony stalk. (ii) The stalk myoneme is connected only to the microzooids. (iii) A rosette contains up to 50 zooids not connected to each other but individually attached to the stalk dish with the scopula. (iv) The ordinary zooids are epistylidid, trumpet‐shaped (~6:1 length:width), about 180 × 30 μm in size, and have an ellipsoidal macronucleus subapically between oral cavity and dorsal side. (v) The myoneme system of the zooids, which can contract individually, forms a tube‐like structure in the narrow posterior half of the cell. (vi) The silverline pattern belongs to the transverse‐striate type. (vii) The oral apparatus is of usual structure, with kinety 1 of peniculus 3 distinctly shortened proximally. (viii) The 18S rRNA places A. arndti n. sp. as a distinct lineage near Vorticella and Carchesium. These data are used to provide an improved diagnosis of the genus Apocarchesium. Features (i)–(iii) and the molecular data indicate that Apocarchesium could be the type genus of a new peritrich family.  相似文献   

14.
Rhagodes Pocock, 1897 is the most speciose genus within the family Rhagodidae and species diagnosis is often very difficult. We found Rhagodes eylandti (Walter, 1889) for the first time again since the 1930s and redescribe some morphological features of the male and compare them with the literature. The main diagnostic characters are illustrated.  相似文献   

15.
McDonagh LM  Stevens JR 《Parasitology》2011,138(13):1760-1777
The Calliphoridae include some of the most economically significant myiasis-causing flies in the world - blowflies and screwworm flies - with many being notorious for their parasitism of livestock. However, despite more than 50 years of research, key taxonomic relationships within the family remain unresolved. This study utilizes nucleotide sequence data from the protein-coding genes COX1 (mitochondrial) and EF1α (nuclear), and the 28S rRNA (nuclear) gene, from 57 blowfly taxa to improve resolution of key evolutionary relationships within the family Calliphoridae. Bayesian phylogenetic inference was carried out for each single-gene data set, demonstrating significant topological difference between the three gene trees. Nevertheless, all gene trees supported a Calliphorinae-Luciliinae subfamily sister-lineage, with respect to Chrysomyinae. In addition, this study also elucidates the taxonomic and evolutionary status of several less well-studied groups, including the genus Bengalia (either within Calliphoridae or as a separate sister-family), genus Onesia (as a sister-genera to, or sub-genera within, Calliphora), genus Dyscritomyia and Lucilia bufonivora, a specialised parasite of frogs and toads. The occurrence of cross-species hybridisation within Calliphoridae is also further explored, focusing on the two economically significant species Lucilia cuprina and Lucilia sericata. In summary, this study represents the most comprehensive molecular phylogenetic analysis of family Calliphoridae undertaken to date.  相似文献   

16.
A total of 104 osteological and external morphological features were examined in 13 species of Acestrorhynchus and 15 outgroup taxa to advance a hypothesis of relationships within the genus. Two most parsimonious hypotheses corroborate the monophyly of Acestrorhynchus but differ in the hypothesized relationships of Acestrorhynchus heterolepis . Three proposed supraspecific assemblages are at least partially correlated with groups of species previously diagnosed on the basis of colour pattern: (1) Acestrorhynchus britskii , Acestrorhynchus grandoculis , Acestrorhynchus microlepis , and Acestrorhynchus minimus ; (2) Acestrorhynchus falcirostris , Acestrorhynchus isalineae , and A. Acestrorhynchus nasutus ; and (3) Acestrorhynchus abbreviatus , Acestrorhynchus altus , Acestrorhynchus falcatus , Acestrorhynchus lacustris , and Acestrorhynchus pantaneiro . In one hypothesis A. heterolepis is proposed as the closest relative of the clade formed by A. falcirostris , A. isalineae , and A. nasutus , and in the alternative hypothesis it is proposed as a sister species of the clade formed by A. abbreviatus , A. altus , A. falcatus , A. lacustris , and A. pantaneiro . Relationships among species of the latter clade remain unresolved. Two independent episodes of reduction of body size are hypothesized to have occurred within the genus: one associated with the clade formed by A. grandoculis and A. minimus , and the other with the clade formed by A. isalineae and A. nasutus . © 2007 The Linnean Society of London, Zoological Journal of the Linnean Society , 2007, 151 , 691–757.  相似文献   

17.
A new genus and species of Draconematidae Filipjev, 1918, Megadraconema cornutum gen. nov., sp. nov., inhabiting subtidal sediments in Jejudo, Korea is described. Megadraconema cornutum gen. nov., sp. nov. is mainly characterized by a long body (1630-2220 μm), presence of a transverse circle of well-developed papillae-like cuticular protrusions at the base of the lip region, a head capsule with reticular structure of subcuticle, an amphid with a pore-like opening, and an internal, bar-shaped fovea. The diagnosis of the family Draconematidae is emended and a key to genus is provided based on their major differential diagnostic characteristics, summarized in a table. Phylogenetic relationships of all the genera within the Draconematidae are discussed for the first time, based on molecular analyses and morphological features. The phylogenetic position of the new genus and relationships within the family Draconematidae based on analysis of molecular sequence data are examined. Analysis of 18S rRNA gene sequences does not support the currently accepted classification, and indicates paraphyly of the subfamily Draconematinae.  相似文献   

18.
Artedidraconids (Plunderfishes) are small benthic notothenioid fishes of the Antarctic and South Georgia shelf and slope. The family Artedidraconidae is monophyletic; however, the relationships within the family have remained poorly explored until now, and based on a small sample of the genus Artedidraco. The present study focuses on the interrelationships among the artedidraconid genera and the phylogeny of the genus Artedidraco. 2,353 base pairs from 77 specimens were sequenced from the partial mitochondrial cytochrome oxidase I gene and cytochrome b gene, the partial mitochondrial control region and the partial nuclear rhodopsin retrogene. The genus Artedidraco is not monophyletic, confirming the preliminary relationships found by Derome et al. (Mol Phylogenet Evol 24:139–152, 2002): Pogonophryne, Dolloidraco and Histiodraco are well embedded within the genus Artedidraco. From Artedidraco skottsbergi and A. loennbergi to A. orianae and A. mirus, the tree shows that there is an increasing number of upper lateral line tubular scales and decreasing number of disc-shaped scales. There is also a trend toward a decrease in the number of epipleural ribs and an increase in number of pleural ribs along the tree.  相似文献   

19.
20.
An orange-pigmented, Gram-negative, nonmotile, strictly aerobic and oxidase- and catalase-positive bacterium (SM-A87(T)) was isolated from the deep-sea sediment of the southern Okinawa Trough area. The main fatty acids were i15 : 0, i17 : 0 3OH, i15 : 1 G, i17 : 1 omega 9c, 15 : 0, i15 : 0 3OH and summed feature 3 (comprising i-15 : 0 2OH and/or 16 : 1 omega 7c). MK-6 was the predominant respiratory quinone. DNA G+C content was 35.8 mol%. Flexirubin-type pigments were absent. Phylogenetic analyses based on 16S rRNA gene sequences revealed that strain SM-A87(T) formed a distinct lineage within the family Flavobacteriaceae, with <93% sequence similarity to the nearest strain of genus Salegentibacter. Moreover, strain SM-A87(T) could be distinguished from the nearest phylogenetic neighbors by a number of chemotaxonomic and phenotypic properties. On the basis of polyphasic analyses, it is proposed that strain SM-A87(T) be classified in a novel genus and a new species in the family Flavobacteriaceae, designated Wangia profunda gen. nov., sp. nov. The type strain is SM-A87(T) (CCTCC AB 206139(T)=DSM 18752).  相似文献   

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