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1.
Current and past parasite transmission may depend on the overlap of host distributions, potentially affecting parasite specificity and co-evolutionary processes. Nonetheless, parasite diversification may take place in sympatry when parasites are transmitted by vectors with low mobility. Here, we test the co-speciation hypothesis between lizard final hosts of the Family Lacertidae, and blood parasites of the genus Schellackia, which are potentially transmitted by haematophagous mites. The effects of current distributional overlap of host species on parasite specificity are also investigated. We sampled 27 localities on the Iberian Peninsula and three in northern Africa, and collected blood samples from 981 individual lizards of seven genera and 18 species. The overall prevalence of infection by parasites of the genus Schellackia was ~35%. We detected 16 Schellackia haplotypes of the 18S rRNA gene, revealing that the genus Schellackia is more diverse than previously thought. Phylogenetic analyses showed that Schellackia haplotypes grouped into two main monophyletic clades, the first including those detected in host species endemic to the Mediterranean region and the second those detected in host genera Acanthodactylus, Zootoca and Takydromus. All but one of the Schellackia haplotypes exhibited a high degree of host specificity at the generic level and 78.5% of them exclusively infected single host species. Some host species within the genera Podarcis (six species) and Iberolacerta (two species) were infected by three non-specific haplotypes of Schellackia, suggesting that host switching might have positively influenced past diversification of the genus. However, the results supported the idea that current host switching is rare because there existed a significant positive correlation between the number of exclusive parasite haplotypes and the number of host species with current sympatric distribution. This result, together with significant support for host–parasite molecular co-speciation, suggests that parasites of the genus Schellackia co-evolved with their lizard hosts.  相似文献   

2.
Abstract

The cercariae and sporocysts (or rediae) of four trematode species are described from the intertidal snail Zeacumantus subcarinatus: a distome xiphidiocercaria assigned to the genus Renicola (family Renicolidae); a monostome xiphidiocercaria belonging either to the genus Microphallus or Megalophallus (family Microphallidae); a magnacercous cercaria of the genus Galactosomum (family Hetero‐phyidae); and a cercaria of the genus Philophthalmus (family Philophthalmidae). The morphological features of these cercariae are compared to previously described cercariae of the same genera. In addition, since the philophthalmid cercaria encysts readily on artificial substrates in the laboratory, the metacercaria of this species is also described. These cercariae are part of a diverse community of at least six digenean species parasitising the snail Z. subcarinatus that, together, have a major impact on the ecology and evolution of this snail.  相似文献   

3.
Cartilaginous fishes are the oldest jawed vertebrates and are also reported to be the hosts of some of the most basal lineages of Cestoda and Aporocotylidae (Digenea) parasites. Recently a phylogenetic analysis of the coccidia (Apicomplexa) infecting marine vertebrates revealed that the lesser spotted dogfish harbours parasite lineages basal to Eimeria Schneider, 1875 and the group formed by Schellackia Reichenow, 1919, Lankesterella Ames, 1923, Caryospora Leger, 1904 and Isospora Schneider, 1881. In the present study we have found additional lineages of coccidian parasites infecting the cownose ray Rhinoptera bonasus Mitchill and the blue shark Prionace glauca Linnaeus. These lineages were also found as basal to species from the genera Lankesterella, Schellackia, Caryospora and Isospora infecting higher vertebrates. These results confirm previous phylogenetic assessments and suggest that these parasitic lineages first evolved in basal vertebrate hosts (i.e. Chondrichthyes), and that the more derived lineages infect higher vertebrates (e.g. birds and mammals) conforming to the evolution of their hosts. We hypothesise that elasmobranchs might host further ancestral parasite lineages harbouring unknown links of parasite evolution.  相似文献   

4.
Örjan Nilsson 《Grana》2013,52(2-3):279-363
The pollen morphology of several genera in Portulacaceae is described. Particular attention has been paid to the genera of the subfamily Montioideae, as a stage of continued monographical studies. Among genera especially dealt with are Claytonia, Montia, Crunocallis, Naiocrene, Neopaxia, Mona, Maxia, Limnalsine, and Montiastrum. In the taxonomical treatment of these genera the pollen morphology has proved to afford many important additional characters.

The pollen grains of Claytonia are distinguished from those of the remainder in being 3-colpate. The grains of the Claytonia-type have many similarities with those of Lewisia, a genus of the subfamily Portulacoideae. The other genera of Montioideae have pantocolpate pollen grains. Among these genera several different pollen types are distinguished, chiefly with regard to the sexine structures and the aperture membranes. The Montiastrum-type is especially interesting, with tholate grains, a particular pollen type not met with in any other genus in the family. The pollen morphology of some genera in the Portulacoideae is also treated. In some species in Calandrina and Talinum pantotreme pollen grains are observed with apertures transitional between pori and colpi. The apertures of the pantotreme grains are arranged in characteristic patterns.

Particular attention has been given to the variation of the pollen morphological characters. This variation has been examined with regard to the differences between different populations of the same species as well as between different species. The greatest variation has been observed in the shape and size of the grains. The structure and sculpture and thickness of the sexine and the aperture membranes are less variable. Some polyploid taxa are connected with the occurrence of pollen grains with divergent and varying aperture numbers.

In a survey of the genera the taxonomical results of the investigation are presented with particular regard to the pollen morphology. The new genus, Maxia Ö. Nilss., is described. One new species, Montia clara Ö. Nilss., is described and some new combinations are made.

Pollen morphological diagnoses are given for 46 different taxa. The aperture conditions for 96 different species are presented.  相似文献   

5.
6.
Staurojoenina is a large and structurally complex genus of hypermastigont parabasalians found in the hindgut of lower termites. Although several species of Staurojoenina have been described worldwide, all Staurojoenina observed to date in different species of North American termites have been treated as the same species, S. assimilis. Here, we characterize Staurojoenina from the North American termite Neotermes jouteli using light microscopy, scanning electron microscopy, and phylogenetic analysis of small subunit ribosomal RNA, and compare it with S. assimilis from its type host, Incisitermes minor. The basic morphological characteristics of the N. jouteli symbiont, including its abundant bacterial epibionts, are similar as far as they may be compared with existing data from S. assimilis, although not consistently identical. In contrast, we find that they are extremely distantly related at the molecular level, sharing a pairwise similarity of SSU rRNA genes comparable to that seen between different genera or even families of other parabasalians. Based on their evolutionary distance and habitat in different termite genera, we consider the N. jouteli Staurojoenina to be distinct from S. assimilis, and describe a new species, Staurojoenina mulleri, in honor of the pioneering parabasalian researcher, Miklos Muller.  相似文献   

7.
8.
The lichen family Teloschistaceae is one of the larger families of lichenized fungi. Currently it includes one very large heterogenous genus, Caloplaca, with some 1000 or more species with a vast variation in morphology, anatomy and chemistry. The rest of the family is split into 10–15 smaller genera, each with 20 or fewer species. There is no modern classification of the family based on molecular data. Here we attempt a first phylogenetic evaluation of a large part of the family, including a total of 337 species. Of these, 162 were used in a combined phylogenetic analysis of the ribosomal RNA sequence markers nrITS, nrLSU and mrSSU, using Bayesian inference. We also analysed all species using nrITS data, split into four different analyses. As a result we propose a new classification of the family, where a total of 39 genera are recognized, of which 31 are newly described or resurrected. The new genera are: Athallia, Austroplaca, Bryoplaca, Calogaya, Cerothallia, Flavoplaca, Gondwania, Haloplaca, Orientophila, Pachypeltis, Parvoplaca, Rufoplaca, Shackletonia, Scutaria, Sirenophila, Solitaria, Squamulea, Stellarangia, Teloschistopsis, Usnochroma, Variospora, Villophora and Wetmoreana. Resurrected genera are Blastenia, Dufourea, Follmannia, Gyalolechia, Leproplaca, Polycauliona, Pyrenodesmia and Xanthocarpia. The species Orientophila subscopularis is described as new. A third subfamily, Teloschistoideae, is proposed to accommodate the genus Teloschistes and related genera, parallel to the two previously recognized subfamilies Xanthorioideae and Caloplacoideae. We also show the large plasticity in both morphological and anatomical characters between closely related species within genera, indicating the low value of these as evolutionary markers. The secondary chemistry is a better marker in some parts of the family. We recognize a large number of geographically delimited clades with clear centres of evolution, but often showing large variation in morphology and anatomy.  相似文献   

9.
10.
ABSTRACT. Three species of bucaniid gastropods from the upper Ordovician of Norway and Sweden are revised: Euomphalopterus excavatus is redescribed as a species of Phragmolites with very wide umbilici and ornamentation similar to that of Offleya. Three out of five specimens from the original type series of Temnodiscus lindstroemi remain, representing two different species of two different genera. The original species name is restricted to a species of Phragmolites, whereas two specimens are considered conspecific with Megalomphala? carinata sp. nov., although the high carina, the flaring aperture and the laterally compressed whorls seen in this species are unusual for the genus. The gastropod subfamily Bucaniinae of the family Bucaniidae is here considered to comprise nine genera. Placement of Phragmolites in this family is supported by its deep slit, tangential aperture, transverse growth lines, spiral and collabral ornamentation and the presence of a longitudinal keel on the base of the whorl.  相似文献   

11.
Thraustochytrium is the type genus of the family Thraustochytriaceae in the class Labyrinthulomycetes. This genus is characterized by zoospore formation, namely, shape of the cell wall of sporangia and presence or absence of a proliferous body. However, there are several issues associated with the taxonomy of this genus, and these include polyphyletic taxa and overlapping of taxonomic features among species. In particular, the first and second species, T. proliferum and T. globosum, were described based on observations of the morphological features of natural samples in the absence of culture conditions. Before addressing the taxonomic issues associated with this genus, it is important to consider the taxonomic features of each species, i.e., the life history under culture conditions and the phylogenetic position. The objective of the present study was to isolate T. globosum, the second described species in the genus Thraustochytrium, from the type locality. We successfully isolated strain NBRC 112723, which exhibited characteristic features of T. globosum. Under culture conditions, strain NBRC 112723 exhibited taxonomic features observed in other thraustochytrid species. Our molecular phylogeny indicated that this strain isolated from the type locality was located in an unidentified thraustochytrid group; moreover, some strains located in this group exhibited characteristic features of strain NBRC 112723. We clearly distinguished T. globosum based on the taxonomic criteria used to classify the T. proliferum type species. Therefore, we propose the establishment of a new genus, Monorhizochytrium, for the species T. globosum in the family Thraustochytriaceae.  相似文献   

12.
Spirotrichonymphea is a class of hypermastigote parabasalids defined by their spiral rows of many flagella. They are obligate hindgut symbionts of lower termites. Despite more than 100 yr of morphological and ultrastructural study, the group remains poorly characterised by molecular data and the phylogenetic positions and taxonomic validity of most genera remain in question. The genus Spirotrichonympha has been reported to inhabit several termite genera, including Reticulitermes, Coptotermes, and Hodotermopsis. The type species for this genus, Spirotrichonympha flagellata, was described from Reticulitermes lucifugus but no molecular data are yet available for this species. In this study, three new Spirotrichonympha species are described from three species of Reticulitermes. Their molecular phylogenetic position indicates that the genus is not monophyletic, as Spirotrichonympha species from Coptotermes, Paraneotermes, and Hodotermopsis branch separately. In contrast, the genus Holomastigotoides is monophyletic, as demonstrated using new sequences from Holomastigotoides species. The presence of Holomastigotoides in Prorhinotermes and the distinct phylogenetic positions of Spirotrichonympha from Reticulitermes and Coptotermes are consistent with a previously proposed symbiont fauna replacement in the ancestor of Reticulitermes.  相似文献   

13.
The genus Xenolecanium Takahashi is reviewed and transferred from the subfamily Myzolecaniinae to the Coccinae (tribe Paralecaniini). The type species Xenolecanium mangiferae Takahashi is redescribed, and Xenolecanium takahashii Kondo sp. nov. from Indonesia is described based on the adult female and first instar nymph. A taxonomic key is provided to separate adult females of the two species of Xenolecanium. Xenolecanium rotundum Takahashi is transferred to become the type species of a new monotypic genus, Takahashilecanium Kondo, which is also placed in the Paralecaniini. The morphological justification for placing Xenolecanium and Takahashilecanium in the Paralecaniini is discussed, and we provide a taxonomic key for separating both genera from all other members of the Paralecaniini.  相似文献   

14.
Brown algae of the order Laminariales, commonly referred to as kelps, are the largest and most productive primary producers in the coastal inshore environment. The genus Ecklonia (Lessoniaceae, Phaeophyceae) consists of seven species with four species in the Northern Hemisphere and three in the Southern Hemisphere. It was recently transferred to the family Lessoniaceae based on phylogenetic analyses of nuclear and chloroplastic markers, though the type of the genus was not included and its relationship with allied genera Eckloniopsis and Eisenia remained unresolved. The present study is the first to produce a phylogeny focussed on the genus Ecklonia. It included sequences from nuclear, mitochondrial, and chloroplastic DNA, for most of the distribution range of the three current Southern Hemisphere species (Ecklonia radiata, Ecklonia maxima, and a sample of a putative Ecklonia brevipes specimen), sequences for East Asiatic species (Ecklonia cava, Ecklonia kurome, and Ecklonia stolonifera), as well as the closely related genera Eckloniopsis and Eisenia. Results confirmed E. radiata and E. maxima as two distinct species in South Africa, E. radiata as a single species throughout the Southern Hemisphere (in South Africa, Australia, and New Zealand) and East Asiatic species as a distinct lineage from the Southern Hemisphere clade. Results further pointed out a close sister relationship between Eckloniopsis radicosa and two Eisenia species (including the type species: Eisenia arborea) to the genus Ecklonia suggesting that the genera Eckloniopsis and Eisenia are superfluous.  相似文献   

15.
16.
The louse genus Carduiceps Clay & Meinertzhagen, 1939 is widely distributed on sandpipers and stints (Calidrinae). The current taxonomy includes three species on the Calidrinae (Carduiceps meinertzhageni, Carduiceps scalaris, Carduiceps zonarius) and four species on noncalidrine hosts. We estimated a phylogeny of four of the seven species of Carduiceps (the three mentioned above and Carduiceps fulvofasciatus) from 13 of the 29 hosts based on three mitochondrial loci, and evaluated the relative importance of flyway differentiation (same host species has different lice along different flyways) and flyway homogenization (different host species have the same lice along the same flyway). We found no evidence for either process. Instead, the present, morphology‐based, taxonomy of the genus corresponds exactly to the gene‐based phylogeny, with all four included species monophyletic. Carduiceps zonarius is found both to inhabit a wider range of hosts than wing lice of the genus Lunaceps occurring on the same group of birds, and to occur on Calidris sandpipers of all sizes, both of which are unexpected for a body louse. The previously proposed family Esthiopteridae is found to be monophyletic with good support. The concatenated dataset suggests that the pigeon louse genus Columbicola may be closely related to the auk and diver louse genus Craspedonirmus. These two genera share some morphological characters with Carduiceps, but no support was obtained for grouping these three genera together. Based on mitochondrial data alone, the relationships among genera within this proposed family cannot be properly assessed, but some previously suggested relationships within this proposed family are confirmed.  相似文献   

17.
Abstract. We investigated the phylogeny and taxonomy of the Prenolepis genus‐group, a clade of ants we define within the subfamily Formicinae comprising the genera Euprenolepis, Nylanderia, gen. rev. , Paraparatrechina, gen. rev. & stat. nov. , Paratrechina, Prenolepis and Pseudolasius. We inferred a phylogeny of the Prenolepis genus‐group using DNA sequence data from five genes (CAD, EF1αF1, EF1αF2, wingless and COI) sampled from 50 taxa. Based on the results of this phylogeny the taxonomy of the Prenolepis genus‐group was re‐examined. Paratrechina (broad sense) species segregated into three distinct, robust clades. Paratrechina longicornis represents a distinct lineage, a result consistent with morphological evidence; because this is the type species for the genus, Paratrechina is redefined as a monotypic genus. Two formerly synonymized subgenera, Nylanderia and Paraparatrechina, are raised to generic status in order to provide names for the other two clades. The majority of taxa formerly placed in Paratrechina, 133 species and subspecies, are transferred to Nylanderia, and 28 species and subspecies are transferred to Paraparatrechina. In addition, two species are transferred from Pseudolasius to Paraparatrechina and one species of Pseudolasius is transferred to Nylanderia. A morphological diagnosis for the worker caste of all six genera is provided, with a discussion of the morphological characters used to define each genus. Two genera, Prenolepis and Pseudolasius, were not recovered as monophyletic by the molecular data, and the implications of this result are discussed. A worker‐based key to the genera of the Prenolepis genus‐group is provided.  相似文献   

18.
王佳华  弋伊  徐俊 《微生物学报》2021,61(3):555-563
康氏菌科(Kangillaceae)是海洋螺杆菌目(Oceanosprillales)下的科级分类单元,包含康氏菌属(Kangiella)、异康氏菌属(Aliikangiella)和Pleionea三个属.在康氏菌属高度精简的基因组中存在异常丰富的胞外蛋白酶编码基因,暗示此类海洋细菌对海洋颗粒有机物中的蛋白质成分降解具...  相似文献   

19.
The world's argasid tick fauna comprises 183 species in four genera, namely Argas, Carios, Ornithodoros and Otobius in the family Argasidae. The ixodid tick fauna consists of 241 species in the genus Ixodes and 442 species in the genera Amblyomma, Anomalohimalaya, Bothriocroton, Cosmiomma, Dermacentor, Haemaphysalis, Hyalomma, Margaropus, Nosomma, Rhipicentor and Rhipicephalus in the family Ixodidae, with the genus Boophilus becoming a subgenus of the genus Rhipicephalus. The family Nuttalliellidae is represented by the monospecific genus Nuttalliella. The species names of these ticks, based on seven previous complete or partial listings, as well as those of recently described new species, are presented in tabular format. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

20.
Ixora is a genus of ca. 400 species in the family Rubiaceae. Since the 1940s, eighty‐one compounds including phenolics, peptides, terpenoids, and sterols have been isolated from six species of the genus Ixora. Pharmacological studies have shown that these compounds and extracts from the Ixora genus have extensive activities, such as antitumor, chemoprotective, and antioxidant activities. In this review, we summarize the phytochemical progress and list the compounds isolated from the genus Ixora. The biological activities of this genus are also covered.  相似文献   

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