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1.
A new genus and species of tetraphyllidean cestode, Caulopatera pagei n. g., n. sp., is described from the grey carpetshark Chiloscyllium punctatum Müller & Henle in Moreton Bay, Australia. The new genus is placed in the Phyllobothriidae, subfamily Phyllobothriinae. Caulopatera n. g. is distinct from all other phyllobothriine genera in having stalked, circular, non-loculate bothridia that lack an apical sucker, testes that are restricted to the region anterior to the cirrus-sac and circum-medullary vitelline follicles. The new genus most closely resembles Carpobothrium Shipley & Hornell, 1906, with which it shares non-loculate, stalked, unhooked bothridia without an accessory sucker and testes that are entirely anterior to the cirrus-sac, but differs from it in that it lacks a slit-like opening in each bothridium and flaps surrounding the opening. The possession of bothridial stalks is consistent with two cestode orders, the Tetraphyllidea and the Rhinebothriidea. The morphology of the bothridial stalks is consistent with other tetraphyllidean genera, in that Caulopatera possesses triangular bothridial stalks surrounding the back of the bothridia, indicating that it belongs in the Tetraphyllidea senso stricto, rather than in the recently recognised Rhinebothriidea.  相似文献   

2.
Novel molecular data are presented to resolve the long-standing issue of the non-monophyly of the elasmobranch-hosted tapeworm order Tetraphyllidea relative to the other acetabulate eucestode orders. Bayesian inference analyses of various combinations of full ssrDNA, and full or partial lsrDNA (D1–D3), sequence data, which included 134 species representing 97 genera across the 15 eucestode orders, were conducted. New ssrDNA data were generated for 82 species, partial lsrDNA data for 53 species, and full lsrDNA data for 29 species. The monophyly of each of the elasmobranch-hosted orders Cathetocephalidea, Litobothriidea, Lecanicephalidea and Rhinebothriidea was confirmed, as was the non-monophyly of the Tetraphyllidea. Two relatively stable groups of tetraphyllidean taxa emerged and are hereby designated as new orders. The Onchoproteocephalidea n. ord. is established to recognise the integrated nature of one undescribed and 10 described genera of hook-bearing tetraphyllideans, previously placed in the family Onchobothriidae, with the members of the order Proteocephalidea. The Phyllobothriidea n. ord. is established for a subset of 12 non-hooked genera characterised by scoleces bearing four bothridia each with an anterior accessory sucker; most parasitise sharks and have been assigned to the Phyllobothriidae at one time or another. Tentative ordinal placements are suggested for eight additional genera; placements for the remaining tetraphyllidean genera have not yet emerged. We propose that these 17 genera remain in the “Tetraphyllidea”. Among these, particularly labile across analyses were Anthobothrium, Megalonchos, Carpobothrium, Calliobothrium and Caulobothrium. The unique association of Chimaerocestus with holocephalans, rather than with elasmobranchs, appears to represent a host-switching event. Both of the non-elasmobranch hosted clades of acetabulate cestodes (i.e. Proteocephalidea and Cyclophyllidea and their kin) appear to have had their origins with elasmobranch cestodes. Across analyses, the sister group to the clade of “terrestrial” cestode orders was found to be an elasmobranch-hosted genus, as was the sister to the freshwater fish- and tetrapod-hosted Proteocephalidea. Whilst further data are required to resolve outstanding nomenclatural and phylogenetic issues, the present analyses contribute significantly to an understanding of the evolutionary radiation of the entire Cestoda. Clearly, elasmobranch tapeworms comprise the backbone of cestode phylogeny.  相似文献   

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4.
Scalithrium gen. n. (Cestoda, Tetraphyllidea) is proposed with Scalithrium minimum (Van Beneden, 1850) n. comb., parasite of Dasyatis pastinaca (Elasmobranchii, Dasyatidae) as type-species. The new genus Scalithrium (Tetraphyllidea, Phyllobothriidae, Rhinebothriinae) is erected for several species previously included in the genus Rhinebothrium. These species have a scolex with four bothridia, the distal surface of which is divided by transverse septa in a single row of loculi. Scalithrium minimum (Van Beneden, 1850) n. comb. is redescribed from specimens collected from the type-host Dasyatis pastinaca in Tunisia and becomes the type-species of the new genus. After Braun (1900) Echeneibothrium variabile Van Beneden, 1850 is considered as type-species of the genus Echeneibothrium. Species of Rhinebothriinae to be transferred into the genus Scalithrium are discussed and a key is proposed for the eight species.  相似文献   

5.
In total, 20 fanrays, Platyrhina sinensis (Rajiformes: Rhinobatidae), collected from the Taiwan Strait, were examined. A new phyllobothriid genus and species (Tetraphyllidea: Phyllobothriidae) was found and described. Biotobothrium platyrhina n. gen., n. sp. is assigned to the Rhinebothriinae Euzet, 1953, because it possesses 4 stalked bothridia that are each divided by septa into numerous small facial loculi but that lack apical suckers. The new genus and species is clearly different from any other in Rhinebothriinae in that each bothridium bears 2 sets of 5 small facial loculi, with 1 set located at each of the distal ends of the bothridium, rather than facial loculi throughout the entire distal surface of the bothridium, as is seen in all other genera in the subfamily. This character has not been previously reported for members of Rhinebothriinae. In addition, the testicular arrangement in the anterior quarter of the proglottid is unique. The posterior range of the vas deferens almost reaches the ovarian bridge, and the morphology of the cirrus sac and several other morphological characters are at variance with presently described species in the subfamily.  相似文献   

6.
The construction of a stable phylogeny for the Cestoda, indicating the interrelationships of recognised orders and other major lineages, has proceeded iteratively since the group first received attention from phylogenetic systematists. Molecular analyses using nuclear ribosomal RNA gene fragments from the small (ssrDNA) and large (lsrDNA) subunits have been used to test competing evolutionary scenarios based on morphological data but could not arbitrate between some key conflicting hypotheses. To the ribosomal data, we have added a contiguous fragment of mitochondrial (mt) genome data (mtDNA) of partial nad1-trnN-trnP-trnI-trnK-nad3-trnS-trnW-cox1-trnT-rrnL-trnC-partial rrnS, spanning 4034-4447 bp, where new data for this region were generated for 18 species. Bayesian analysis of mtDNA and rDNA as nucleotides, and where appropriate as amino acids, demonstrated that these two classes of genes provide complementary signal across the phylogeny. In all analyses, except when using mt amino acids only, the Gyrocotylidea is sister group to all other Cestoda (Nephroposticophora), and Amphilinidea forms the sister group to the Eucestoda. However, an earliest-diverging position of Amphilinidea is strongly supported in the mt amino acid analysis. Amphilinidea exhibit a unique tRNA arrangement (nad1-trnI-trnL2-trnP-trnK-trnV-trnA-trnN-nad3), whereas Gyrocotylidea shares that of the derived lineages, providing additional evidence of the uniqueness of amphilinid genes and genomes. The addition of mtDNA to the rDNA genes supported the Caryophyllidea as the sister group to (Spathebothriidea+remaining Eucestoda), a hypothesis consistently supported by morphology. This relationship suggests a history of step-wise evolutionary transitions from simple monozoic, unsegmented tapeworms to the more familiar polyzoic, externally segmented (strobilate) forms. All our data partitions recovered Haplobothriidea as the sister group to Diphyllobothriidae. The sister-group relationship between Diphyllidea and Trypanorhyncha, as previously established using rDNA, is not supported by the mt data, although it is supported by the combined mt and rDNA analysis. With regards to the more derived taxa, in all except the mt amino acid analysis, the following topology is supported: (Bothriocephalidea (Litobothriidea (Lecanicephalidea (Rhinebothriidea (Tetraphyllidea, (Acanthobothrium, Proteocephalidea), (Nippotaeniidea, Mesocestoididae, Tetrabothriidea, Cyclophyllidea)))))), where the Tetraphyllidea are paraphyletic. Evidence from the mt data provides strong (nucleotides) to moderate (amino acids) support for Tetraphyllidea forming a group to the inclusion of Proteocephalidea, with the latter consistently forming the sister group to Acanthobothrium. The interrelationships among Nippotaeniidea, Mesocestoididae, Tetrabothriidea and Cyclophyllidea remain ambiguous and require further systematic attention. Mitochondrial and nuclear rDNA data provide conflicting signal for certain parts of the cestode tree. In some cases mt data offer results in line with morphological evidence, such as the interrelationships of the early divergent lineages. Also, Tetraphyllidea, although remaining paraphyletic with the inclusion of the Proteocephalidea, does not include the most derived cestodes; a result which has consistently been obtained with rDNA.  相似文献   

7.
8.
The parasites of hosts of conservation concern are often poorly known. This is the case with the iconic group of elasmobranchs known as the sawfish of the genus Pristis, all four species of which are considered as Endangered or Critically Endangered by the International Union for Conservation of Nature (IUCN, Switzerland). Examination of cestodes from three species of sawfish (Pristis pristis, Pristis clavata, and Pristis zijsron) in Australia and one of their close relatives, the also critically endangered widenose guitarfish, Glaucostegus obtusus, in India, collected over the past 25 years, yielded four new species of tapeworms which are described herein. All four belong to the previously monotypic Mixobothrium; the diagnosis of the genus is revised to accommodate the new species. Among the new taxa is a species that had been included in previous molecular phylogenies but whose identity and affinities within the order Rhinebothriidea, and thus also its familial placement, were unclear. This species exhibits the morphological features of Mixobothrium and thus its identity is, at long last, revealed. Sequence data generated for the 28S rDNA gene for three of the new species, as well as an additional new but yet undescribed species from Pristis pectinata from Florida (USA), confirms the uniqueness of this group among the rhinebothriideans. The new family Mixobothriidae is established to house these taxa. The members of this family differ from all but one of the five other families of rhinebothriideans in lacking apical suckers on their bothridia. They are also distinctive in that their bothridia are divided into three regions. The anterior and posterior regions have similar locular configurations to one another and differ from the locular configuration of the middle region. As a consequence, the bothridia are symmetrical along both their vertical and horizontal axes. We predict that a focus on species of guitarfish in the genus Glaucostegus will be the most productive approach for discovering additional diversity in this family of cestodes.  相似文献   

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11.
The present study analyzed the drosophilid assemblages in different levels of urbanization in the city of Porto Alegre, Rio Grande do Sul, Brazil. Collections were carried out in 2008 in three different environments: a highly urbanized area????Jardim Botanico,?? a forested area with intermediary urbanization????Parque Gabriel Knijnik,?? and in a relatively well-preserved forested area, although threatened by the urban growth????Morro Santana.?? In Jardim Botanico, 36 species belonging to four genera were found, with high abundance of exotic species as Drosophila simulans Sturtevant and Zaprionus indianus (Gupta). In Parque Gabriel Knijnik, 33 species that belonged to four genera were found, with higher abundances of native species belonging to the Drosophila tripunctata species group and Drosophila willistoni species subgroup, and lower abundance of exotic species. As for Morro Santana, 32 species and three genera were found, with higher abundances of native groups, low representativeness of exotic species, and absence of Zaprionus indianus. The analysis of the Jaccard index showed higher similarity in the species composition between samples collected in summer and autumn, and between samples collected in winter and spring. On the other hand, the Morisita index differentiated Jardim Botanico from the other two studied sites. Our results show that Morro Santana is an important area of native biodiversity, reinforcing, therefore, the inclusion of this area in the project for the creation of an ecological corridor as proposed by the Ministry of the Environment of Brazil.  相似文献   

12.
Subtribe Galipeinae (tribe Galipeeae, subfamily Rutoideae) is the most diverse group of Neotropical Rutaceae, with 28 genera and approximately 130 species. One of its genera is Almeidea, whose species are morphologically similar to those of the genus Conchocarpus. Species of Almeidea occur in the Atlantic Rain Forest of Eastern Brazil, with one species (Almeidea rubra) also present in Bolivia. The objective of this study was to perform a phylogenetic analysis of Almeidea, using a broader sampling of Galipeinae and other Neotropical Rutaceae, the first such study focused on this subtribe. To achieve this objective, morphological data and molecular data from the nuclear markers ITS-1 and ITS-2 and the plastid markers trnL-trnF and rps16 were obtained. Representatives of eight genera of Galipeinae and three genera of Pilocarpinae (included also in Galipeeae) and Hortia (closely related to Galipeeae) were used. Five species of Almeidea and seven of Conchocarpus were included, given the morphological proximity between these two genera. Individual (for each molecular marker) and combined phylogenetic analyses were made, using parsimony and Bayesian inference as optimization criteria. Results showed Galipeinae as monophyletic, with the species of Almeidea also monophyletic (supported by the presence of pantocolporate pollen) and nested in a clade with a group of species of Conchocarpus, a non-monophyletic group. Additionally, C. concinnus appeared in a group with Andreadoxa, Erythrochiton, and Neoraputia, other members of Galipeinae. As a result, Conchocarpus would be monophyletic only with the exclusion of a group of species related to C. concinnus and with the inclusion of all species of Almeidea with the group of species of Conchocarpus that includes its type species, C. macrophyllus. Thus, species of Almeidea are transferred to Conchocarpus, and the new combinations are made here.  相似文献   

13.
Strains originally affiliated to the genera Scopulariopsis and Microascus were compared regarding the scopularide production in order to investigate their ability to produce the cyclodepsipeptides and select the best suited candidate for subsequent optimisation processes. Phylogenetic calculations using available sequences of the genera Scopulariopsis and Microascus revealed that most of the sequences clustered within two closely related groups, comprising mainly Scopulariopsis/Microascus brevicaulis and Microascus sp., respectively. Interestingly, high yields of scopularide A were exhibited by three strains belonging to S./M. brevicaulis, while lower titres were observed for two strains of Microascus sp. Close phylogenetic distances within and between the two groups supported the proposed combination of both genera into one holomorph group. Short phylogenetic distances did not allow a clear affiliation at the species level on the basis of ribosomal DNA sequences, especially for Microascus sp. strains. Additionally, several sequences originating from strains assigned to Scopulariopsis exhibited a polyphyletic nature. The production pattern is in accordance with the phylogenetic position of the strains and significant production of scopularide B could only be observed for the S./M. brevicaulis strain LF580. Thus, the phylogenetic position marks the biotechnologically interesting strains and matters in optimisation strategies. In conclusion, the ability of all five strains to produce at least one of the scopularides suggests a distribution of the responsible gene cluster within the holomorph group. Setting the focus on the production of the cyclodepsipeptides, strain LF580 represents the best candidate for further strain and process optimisation.  相似文献   

14.
Proteocephalidean tapeworms form a diverse group of parasites currently known from 315 valid species. Most of the diversity of adult proteocephalideans can be found in freshwater fishes (predominantly catfishes), a large proportion infects reptiles, but only a few infect amphibians, and a single species has been found to parasitize possums. Although they have a cosmopolitan distribution, a large proportion of taxa are exclusively found in South America. We analyzed the largest proteocephalidean cestode molecular dataset to date comprising more than 100 species (30 new), including representatives from 54 genera (80%) and all subfamilies, thus significantly improving upon previous works to develop a molecular phylogeny for the group. The Old World origin of proteocephalideans is confirmed, with their more recent expansion in South America. The earliest diverging lineages are composed of Acanthotaeniinae and Gangesiinae but most of the presently recognized subfamilies (and genera) appear not to be monophyletic; a deep systematic reorganization of the order is thus needed and the present subfamilial system should be abandoned. The main characters on which the classical systematics of the group has been built, such as scolex morphology or relative position of genital organs in relation to the longitudinal musculature, are of limited value, as demonstrated by the very weak support for morphologically-defined subfamilies. However, new characters, such as the pattern of uterus development, relative ovary size, and egg structure have been identified, which may be useful in defining phylogenetically well-supported subgroups. A strongly supported lineage infecting various snakes from a wide geographical distribution was found. Although several improvements over previous works regarding phylogenetic resolution and taxon coverage were achieved in this study, the major polytomy in our tree, composed largely of siluriform parasites from the Neotropics, remained unresolved and possibly reflects a rapid radiation. The genus Spasskyellina Freze, 1965 is resurrected for three species of Monticellia bearing spinitriches on the margins of their suckers.  相似文献   

15.
The digestive systems of 86 canefield rats from Ingham, Queensland were examined for parasites. One species of cestode and seven species of nematode were found, all but one being new host records. The helminth community was characterised in terms of core, secondary and satellite species. No core species were identified, but Nippostrongylus typicus and Odilia emanuelae were identified as secondary species. All other species were identified as satellite species. The strongyloid nematode Ancistronema coronatum n. g., n. sp. is described. Ancistronema differs from other genera in the Chabertiidae in having a short buccal capsule and in the number and shape of the elements of the internal and external leaf crowns. This is the first record of a strongyle from Australian rodents. It is postulated that it came into Australia with ancestral Rattus sp. hosts which colonised Australia from Indonesia less than a million years ago.  相似文献   

16.
David M. Johnson 《Brittonia》1989,41(4):356-378
The relationship between the Asian generaDisepalum Hook. f. andEnicosanthellum Ban (Annonaceae) is examined in a revisionary study. Despite the disparate perianth morphologies of the two genera, other characters support inclusion of all species in a single genus with nine species. The monocarp stalks in all species are found to be derived from the receptacle rather than the ovary, and are thus not homologous with those found in most other Annonanceae genera. Cladistic analysis indicates that the species on the mainland of Asia and of montane habitats are more primitive than the species of the lowlands and of Sumatra and Borneo. Two new combinations,Disepalum petelotii andD. plagioneurum, are necessary as a result of merging the two genera, and one species,D. aciculare, is described as new.  相似文献   

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18.
A parasite assemblage of Sebastes miniatus from northwestern Baja California, México, was composed of a total of 12 species: five ectoparasites (two monogeneans and three parasitic copepods) and seven endoparasites (two digeneans, one cestode, three nematodes, and one acanthocephala). Five of these parasites constituted new genera records to the genus Sebastes, and nine were new geographic records. The most abundant species were the endoparasites Parabothriocephalus sagitticeps, Hysterothylacium sp., and Anisakis sp., and the specific richness ranged from 1 to 8 parasite species per host. The most important parasite species in terms of prevalence were Microcotyle sebastis (93 %) and Anisakis sp. (92 %). The mean abundance of parasites found in S. miniatus showed significant variations over the year, with maximum values (31.7 individuals/host) in August, and minimum (0.39 individuals/host) in February. P. sagitticeps showed the highest mean intensity of infection (190.4 parasites/host), followed by Anisakis sp. (127.2 parasites/host) and Hysterothylacium sp. (46.6 parasites/host). The presence of larval stages of the nematodes Anisakis, Pseudoterranova, and Hysterothylacium is particularly important due to their high abundance and prevalence and because they may represent a human health risk (anisakiasis). Rockfishes (family Scorpaenidae) of the genus Sebastes constitute one of the most important groundfish resources in the American and Mexican northern Pacific Ocean, both for recreational and for the commercial fisheries of California and Baja California. These rockfish species makes up a substantial part of the Mexican cuisine.  相似文献   

19.
Aloculibothrium dasyatii n. gen. n. sp. is described from the spiral intestine of Dasyatis sephen Forsskal, 1775 captured at Digha coastal waters, Bay of Bengal, India. This species is placed under the famil Onchobothriidae (Braun, 1900) and erected a new genus Aloculibothrium to accommodate this specimen. The body is 24.22–36.58 mm long and with 310–325 proglottids; scolex rectangular with two parts; anterior bearing four bothridia with paired bifurcated hooks, divided into inner and outer prong and posterior with fleshy collar. The cestode has been compared with all the existing twelve different valid genera under the family Onchobothriidae but to accommodate the present specimens a new genera Aloculibothrium is erected.  相似文献   

20.
利用DNA测序技术对台湾海峡部分鱼类绦虫的16S rRNA和18S rRNA基因片段序列进行了分析。使用PAUP4·0b10软件构建的进化树显示,目前关于绦虫二叶目、锥吻目、假叶目、盘头目和四叶目的划分是比较合理的,绦虫进化基本遵循了头节形态从简单到复杂的进化规律。报道了国内首次发现的双叶目绦虫,进化树结果初步支持了巨槽属和棘头属的划分。此外,结果也支持了前孔属绦虫的分类地位。但是,对耳槽属绦虫与阶室属绦虫的形态学划分与分子系统学相矛盾,利用16S rRNA基因对盘头目各种的进化树分析与形态学差异很大,这些问题都需要更多研究来进行深入分析。  相似文献   

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