Embryogenesis and the first-stage larva of Thelazia lacrymalis

2003 ◽  
Vol 77 (3) ◽  
pp. 227-233 ◽  
Author(s):  
H. Dongus ◽  
P. Beelitz ◽  
H. Schöl
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Reproductive System ◽  
Distal Part ◽  
Developmental Stages ◽  
Nematode Species ◽  
Stage Larva ◽  
Female Reproductive System ◽  
Egg Membrane ◽  
Scanning Electron

AbstractThe female reproductive system of Thelazia lacrymalis (Nematoda: Thelaziidae) was investigated by light and scanning electron microscopy (SEM) with regard to the developmental stages and the stage deposited by the gravid nematode. Female T. lacrymalis have a didelphic and opisthodelphic type of reproductive system with paired ovaries, oviducts and uteri and a single vagina and vulva. Round and spindle-shaped primary oocytes are documented within the ovaries and oviducts, respectively. The distal part of each uterus provides a fertilization chamber filled with spermatozoa, followed by a sphincter-like part. Further anterior, the uteri broaden gradually containing dividing zygotes, small and large morulae, tadpole-stage embryos and horseshoe-shaped embryos which increase in length and become slimmer forming pretzel-stage embryos and larvae rolled up. The larvae stretch gradually and finally lie straight but still covered with their egg membrane in the vagina. The egg membrane encloses the whole larva and is enlarged at the pointed tail of the larva forming a bulb. At the SEM level, the first-stage larva is shown to have a terminal mouth and three hooks directed posteriorly and a striated cuticle. As morphologically identical larvae were also found in lavages of the conjunctival sac of horses infected with T. lacrymalis, this nematode species can be described as ovoviviparous.

Microstructure of Female Reproductive System of Phenacoccus fraxinus Tang (Hemiptera: Coccoidea: Pseudococcidae)

2008 ◽  
Vol 43 (4) ◽  
pp. 362-372 ◽  
Author(s):  
Xiaohong Fu ◽  
Yingping Xie ◽  
Xiaomin Zhang ◽  
Weimin Liu
Keyword(s):  
Electron Microscopy ◽  
Reproductive System ◽  
Lipid Droplets ◽  
Nurse Cells ◽  
Serial Sections ◽  
Female Reproductive System ◽  
Follicular Cells ◽  
Yolk Lipid ◽  
Egg Chamber ◽  
Scanning Electron

The structure of the female reproductive system of the mealybug, Phenacoccus fraxinus Tang (Hemiptera: Coccoidea: Pseudococcidae), was studied using standard histological examination of serial sections of tissues embedded in paraffin and by scanning electron microscopy. Our studies revealed that the ovary of P. fraxinus has paired lateral oviducts comprised of numerous short ovarioles. Each ovariole consists of 1 trophic chamber, 1 egg chamber and 1 pedicel which connect to the bottom of the egg chamber. Three nurse cells were observed in the trophic chamber, whereas yolk, lipid droplets and an oocyte were seen in the egg chamber. Follicular cells were arranged along the wall of the egg chamber and extended to form the pedicel. Many tracheae and tracheoles of various thicknesses were observed innervating the clusters of ovaries.

Comparative Development of Some Taxonomically Critical Floral Inflorescence Features in Cyperaceae

1991 ◽  
Vol 39 (2) ◽  
pp. 119 ◽  
Author(s):  
JJ Bruhl
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Developmental Stages ◽  
Floral Morphology ◽  
Developmental Studies ◽  
Comparative Development ◽  
Inflorescence Morphology ◽  
The Family ◽  
Scanning Electron

Morphology at different developmental stages was investigated by dissection and by scanning electron microscopy (SEM) in five sedges: Eleocharis (three species) and Schoenoplectus (both Cyperoideae, Scirpeae), and Lepidosperma (Caricoideae, Schoeneae). In each case all the perianth segments (scales or bristles) were positioned outside the staminal primordia or stamens, consistent with classical interpretations of flowers. Putative exceptions and previous alternative interpretations of floral morphology in the Cyperaceae are discussed. SEM developmental studies of Hypolytreae (e.g. Scirpodendron) are needed for further clarification of interpretative floral/inflorescence morphology in the family.

scholarly journals Fine structure and distribution of antennal sensilla of stink bug Arma chinensis (Heteroptera: Pentatomidae)

2019 ◽  
Vol 25 (4) ◽  
pp. 186-198 ◽  
Author(s):  
Jian Zhang ◽  
Xiaojun Zhang ◽  
Chunyu Liu ◽  
Lipeng Meng ◽  
Yulin Zhou
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Distal Part ◽  
Antennal Sensilla ◽  
Stink Bug ◽  
Sensilla Basiconica ◽  
Sensilla Trichodea ◽  
Morphology And Structure ◽  
Heteroptera Pentatomidae ◽  
Scanning Electron

Scanning electron microscopy was used to examine the morphology, ultrastructure, and distribution of antennal sensilla of the stink bug Arma chinensis. Two types of sensilla trichodea (ST1–2), four types of sensilla basiconica (SB 1– 4), one type of sensilla chaetica (SCH), one type of sensilla cavity (SCA) and one type of sensilla coeloconica (SCO) were distinguished on the antennae in both sexes. ST1 and ST2 were absent from the scape and pedicel. SB1 were absent from the scape. SB2 were distributed throughout the antennae. SB3 were located on the second pedicel and the two flagellomeres. SB4 were absent from the second flagellomere. SCH was observed on the second pedicel and the two flagellomeres. SCA and SCO occurred only on the second flagellomere. SB1 clusters occurred on the distal part of the second flagellomere. We compared the morphology and structure of these sensilla to other Heteroptera and discuss their possible functions.

scholarly journals 738 Text ANATOMICAL DESCRIPTION OF THE FRUIT-RECEPTACLE DETACHMENT AREA IN CAYENNE PEPPER

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 538f-538
Author(s):  
Kay P. Gersch ◽  
Carl E. Motsenbocker ◽  
Grezory A. Lang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Developmental Stages ◽  
Histochemical Staining ◽  
Distinct Region ◽  
Cell Type ◽  
Mature Fruit ◽  
Cell Layers ◽  
Or Organization ◽  
Scanning Electron

Two genotypes of cayenne pepper, Capsicum annuun, have been previously identified which differ significantly in ease of fruit detachment force. Both greenhouse- and field-grown plants of these genotypes, Cajun1-9027 and Cap-9004, were investigated for differences in cell type or organization where the fruit and receptacle join. Scanning electron microscopy revealed that mature fruit of genotype Cajun1-9027, which does not separate, exhibits a distinct region of sclerified cells that extend from the periphery of the fruit into the receptacle for at least 15 cell layers. In contrast, mature fruit of the more readily detachable genotype, Cap-9004, had fewer sclerified cells at the point of detachment. Neither genotype exhibits a well-defined abscission zone prior to, or at, maturity. Interpretation of histochemical staining of fruit-receptacle sections following ethylene treatment at different fruit developmental stages will be discussed.

The surface topography of Eudiplozoon nipponicum (Monogenea) developmental stages parasitizing carp (Cyprinus carpio L.)

2010 ◽  
Vol 5 (5) ◽  
pp. 702-709 ◽  
Author(s):  
Iveta Hodová ◽  
Iveta Matejusova ◽  
Milan Gelnar
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Food Intake ◽  
Developmental Stages ◽  
Gill Tissue ◽  
Free Swimming ◽  
Carp Cyprinus Carpio ◽  
Sensory Structures ◽  
Eudiplozoon Nipponicum ◽  
Scanning Electron

AbstractUsing scanning electron microscopy (SEM), the external morphology of all developmental stages (egg, oncomiracidium, diporpa, just fused juvenile and adult) of the parasite, Eudiplozoon nipponicum (Monogenea, Diplozoidae), from the gills of carp was studied. During the ontogeny, the tegument, tegumentary and sensory structures are subsequently developed. The tegument of free swimming oncomiracidium occurs in two types — the ciliated and non-ciliated with numerous uniciliated sensory structures. An attachment apparatus starts to form during the oncomiracidium stage. Further developmental stages are adapted to the environment of the gills. Tegumentary folds become more apparent later in development and assist to the parasite’s attachment. In connection with its reproductive strategy, the two morphological structures of diporpa (ventral sucker and dorsal papilla) appear to play important role. On the gills, two individuals need to meet and these structures mediate the fusion between two diporpae. The hindbody of adult parasite is highly modified for attachment. The haptor, folds and lobular extensions are most developed. The forebody is flexible and able to interact with host gill tissue via the mouth and associated mouth structures. The process of food intake of the parasite was discussed.

scholarly journals Comparison of synandrium structure and development in three species from the Myristicaceae

Botany ◽  
2017 ◽  
Vol 95 (1) ◽  
pp. 89-99 ◽  
Author(s):  
Gui-Fang Yang ◽  
Feng-Xia Xu
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Vascular Bundle ◽  
Developmental Stages ◽  
Floral Meristem ◽  
Stamen Primordia ◽  
Floral Apex ◽  
Morphology And Structure ◽  
Myristica Fragrans Houtt ◽  
Scanning Electron

Species of Myristicaceae have diverse morphology and structure of their synandria, making them an interesting group for androecium evolution research. To clarify the morphology, structure, and origin of the synandrium, scanning electron microscopy and histology were performed on staminate flowers of Horsfieldia pandurifolia H.H.Hu, H. tetratepala C.Y.Wu & W.T.Wang, and Myristica fragrans Houtt. at different developmental stages. A whorl of stamen primordia was rapidly initiated around the margin of the floral apex in groups of two in H. pandurifolia and groups of three in M. fragrans. Each stamen primordium grew longitudinally, producing a pair of anther lobes and four microsporangia, accompanying one vascular bundle in H. pandurifolia and M. fragrans. In H. tetratepala, three stamen primordia groups were formed, and each group with several anthers was supported by one vascular bundle, indicating a secondary increase of stamen. Three types of synandrium origin were observed: in M. fragrans, the central sterile column tissues originated from the elongate receptacle; in H. pandurifolia and H. tetratepala they were derived from a combination of floral meristem and fused connectives, and a combination of receptacular tissue and stamen groups. The diverse origins of the central sterile column suggest that the synandrium develops differently and independently in different genera and species of Myristicaceae.

scholarly journals Leaf teeth in eudicots: what can anatomy elucidate?

2020 ◽  
Vol 193 (4) ◽  
pp. 504-522
Author(s):  
Alex Batista Moreira Rios ◽  
Gisele Cristina de Oliveira Menino ◽  
Valdnéa Casagrande Dalvi
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Leaf Blade ◽  
Developmental Stages ◽  
Extrafloral Nectaries ◽  
Scanning Electron

Abstract Leaf teeth are projections on the leaf blade margin. They are structurally variable, with characters that are important for taxonomy and phylogeny, but there is a paucity of information on the anatomy of these structures and little understanding of the features and their functions. Here we describe and compare the leaf tooth anatomy of 47 eudicot species. Toothed margin samples from leaves at different developmental stages were collected, fixed and studied under light and scanning electron microscopy. We identified eight leaf tooth morphotypes, six of which occurred with glands. Hydathodes were the most common glands, being found in 11 species; colleters were found in ten species and extrafloral nectaries were found in two species. Cunonioid teeth either devoid of glands or associated with hydathodes were found in Lamiales, Asterales and Apiales. Dillenioid teeth associated with hydathodes were found in Dilleniales. Spinose teeth associated with colleters were found in Aquifoliales. In rosids, we found begonioid, malvoid, theoid, urticoid and violoid teeth, which may be associated with either colleters or nectaries or lack an associated gland. For each family studied, there was only one type of association between gland and tooth, demonstrating the systematic potential of these glands in eudicots.

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