scholarly journals Leeches as the intermediate host for strigeid trematodes – genetic diversity and taxonomy of the genera Australapatemon Sudarikov, 1959 and Cotylurus Szidat, 1928

2020 ◽  
Author(s):  
Ewa Pyrka ◽  
Gerard Kanarek ◽  
Grzegorz Zaleśny ◽  
Joanna Hildebrand

Abstract BackgroundLeeches (Hirudinida) play a significant role as intermediate hosts in the circulation of trematodes in the aquatic environment. However, the species richness, molecular diversity and phylogeny of larval stages of Strigeidae trematodes (tetracotyle) occurring in this group of aquatic invertebrates remain poorly understood. In the present work, on the basis of recently obtained sequences of several molecular markers we analysed several aspects of the ecology, taxonomy and phylogeny of the genera Australapatemon and Cotylurus, which utilise leeches as intermediate hosts.MethodsFrom April 2017 to September 2018, 153 leeches were collected from several sampling stations in small rivers with slow-flowing waters and related drainage canals located in three regions of Poland. The distinctive forms of tetracotyle metacercariae collected from leeches supplemented with adult Strigeidae specimens sampled from a wide range of water birds were analysed using the 28S rDNA partial gene, ITS2 region and the COI fragment.ResultsAmong investigated leeches, metacercariae of the tetracotyle type were detected in the parenchyma and musculature of 62 specimens (prevalence 40.5%) with a mean intensity reaching 19.9 ind. The taxonomic generic affiliation of metacercariae derived from leeches revealed the occurrence of two Strigeidae genera: Australapatemon Sudarikov, 1959 and Cotylurus Szidat, 1928. Phylogenetic reconstructions based on the partial 28S rRNA gene, ITS2 region and partial COI gene confirmed the separation of the Australapatemon and Cotylurus clades. Unfortunately, regarding currently available molecular data and our results, it is not possible to precisely define the taxonomic position of the recently sequenced tetracotyle of Australapatemon. On the other hand, on the basis of the obtained sequences, supplemented with previously published data, the metacercariae of Cotylurus detected in leeches were identified as two species: C. strigeoides Dubois, 1958 and C. syrius Dubois, 1934. This is the first record of C. syrius from the intermediate host.ConclusionsThe results suggest the separation of ecological niches and life cycles between C. cornutus (Rudolphi, 1808) and C. strigeoides/C. syrius with potential serious evolutionary consequences for a wide range of host–parasite relationships. Moreover, phylogenetic analyses corroborated the polyphyletic character of C. syrius, the unclear status of C. cornutus and the separate position of Cotylurs raabei Bezubik, 1958 within Cotylurus. The data demonstrate the inconsistent and confusing taxonomic status of the sequenced tetracotyle of Australapatemon, resulting, in our opinion, from the limited availability of fully reliable, comparative sequences of related taxa in GenBank.

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Ewa Pyrka ◽  
Gerard Kanarek ◽  
Grzegorz Zaleśny ◽  
Joanna Hildebrand

Abstract Background Leeches (Hirudinida) play a significant role as intermediate hosts in the circulation of trematodes in the aquatic environment. However, species richness and the molecular diversity and phylogeny of larval stages of strigeid trematodes (tetracotyle) occurring in this group of aquatic invertebrates remain poorly understood. Here, we report our use of recently obtained sequences of several molecular markers to analyse some aspects of the ecology, taxonomy and phylogeny of the genera Australapatemon and Cotylurus, which utilise leeches as intermediate hosts. Methods From April 2017 to September 2018, 153 leeches were collected from several sampling stations in small rivers with slow-flowing waters and related drainage canals located in three regions of Poland. The distinctive forms of tetracotyle metacercariae collected from leeches supplemented with adult Strigeidae specimens sampled from a wide range of water birds were analysed using the 28S rDNA partial gene, the second internal transcribed spacer region (ITS2) region and the cytochrome c oxidase (COI) fragment. Results Among investigated leeches, metacercariae of the tetracotyle type were detected in the parenchyma and musculature of 62 specimens (prevalence 40.5%) with a mean intensity reaching 19.9 individuals. The taxonomic generic affiliation of metacercariae derived from the leeches revealed the occurrence of two strigeid genera: Australapatemon Sudarikov, 1959 and Cotylurus Szidat, 1928. Phylogenetic reconstructions based on the partial 28S rRNA gene, ITS2 region and partial COI gene confirmed the separation of the Australapatemon and Cotylurus clades. Taking currently available molecular data and our results into consideration, recently sequenced tetracotyle of Australapatemon represents most probably Au. minor; however, unclear phylogenetic relationships between Au. burti and Au. minor reduce the reliability of this conclusion. On the other hand, on the basis of the obtained sequences, supplemented with previously published data, the metacercariae of Cotylurus detected in leeches were identified as two species: C. strigeoides Dubois, 1958 and C. syrius Dubois, 1934. This is the first record of C. syrius from the intermediate host. Conclusions The results of this study suggest the separation of ecological niches and life cycles between C. cornutus (Rudolphi, 1808) and C. strigeoides/C. syrius, with potential serious evolutionary consequences for a wide range of host–parasite relationships. Moreover, phylogenetic analyses corroborated the polyphyletic character of C. syrius, the unclear status of C. cornutus and the separate position of Cotylurus raabei Bezubik, 1958 within Cotylurus. The data demonstrate the inconsistent taxonomic status of the sequenced tetracotyle of Australapatemon, resulting, in our opinion, from the limited availability of fully reliable, comparative sequences of related taxa in GenBank.


Parasitology ◽  
2020 ◽  
Vol 147 (13) ◽  
pp. 1469-1479
Author(s):  
Y. V. Tatonova ◽  
A. V. Izrailskaia ◽  
V. V. Besprozvannykh

AbstractMature worms of Stephanoprora amurensis sp. nov. were obtained in an experimental study of its life cycle. In the Russian southern Far East, this trematode circulates using freshwater snails Parajuga subtegulata, freshwater fish and birds as the first, second intermediate and final hosts, respectively. Stephanoprora amurensis sp. nov. differs from the well-known representatives of Stephanoprora in a number of morphometric indicators of the developmental stages. The validity of the species was also confirmed by nuclear and mitochondrial DNA markers. In addition, new genetic data were obtained for Echinochasmus suifunensis and Echinochasmus milvi. An analysis of phylogenetic relationships within Echinochasmidae based on the 28S rRNA gene and ITS2 region identified two clusters, one of which combines species of Echinochasmus with 20–22 collar spines and short-tailed cercariae, and the other which includes Stephanoprora spp. and a number of representatives of Echinochasmus with 24 collar spines and long-tailed cercariae. The results of phylogenetic analysis based on ITS2 data show interfamily level of differences between the two clusters and intergeneric differentiation between the three subclusters uniting the species of Stephanoprora and Echinochasmus.


Nematology ◽  
2017 ◽  
Vol 19 (3) ◽  
pp. 333-350 ◽  
Author(s):  
Shigeyuki Sekimoto ◽  
Taketo Uehara ◽  
Takayuki Mizukubo

The Korean cyst nematode, Heterodera koreana, was recorded for the first time from Japan and characterised morphologically, morphometrically and molecularly. In total, 41 populations were detected from soil samples collected from the rhizosphere of four bamboo species in Japan: 31 populations from moso bamboo (Phyllostachys edulis), seven from madake (P. bambusoides), two from henon bamboo (P. nigra var. henonis) and one from fish pole bamboo (P. aurea). The morphology and morphometrics of the Japanese population were in agreement with those of the original description of H. koreana from South Korea and other subsequent descriptions from China and Iran, with the exception of some minor differences. The results of the phylogenetic analyses of the D2-D3 expansion segments of 28S rRNA gene and ITS rRNA gene sequences confirmed the species identification and phylogenetic relationship of H. koreana with other Heterodera species. The COI mtDNA gene sequences were obtained for the first time for H. koreana. Three COI haplotypes found in Japanese H. koreana populations showed a characteristic geographical distribution in Japan.


Zootaxa ◽  
2020 ◽  
Vol 4819 (2) ◽  
pp. 295-315
Author(s):  
HIROSHI KAJIHARA

The heteronemertean Cerebratulus orochi sp. nov. is described based on material collected intertidally at a muddy beach in Akkeshi, northern Japan. For the last 80 years, the species has been confused with Cerebratulus marginatus Renier, 1804; the latter was originally described from the Adriatic and once believed to occur in many places in the northern hemisphere including Japan. Cerebratulus orochi sp. nov. is morphologically different from all the congeners including C. marginatus by the following combination of characters: several layers of diagonal-muscle meshwork coated with connective tissue, proximo-distally distributed in cross section from the distal portion of the body-wall outer longitudinal muscle layer to the cutis-gland zone throughout the anterior portion of the body from the precerebral to the foregut regions; the cephalic vascular system consisting of lateral and mid-dorsal vessels; and the sub-rhynchocoelic vessel possessing a pair of antero-lateral diverticula before the former forks posteriorly into a pair of lower lateral vessels in the post-cerebral, pre-oral region. Previous records of C. marginatus from Japanese waters are no longer considered to be substantiated. Multi-locus phylogenetic analyses based on the mitochondrial 16S rRNA and cytochrome c oxidase subunit I (COI), as well as the nuclear 18S rRNA, 28S rRNA, and histone H3 genes among heteronemerteans comprising the “Cerebratulus clade” indicated that C. orochi sp. nov. was closely related to C. cf. marginatus from the US Pacific coast. A MegaBLAST search at the NCBI website with the 16S rRNA gene sequence from C. orochi sp. nov. followed by a couple of species delimitation analyses suggests that larvae of the species are also distributed in Vostok Bay, Far East Russia.


2009 ◽  
Vol 42 (1) ◽  
pp. 83-96 ◽  
Author(s):  
Chitra Bahadur BANIYA ◽  
Torstein SOLHØY ◽  
Yngvar GAUSLAA ◽  
Michael W. PALMER

AbstractThis study of elevation gradients of lichen species richness in Nepal aimed to compare distribution patterns of different life-forms, substratum affinities, photobiont types, and Nepalese endemism. Distribution patterns of lichens were compared with elevational patterns shown by a wide range of taxonomic groups of plants along the Nepalese Himalayan elevational gradient between 200–7400m. We used published data on the elevation records of 525 Nepalese lichen species to interpolate presence between the maximum and minimum recorded elevations, thereby giving estimates of lichen species richness at each 100-m elevational band. The observed patterns were compared with previously published patterns for other taxonomic groups. The total number of lichens as well as the number of endemic species (55 spp.) showed humped relationships with elevation. Their highest richness was observed between 3100–3400 and 4000–4100m, respectively. Almost 33% of the total lichens and 53% of the endemic species occurred above the treeline (>4300m). Non-endemic richness had the same response as the total richness. All growth forms showed a unimodal relationship of richness with elevation, with crustose lichens having a peak at higher elevations (4100–4200m) than fruticose and foliose lichens. Algal and cyanobacterial lichen richness, as well as corticolous lichen richness, all exhibited unimodal patterns, whereas saxicolous and terricolous lichen richness exhibited slightly bimodal relationships with elevation. The highest lichen richness at mid altitudes concurred with the highest diversity of ecological niches in terms of spatial heterogeneity in rainfall, temperature, cloud formation, as well as high phorophyte abundance and diversity implying large variation in bark roughness, moisture retention capacity, and pH. The slightly bimodal distributions of saxicolous and terricolous lichens were depressed at the elevational maximum of corticolous lichens.


Nematology ◽  
2017 ◽  
Vol 19 (6) ◽  
pp. 681-695 ◽  
Author(s):  
László Barsi ◽  
Francesca De Luca

Paralongidorus francolambertii sp. n., a bisexual species found in the rhizosphere of silver lime (Tilia tomentosa) and common juniper (Juniperus communis), is described. The species is characterised by its medium to large size (L = 5.86-8.29 mm) and slender body (a = 143-197), a lip region flattened with rounded profile, clearly offset from the body by a deep constriction, a narrow neck between the head and body, a shoulder-like body posterior to the neck, a stirrup-shaped amphidial fovea, with conspicuous slit-like aperture, lying on the lateral cuticular collar, a moderately long odontostyle ca 140 μm long, a guide ring located at ca 28 μm from anterior end, a tail terminus with thickened outer cuticular layer in both sexes, and males with spicules ca 52 μm long. The D2-D3 expansion domains of the 28S rRNA gene and the ITS-containing region of P. francolambertii sp. n. were amplified and sequenced. Phylogenetic analyses by using the Maximum Likelihood method showed that P. francolambertii sp. n. had a sister relationship with P. rex and that all Paralongidorus species formed a well-supported group.


Nematology ◽  
2015 ◽  
Vol 17 (8) ◽  
pp. 953-966 ◽  
Author(s):  
Alberto Troccoli ◽  
Monica Oreste ◽  
Eustachio Tarasco ◽  
Elena Fanelli ◽  
Francesca De Luca

Several juvenile and adult nematodes were isolated after dissection of pupae and adults of the red palm weevil,Rhynchophorus ferrugineus, recovered from an infestedPhoenix canariensisChabaud exemplar in Bari, Italy. Two species of nematodes were recovered,Teratorhabditis synpapillataandMononchoides macrospiculumn. sp. which is described herein. The mitochondrial cytochrome oxidase I (COI), the ITS-containing region, the 18S rRNA gene (SSU) and the D2-D3 expansion domains of the 28S rRNA gene (LSU) were amplified and sequenced. The new species,M. macrospiculumn. sp., is described at morphological and molecular level. Phylogenetic analyses using SSU and LSU sequences placedM. macrospiculumn. sp. together withM. composticolaandM. striatus. The sequences of the Italian population ofT. synpapillataare identical to those ofT. synpapillatafrom Japan. This is the first report on the association ofM. macrospiculumn. sp. andT. synpapillatawith the red palm weevil in Europe.


2021 ◽  
Vol 11 ◽  
Author(s):  
Ying Su ◽  
Yuanzhi Yang ◽  
Xiao-Yu Zhu ◽  
Xiao-Hua Zhang ◽  
Min Yu

Quorum sensing (QS) is a density-dependent communicating mechanism that allows bacteria to regulate a wide range of biogeochemical important processes and could be inhibited by quorum quenching (QQ). Increasing researches have demonstrated that QS can affect the degradation of particulate organic matter (POM) in the photic zone. However, knowledge of the diversity and variation of microbial QS and QQ systems in sinking POM is scarce. Here, POM samples were collected from surface seawater (SW), bottom seawater (BW), and surficial sediment (SS) in the Yellow Sea of China. 16S rRNA gene amplicon and metagenome sequencing were performed to analyze the community structure of particle-associated microorganisms and distribution of QS genes [acylated homoserine lactone (AHL) synthesizing gene luxI and AHL sensing gene luxR] and QQ genes (genes encoding for AHL lactonase and acylase) in POM. Shifting community structures were observed at different sampling depths, with an increase of microbial abundance and diversity from SW to BW. Along with the variation of microbial communities, the abundances of luxI and luxR decreased slightly but were restored or even exceeded when POM arrived at SS. Comparatively, abundances of AHL lactonase and acylase remained constant during the transportation process from SW to BW but increased dramatically in SS. Correlation tests indicated that abundances of luxI and luxR were positively correlated with temperature, while those of AHL acylase were positively correlated with depth, SiO42–, PO43–, and NO3–, but negatively correlated with temperature and pH. According to phylogenetic analyses, the retrieved QS and QQ genes are more diverse and distinctive than ever experimentally identified. Besides, the vertical transmission of QS and QQ genes along with POM sinking was observed, which could be one of the key factors leading to the prevalence of QS and QQ genes in marine ecosystems. Overall, our results increase the current knowledge of QS and QQ metabolic pathways in marine environment and shed light on the intertwined interspecies relationships to better investigate their dynamics and ecological roles in POM cycling.


2017 ◽  
Vol 66 (1) ◽  
pp. 39-56
Author(s):  
Nilgun Tekin ◽  
Arzu Coleri Cihan ◽  
Basar Karaca ◽  
Cumhur Cokmus

Alkaline proteases have biotechnological importance due to their activity and stability at alkaline pH. 56 bacteria, capable of growing under alkaline conditions were isolated and their alkaline protease activities were carried out at different parameters to determine their optimum alkaline protease production conditions. Seven isolates were showed higher alkaline protease production capacity than the reference strains. The highest alkaline protease producing isolates (103125 U/g), E114 and C265, were identified as Bacillus licheniformis with 99.4% and Bacillus mojavensis 99.8% based on 16S rRNA gene sequence similarities, respectively. Interestingly, the isolates identified as Bacillus safensis were also found to be high alkaline protease producing strains. Genotypic characterizations of the isolates were also determined by using a wide range of molecular techniques (ARDRA, ITS-PCR, (GTG)5-PCR, BOX-PCR). These different techniques allowed us to differentiate the alkaliphilic isolates and the results were in concurrence with phylogenetic analyses of the 16S rRNA genes. While ITS-PCR provided the highest correlation with 16S rRNA groups, (GTG)5-PCR showed the highest differentiation at species and intra-species level. In this study, each of the biotechnologically valuable alkaline protease producing isolates was grouped into their taxonomic positions with multi-genotypic analyses.


Minerals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1064
Author(s):  
Sirio Consani ◽  
Stefano Ghignone ◽  
Marina Pozzolini ◽  
Marco Giovine ◽  
Luigi Vezzulli ◽  
...  

Acid mine drainage (AMD) is a common environmental problem in many sulphide mines worldwide, and it is widely accepted that the microbial community plays a major role in keeping the process of acid generation active. The aim of this work is to describe, for the first time, the microbial community thriving in goethite and jarosite Fe precipitates from the AMD of the Libiola mine. The observed association is dominated by Proteobacteria (>50%), followed by Bacteroidetes (22.75%), Actinobacteria (7.13%), Acidobacteria (5.79%), Firmicutes (2.56%), and Nitrospirae (1.88%). Primary producers seem to be limited to macroalgae, with chemiolithotrophic strains being almost absent. A phylogenetic analysis of bacterial sequences highlighted the presence of heterotrophic bacteria, including genera actively involved in the AMD Fe cycle and genera (such as Cytophaga and Flavobacterium) that are able to reduce cellulose. The Fe precipitates constitute a microaerobic and complex environment in which many ecological niches are present, as proved by the wide range of bacterial species observed. This study is the first attempt to quantitatively characterize the microbial community of the studied area and constitutes a starting point to learn more about the microorganisms thriving in the AMD of the Libiola mine, as well as their potential applications.


Sign in / Sign up

Export Citation Format

Share Document