scholarly journals External female genitalia of Triatoma jatai, Triatoma costalimai and Triatoma williami (Hemiptera: Reduviidae: Triatominae)

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Simone Caldas Teves ◽  
Teresa Cristina Monte Gonçalves ◽  
Simone Patrícia Carneiro de Freitas ◽  
Catarina Macedo Lopes ◽  
Ana Laura Carbajal-de-la-Fuente ◽  
...  

Abstract Background Taxonomic identification of triatomines is generally performed based on aspects of their external morphology. However, the use of a multidisciplinary approach, considering morphological aspects of the external genitalia, morphometry, genetics, and phylogeography has been suggested, especially for similar and/or cryptic species. The rupestral species Triatoma jatai Gonçalves et al., 2013, Triatoma costalimai Verano & Galvão, 1959 and Triatoma williami Galvão et al., 1965, which are morphologically similar, have been found naturally infected with Trypanosoma cruzi (Chagas, 1909) in wild, peridomestic, and intradomestic environments, representing a risk of new outbreaks of Chagas disease. This study presents morphological description complementation of these species, with an emphasis on the structures of the female external genitalia, using scanning electron microscopy. Methods The females of T. jatai and T. costalimai (n = 10 of each) were captured in the Brazilian municipalities of Paranã and Aurora do Tocantins and were identified with the use of a dichotomous key for the Matogrossensis subcomplex. Females of T. williami (n = 5), were obtained from a laboratory colony. The females were cut transversely at the sixth abdominal segment and examined under scanning electron microscopy (SEM) at the Oswaldo Cruz/Fiocruz Institute Electronic Microscopy Platform. Results It was possible to differentiate the three species based on the characteristics of urotergites VII, VIII and IX and urosternite VII, as well as the genital plaques, gonocoxites, and gonapophyses. To our knowledge, morphological differences in the spines present on gonapophysis 8 in triatomines are described here for the first time. Conclusions The results show that external genitalia of females are useful structures to differentiate T. costalimai, T. jatai and T. williami. SEM analysis contributes to and corroborates, together with other tools morphological and molecular, the distinction of the three species.

2020 ◽  
Author(s):  
Simone Caldas Teves ◽  
Teresa Cristina Monte Gonçalves ◽  
Simone Patricia Carneiro de Freitas ◽  
Catarina Macedo Lopes ◽  
Ana Laura Carbajal-de-la-Fuente ◽  
...  

Abstract BackgroudTaxonomic identification of triatomines is generally performed based on aspects of their external morphology. However, the use of a multidisciplinary approach, considering morphological aspects of the external genitalia, morphometry, genetics, and phylogeography has been suggested, especially for similar and/or cryptic species. The rupestral species Triatoma jatai Gonçalves et al. 2013, Triatoma costalimai Verano & Galvão 1959, and Triatoma williami Galvão et al. 1965, which are morphologically similar, have been found with natural infection by Trypanosoma cruzi (Chagas, 1930) in wild, peridomestic, and intradomestic environments, representing a risk of new outbreaks of Chagas disease. This study presents a morphological description complementation of these species, with an emphasis on the structures of the female external genitalia, using scanning electron microscopy. MethodsFemale specimens of T. jatai and T. costalimai captured in Brazilian Municipalites of Paranã and Aurora do Tocantins were identified with the use of a dichotomous key for the sub-complex Matogrossensis, as well T. williami, obtained by colony of reference laboratory in triatomines. The insects were sectioned with a scalpel in the transverse direction at the height of the sixth abdominal segment. The terminal portion of the abdomen was washed, dehydrated in an alcoholic series and mounted on a metallic support on double-sided adhesive tape in the ventral or dorsal positions. Samples were then left in an oven and in a desiccator containing silica gel for drying until metallization. They were metallized with gold and examined using a scanning electron microscope at the Oswaldo Cruz/FIOCRUZ Institute Electronic Microscopy Platform. ResultsIt was possible to differentiate between the species based on characteristics of the 7th, 8th, and 9th urotergites and 7th urosternite, as well as the genital plaques, gonocoxites, and gonapophyses. For the first time, morphological differences in the thorns present on gonocoxite 8 are described in triatomines.ConclusionsWe results show that external genitalia of female it is a useful structure to differentiate T. jatai, T. costalimai and T. williami. The scanning electron microscopy contribute and corroborate, together with other tools morphological and molecular, to the differentiation of T. jatai, T. costalimai and T. williami, as well as expand the taxonomic knowledge. It may also help to understand if there is reproductive compatibility between T. jatai and T. costalimai as well possible formation of hybrids under artificial conditions. This one is underway in order to fully contemplate all definitions of biological species.


2019 ◽  
Vol 2019 ◽  
pp. 1-9
Author(s):  
Margareth Alves Ribeiro Cardozo de Almeida ◽  
Simone Patrícia Carneiro Freitas ◽  
Maria Luiza Ribeiro de Oliveira ◽  
Nathanielly Rocha Casado de Lima ◽  
Elizabeth Ferreira Rangel ◽  
...  

In Brazil, Triatoma rubrovaria (Blanchard, 1843) is the most important species in epidemiological terms in the State of Rio Grande do Sul, due to its wide geographical distribution in this state, followed by T. carcavalloi (Jurberg, Rocha & Lent, 1998) and T. circummaculata (Stål, 1859). Structural analysis of the ventral region of the head (rostrum and buccula), thorax (stridulatorium sulcus and scutellum), and external female genitalia of adults of T. rubrovaria, T. carcavalloi, and T. circummaculata is described here. Scutellum, head, rostrum, and part of the thorax (prosternum) containing the stridulatory sulcus, in both male and female, and the sixth abdominal segment of the female, containing the external genitalia, were processed for scanning electron microscopy studies as routine. Morphological differences in the analyzed structures for all the three Triatoma species studied were detected under scanning electron microscopy. This study confirms the grouping of the T. rubrovaria, T. carcavalloi, and T. circummaculata in ‘T. rubrovaria subcomplex’ by their morphological similarities.


Author(s):  
M.E. Lee ◽  
A. Moller ◽  
P.S.O. Fouche ◽  
I.G Gaigher

Scanning electron microscopy of fish scales has facilitated the application of micro-structures to systematics. Electron microscopy studies have added more information on the structure of the scale and the associated cells, many problems still remain unsolved, because of our incomplete knowledge of the process of calcification. One of the main purposes of these studies has been to study the histology, histochemistry, and ultrastructure of both calcified and decalcified scales, and associated cells, and to obtain more information on the mechanism of calcification in the scales. The study of a calcified scale with the electron microscope is complicated by the difficulty in sectioning this material because of the close association of very hard tissue with very soft tissues. Sections often shatter and blemishes are difficult to avoid. Therefore the aim of this study is firstly to develop techniques for the preparation of cross sections of fish scales for scanning electron microscopy and secondly the application of these techniques for the determination of the structures and calcification of fish scales.


2020 ◽  
Vol 861 ◽  
pp. 378-382
Author(s):  
Sophoan Phal ◽  
Muhammad Rafiullah Khan ◽  
Pattarin Leelaphiwat ◽  
Vanee Chonhenchob

Sodium alginate based films containing turmeric oil (TEO) at different concentrations (1, 2 and 3%) were developed. The film with no TEO was used as control. Incorporation of TEO had the effects on the film properties. With increasing TEO concentrations, thickness, elongation at break, permeability of oxygen and water vapor of the films significantly (p ≤ 0.05) increased. Whereas moisture content, tensile strength and modulus of elasticity significantly (p ≤ 0.05) decreased. Scanning electron microscopy (SEM) analysis showed more numerous pores and rougher surface of the antifungal films than the control film.


Nematology ◽  
2001 ◽  
Vol 3 (8) ◽  
pp. 817-832 ◽  
Author(s):  
Walter Sudhaus ◽  
Karin Kiontke ◽  
Albrecht Manegold

AbstractA detailed morphological description is presented of Diplogasteroides nasuensis Takaki, 1941 and D. magnus Völk, 1950, using light and scanning electron microscopy. Neoaplectana melolonthae Weiser, 1958 and Diplogasteroides (Rhabdontolaimus) berwigi Rühm, 1959 are synonymised with D. nasuensis. This gonochoristic species is distinguished from the hermaphroditic D. magnus by the dorsal metastomal decoration which consists of bristle-like protrusions instead of a more or less uniform tooth. The spermatocytes in D. nasuensis are twice as big as those in hermaphrodites of D. magnus. Dauer juveniles of D. nasuensis are considerably bigger than those of D. magnus. Dauer juveniles of both species are present on wood cockchafer (Melolontha hippocastani) larvae and adults but, on adult beetles, D. nasuensis dauer juveniles enter the genital pouch, whereas those of D. magnus are found under the hind coxae. In Germany, D. nasuensis is found only on M. hippocastani. D. magnus dauer juveniles are also found on a variety of other Scarabaeidae. Further small differences distinguish the two species. The genus Diplogasteroides is proposed to be taken in a broad sense. Several genera names are synonymised with Diplogasteroides.


1979 ◽  
Vol 16 (8) ◽  
pp. 1621-1628 ◽  
Author(s):  
Donald E. Champagne ◽  
C. R. Harington ◽  
Don E. McAllister

A nodule containing the cranium of a deepwater sculpin, Myoxocephalus thompsoni (Girard), was discovered in Pleistocene Champlain Sea deposits at Green Creek, 10 km east of Ottawa, Ontario, Canada, and represents the first fossil reported for the species. It provides an additional basis for refuting derivation of the species from a post-Wisconsin marine submergence and suggests an origin at the beginning of the Wisconsin or earlier. Habitat preferences of the species favour an oligotrophic lacustrine environment with bottom summer temperatures below 8 °C in the Champlain Sea or nearby lake basin. The head length of the fossil is 28 mm, the estimated standard length 86 mm. Use of a longwave ultraviolet lamp with the fossil improved contrast between the bones and the clay matrix in photographs. Scanning electron microscopy (SEM) analysis of bone in the fossil failed to detect the presence of strontium.


Genes ◽  
2018 ◽  
Vol 9 (8) ◽  
pp. 417 ◽  
Author(s):  
John Yason ◽  
Kevin Tan

Blastocystis is a common intestinal protistan parasite with global distribution. Blastocystis is a species complex composed of several isolates with biological and morphological differences. The surface coats of Blastocystis from three different isolates representing three subtypes were analyzed using scanning electron microscopy. This structure contains carbohydrate components that are also present in surface glycoconjugates in other parasitic protozoa. Electron micrographs show variations in the surface coats from the three Blastocystis isolates. These differences could be associated with the differences in the pathogenic potential of Blastocystis subtypes. Apart from the surface coat, a plasma membrane-associated surface antigen has been described for Blastocystis ST7 and is associated with programmed cell death features of the parasite.


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