Morphological and molecular studies on life cycle stages of Diphtherostomum brusinae (Digenea: Zoogonidae) from northern Portugal

2009 ◽  
Vol 83 (4) ◽  
pp. 321-331 ◽  
Author(s):  
S. Pina ◽  
J. Tajdari ◽  
F. Russell-Pinto ◽  
P. Rodrigues
Keyword(s):  
Electron Microscopy ◽  
Life Cycle ◽  
Definitive Host ◽  
Rectangular Band ◽  
The North ◽  
Life Cycle Stages ◽  
Nassarius Reticulatus ◽  
Diplodus Sargus ◽  
Molecular Studies ◽  
Scanning Electron

AbstractDiphtherostomum brusinae was first recorded by the present study in the north of Portugal. Sporocysts, containing cercariae and encysted metacercariae, were observed in the gonads and digestive gland of the gastropod Nassarius reticulatus. Metacercariae were also found infecting the foot, mantle border and gills of the cockle Cerastoderma edule. The adult form was lodged in the rectum of the definitive host Diplodus sargus. The morphology of the three parasitic stages was studied by light (LM) and scanning electron microscopy (SEM). Despite the close similarity between cercaria and metacercaria, SEM data provided information that allowed their differentiation, namely the presence of a dense crown of microvilli around the oral cavity of the cercariae, which was absent in the metacercariae. In addition, the metacercariae presented a specific pre-acetabular rectangular band with conspicuous triangular spines. The adult showed characteristics of D. brusinae species, in particular the presence of acetabular lips, compact vitellaria and large elliptical eggs. Sequenced ITS1 data clearly demonstrated that the cercariae and metacercarial cysts from N. reticulatus, the cysts from C. edule and the adult isolated from D. sargus were life cycle stages that belonged to the same species, i.e. D. brusinae. Two transmission strategies in the life cycle of this species were observed: (1) cercariae encyst within the sporocysts of N. reticulatus and await ingestion by the definitive host; and (2) N. reticulatus naturally emits cercariae; they encyst in C. edule or the environment and are ingested by the definitive host.

Brachylaima cribbi(Digenea: Brachylaimidae): scanning electron microscopical observations of the life-cycle stages

2002 ◽  
Vol 76 (3) ◽  
pp. 207-215 ◽  
Author(s):  
A.R. Butcher ◽  
J.K. Brealey ◽  
D.I. Grove ◽  
R.B. Dymock
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Life Cycle ◽  
Adult Worm ◽  
Genital Pore ◽  
Land Snails ◽  
Intermediate Hosts ◽  
Mature Adult ◽  
Life Cycle Stages ◽  
Scanning Electron

AbstractBrachylaima cribbiis a recently described species of terrestrial trematode that infects mammals and birds with helicid land snails as its first and second intermediate hosts. The adult worm is 2.5–6.0 mm long by 0.5–0.8 mm wide being a long slender cylindrical worm with oral and ventral suckers in the anterior quarter and genital pore in the posterior quarter. Scanning electron microscopy shows that there is a dense covering of tegumental spines at the anterior end which diminishes towards the posterior extremities of the worm. Development of spines was observed in juvenile and mature adult worms. In young worms 1–3 weeks post infection (wpi) spines appear as buds with a serrated edge each having 1–4 spikes per spine. As the worm ages the spines broaden and by 5 wpi the number of spikes per spine increases to an average of 8.1. The serial development of oral sucker papillae in the cercaria, metacercaria and adult worm was observed with the finding of an elongated papilla with a bifurcated tip on the cercaria becoming a shorter and thicker elongated papilla with a large central stoma on the metacercaria. In the adult worm, this papilla becomes dome-shaped with a small central stoma. For some of these papillae a cilium could be seen extended from the central stoma. Other life-cycle stages illustrated were the hatched egg with an extruded egg membrane minus an operculum and a portion of the branched sporocyst dissected from the digestive gland of the land snailTheba pisanashowing a terminal birth pore. Scanning electron microscopy morphological features of the adult worm observed for the first time in aBrachylaimawere the unarmed cirrus extended from the genital pore with released sperm present and the Laurer's canal opening visible in tegumental folds on the dorsal surface approximately 300 μm posterior to the genital pore.

scholarly journals The haplo-diplontic life cycle expands niche space of coccolithophores

2020 ◽  
Author(s):  
Joost de Vries ◽  
Fanny Monteiro ◽  
Glen Wheeler ◽  
Alex Poulton ◽  
Jelena Godrijan ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Life Cycle ◽  
Species Abundance ◽  
Cycle Phase ◽  
Niche Space ◽  
Abundance Data ◽  
Life Cycle Stages ◽  
Life Cycle Phase ◽  
Scanning Electron

Abstract. Coccolithophores are globally important marine calcifying phytoplankton that utilize a haplo-diplontic life cycle. The haplo-diplontic life cycle allows coccolithophores to divide in both life cycle phases, and has been proposed to allow coccolithophores to expand their niche space. To-date research has however largely overlooked the life cycle of coccolithophores, and has instead focused on the diploid life cycle phase. Through a synthesis of global scanning electron microscopy (SEM) coccolithophore abundance data (n = 2534), we show that the haploid life cycle phase contributes significantly to coccolithophore abundance, constituting ≈18 % of species abundance for which haploid-diploid pairs are defined. Using hypervolumes to quantify the niche space of coccolithophores, we furthermore show that the haploid and diploid life cycle phases inhabit contrasting niches, and that this allows coccolithophores to expand their niche space by ≈17 %. Our results highlight that future coccolithophore research should consider both life cycle stages, as omission of the haploid life cycle phase in current research limits our understanding of coccolithophore ecology.

scholarly journals Intracellular Siderophore Detection in an Egyptian, Cobalt-Treated F. solani Isolate Using SEM-EDX with Reference to its Tolerance

2017 ◽  
Vol 66 (2) ◽  
pp. 235-243 ◽  
Author(s):  
Farrag M. Rasha
Keyword(s):  
Electron Microscopy ◽  
Cell Wall ◽  
Fusarium Solani ◽  
X Ray ◽  
Cobalt Uptake ◽  
Molecular Studies ◽  
Control Regime ◽  
Co Concentrations ◽  
Scanning Electron

An Egyptian, plant pathogenic Fusarium solani isolate was grown on cobalt concentrations of 0, 50, 200, 500, 800, and 1000 ppm. The isolate survived concentrations up to 800 ppm, however failed to grow at 1000 ppm. Morphology and elemental analysis of the isolate under the investigated Co concentrations were studied using Scanning electron microscopy (SEM) and energy dispersive X-ray microanalysis (EDX). The isolate reserved its morphology up to a concentration of 200 ppm. Morphological distortions were dramatic at 500 and 800 ppm. EDX detected Co uptake through the hyphae, microconidia, macroconidia, and chlamydospores. Iron, calcium, and potassium were also detected. EDX results showed a linear relationship between Co% and Fe% up to a concentration of 500 ppm reflecting the possible ability of the isolate to synthesize intracellular siderophores storing iron and their release out of the vacuoles. The participation of such siderophores in conferring tolerance against cobalt is discussed. At 800 ppm, the % of Fe was greatly reduced with an accompanying increase in morphological distortions and absence of microconidia. Increasing the implicated cobalt concentrations resulted in increasing the percentages of the chelated cobalt reflecting the possible implication of the cell wall as well as extracellular siderophores in the uptake of cobalt. The current results recommend the absence of cobalt in any control regime taken to combat the investigated F. solani isolate and highlights the accomplishment of biochemical, ultrastructural, and molecular studies on such isolate to approve the production of siderophores and the role of cell wall in cobalt uptake.

scholarly journals Description of the Demicyclic life Cycle of Puccinia Sherardiana in Sphaeralcea Angustifolia in Mexico.

2021 ◽  
Author(s):  
Magnolia Moreno-Velázquez ◽  
Jesús Ricardo Sánchez-Pale ◽  
Ricardo Tapia-Nuño ◽  
Moisés Camacho-Tapia ◽  
José Manuel Cambrón-Crisantos ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Life Cycle ◽  
Pathogenic Fungus ◽  
Morphological Characteristics ◽  
Identity Verification ◽  
Pathogenicity Tests ◽  
Koch Postulates ◽  
Scanning Electron ◽  
Observation Period

Abstract During 2017-2019, leaves and stems with dark brown lesions containing hypophyllous telia surrounded by chlorotic halos were collected from Sphaeralcea angustifolia plants located in Axapusco, State of Mexico. Based on the morphological characteristics of pycnia, aecia and telia observed by light microscopy and scanning electron microscopy, the fungus Puccinia sherardiana was identified. Uredial stage was not present during the observation period. Identity verification was carried out by phylogenetic analysis with sequences of part of the 28S gene from ribosomal DNA. In addition, pathogenicity tests were done on S. angustifolia leaves by inoculating teliospores. The inoculated plants developed symptoms 15 days after inoculation, the signs beginning with the presence of aecia in the epidermis of the host and later telia were formed, completing the Koch Postulates. Puccinia sherardiana was previously described as a rust with a microcyclic life cycle on species of the genera Alcea, Malvastrum, Sidalcea and Sphaeralcea , belonging to the Malvaceae family, however, this study revealed that this plant pathogenic fungus has a demicyclic life cycle.

Molecular and morphological studies identify a new genus within the Heterolepismatinae (Zygentoma: Lepismatidae)

Zootaxa ◽  
2021 ◽  
Vol 5030 (1) ◽  
pp. 1-118
Author(s):  
GRAEME B. SMITH ◽  
ANDREW MITCHELL ◽  
RAFAEL MOLERO-BALTANÁS
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Anterior Margin ◽  
New Genus ◽  
Sequence Data ◽  
Morphological Characters ◽  
Type Series ◽  
Morphological Studies ◽  
Molecular Studies ◽  
Scanning Electron

Molecular studies using COI and 28S sequence data strongly identify a clade within the Heterolepismatinae distinct from the majority of species so far sequenced. The independence of the clade is supported by several morphological characters including a glabrous anterior margin to the frons, large trapezoidal thoracic sternites, tarsal trichobothria, long, conical parameres which in some species consist of two segments, and the presence of triangular or rounded subrectangular scales on the femora, tibia and clypeus. This clade is described as a new genus Visma n. gen. containing ten new species V. advenum n. sp., V. bingara n. sp., V. brayi n. sp., V. bundjalung n. sp., V. brigalowsum n. sp., V. capricornia n. sp., V. pallidum n. sp., V. powellheueri n. sp., V. tenebrosum n. sp. and V. xanthorrhoea n. sp.. Heterolepisma stilivarians Silvestri, 1908 is redescribed from the holotype and transferred to the new genus. The remaining H. stilivarians type series is found to be different to the holotype and removed from the type series. It is considered possible that H. annectens Silvestri, 1924 may also belong to this genus. Scanning electron microscopy of scale shape and rib-spacing is shown to be a useful tool to separate at least some species of the genus and considered to have greater potential if well preserved material is available.  

Redescription of the species Procloeon (Pseudocentroptilum) fascicaudale (Sowa, 1985) (Ephemeroptera: Baetidae) with notes to its taxonomic position, biology and distribution

Zootaxa ◽  
2018 ◽  
Vol 2490 (1) ◽  
pp. 16 ◽  
Author(s):  
PAVEL SROKA ◽  
ROMAN J. GODUNKO ◽  
TOMÁŠ SOLDÁN
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Life Cycle ◽  
Species Group ◽  
Taxonomic Position ◽  
Time Variability ◽  
Color Patterns ◽  
Distributional Patterns ◽  
First Time ◽  
Scanning Electron

Based on the extensive material recently collected on the Island of Rhodos, Greece (terra typica) in May, 2005, a redescription of Procloeon (Pseudocentroptilum) fascicaudale (Sowa, 1985) is presented. Larval characters are completed, female subimago described and the egg chorionic structures illustrated by means of scanning electron microscopy for the first time. Variability in color patterns and critical characters distinguishing eggs, larvae and male imagines from other Westpalaearctic species of the subgenus Pseudocentroptilum Bogoescu, 1947 (the representatives of the Procloeon (Pseudocentroptilum) motasi species-group in particular) are described and discussed. Distributional patterns of the species, its abundance, possible faunistic origin, some aspects of larval and imago’s biology, and life cycle of the species are briefly stated. Delimitation and recent concepts of the taxa Procloeon Bengtsson, 1915 and Pseudocentroptilum within the subfamily Cloeoninae Kazlauskas, 1972, taxonomic position and affinities of P. fascicaudale are discussed.

scholarly journals Xiphidiocercariae from naturally infected Lymnaea columella (Mollusca, Gastropoda) in urban area: morphology and ultrastructure of the larvae and histological changes in the mollusc host

2019 ◽  
Vol 79 (3) ◽  
pp. 446-451
Author(s):  
E. Paviotti-Fischer ◽  
E. J. Lopes-Torres ◽  
M. A. J. Santos ◽  
S. V. P. B. Brandolini ◽  
J. Pinheiro
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Life Cycle ◽  
Urban Area ◽  
Urban Agriculture ◽  
Economic Activity ◽  
Epithelial Tissue ◽  
Intermediate Hosts ◽  
Histological Changes ◽  
Scanning Electron

Abstract Urban agriculture is very common in the cities, as Rio de Janeiro and adjacencies, being important as economic activity. However, this practice can create appropriate conditions for establishment and maintenance of life cycle of many parasites. Lymneid snails can act as intermediate hosts of many trematodes species, including those that infect humans and wild and domestic. In the present study, the snail Lymnaea columella was collected from an urban watercress plantations and the morphology of cercariae released by them was analyzed by light and scanning electron microscopy. The specimens were identified as xiphidiocercariae, belonging to the Cercariae Ornatae group, of the order Plagiorchiiformes. Histological examination of the digestive gland of the infected snails revealed the presence of developing sporocysts, with hemocitary infiltration and metaplasia in the epithelial tissue.

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