Search

This study performed a histomorphometric analysis of the retina and estimated the visual acuity of three fruit-eating bats of the genus Artibeus, including Artibeus lituratus, Artibeus planirostris and Artibeus obscurus. In total, 13 animals were used for this study, in which the retinas were hemidisected, fixed, cut, and stained. The visual acuity was determined by the density of ganglion cells in the retina and the retinal layers were also measured from histological sections. The retinas of these bats are avascular, do not present tapetum lucidum in any quadrant, and have the 10 retinal layers common in mammals. Moreover, it was observed that the thickness of the retina in the central region was significantly higher in all measured parameters (p

In this study, reproductive stages and ovarian histophysiology were investigated in adult female Artibeus planirostris in the municipality of Vitoria de Santo Antao, Pernambuco, Northeastern Brazil. They were captured over one night each month (November 2016 to November 2017). Based on the monthly average precipitation, the dry (September to February) and rainy (March to August) months were grouped. Through external body morphology, females were classified as inactive, pregnant, lactating, and post-lactating. Only the inactive (n = 13) were euthanized for morphophysiological analyzes. Blood samples were obtained for estrogen measurement and, after euthanasia, the ovaries were collected and processed by routine histological techniques. In morphometry, were considered: the area of the ovary, the presence, and the area of the ovarian follicles (unilaminar and multilaminar primary, antral, and Graafian), as well as the quantification of the corpus luteum. In immunohistochemistry, PCNA (Proliferating cell nuclear antigen) was used. The results showed pregnant females only in dry months, however inactive, lactating, and post-lactating females were collected in dry and rainy months. Estrogen levels and the presence of positive PCNA cells were higher in the rainy months. The Graafian follicle occurred only in these months, whereas the corpus luteum was found in all specimens from the dry months. Although A. planirostris has a tendency to start gestation in dry months and mating from mid to the end of the rainy months, this species showed adaptability influenced by environmental variations throughout the reproductive cycle, indicating a aseasonal polyestry.

Bats belong to the order Chiroptera, family Phyllostomidae, and present a wide diversity of reproductive strategies. However, information on the reproductive biology of male bats is scarce, mainly in the Northeast Region of Brazil. Thus, this study evaluated the seasonal testicular histomorphometry of the bat Carollia perspicillata in fragments of the Atlantic Forest in Pernambuco state. To this end, adult males were collected, euthanized for removal of the testicles, and later submitted to a routine histological technique. Histomorphometric analysis included assessment of the areas of tubular and intertubular compartment occupation, as well as quantification of spermatocytes, rounded spermatids, elongated spermatids, and Sertoli and Leydig cells. Results indicated that this bat species presents reproductive seasonality, because significantly higher averages of the testicular parameters were observed in the rainy season, which is a period of greater availability of food resources. Such inferences indicate that there is a synchrony between peak spermatogenesis and hormonal inversion in the months of high precipitation; furthermore, a higher carrying capacity of the Sertoli cells is noted. C. perspicillata males possibly present greater sperm and androgenic activity in the rainy season, associated with increased tubular area and number of spermatogenic cells, as well as with the intertubular area and number of Leydig cells, respectively. RESUMO: Os morcegos pertencem a ordem Chiroptera, família Phyllostomidae, e apresentam ampla diversidade de estratégias reprodutivas. Entretanto, as informações relacionadas à biologia reprodutiva dos machos são escassas, principalmente no Nordeste do Brasil. Dessa forma, o trabalho avaliou a histomorfometria sazonal testicular de Carollia perspicillata em fragmentos de Mata Atlântica de Pernambuco. Para tanto, os machos adultos foram coletados, eutanasiados para a remoção dos testículos, e posteriormente submetidos à técnica histológica de rotina. As análises histomorfométricas avaliaram as áreas de ocupação do compartimento tubular e intertubular, assim como a quantificação dos espermatócitos, espermátides arredondadas, espermátides alongadas, células de Sertoli e de Leydig. Os resultados indicaram que a espécie apresenta sazonalidade reprodutiva, visto que maiores médias significativas dos parâmetros testiculares foram encontradas na estação chuvosa, que é um período de maior disponibilidade de recursos alimentares. Tais inferências indicam que existe uma sincronia entre o pico de espermatogênese e investimento hormonal nos meses de alta precipitação, atrelado a isso, nota-se ainda, uma maior capacidade de suporte das células de Sertoli. Os machos de C. perspicillata possivelmente apresentam uma maior atividade espermática e androgênica na estação chuvosa, associadas ao aumento da área tubular e do número de células espermatogênicas, assim como da área intertubular e do número das células de Leydig, respectivamente.

RESUMO Esse estudo objetivou avaliar sazonalmente a histomorfometria do epidídimo de Dermanura cinerea (Gervais, 1856) em um fragmento de Mata Atlântica no nordeste do Brasil. Foram utilizados 18 espécimes machos adultos capturados por redes de neblina. As coletas ocorreram mensalmente ao longo de dezoito meses, durante duas noites consecutivas e os dados meteorológicos foram fornecidos pelo Instituto Nacional de Meteorologia. Depois de eutanasiados, os espécimes tiveram os epidídimos coletados e esses órgãos foram fixados e processados. As lâminas histológicas foram coradas por Hematoxilina - Eosina e analisadas em microscopia óptica. Os parâmetros morfométricos analisados foram as áreas do túbulo, do lúmen e do epitélio das regiões do segmento inicial, cabeça, corpo e cauda do epidídimo. Os dados histomorfométricos obtidos foram submetidos às análises no teste U de Mann-Whitney. Os resultados revelaram que D. cinerea apresentou espermatozoides em todas as regiões do epidídimo, exceto no segmento inicial. As maiores médias das áreas tubular, do lúmen e do epitélio nas quatro regiões, foram constatadas durante os meses secos. Portanto, D cinerea apresentou maior sensibilidade na região da cauda do epidídimo, ao longo dos meses com baixos índices pluviométricos. Isso indica que as condições ambientais apresentam considerável influência sobre a morfofisiologia epidídimária dessa espécie, sobretudo, em relação ao armazenamento de espermatozoides na cauda desse órgão, em área de Mata atlântica do nordeste brasileiro. ABSTRACT Description and seasonal variation in epididymal histomorphometry of Dermanuracinerea (Chiroptera: Phyllostomidae) in a fragment of the Atlantic Forest in the Northeastern Brazil. This study aimed to evaluate seasonal patterns in the histomorphometry of the epididymis of Dermanura cinerea (Gervais, 1856) in a fragment of the Atlantic Forest in the Northeastern Brazil. Eighteen adult male specimens captured by mist net were used. The field-work occurred monthly over 18 months, during two consecutive nights. Meteorological data (precipitation) were obtained from the National Institute of Meteorology. After euthanasia, specimens had the epididymis collected, which were fixed and processed. The histological slides produced were stained by Hematoxylin - Eosin and analyzed by optical microscopy. The morphometric parameters analyzed were the tubular, lumen and epithelium areas, of the regions of the initial segment, caput, corpus and cauda of the epididymis. The histomorphometric data were submitted to the Mann-Whitney U test analyzes. The results showed that D. cinerea presented spermatozoa in all regions of the epididymis, except in the initial segment. The highest averages of the tubular, lumen and epithelial areas in the four regions were observed during the dry months. Therefore, D cinerea presented greater sensibility in the region of the cauda of the epididymis, during the months with low rainfall indices. This indicates that environmental conditions have considerable influence on the epididymal morphophysiology of this species, especially in relation to the storage of sperm in the tail of this organ, in area of Atlantic forest in northeastern Brazil.

RESUMO Esse estudo analisou o estágio reprodutivo, a histologia e a morfometria dos testículos de Dermanura cinerea (Gervais, 1856) em fragmento de Mata Atlântica no Litoral Sul de Pernambuco. Os espécimes foram capturados por redes de neblina e as coletas ocorreram mensalmente, ao longo de duas noites consecutivas, durante 18 meses. Os dados meteorológicos foram agrupados em meses chuvosos e secos. Foram utilizados 18 espécimes adultos, os quais foram classificados em machos com testículos descendentes e não descendentes. Para as análises histológicas, os testículos foram coletados, fixados e processados seguindo a técnica histológica de rotina. As lâminas obtidas foram coradas por Hematoxilina-Eosina. Nas análises morfométricas foram mensuradas a área de ocupação do compartimento tubular e intertubular, quantificados o número de células de Leydig, de Sertoli, de espermatócitos e de espermátides alongadas. Os dados morfométricos foram submetidos às análises estatísticas. Dermanura cinerea apresentou maior atividade de produção espermática em meses secos e maior produção hormonal em meses chuvosos. Essas informações estão relacionadas também com o padrão reprodutivo das fêmeas e com a elevação nos índices pluviométricos, já que é um fator determinante na mediação da disponibilidade alimentar das espécies frugívoras, como D. cinerea em área de Mata Atlântica de Pernambuco. ABSTRACT This study analyzed the reproductive stage, histology and morphometry of the testes of Dermanura cinerea (Gervais, 1856) in Atlantic Forest fragment on the South Coast of Pernambuco. Specimens were captured by mist net, and collections occurred monthly over two consecutive nights for 18 months. The meteorological data were grouped in rainy and dry months. Eighteen adult specimens were used, which were classified in males with descendant testes and with testes no descendant. For the histological analysis, the testes were collected, fixed and processed following the routine histological technique. The slides obtained were stained by Hematoxylin-Eosin. In the morphometric analysis the area of occupation of the tubular and intertubular compartment were measured, the number of Leydig, Sertoli, spermatocytes and elongated spermatids were quantified. The morphometric data were submitted to statistical analysis. Dermanura cinerea presented higher sperm production activity in dry months and higher hormone production in rainy months. This information is also related to the reproductive pattern of the females and to the increase in rainfall indexes, since it is a determinant factor in the mediation of the food availability of the frugivorous species, such as D. cinerea in the Atlantic Forest area of Pernambuco.

This study aimed to analyze the reproductive stage, histology and morphometry of the ovary of Dermanura cinerea in an Atlantic Forest fragments in the Biological Reserve of Saltinho, Pernambuco, Brazil. Adult females were captured monthly by mist net, during two consecutive nights from June/2014 to November/2015. The meteorological data were provided by the National Institute of Meteorology and grouped together with the reproductive data, in six periods: period I (June to August/2014), period II (September to November/2014), period III (December/2014 to February/2015), period IV (March to May/2015), period V (June to August/2015) and period VI (September to November/2015). The females were classified according to their reproductive stages in: Inactive, pregnant, lactating and postlactating. Among the 25 females caught, 10 inactive females were selected for the histomorphometric analysis of the ovaries and then they were euthanized. After that, the specimens had their ovaries removed, fixed, processed and included in Paraplast. The organs were cut and stained by Hematoxylin - Eosin and the histological slides produced were submitted to the appropriate optical microscope analysis. Each type of ovarian follicle was estimated according to the histological characteristics evidenced for other mammals. In the morphometric analysis, it was considered: The area of the ovary (measured in square millimeter), Quantification of different types of ovarian follicles (unilaminar and multilaminar primary follicles, antral and matures) and corpus luteum, as well as the area of each by those different follicles (measured in square micrometer) The results indicated that 16 females were inactive, 5 were lactating, 4 were pregnant and no post-lactating. The histological analysis revealed that the ovaries of D. cinerea exhibit characteristics, structures and cellular types similar to other mammals. The morphometric data of the study area were statistically evaluated using the Student’s t-test. Therefore, ovarian histomorphometric analysis are very important to infer with greater certainty about the reproduction of a species. Thus, it was observed that females of D. cinerea exhibit two reproductive peaks, that is, they can give birth either at the end of dry periods or from the beginning to the middle of the rainy season. The main feature observed in the ovary of this species, found in the Atlantic Forest area of the state of Pernambuco, is the preparation of the ovarian cortex to ovulate in months of high rainfall throughout the year. Therefore, this species tries to adjust its reproductive period with the variations of the environmental conditions, so that the reproduction might occur during the period more favorable for the maintenance of their offspring.