Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 118
Filter
1.
Braz. j. biol ; 84: e249808, 2024. tab, graf
Article in English | LILACS, VETINDEX | ID: biblio-1345554

ABSTRACT

Abstract The sexing of species is an important tool for population management. In tortoises and turtles, sexing is usually done according to secondary characteristics, such as plastron morphology or phallus eversion techniques. In this paper, we present the phallus eversion method and compare its efficiency to other existing techniques. This new method aims at shortening the management time and reducing the physical aftereffects on the animals, fostering the clinical and reproductive management of Geoffroy's side-necked turtle (Phrynops geoffroanus) and related species. A sample of fifty individuals was taken in the central region of Piauí state, Northeastern Brazil. The proposed method consisted of moving the head from its resting position. The methods achieving a success rate higher than 80% were compared to each other as for the stimulation time required for phallus eversion. The method as here proposed achieved 100% efficiency in the sex determination of specimens with a linear carapace length between 10 and 34 cm. Also, when compared to the second most efficient method, it substantially reduced the time needed for managing the specimens (91%), avoiding possible sequelae in the individuals handled.


Resumo A sexagem das espécies é uma ferramenta importante para o manejo populacional. Em tartarugas, cágados e jabutis, a sexagem geralmente é feita de acordo com características secundárias, como morfologia do plastrão ou técnicas de eversão do falo. Neste artigo, apresentamos o método de eversão do falo e comparamos sua eficiência com outras técnicas existentes. Este novo método visa encurtar o tempo de manejo e reduzir os efeitos colaterais físicos nos animais, promovendo o manejo clínico e reprodutivo do cágado-de-barbicha (Phrynops geoffroanus) e espécies relacionadas. Uma amostra de cinquenta indivíduos foi coletada na região central do estado do Piauí, Nordeste do Brasil. O método proposto consiste em remover a cabeça de sua posição de repouso. Os métodos que obtiveram índice de sucesso superior a 80% foram comparados entre si quanto ao tempo de estimulação necessário para a eversão do falo. O método aqui proposto alcançou 100% de eficiência na determinação do sexo de espécimes com comprimento de carapaça linear entre 10 e 34 cm. Além disso, quando comparado ao segundo método mais eficiente, reduziu substancialmente o tempo necessário para o manejo dos espécimes (91%), evitando possíveis sequelas nos indivíduos manuseados.


Subject(s)
Animals , Turtles , Brazil
2.
Braz. j. biol ; 842024.
Article in English | LILACS-Express | LILACS, VETINDEX | ID: biblio-1469244

ABSTRACT

Abstract The sexing of species is an important tool for population management. In tortoises and turtles, sexing is usually done according to secondary characteristics, such as plastron morphology or phallus eversion techniques. In this paper, we present the phallus eversion method and compare its efficiency to other existing techniques. This new method aims at shortening the management time and reducing the physical aftereffects on the animals, fostering the clinical and reproductive management of Geoffroys side-necked turtle (Phrynops geoffroanus) and related species. A sample of fifty individuals was taken in the central region of Piauí state, Northeastern Brazil. The proposed method consisted of moving the head from its resting position. The methods achieving a success rate higher than 80% were compared to each other as for the stimulation time required for phallus eversion. The method as here proposed achieved 100% efficiency in the sex determination of specimens with a linear carapace length between 10 and 34 cm. Also, when compared to the second most efficient method, it substantially reduced the time needed for managing the specimens (91%), avoiding possible sequelae in the individuals handled.


Resumo A sexagem das espécies é uma ferramenta importante para o manejo populacional. Em tartarugas, cágados e jabutis, a sexagem geralmente é feita de acordo com características secundárias, como morfologia do plastrão ou técnicas de eversão do falo. Neste artigo, apresentamos o método de eversão do falo e comparamos sua eficiência com outras técnicas existentes. Este novo método visa encurtar o tempo de manejo e reduzir os efeitos colaterais físicos nos animais, promovendo o manejo clínico e reprodutivo do cágado-de-barbicha (Phrynops geoffroanus) e espécies relacionadas. Uma amostra de cinquenta indivíduos foi coletada na região central do estado do Piauí, Nordeste do Brasil. O método proposto consiste em remover a cabeça de sua posição de repouso. Os métodos que obtiveram índice de sucesso superior a 80% foram comparados entre si quanto ao tempo de estimulação necessário para a eversão do falo. O método aqui proposto alcançou 100% de eficiência na determinação do sexo de espécimes com comprimento de carapaça linear entre 10 e 34 cm. Além disso, quando comparado ao segundo método mais eficiente, reduziu substancialmente o tempo necessário para o manejo dos espécimes (91%), evitando possíveis sequelas nos indivíduos manuseados.

3.
Article | IMSEAR | ID: sea-217505

ABSTRACT

Background: A balanced sex ratio is needed to stabilize India, a patriarchal subcontinent. Aim and Objective: The study aims to find out whether there is any association between the socio-demographic characters and perceived gender preference among the study subjects. Materials and Methods: The study is an observational, descriptive study with cross-sectional study design. An exit interview of 80 pregnant mothers, both primi and multigravida, selected by systematic random sampling attending antenatal clinic of Medical College, Kolkata for 1st time was conducted for 1 month, using a pre-designed pre-tested semi-structured data collection form after ethics committee approval. Statistical analyses were done using Chi-square tests, at P ? 0.05 level of significance in Statistical Package for Social Sciences. Results: Mean age of study participants was 24.15 ± 4.38 years. The majority (77.5%) of them belonged to age group 20–29 years. 58.8% mothers were nulliparous, 53.8% from rural areas, 63.7% followed Islam, 52.5% from joint family, 31.3% belonged to middle class. 95% of the mothers had no history of abortion. Regarding education, the majority (32.5%) of the study participants were educated till secondary level. Among their husbands, 28.7% were educated till middle level. 40% study participants had no any gender preference, 40% had male preference and 20% had female preference. Main reason behind male preference was an earlier female child. Some preferred daughters due to their earlier male child. Nulliparous mothers had no gender preference while lesser-educated mothers had gender preference. Conclusion: The majority of the study participants had gender preference. Male preference was more than female preference.

4.
Afr. J. reprod. Health (online) ; 26(4): 1-6, 2022-06-03. Tables
Article in English | AIM | ID: biblio-1381441

ABSTRACT

The study attempts at estimating the sex-ratio at birth in Nigeria. The study focuses on demographic surveys with complete maternity histories, including some 0.50 million births. It compares results with published estimates from births in health facilities and a few data from vital registration, including some 1.13 million births. Results from demographic surveys give an estimate of about 106 boys for 100 girls. There were no significant variations by large region in the country, and no significant trend over the years (1990-2018). Published estimates provided a similar value (106.2), with somewhat lower value in health facilities (105.3), and somewhat higher values in local vital registration (106.8), and major variations among available studies. Despite uncertainty, Nigeria appears to have higher sex-ratios than most African countries, with the exception of Ethiopia, and higher values than its five neighboring countries. Reasons for these high values of the secondary sex-ratio are discussed. (Afr J Reprod Health 2022; 26[4]: 92-97).


Subject(s)
Women , Demography , Vital Statistics , History , Hospitals, Maternity , Parturition , Men , Nigeria
5.
Rev. biol. trop ; 69(supl. 1)mar. 2021.
Article in English | LILACS, SaludCR | ID: biblio-1507743

ABSTRACT

Introduction: The exploitation of the sea cucumber (Holothuria (Panningothuria) forskali) in Ría de Vigo (NW Spain) is recent (2015) and it has been done until now with scarce or no information about some key biological aspects as reproduction, recruitment or growth. Objective: To describe the reproductive cycle of H. forskali in Ría de Vigo. Methods: We sampled fortnightly throughout 2018. We calculated gonadal condition indices (GCI) and gametogenic stages by classic histological methods. Results: The reproductive cycle of H. forskali in the Ría de Vigo is characterized by a sexual resting stage during spring, when temperature and daylight hours are lower; the beginning of gametogenesis during summer, when temperature is higher, daylight hours longer and the sea bottom is rich in nutrients; then, a period of spawns interspersed with a gonadal restoration during autumn and winter, when temperature is lower and food is scarce. Sex ratio is 1:1, however, the studied population is not synchronized, because females initiate maturation earlier. The comparison of the histological results with GCI indices suggest that GCI is a good indicator for gonadal stage. Fishery management strategies, such as a closure period, must be adapted to the reproductive stage. We recommend avoiding fishing between November and February to increase spawning potential ratio and, consequently, recruitment.


Introducción: La explotación del pepino de mar (Holothuria (Panningothuria) forskali) en la Ría de Vigo (NO España) es reciente (2015) y se ha llevado a cabo con poca o ninguna información sobre algunos aspectos biológicos claves como la reproducción, el reclutamiento o el crecimiento. Objetivo: Describir el ciclo reproductivo de H. forskali en un banco de la Ría de Vigo. Métodos: Se tomaron muestras quincenales durante el 2018. Se calcularon índices de condición gonadal (ICG) y se obtuvieron los estados gonadales siguiendo métodos histológicos clásicos. El estado gonadal de cada individuo se asignó de acuerdo con una escala modificada por otros autores, y en ella se describe un nuevo estado de recuperación gonadal, no descrito hasta ahora para esta especie. Resultados: El ciclo reproductivo de H. forskali se caracteriza por una etapa de reposo sexual en primavera, un inicio de la gametogénesis durante el verano y un período de puestas sucesivas intercaladas con recuperaciones gonadales durante el otoño e invierno. La proporción de sexos es 1:1 y la población estudiada no está sincronizada, las hembras inician la maduración antes. La comparación de los resultados histológicos con los índices ICG sugiere que este índice es un buen indicador del estado gonadal. El período de veda debe adaptarse a la etapa reproductiva, por lo que recomendamos evitar la extracción del recurso al menos entre noviembre y febrero para asegurar un mayor número de puestas y, en consecuencia, el reclutamiento.


Subject(s)
Animals , Sea Cucumbers/anatomy & histology , Abiotic Factors , Gonads , Spain , Fishing Industry
6.
West Indian med. j ; 69(2): 129-133, 2021. tab, graf
Article in English | LILACS | ID: biblio-1341878

ABSTRACT

ABSTRACT Objective: In humans, males' births exceed females' births. This ratio is conventionally referred to as M/F and is used to denote male births divided by total births. This ratio is influenced by a large number of factors and has been shown to exhibit seasonality. This study was carried out in order to ascertain whether seasonal variation in M/F exists in the United States of America and whether such variations are influenced by race. Materials and Methods: Data on births by gender and race from 2003 to 2013 were obtained from Centres for Disease Control and Prevention Wonder section as four races: White, Black/African American, Asian/Pacific Islander and American Indian/Alaska Native. ANOVA and ARIMA tests were carried out. Results: This study analysed 45 103 146 live births (M/F 0.51182) over 2003 to 2013. M/F was highest in Asian/Pacific Islander (p < < 0.0001), followed by White (p = 0.002), American Indian/Alaska Native (p = 0.04) and Black/African American. Significant seasonality was present overall, with a peak in June, for Whites more than Black/African American. Conclusion: Parental stress lowers M/F, and lower M/F found in Black/African and American Indian/Alaskan births may be stress related. The dampened seasonality noted in Black/African American births may also be due to this phenomenon. More males were born in spring, as in other species, with interesting inter-racial differences.


Subject(s)
Humans , Male , Female , Infant, Newborn , Seasons , Sex , Birth Rate , Racial Groups
7.
Rev. biol. trop ; 68(3)sept. 2020.
Article in English | LILACS-Express | LILACS | ID: biblio-1507699

ABSTRACT

Introduction: Understanding the various aspects of the reproductive biology of fish is a key step towards applying effective strategies for sustainable management of fishery resources. Objective: We aimed to evaluate the sex ratio, reproductive period and lengths at first maturity for 30 fish species caught in the Verde River, upper Paraná River Basin, Brazil. Methods: Fish were sampled monthly from November 2010 to March 2011 and from October 2011 to February 2012, and sampled quarterly from May to August in 2011 and 2012; totaling 14 samples. Fish were measured and weighed in the laboratory. In addition, gender and gonadal developmental stage were identified macroscopically. Subsequently, the sex ratio was determined and significant differences were tested using the chi-square (χ²) method. The reproductive period was determined with the use of gonadal developmental stages and the gonadosomatic index. Lastly, length at first maturity was estimated only for the species that presented individuals with sufficient immature and mature gonads to adjust the model. Results: Of the captured individuals, 51.5 % were male, and 48.5 % were female. Fifteen species showed significant differences in their sex ratios. The reproductive period for most species occurred from October to February, with reproductive peaks in November, December and January. The length at first maturity was estimated for only five species, including Salminus brasiliensis, a keystone species. Conclusions: The sex ratios revealed that for many species, there is a predominance of males over females, which was not expected for this parameter. The reproductive period follows the same pattern observed in Neotropical fish. However, it is noteworthy that some species are starting their reproduction in August. Lastly, estimating length at first maturity for most Neotropical fish remains a challenge, which may lead to difficulties in the use of protective measures to maintain fisheries and conserve fish species.


Introducción: Comprender los aspectos de la biología reproductiva de los peces es un paso fundamental para la aplicación de estrategias efectivas para la administración sostenible de los recursos pesqueros. Objetivo: Este estudio tuvo como objetivo evaluar la proporción sexual, el período reproductivo y la longitud en la primera madurez para 30 especies de peces capturados en el río Verde, cuenca alta del río Paraná, Brasil. Métodos: Se tomaron muestras de peces mensualmente de noviembre 2010 a marzo 2011 y de octubre 2011 a febrero 2012, y trimestralmente de mayo hasta agosto de 2011 y 2012; totalizando 14 muestras. En el laboratorio, los peces capturados fueron medidos y pesados. Además, el sexo y la etapa de desarrollo gonadal se identificaron macroscópicamente. Posteriormente, se determinó la proporción sexual y se analizó si había diferencias significativas utilizando el método de chi-cuadrado (χ²). El período reproductivo fue determinado con el uso de las etapas de desarrollo gonadal y el índice gonadosomático. Finalmente, la longitud en la primera madurez fue estimada solamente para las especies que presentaron individuos con suficientes gónadas inmaduras y maduras para ajustar el modelo. Resultados: De los individuos capturados, el 51.5 % fueron machos y el 48.5 % hembras. Quince especies presentaron diferencias significativas en la proporción sexual. El período reproductivo para la mayoría de las especies ocurrió de octubre a febrero, con picos reproductivos en noviembre, diciembre y enero. La longitud en la primera madurez fue estimada solamente para cinco especies, incluyendo Salminus brasiliensis, una especie clave. Conclusiones: La proporción sexual reveló que para muchas especies hay predominio de machos sobre hembras, lo cual no se esperaba para este parámetro. El período reproductivo sigue el mismo patrón observado en peces neotropicales. Sin embargo, vale la pena señalar que algunas especies están comenzando su reproducción en el mes de agosto. Por último, estimar la longitud en la primera madurez para la mayoría de los peces neotropicales sigue siendo un reto, lo que puede llevar a dificultades en el uso de medidas de protección para mantener la pesca y conservar las especies de peces.

8.
Rev. biol. trop ; 68(3)sept. 2020.
Article in English | LILACS-Express | LILACS | ID: biblio-1507706

ABSTRACT

Introduction: Sea turtles have temperature dependent sex determination. The increase in global temperature leads to higher nest temperatures that can cause a prevalence of females, threatening the future of these species. Objective: The present work aims to evaluate the trend of incubation temperatures and the incubation period, as well as to estimate the sex ratio in nests of Chelonia mydas at Antonio and La Barca beaches, Southwestern Cuba, during the seasons from 2012 to 2018. Methods: Temperature data loggers were placed in green turtle nests with a representativeness that varied between the years analyzed. To assess the temporal variation of temperatures and incubation periods, a Kruskal-Wallis test was performed in each case. Sex ratio was estimated from its relation with temperature and incubation duration. Results: At La Barca beach, there was a 1.5 °C increase in the mean nest temperature from 2012 to 2018, although no differences were found in the period from 2015 to 2018. At Antonio beach, there is no trend since no differences were found in the mean nest temperature except for the years 2013 and 2017, which had lower temperatures than the other seasons. In both beaches mean nest temperature exceeded 30 °C in most of the years. As a result, there was a predominance of nests with incubation periods shorter than 55 days. With these values, a female hatchling production over 90 % is expected in both study sites. Conclusions: In correspondence with the registered temperature and incubation period values, most of the years reflect a hatchling production biased towards females in both beaches.


Introducción: La determinación del sexo en tortugas marinas depende de la temperatura. El aumento de la temperatura global conlleva a temperaturas más altas en los nidos, lo cual puede provocar un predominio de las hembras, amenazando el futuro de estas especies. Objetivo: El presente trabajo busca evaluar la tendencia de las temperaturas y los períodos de incubación, así como estimar la proporción sexual en nidos de Chelonia mydas,en las playas Antonio y La Barca, suroeste de Cuba, durante las temporadas del 2012 al 2018. Métodos: Se colocaron sensores para registrar la temperatura en los nidos de esta especie con una representatividad que varió entre los años analizados. Para evaluar la variación temporal de las temperaturas y los periodos de incubación, se realizó una prueba de Kruskal-Wallis en cada caso. Las estimaciones de las proporciones sexuales se realizaron a partir de la temperatura y duración de la incubación. Resultados: En playa La Barca, hubo un incremento de 1.5 °C en la temperatura promedio del nido del 2012 al 2018, aunque no se encontraron diferencias en el periodo de 2015-2018. En playa Antonio, no hay tendencia ya que no se encontraron diferencias en la temperatura promedio del nido, excepto para el 2013 y 2017, los cuales tuvieron temperaturas menores que en las otras temporadas. En ambas playas la temperatura promedio del nido excedió 30 °C en la mayoría de los años. Como resultado, hubo un predominio de nidos con periodos de incubación inferiores a 55 días. Con estos valores, se espera una producción de hembras en las crías superior al 90 % en ambos sitios de estudio. Conclusiones: En correspondencia con los valores de temperatura y periodo de incubación registrados, la mayoría de los años refleja una producción de crías sesgada hacia las hembras en ambas playas.

9.
Article | IMSEAR | ID: sea-202869

ABSTRACT

Introduction: The proportion of girls “missing” has risensharply, there are obvious moral and human concernsgenerated by such extreme manifestation of gender inequity.In India, increase in overall sex ratio shown by the 2011census is applauded at several forums. However, decline inthe child sex ratio i.e. number of girls to boys in 0-6 years agegroup fell from 927 in 2001 to 914 in 2011. It is the lowestsince independence. Haryana is among the most affected stateregarding imbalance of child sex ratio. Therefore, this studywas conducted to assess the present child sex ratio and itstrend in Agroha village of Haryana.Material and Methods: This community based cross sectionalstudy was conducted in Agroha village of Haryana. Fivehundred and fifteen mothers having children in the age groupof less than 6 years were selected for the study. The primarytool in this study was predesigned and pretested interviewschedule for recording of family and individual information.Data were analyzed by using appropriate statistical tests (viz.Proportions, Mean ± SD, Chi-square test etc.).Results: With increasing parity significant decline in child sexratio was observed. Sex Ratio for 1st birth order children was929 females per 1000 males. It fell in the 2nd birth order to 830,3rd birth order to 699, 4th birth order to 462, 5th birth order to417 and still further to only 308 for 6th birth order. There was asignificant linear relationship between adverse child sex ratioin the study population with increasing birth order.Conclusion: As masculinisation with increasing parity wasobserved in the study area, it is concluded that Haryana has yeta long way to go in her fight against declining child sex ratio.

10.
Article | IMSEAR | ID: sea-202011

ABSTRACT

Background: The preference for a son over female offspring continues to be a prevailing norm within the ancient Indian family. Sons are expected to work within the fields, give bigger financial gain and look after parents. Additionally, in Indian patriarchal society, sons are a unit responsible for the preservation of the family name. The preference for a son and female feticide continues to be a prevailing norm in ancient Indian families (urban and rural) leading to declining sex ratio to an alarming level. With this background the following study was conducted in Gautam Buddha Nagar with the objective of finding out gender bias in rural and urban area.Methods: A study was carried out in rural and urban field practice area of the Department of Community Medicine, district Gautam Buddha Nagar of Uttar Pradesh. The study was conducted among 270 married women of reproductive age group. The women were interviewed using a semi structure questionnaire.Results: More than half of the respondents in the rural areas (57.7%) preferred son while in the urban areas, 43% of women preferred a son. The most important reason for preferring a son in the rural area was a support to the parents. While in urban area son was preferred because of the continuation of a family line.Conclusions: Preference for son was found to be high. Further amendments in the existing laws and quality education may help in breaking gender stereotypes and minimizing gender bias.

11.
Biota Neotrop. (Online, Ed. ingl.) ; 20(4): e20201020, 2020. graf
Article in English | LILACS-Express | LILACS | ID: biblio-1131955

ABSTRACT

Abstract The present study analyzes the population structure of Palaemon pandaliformis, based on sex ratio, the frequency distribution in defined size classes and the reproductive biology of samples captured in seasonal collections (winter 2011 to autumn 2012) with sieves under marginal vegetation. A total of 1,043 specimens were obtained, 222 juveniles, 465 males and 356 females, being that of this total of females, 58.42% were in the ovigerous condition. The average size of the carapace for both sexes varied between 4 and 6 mm (p> 0.05) only the ovigerous females had higher averages (p <0.0001). The sex ratio differed with 1:0.76 for males (p = 0.0001), although juvenile individuals and females were present in all sampled periods, except ovigerous females in autumn. Highest abundances were observed during the winter and spring period (p = 0.0001), decreasing in the periods with higher water temperature and salinity (summer and autumn). Was observed a continuous recruitment due to the presence of juveniles in all seasons, with greater abundance in winter and spring. Thus, based on the presence of ovigerous females in almost all seasons and juveniles in all, the reproduction for P. pandaliformis can be defined as seasonal-continuous with peak in winter period.


Resumo O presente estudo analisou a estrutura populacional de Palaemon pandaliformis, com base na razão sexual, distribuição de frequência em classe de tamanho e biologia reprodutiva de amostras capturadas em coletas sazonais (inverno/2011 a outono/2012), com peneiras sob a vegetação marginal. Um total de 1.043 exemplares foi obtido, sendo 222 juvenis, 465 machos e 356 fêmeas, sendo que deste total de fêmeas, 58.42 % estavam na condição ovígeras. O tamanho médio da carapaça, para ambos os sexos, variou entre 4 e 6 mm (p>0,05), apenas as fêmeas ovígeras apresentaram maiores médias (p<0,0001). A razão sexual diferiu em 1:0,76 para machos (p=0,0001), embora os indivíduos jovens e as fêmeas estiveram presentes em todos os períodos amostrados, exceto as fêmeas ovígeras no outono. As maiores abundâncias foram observadas durante o período de inverno e primavera (p=0,0001), diminuindo nos períodos de maior temperatura e salinidade da água (verão e outono). Foi observado um recrutamento contínuo devido a presença de juvenis em todas as estações, com maior abundância no inverno e primavera. Assim, com base na presença de fêmeas ovígeras em quase todas as estações e juvenis em todas, a reprodução de P. pandaliformis pode ser definida como sazonal-contínua, com pico no período do inverno.

12.
Biota Neotrop. (Online, Ed. ingl.) ; 20(2): e20190872, 2020. tab, graf
Article in English | LILACS-Express | LILACS | ID: biblio-1100924

ABSTRACT

Abstract The study of population and reproductive traits provides information about the ecological structure of natural populations. This study aimed to characterize dynamics and reproductive traits of Hyalella palmeirensis from a natural pond from southern Brazil. The amphipods were sampled monthly (August 2012 to July 2013) by a person with the aid of a hand net for 20 minutes. Ovigerous females and pre-copulatory pairs were individualized in the field. A total of 12,325 individuals were sampled, being 1,421 males, 6,983 females (including 215 ovigerous females) and 3,921 juveniles. Paired and unpaired males were significantly greater in size than females. There was a positive correlation between body size (CL) of paired males and females. Males and females showed bimodal distribution. Total sex ratio favored females, and these were more frequent in almost all months. Ovigerous females and precopulatory pairs were found throughout the year, but with high frequency in winter and autumn, respectively, characterizing a seasonal reproduction. Juveniles were sampled throughout the year, with greater intensity in the spring. The mean fecundity was 19.6 ± 4.34 eggs. No reduction in the number of eggs was observed during embryonic development. The results observed in H. palmeirensis demonstrate that this species has a population and reproductive dynamics very similar to other species of Hyalella already analyzed in southern Brazil. Moreover, it can be seen that although the H. palmeirensis occurs in an environment with anthropic influence (soy cultivation,) the population is managing to remain in the area, with reproduction and recruitment in most months of year.


Resumo O estudo dos aspectos populacionais e reprodutivos providenciam informações sobre a estrutura ecológica das populações naturais. Este estudo teve como objetivo caracterizar aspectos populacionais e reprodutivos de Hyalella palmeirensis de uma lagoa do sul do Brasil. Os anfípodos foram amostrados mensalmente (agosto/2012 a julho/2013) por uma pessoa com o auxílio de puçá por 20 minutos. Fêmeas ovígeras e casais em comportamento pré-copulatório foram individualizados no campo. Um total de 12.325 indivíduos foram amostrados, sendo 1.421 machos, 6.983 fêmeas (incluindo 215 fêmeas ovígeras) e 3.921 juvenis. Machos pareados e não pareados são significativamente maiores em tamanho do que as fêmeas. Houve uma correlação positiva entre o tamanho do corpo (CC) de machos e fêmeas pareados. Machos e fêmeas apresentaram distribuição bimodal. A proporção sexual total favoreceu as fêmeas, e estas foram mais frequentes em quase todos os meses. Fêmeas ovígeras e casais em pré-cópula foram amostrados ao longo do ano, mas com elevada frequência no inverno e outono, respectivamente, caracterizando uma reprodução sazonal. Os juvenis foram amostrados ao longo do ano, com maior intensidade na primavera. A fecundidade média foi de 19,6 ± 4,34 ovos. Não houve redução no número de ovos durante o desenvolvimento embrionário. Os resultados observados em H. palmeirensis demonstram que esta espécie possui uma dinâmica populacional e reprodutiva muito similar a outras espécies de Hyalella já analisadas no sul do Brasil. Além disto, apesar de H. palmeirensis ocorrer num ambiente com influência antrópica (cultivo de soja), sua população está conseguindo se manter na área, com reprodução e recrutamento na maioria dos meses do ano..

13.
Braz. j. biol ; 79(4): 735-741, Nov. 2019. graf
Article in English | LILACS | ID: biblio-1001472

ABSTRACT

Abstract We studied the reproductive biology of Otocinclus vittatus in the southern Pantanal, Brazil. A total of 1066 fishes were analyzed (490 males, 488 females and 88 individuals of undetermined sex), sampled with a rectangular sieve and a seine net from February/2009 to January/2011. Variations in the sex ratio, seasonality in reproduction, fecundity, and size at first maturity were estimated. No variations were detected in the total sex ratio for the study period as a whole; although ratio has varied over time. The gonadosomatic index varied according to the river level, but not according to water temperature and rainfall. The mean fecundity was estimated at 84.1 oocytes, with a positive correlation with standard length. The size at first maturity (L50) estimated was 18.7 mm for females and 20.1 mm for males.


Resumo Estudamos a biologia reprodutiva de Otocinclus vittatus no Pantanal Sul, Brasil. Um total de 1066 peixes foram analisados (490 machos, 488 fêmeas e 88 de sexo indeterminado), amostrados com tela de isca e rede de arrasto entre Fevereiro/2009 e Janeiro/2011. Foram estimadas as variações na proporção sexual, a sazonalidade na reprodução e o tamanho da primeira maturação. Não foi detectada variação na proporção sexual total para o período de estudo como um todo; embora a proporção tenha variado ao longo do tempo. O índice ganadossomático variou de acordo com o nível do rio, mas não de acordo com a temperatura da água e a pluviosidade. A média de fecundidade foi estimada em 84.1 ovócitos, com uma correlação positiva com o comprimento padrão. O tamanho de primeira maturação (L50) foi estimado em 18.7 mm para fêmeas e 20.1 mm para machos.


Subject(s)
Animals , Male , Female , Reproduction/physiology , Catfishes/growth & development , Catfishes/physiology , Fertility , Paraguay , Seasons , Sex Ratio , Rivers , Ecology/methods
14.
Braz. j. biol ; 79(4): 639-645, Nov. 2019. tab, graf
Article in English | LILACS | ID: biblio-1001491

ABSTRACT

Abstract In order to evaluate aspects of reproductive biology of the "pequira" ( Bryconamericus stramineus) in the elevator of the Funil Dam - MG, fish capture was carried out from November 2008 to January 2009 and 317 individuals were collected. The mean standard length (SL) of the population was 4.96 cm and mean weight 1.80 g. The females had SL of 5.0 cm, while males had a SL of 4.6 cm. A sex ratio of 2.20: 1 (females: male) was observed. Our results show that 73% of the individuals analyzed were considered adults. The species presented low fecundity, mean of 470.9 oocytes per female and a mean diameter of 221.08 μm, with an increase in oocyte diameter over the evaluation period. The length of the first gonadal maturation was estimated at 5.0 cm. The results obtained in this work suggest that the reproductive cycle of the species occurs in the analyzed period. Although this species does not have migratory reproductive habits, the presence of adults in the reproductive stage was observed in the transposition area, which suggests a search for new environments for spawning.


Resumo Com o objetivo de avaliar aspectos da biologia reprodutiva da pequira Bryconamericus stramineus no elevador da represa do Funil - MG foram realizadas capturas entre os meses de novembro de 2008 a janeiro de 2009, sendo coletados 317 indivíduos. O comprimento padrão (CP) médio da população foi de 4,96 cm e peso médio de 1,80 g. As fêmeas apresentaram CP de 5,0 cm, enquanto que os machos obtiveram um CP de 4,6 cm. Foi observada proporção sexual de 2,20:1(fêmeas:macho). Dos indivíduos analisados, 73% foram considerados adultos. A espécie apresentou baixa fecundidade, com média de 470,9 ovócitos por fêmea e diâmetro médio de 221,08 μm, ocorrendo aumento no diâmetro de ovócitos com o decorrer do tempo no período avaliado. O comprimento de primeira maturação gonadal foi estimado em 5,0 cm. Os resultados obtidos neste trabalho sugerem que o ciclo reprodutivo da espécie ocorre no período analisado. Embora esta espécie não tenha hábitos reprodutivos migratórios, a presença de adultos no estágio reprodutivo foi observada na área de transposição, o que sugere a busca de novos ambientes para a reprodução.


Subject(s)
Animals , Female , Reproduction/physiology , Characidae/growth & development , Characidae/physiology , Seasons , Sex Ratio , Brazil , Rivers , Fertility
15.
Article | IMSEAR | ID: sea-188011

ABSTRACT

A rapid assessment of the sex ratio of the fiddler crab, Uca tangeri, was undertaken in two mangrove habitats on the Bonny River which were undergoing intense human impact as a result of dredging and urbanization activities. The contrasting adult sex ratios of 4:1 of male to female at Eagle Island and 1:2.6 at Rumuolumini and or juveniles showing 2.4:1 (Eagle Island) and 1:1.8 (Rumuolumini) were highly significant (χ2 test, P<0.05). This shows evidence of studies supporting deviation in Uca spp from the 1:1 proportion. Evidence of anthropogenic activity and intensive socioeconomic exploitation provided no explanation for the contrasting high deviation in ratio of males to females between Eagle Island and Rumuolumeni habitats. Megalopae settlement is evident but the physical, chemical and interspecific cues that determine gender balance are necessary for any intended future conservation planning.

16.
Article | IMSEAR | ID: sea-205452

ABSTRACT

Background: Today, female feticide and gender preference are a big problem in India. Although there is so much emphasis against it, the problem has become aggravated. In this context, various studies showed that the male child preference leads to skewed sex ratio. The present paper is an attempt to determine the view of the people for giving their preference to the male child. Objectives: The objectives were to study the preference of women for gender of child, as well as reasons for preference for it, and association between socioeconomic factors and demographic factors with gender preference. Materials and Methods: It is a community-based cross–sectional study, in which 500 married women of 15–49 years of reproductive age group, 150 randomly selected women from one urban municipal ward, and 350 randomly selected women from seven villages of rural area were constituted the study population. Widow and separated women were excluded from the study. A pre-tested, semi‑structured questionnaire was administered to each individual to collect information. Microsoft Excel 2007 software and the Chi‑square test were used. Results: Almost half of the women (51.4%) have preference for male child. Women from lower age group (65.25%), currently married (66.42%), Muslim religion (72.22%), lower education (59.01%), and low socioeconomic status (66.67%) and those who are laborer (71.83%) have male child preference. Conclusions: This study concludes that more number of females have preference for male child in women of younger age group. Muslim religion and its customs, thoughts, and rearing practices make difference. Lower socio-economic status and poor education are also major contributory factor. Male child will support in old age and will take social responsibilities are the main basic reasons found to be associated with male child preference.

17.
Article | IMSEAR | ID: sea-201083

ABSTRACT

Background: The infertility due to various reasons is increasing and correspondingly the number in vitro fertilization (IVF) centers is also increasing. Some procedures in these centers can deliver desired sex of the unborn child. The gender discrimination in India has already resulted unfavorable child sex ratio for girls. Maharashtra is one of the badly affected states. It is feared that the child sex ratio may further decline due to IVF centers. The study was carried out to measure correlation between number of IVF centers with various indicators of sex ratio infertility, and some socio-economic factors.Methods: The study was conducted in 2014 using secondary data. District wise internet search by using words ‘In-Vitro Fertilization center’ and ‘infertility treatment center’ was carried out. Whenever IVF center/procedure was noticed on the internet, the center with its address was included in that district list.Results: There was positive correlation between IVF centers and urbanization, per capita income, female literacy and negative correlation with population sex ratio and no correlation with sex ratio at birth or child sex ratio. The best correlation was observed with urbanization, which explains the observed correlation with other variables.Conclusions: The number of IVF centers is not related with magnitude of infertility and not affecting sex ratio whereas IVF density seems to be an outcome of extent of urbanization.

18.
Braz. j. biol ; 79(1): 70-79, Jan.-Mar 2019. graf
Article in English | LILACS | ID: biblio-983996

ABSTRACT

Abstract Population and reproductive aspects allow the knowledge and understanding of population dynamics and the influence of environmental factors, in addition to ensure the success of a species continuity. Thus, the aim of this study was to analyze population and reproductive traits of the species Hyphessobrycon eques in southern Pantanal, Brazil. Monthly samplings were conducted from February/2009 to January/2011, with 617 individuals analyzed, being 365 females and 262 males. A similar form of distribution in length and weight between the sexes was observed. There was no significant variation in sex ratio over time, with higher proportion of females during the entire sampled period. Both sexes presented a angular coefficient of Weight/Length (b) relationship greater than 3, with speed of increase in weight greater than in length. For females, a long reproductive period was observed, with greater reproductive intensity from January through June. No significant correlation was observed between the Gonadosomatic Index (GSI) and the average temperature, rainfall and river level, despite the fact that reproductive activity occurs in autumn/winter, when there are favorable conditions due to flooding. The size at first maturation (L50) was 20.2 mm, with confidence interval varying from 19.7 through 20.7 mm. The average fecundity was 191.9 oocytes/females and was significantly related to the standard length and total weight (g), demonstrating a relation with energy accumulation to invest in reproduction. The long reproductive period, intensified by partial spawning, higher proportion of females and low L50, show that the species has strategies necessary for survival and rapid population growth, common in small species characterized as r-strategists.


Resumo Os aspectos populacionais e reprodutivos permitem o conhecimento e a compreensão da dinâmica populacional e da influência de fatores ambientais, assegurando o sucesso da continuidade de uma espécie. Desta forma, o presente trabalho teve como objetivo analisar os traços populacionais e reprodutivos da espécie Hyphessobrycon eques no Sul do Pantanal, Brasil. Foram realizadas amostragens mensais de Fevereiro/2009 a Janeiro/2011, com um total de 617 indivíduos analisados, sendo 365 fêmeas e 262 machos. Foi observada que a distribuição foi similar em comprimento e peso entre os sexos. Não ocorreu variação significativa na proporção sexual ao longo do tempo, com maior proporção de fêmeas durante todo período amostrado. Ambos os sexos apresentaram um coeficiente angular da relação Peso/Comprimento (b) maior que 3, com velocidade do incremento em peso maior do que em comprimento. Para as fêmeas, foi observado um período reprodutivo longo, com maior intensidade reprodutiva de Janeiro e Junho. Não foi observada correlação significativa entre o Índice Gonadossomático (IGS) e a temperatura média, pluviosidade e nível do rio, apesar de ocorrer atividade reprodutiva no outono/inverno, período que há condições favoráveis decorrentes da inundação. O tamanho de primeira maturação (L50) foi de 20,2 mm, com intervalo de confiança variando entre 19,7 e 20,7 mm. A fecundidade média foi de 191,9 ovócitos/fêmea e esteve relacionada significativamente ao comprimento padrão e peso total (g), demonstrando uma relação com acúmulo de energia para investir na reprodução. O período reprodutivo longo, intensificado pela desova parcelada, maior proporção de fêmeas e baixo L50, mostram que a espécie possui estratégias necessárias para sobrevivência e rápido crescimento da população, comum em espécies de pequeno porte caracterizadas como r-estrategistas.


Subject(s)
Animals , Male , Female , Rain , Reproduction , Water Movements , Fertility , Characidae/physiology , Gonads/growth & development , Seasons , Sex Ratio , Temperature , Brazil , Rivers
19.
Journal of Clinical Hepatology ; (12): 2754-2758, 2019.
Article in Chinese | WPRIM | ID: wpr-778686

ABSTRACT

ObjectiveTo investigate the role and mechanism of endoplasmic reticulum stress in the formation of sex difference in liver diseases. MethodsA retrospective analysis was performed to investigate the sex distribution of 23 043 patients with liver diseases in the outpatient service of hepatology and 1110 patients with liver diseases in Department of Hepatology in Zunyi Medical University in 2018. A mouse model of acute liver injury was established by intraperitoneal injection of carbon tetrachloride to confirm the sex difference of liver injury and investigate the mechanism of action of endoplasmic reticulum stress in the formation of sex difference in liver injury. A one-way analysis of variance was used for comparison of continuous data between multiple groups, and the least significant difference t-test was used for further comparison between two groups. The chi-square test was used for comparison of categorical data. ResultsAmong the patients in the outpatient service and the hospitalized patients, the male patients had a significantly higher incidence rate than the female patients, with a male/female ratio of 1.56∶1 in the patients in the outpatient service and 1.86∶1 in the hospitalized patients, and there was a significant difference between the two groups of patients (χ2=7.517, P=0.003). The animal model study showed that compared with the female mice with acute liver injury induced by carbon tetrachloride, the male mice had significantly higher death rate (50% vs 30%, P<0.05), serum levels of alanine aminotransferase (5767.8±518.8 U/L vs 4749.5±378.0 U/L, P<0.05) and total bilirubin (6.20±0.88 mmol/L vs 4.83±0.57 mmol/L, P<0.05), liver necrotic area (47.50%±4.65% vs 38.80%±5.00%, P=0.043), and protein expression of the marker for hepatocyte apoptosis clea-caspase-3 (26.00±2.11 vs 18.40±1.54, P=0.042). Compared with the control mice, the model mice had significant increases in the expression of p-PERK, XBP1s, P58IPK, and CHOP in the liver (all P<0.05). Compared with the female model mice, the male model mice had significantly higher expression of XBP1s (25.92±2.11 vs 15.54±1.21, P=0.033), P58IPK (28.60±2.43 vs 13.56±1.13, P=0.026), and CHOP (27.15±2.61 vs 18.18±1.81, P=0.038) and significantly lower expression of p-PERK (16.82±0.11 vs 22.84±0.03, P=0.043) in the liver. Immunohistochemistry also showed that the male mice had significantly higher expression of CHOP than the female mice (1.00±0.11 vs 0.62±0.03, P=0.032). ConclusionThe uncoordinated activation of the endoplasmic reticulum stress signaling pathway may be involved in the formation of sex difference in liver diseases.

20.
Korean Journal of Schizophrenia Research ; : 51-55, 2019.
Article in Korean | WPRIM | ID: wpr-760318

ABSTRACT

OBJECTIVES: Late-onset schizophrenia (LOS, age at first onset ≥40 years) is characterized by including predominance of women, better premorbid social adjustment and lower severity of positive/negative symptoms. However, few studies have been conducted on LOS, especially in Asian countries. This study aimed to examine the clinical features of LOS in comparison with early-onset schizophrenia (EOS). METHODS: By retrospectively reviewing medical records, we assessed demographic data and clinical features of 76 LOS (20 males) and 357 EOS (144 males) who admitted to the psychiatric ward of a general hospital. RESULTS: The mean ages of onset were 47.3±5.1 (LOS) and 25.7±6.5 (EOS) years. There were significantly more women in LOS (73.7%) than EOS (59.6%). Significantly more LOS patients had a marital (88.2% vs. 25.8%) and employment history (28.9% vs. 13.1%) than EOS. Patients with LOS had fewer negative (14.3±9.0 vs. 19.9±9.3), general psychopathology score (36.9±11.1 vs. 42.3±13.9) than EOS patients. CONCLUSION: In line with previous studies, this study demonstrated that LOS patients have better premorbid social adjustment. Our finding also replicates previous findings that LOS patients differ from EOS in predominance of women and relative lack of negative symptoms. These results suggest that LOS may be a distinct subtype of schizophrenia.


Subject(s)
Female , Humans , Age of Onset , Asian People , Employment , Hospitals, General , Korea , Medical Records , Psychopathology , Retrospective Studies , Schizophrenia , Sex Ratio , Social Adjustment
SELECTION OF CITATIONS
SEARCH DETAIL