• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 34
  • 29
  • 7
  • 3
  • 3
  • 3
  • 2
  • 2
  • 1
  • Tagged with
  • 106
  • 28
  • 16
  • 15
  • 12
  • 11
  • 10
  • 10
  • 10
  • 9
  • 8
  • 8
  • 7
  • 7
  • 7
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Effects of methoprene on the survivorship of adult Aedes mosquitoes: a strategy or inactivating released mosquitoes

Brabant, Peter J, III 01 January 2012 (has links)
Methoprene is a Juvenile Hormone (JH) analogue commonly used for the control of mosquito larvae. When applied to a mosquito breeding site, methoprene enters the haemolymph, where it mimics the function of JH and interferes with normal metamorphosis, resulting in larval mortality. Methoprene is commonly used for the control of larvae and has not been used as an adulticide, due to an absence of acute effects. This study evaluated possible chronic effects caused by the exposure of adult Aedes mosquitoes to methoprene. Methoprene was applied, in both technical grade and the commercially available Altosid®, topically to adults through droplet application on the abdomen and as a spray application. Mosquitoes were examined for treatment effects on ovary development, adult male and female mortality, and fecundity. The results demonstrate that relatively high doses are required to affect adult survivorship. In contrast, significant impacts on both fecundity and egg hatch were observed for females treated at the lower dosages. I discuss the results in relation to autocidal strategies for mosquito control in which the release of fecund females is to be avoided.
42

Aspects of the reproductive biology and endocrinology of the substrate-spawning cichlid Tilapia zillii

Coward, Kevin January 1997 (has links)
This study investigated several, previously little-known, aspects of reproductive physiology and endocrinology in the substrate-spawning cÌchlid Tilapia zillii; a tilapia that is becoming increasingly popular in world aquaculture. Studies were undertaken in controlled laboratory aquaria, thereby reducing the potential influence of environmental variation evident in many previous field studies of this species. Analysis involved two strains of T. zillii: strain 'A' (T. zillii) and strain 'B' (formerly known as Tilapia tholloni). Spawning periodicity and total fecundity generally increased with fish size. Egg size varied within a narrow window and did not generally increase with fish size though fish weighing 100 - 200g tended to produce the largest eggs. The best estimate of spawning periodicity was considered to be 'mean days elapsed/spawn' as this figure was based upon both spawning and non-spawning fish in an experimental group. Mean days elapsed/spawn increased with increasing fish size and averaged 61.4 days and 37.5 days in strains 'A' and 'B' respectively. The shortest reproductive cycles observed were just 7 days and 6 days for strains 'A' and 'B' respectively. Total fecundity ranged from 461 - 11640 eggs/clutch. Mean total fecundity was 3606+/-280 in strain 'A' and 3560+/-243 in strain 'B'. Mean egg diameter was 1.5+/-0.04mm and 1.4+/-0.08mm in strains 'A' and 'B' respectively. Fecundity and egg size also varied over successive spawns in serial-spawning females but these variations did not appear to be related to spawning periodicity. Regression analysis revealed strong relationships between fish size (weight and length) and total fecundity, relative fecundity and total egg volume. Relationships between fish size and egg size were generally much weaker. Fecundity and egg size were related to the length of the preceding inter-spawn-interval (ISI) in fish of certain weight categories but not others, providing limited evidence that length of ISI may in par, control fecundity and egg size in this species. Ovarian recrudescence was classified into ten distinct developmental stages based upon oocyte size, biochemical properties and structure. This classification scheme was comparable to classification schemes developed for other teleosts but represents the first detailed description of oocyte growth in a substrate-spawning tilapia. Radioimmunoassay and stereological analysis provided valuable and novel data concerning the dynamics of ovarian development in this species. Levels of 17ßoestradiol (E2) and testosterone (T) peaked within 6 days of spawning, suggesting that vitellogenesis began as early as day 2 or 3 post-spawning. By day 8, ovaries were dominated by large late-vitellogenic/maturing oocytes (stages 6 & 7) occupying 60 - 70% of the ovary. Gonadosomatic index (GSI) reached maximal levels by day 14. Since the proportion of stage 6/7 oocytes exhibited little change from day 8 onwards, it is suggested that pre-vitellogenic oocytes are recruited into vitellogenic growth immediately after spawning and complete vitellogenesis as early as day 8 postspawning. Analysis of serial-spawning fish found that initial post-spawn E2 and T peaks (on days 2 - 6) were much lower after the second spawning. Sex steroid levels were also found to be suppressed in confined T. zillii (i.e. where stocking densities were > lOkg/m3). Confined females failed to spawn but displayed a marked tendency to do so after transfer to individual aquaria. Serum E2 and T were suppressed during confinement but increased rapidly following transfer to individual aquaria (coincident with resumed spawning activity). It is suggested that levels of E2 and T under confinement are not sufficient to allow completion of vitellogenic growth and are most probably suppressed via a pheromonal mechanism. Finally, the present study investigated the effect of prolonged food restriction on various aspects of reproduction. T. zillii were rationed from first feeding and throughout the following 17 months. Despite very large differences in fish size, no significant differences were detected in total fecundity, egg diameter nor total egg volume once data had been adjusted for differences in fish size. These data suggest that despite very large differences in food availability throughout the periods of sexual differentiation and on-growing, investment in reproduction remained relatively consistent. It appeared that during food restriction, T. zillii sacrificed body weight and growth so as to maintain reproductive investment. In summary, this study provides valuable and novel information regarding the reproductive physiology and endocrinology of female T. zillii and suggests that this species may be a suitable 'model' species for future work on fecundity and ovarian development.
43

Interference in White Bass Reproduction by Two Introduced Predators in Barren River Lake, Kentucky

Fose, Jacob Franklin 01 December 2013 (has links)
White bass Morone chrysops are native to the Mississippi River and its tributaries. This range includes the Barren River in south central Kentucky. Over the last thirty years, the population of white bass in Barren River Lake, a reservoir of the Barren River, has been in decline. During that same time, two congeners of white bass have been introduced to the lake. Hybrid striped bass Morone chrysops × Morone saxatilis were introduced in 1979 and yellow bass Morone mississippiensis were first discovered in 2000. Due to the similar life histories and spawning strategies of all three Morone species, I hypothesized that the two introduced species are interfering with reproduction of the native white bass. In the springs of 2012 and 2013 I sampled fish from within a five kilometer stretch of Barren River upstream of the lake. I collected 144 white bass, 111 yellow bass and 29 hybrid striped bass. Detection of species at spawning sites was staggered with yellow bass and hybrid striped bass arriving after white bass but leading to a period of co-occurrence. White bass on the spawning sites appeared healthy: fecundity (75,200 to 741,150 eggs per female), mean gonadosomatic indices (peaked at 10.7% and 23.7% in sequential years), mean relative weight (93.8), and length at age (above the 50th percentile). Of the yellow bass stomachs examined, 21.6% contained fish eggs or larval fish. Based on arrival times and evidence of egg and larval fish predation, it is likely that yellow bass are directly impacting white bass spawning success through reproductive interference and the consumption of white bass offspring. Schoener’s index values revealed a significant degree of dietary overlap between white bass and yellow bass in larval fish, post larval fish, and arthropods (Cxy = 0.992,0.994, and 0.804, respectively), and between white bass and hybrid striped bass in arthropods (Cxy = 0.851). Information from this study may elucidate causes of the declining white bass population and aid in its management in Barren River Lake.
44

Caracterização populacional de Cichla kelberi (Perciformes: Cichlidae) no reservatório do Lobo (Broa), Brotas / Itirapina - SP. / Populational characterization of Cichla kelberi (Perciformes: Cichlidae) in the Lobo reservoir (Broa), Brotas / Itirapina SP.

Souza, Jussara Elias de 23 February 2007 (has links)
Made available in DSpace on 2016-06-02T19:31:37Z (GMT). No. of bitstreams: 1 DissJES.pdf: 3251640 bytes, checksum: 1a2925395aad5a4359dc8d598a17edc7 (MD5) Previous issue date: 2007-02-23 / Financiadora de Estudos e Projetos / The Cichla kelberi population was characterized in terms of sexual proportion, size structure and some reproductive aspects. The collects were made in two distinct periods. The first, from November 2002 to November 2003 and the second, from December 2004 to May 2006. The sexual proportion showed significantly difference from 1:1 with predominance of females. Total length varied from 3.4 to 40.1cm, with large frequency on the small sized classes. These smallest individuals occurred around all the year, but mainly in the warmer months. Females and males reached similar maximum length. Individuals with Mature or Partial Spent gonads occurred mainly from November to April, indicating that Cichla kelberi has a long reproductive period, a biological evidence that it is a species well adapted in this reservoir, showing partial spawning and an absolute fecundity ranging from 6089 to 6908 oocytes. / Foi caracterizada a composição da população de Cichla kelberi quanto à proporção sexual, composição em comprimento e algumas características reprodutivas. As coletas foram realizadas em dois períodos. O primeiro, de novembro de 2002 a novembro de 2003 e o segundo, de dezembro de 2004 a maio de 2006. A proporção sexual foi significativamente diferente de 1:1, com predomínio de fêmeas. Os comprimentos totais variaram de 3,4 a 40,1cm, com altas freqüências nas classes de menor tamanho. A ocorrência de indivíduos nas menores classes deu-se ao longo de todo o ano, com maior incidência nos períodos mais quentes. Fêmeas e machos atingem comprimentos máximos similares. Indivíduos com gônadas Maduras ou Semi Esgotadas ocorreram com maior freqüência de setembro a abril, indicando que Cichla kelberi apresenta um longo período reprodutivo, uma condição biológica que indica a boa adaptação da espécie neste reservatório. A desova é do tipo parcelada e com fecundidade absoluta de variando de 6089 a 6908 ovócitos.
45

Estrutura populacional e aspectos reprodutivos do Octopus insularis Cephalopodas: Octopodidae: implica??es para o manejo da pesca de polvo no munic?pio de Rio de Fogo-RN

Lima, Fran?oise Dantas de 12 April 2012 (has links)
Made available in DSpace on 2014-12-17T14:33:07Z (GMT). No. of bitstreams: 1 FrancoisDL_DISSERT.pdf: 3556311 bytes, checksum: b2824c8c883f702ac921cf26dfeaf4d7 (MD5) Previous issue date: 2012-04-12 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / In northeastern Brazil, Octopus insularis is the most commercially important cephalopod species and its capture has been performed for several years by the lobster fishermen in the region. In order to obtain information about the reproductive biology, 1108 specimens were collected between November 2009 and September 2011 in the landings and fish markets of Rio do Fogo (RN). For each specimen the mantle length (CM) and total fresh weight (PT) were recorded. Gonads of 264 males and 295 females were examined macroscopically and histologically to assess sexual maturation and determine reproductive indices. Four reproductive stages were determined for males (immature, maturing, mature and post-mature) and females (immature, early maturing, late maturing and mature). The average of eggs recorded in the female s gonads was 93.820 and 39 was the average of spermatophores found in male Needham s complex. Spermathecae with sperm were found in females with 69 mm CM (immature). Males and females become sexually mature at 64.41 and 98.50 mm of CM, respectively. The weight at sexual maturity was 270 g for males and 630 g for females. The values of the size and weight at sexual maturity found in this study show that males mature at smaller sizes than females. For both sexes the maturation peaks occurred in February and November 2010 and also in September 2011. The periods of maximum reproductive activity lasted about 3 months and it seems to occur every 7 10 months. Only one spent female (stage V) was found and the number of mature females was low. Presumably, mature females migrate to deep waters with complex habitat to protect the offspring, indicating that fishery by snorkeling with maximum depth of 15 meters is not reaches this part of the stock. Finally, it is noticeable the importance of the establishment of management strategies for the exploitation of O. insularis different of the ones used for O. vulgaris, once the species have distinct biological features / No Nordeste do Brasil, Octopus insularis ? a esp?cie de polvo de maior import?ncia comercial e sua captura tem sido realizada durante muitos anos pelos mesmos pescadores de lagosta da regi?o. Visando obter informa??es a respeito da biologia reprodutiva dessa esp?cie, foram realizadas amostragens entre novembro de 2009 e setembro de 2011, nas quais foram registrados o comprimento do manto (CM) e o peso fresco total (PT) de 1.108 exemplares presentes nos desembarques e peixarias do munic?pio de Rio do Fogo (RN). Desse total foram coletadas aleatoriamente 264 g?nadas de machos e 295 de f?meas, as quais foram analisadas quanto ao grau de matura??o e pesadas para obten??o dos ?ndices reprodutivos. Foram determinados quatro est?gios reprodutivos macro e microsc?picos para machos (imaturo, maturando, maduro, p?s-maduro) e f?meas (imatura, in?cio da matura??o, final da matura??o, madura), al?m de determinada a fecundidade. O n?mero m?dio de ovos encontrados nos ov?rios das f?meas foi 93.820 e uma m?dia de 39 espermat?foros no saco de Needham nos machos. Foram encontradas f?meas com espermatozoa na espermateca a partir de 69 mm de CM, ainda imaturas. O CM da primeira matura??o (L50) foi 64,41 e 98.5 mm e o peso foi 270 e 630 g em machos e f?meas, respectivamente, evidenciando que os machos maturam em um tamanho e peso inferiores ?s f?meas. Os picos de matura??o foram registrados em fevereiro e novembro/2010 e setembro/2011. As ?pocas de maior atividade reprodutiva duraram cerca de 3 meses e ocorreram em intervalos de 7 a 10 meses. Apenas uma f?mea no est?gio V foi encontrada e o n?mero de f?meas no est?gio IV foi baixo. Provavelmente as f?meas maduras migram para ?guas mais profundas de habitats mais complexos com o intuito de realizar a desova, indicando que a pesca atrav?s do mergulho livre, realizada at? a profundidade m?xima de 15 m, n?o est? acessando essa parcela do estoque. Finalmente fica evidenciada a import?ncia de se estabelecerem estrat?gias de manejo para a explora??o de O. insularis, as quais devem diferir das normas atuais aplicadas ? pesca de O. vulgaris, pois as duas esp?cies possuem caracter?sticas biol?gicas distintas
46

Biologia da mosca-minadora Liriomyza trifolii (Burgess) (Diptera : Agromyzidae), criada em meloeiro,Cucumis melo L., em diferentes temperaturas / Biology of the leafminer Liriomyza trifolii (Burgess) (Diptera : Agromyzidae), reared in melon, Cucumis melo L., at different temperatures

LIMA, Marcos Aurélio Araújo 03 November 2008 (has links)
Submitted by (edna.saturno@ufrpe.br) on 2016-11-28T13:24:21Z No. of bitstreams: 1 Marcos Aurelio Araujo Lima.pdf: 265280 bytes, checksum: ad282a74478ab0633f0cbad41f436c79 (MD5) / Made available in DSpace on 2016-11-28T13:24:21Z (GMT). No. of bitstreams: 1 Marcos Aurelio Araujo Lima.pdf: 265280 bytes, checksum: ad282a74478ab0633f0cbad41f436c79 (MD5) Previous issue date: 2008-11-03 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / In the last years the leafminer Liriomyza trifolii (Burgess) has become a serious pest on melon crops. To develop a pest management program it is important to know some biological aspects of this insect species. Thus, the objective of this work was to study the biology of L. trifolii, to determine its thermal requirements and its fertility life table reared in melon under different temperatures. The temperatures studied were 20, 22, 25, 28, 30 e 33ºC. Egg hatching occurred within 2.8 (30ºC) to 6.6 (20ºC) days. Larval period ranged from 2.4 to 5.9 days, at 33 and 20ºC, respectively. A variation of 7.8 (33ºC) to 19.7 (20ºC) and 13.1 (33ºC) to 32.2 (20ºC),respectively, was observed for pupal stage and from egg to adult emergence. Larvae viability was always higher than 79%, while pupae viability was always lower than 83%, reaching 35% at 20ºC. The lower threshold temperature for eggs, larvae, pupae and egg-adult periods was 12.46,13.04, 13.20 and 12.95ºC, respectively. Thermal requirement (K) for egg, larva, pupa and from egg laying to adult emergence was 47.98, 41.54, 120.19 and 211.86 degree-days. Based on thermal requirements determined for L. trifolii and average temperatures for Mossoró, Apodi and Jaguaruana were estimated that it’s able to complete up to 23 generations per year in these areas. The mean duration of one generation (T) was 23.68 and 18.15 days, respectively, at thetemperatures of 25 and 28ºC. The net reproductive rate (Ro) was higher at 25ºC, corresponding to an increase of 86.20 times at each generation. The intrinsic rate of population increase (rm) was 0.18 (25ºC) and 0.15 (28ºC) and the finite ratio of population increase ( ) was 1.21(25ºC) and 1.17 (28ºC). The best performance of L. trifolii was at 25ºC. / Nos últimos anos as áreas cultivadas com meloeiro têm apresentado diminuição em sua produtividade devido à ocorrência da mosca-minadora, Liriomyza trifolii (Burgess). Para que se possa realizar um manejo adequado é necessário que se conheçam alguns aspectos biológicos desse inseto. Esta pesquisa teve como objetivos estudar a biologia, determinar as exigências térmicas e tabela de vida de fertilidade de L. trifolii com base nos dados obtidos do desenvolvimento deste inseto nas temperaturas de 20, 22, 25, 28, 30 e 33ºC. A duração do período embrionário variou de 2,8 (30ºC) a 6,6 (20ºC) dias. A duração da fase de larva foi de 2,4 a 5,9 dias, nas temperaturas de 33 e 20ºC, respectivamente. Ocorreu uma variação de 7,8 (33ºC) a 19,7 (20ºC) e 13,1 (33ºC) a 32,2 (20ºC), respectivamente, para a fase de pupa e tempo total de desenvolvimento. A viabilidade da fase de larva foi sempre superior a 79%. A viabilidade pupal foi sempre inferior a 83% e chegando a 38,1% na temperatura de 20ºC. Para as fases de ovo, larva, pupa e ovo-adulto os valores das temperaturas base foram de 12,46, 13,04, 13,20 e 12,95ºC. A constante térmica (K) para as fases de ovo, larva, pupa e tempo total de desenvolvimento foram de 47,98; 41,54; 120,19 e 211,86 graus-dia. Baseados nas exigências térmicas determinadas para L. trifolii e nas normais térmicas para Mossoró, Apodi e Jaguaruana estimou-se que a mesma pode completar mais 23 gerações/ano em ambas as localidades. A duração média da geração (T) foi igual a 23,68 e 18,15 dias, respectivamente, nas temperaturas de 25 e 28ºC. A taxa líquida de reprodução (Ro) foi maior na temperatura de 25ºC, correspondendo a um aumento de 86,20 vezes a cada geração. A taxa líquida de crescimento populacional (rm) foi de 0,18 (25ºC) e 0,15 (28ºC) e a razão finita de aumento ( ) 1,21 (25ºC) e 1,17 (28ºC). Diante de todos os parâmetros biológicos estudados, a melhor temperatura para o desenvolvimento de L. trifolii foi 25ºC.
47

Efeitos do Programa Bolsa FamÃlia na fecundidade das mulheres beneficiÃrias / Effects of the Bolsa FamÃlia beneficiaries in the fertility of women

Patricia SimÃes 31 March 2011 (has links)
nÃo hà / Na chamada nova geraÃÃo de polÃticas sociais, destaca-se o Programa Bolsa FamÃlia, que adquiriu o sinÃnimo de âinstrumento para reduÃÃo da desigualdadeâ, por fazer uma redistribuiÃÃo da renda diretamente dos cofres pÃblicos para a populaÃÃo que vive em situaÃÃo de pobreza. Entretanto, a ambiguidade das consequÃncias teÃricas que este tipo de benefÃcio pode causar na sociedade ressalta a importÃncia da realizaÃÃo de estudos cientÃficos sobre este tema. Surgem dÃvidas quanto a sua efetividade nas transformaÃÃes da sociedade quando a abordagem deste programa à feita no contexto do fenÃmeno da transiÃÃo demogrÃfica, em especial a questÃo da fecundidade. Se por um lado as condicionalidades objetivam o investimento em capital humano, o aumento da renda familiar, atravÃs dos benefÃcios monetÃrios concedidos, pode incentivar as famÃlias beneficiÃrias a terem mais filhos. Utilizase a temÃtica dos programas de transferÃncia de renda, adotando o Programa Bolsa FamÃlia como objeto principal de estudo, para verificar a influÃncia desta polÃtica nas taxas de fecundidade das beneficiÃrias. Para tal, sÃo utilizadas as amostras coletadas pelas Pesquisas de Demografia e SaÃde, do projeto MEASURE DHS, dos anos de 1991 e 2006. No primeiro momento à feita um diferenÃa-da-diferenÃa para comparar as taxas de fecundidade das elegÃveis e das nÃo elegÃveis somente para a regiÃo Nordeste. No segundo, à feita a avaliaÃÃo do benefÃcio na fecundidade das beneficiÃrias da regiÃo Nordeste e, tambÃm, de todo o Brasil. SÃo encontrados efeitos positivos quanto à efetividade do programa na reduÃÃo das taxas de fecundidade esperadas das beneficiÃrias quando estas sÃo comparadas com as elegÃveis nÃo beneficiÃrias. / Among social policies of the new generation, there is the Bolsa FamÃlia Program, which acquired the synonym of "instrument for reducing inequality", because it makes a redistribution of income directly from government coffers to the population living in poverty. However, the ambiguity of the theoretical consequences that this type of benefit can have on society emphasizes the importance of scientific studies about this topic. Some questions arise regarding the effectiveness of this kind of policy in social change when the approach of this program is done in the context of the demographic transition, in particular the subject of fecundity. By one hand, conditionalities aim investment in human capital, but increasing household income through monetary benefits may encourage the beneficiary families to have more children. We use the theme of income transfer programs, adopting the Bolsa FamÃlia Program as main object of study, to investigate the influence of this policy in fecundity rates of the beneficiaries. For this purpose, we use the samples collected by the Demographic and Health Surveys, from MEASURE DHS project, of the years 1991 and 2006. First we make a diference-in-diference to compare the fecundity rates of eligible and ineligible women only for the Northeast region of Brasil. Second, we evaluate the benefit on the beneficiaries fecundity for the Northeast region an also for the whole country. We found positive effects regarding the effectiveness of the program in the reduction of beneficiaries expected fecundity rates when they are compared with those eligible women but not beneficiaries.
48

Influência da nutrição e temperatura na reprodução de representantes de Noctuidae, Crambidae, Tortricidae e Elachistidae / Influence of nutrition and temperature on the reproduction of species from Noctuidae, Crambidae, Tortricidae and Elachistidae

Patrícia Milano 01 April 2008 (has links)
Este trabalho teve como objetivo verificar a estratégia reprodutiva de seis lepidópterospraga, os noctuídeos Anticarsia gemmatalis, Heliothis virescens e Spodoptera frugiperda (Noctuidae), Diatraea saccharalis (Crambidae), Gymnandrosoma aurantianum (Família) e Stenoma catennifer (Elachistidae), tendo como alvo principal o uso de recursos nutricionais na fase adulta para sustentar o processo de reprodução e o efeito da atividade de cópula e temperatura na reprodução dessas espécies. Apesar de todas as espécies apresentarem índice de ovigenia bem inferior a 1, indicando a maturação de oócitos no decorrer da vida adulta, apenas A. gemmatalis e H. virescens necessitaram de alimentação na fase adulta para sustentar o processo reprodutivo, enquanto as demais espécies se utilizam dos nutrientes armazenados durante a fase larval. A partir destes resultados, foram escolhidas duas espécies que apresentavam estratégias reprodutivas distintas. Uma que utilizava apenas os nutrientes armazenados na fase imatura, S. frugiperda, enquanto a outra necessitava adquirir nutrientes na fase adulta para a sua reprodução, A. gemmatalis, para se verificar o efeito da freqüência de cópula e de seus efeitos na fecundidade, fertilidade e longevidade de adultos com estratégias reprodutivas distintas. A freqüência de cópula afetou de forma semelhante a longevidade de ambas espécies, havendo redução na longevidade com o aumento no número de cópulas. Porém, a fecundidade de S. frugiperda mostrou correlação positiva com a freqüência de cópula, não sendo verificado nenhum efeito na fecundidade de A. gemmatalis. Machos de ambas as espécies podem contribuir de forma semelhante para a reprodução da fêmea, independentemente de sua experiência prévia. Assim, a reprodução de fêmeas que copularam com machos experientes (2 cópulas prévias) foi similar àquela de fêmeas acasaladas com machos virgens. No entanto, a duração da cópula aumentou com a experiência do macho, sendo a terceira cópula mais longa do que a primeira. A relação da temperatura (15, 20, 25, 30 e 35ºC) e freqüência de cópula também foi investigada para essas espécies, sendo observado que as temperaturas extremas (15 e 35oC) afetaram a freqüência de cópula de ambas espécies. Porém, a temperatura demonstrou afetar as interações entre o número de cópulas e demais atributos biológicos relacionados à reprodução apenas para S. frugiperda mantidas a 25ºC, onde o aumento no número de cópulas resultou em maior fecundidade. / This paper deals with the reproductive strategies of six lepidopteran species, considering the use of food sources in the adult stage and the effect of mating activity and temperature in the reproduction of those species. The lepidopteran species were: Anticarsia gemmatalis, Heliothis virescens, Spodoptera frugiperda (Noctuidae), Diatraea saccharalis (Crambidae), Gymnandrosoma aurantianum (Tortricidae), and Stenoma catenifer (Elachistidae). From this group two species with different reproductive strategies were selected: S.frugiperda, which uses the nutrients stored during the larval stage, and A.gemmatalis, which uses nutrients acquired in the adult stage. Then one verified the mating frequency and its effects on adult fecundity, fertility and longevity. For both species longevity decreased as the number of matings increased. Female reproduction was similar either when they mated with virgin males or non virgin males. However mating duration was different for the third mating was longer than the first one. The temperatures of 15º and 35ºC did affect the mating frequency of both species. The frequency of matings was positively related to fecundity but only for S.frugiperda. Also S.frugiperda at 25ºC presented higher fecundity with the increasing in the number of matings.
49

Biologia reprodutiva de fêmeas de Astyanax fasciatus com números de cromossomos diferentes vivendo em ambiente natural e no cativeiro / Reproductive biology of Astyanax fasciatus females with different chromosome numbers living in natural environment and in captivity

Gabriela Brambila de Souza 02 February 2015 (has links)
Ações antrópicas, como a construção de reservatórios, alteraram a migração de peixes que afeta a função normal do eixo hipotalamo-hipófise-gônadas. Para atenuar o impacto ambiental sobre a biota, existem programas de repovoamento com objetivo de reproduzir as espécies de peixes atingidas pelas barragens. Na piscicultura de Ponte Nova, na Bacia do Alto Tietê, o peixe migratório Astyanax fasciatus é rotineiramente produzido para o repovoamento com protocolos de reprodução artificial convencionais, mas o seu sucesso varia entre as fêmeas. Um estudo de citogenética detectou que o número de cromossomos foi diferente entre os reprodutores, uma característica comum em A. fasciatus. O objetivo do presente estudo foi estudar a fisiologia reprodutiva de Astyanax fasciatus com diferentes números de cromossomos, em ambiente natural (AN) e em cativeiro (Cat) e as possíveis alterações que possam explicar diferentes resultados de resposta à reprodução induzida em cativeiro. Fêmeas adultas de cada grupo experimental (G1-46 cromossomos; com baixa resposta à reprodução induzida; e G2 - 48 cromossomos; com boa resposta à reprodução induzida) foram coletadas em Cat e em AN ao longo de um ano. Amostras de sangue foram retiradas para análise plasmática de estradiol (E2), e os ovários para o cálculo da fecundidade relativa (FR), diâmetro oocitários, Índice Gonadossomático (IGS) e análises histológicas para identificação do estágio de maturação. As fêmeas do G1 nos dois ambientes iniciaram a fase vitelogênica do ciclo reprodutivo no inverno com o aumento da concentração de E2 plasmático. Nas fêmeas de AN, neste mesmo grupo, a maior porcentagem de oócitos vitelogênicos foi mantida nos ovários desde a primavera até o verão, período no qual a concentração de E2 continuou elevada no plasma. Por outro lado, no Cat, as concentrações de E2 não se mantiveram elevadas nas demais estações do ano, limitando-se apenas ao pico do inverno. Mesmo assim, as fêmeas confinadas mantiveram a FR significativamente mais elevada quando comparadas àquelas de AN, assim como maiores porcentagens de oócitos vitelogênicos, evidenciando a ausência de desova e lentidão no processo de reabsorção do vitelo. Já as fêmeas do G2, em AN iniciaram a fase vitelogênica do seu ciclo reprodutivo no outono, com o aumento progressivo dos níveis de E2 que atingiram seu pico na primavera, com a desova ocorrendo no verão. Por outro lado, a permanência no Cat, de alguma forma, alterou a sensibilidade às dicas ambientais do ciclo sazonal, e os níveis de E2 e a FR se mantiveram altos praticamente o ano todo. Estes dados sugerem que A. fasciatus com números diferentes de cromossomos têm padrões reprodutivos diferentes tanto em Cat como em AN e que em cativeiro fêmeas do G1 terão maior sucesso na indução quando manipuladas logo após o inverno, já fêmeas do G2 em Cat parecem ter sucesso na indução praticamente o ano todo / Anthropic actions, such as the construction of reservoirs, alter fish migration affecting the normal function of the brain-pituitary-gonads axis. To mitigate the environmental impact on the biota, fish restocking programs aim to reproduce fish species affected by dams. In the Ponte Nova Fish Farm, in the Upper Tietê River Basin, the migratory fish Astyanax fasciatus is routinely produced for restocking with a conventional artificial breeding protocol, but its success varies among the females. A cytogenetic study detected that the number of chromosomes was different among the broodstocks, a common feature in A. fasciatus. The purpose of this study was to study the reproductive physiology of Astyanax fasciatus with different numbers of chromosomes in a natural environment (AN) and captivity (Cat) and the possible changes that might explain different results in the success of induced reproduction in captivity. Adult females of each experimental group (G1-46 chromosomes; with low response to induced reproduction, and G2 - 48 chromosomes, with good response to induced reproduction) were collected in Cat and AN over one year. Blood samples were taken to analyze plasma estradiol (E2), and samples of ovaries to calculate the relative fecundity (FR), oocyte diameter, gonadosomatic index (GSI) and histological analyzes to identify the maturation stage. Females of G1, in both environments, started the vitellogenic phase of the reproductive cycle in the winter, with an increase in E2 levels. In the wild animals, the highest percentage of vitellogenic oocytes was maintained in the ovaries from spring to summer, a period in which E2 levels remained high. On the other hand, in captivity, a higher level of E2 was observed only in winter. Even so, the females in captivity maintained the fecundity significantly higher when compared with the wild ones, and also a higher percentage of vitellogenic oocytes, evidencing the absence of spawning and a delay in the yolk absorption. In G2, the vitellogenic stage of oocytes in wild females started in the fall, with a progressive increase in E2 levels, reaching its peak in spring, with the spawning in summer. On the other hand, remaining in the captivity, somehow altered the availability to the environmental tips of the seasonal cycle, and E2 levels as well as the FR virtually remained high throughout the year. These data suggest that A. fasciatus with different numbers of chromosomes have different reproductive patterns, both in a Cat and AN. G1 females could succeed in induced reproduction when handled immediately after winter, while G2 females seem to succeed the artificial reproductive induction throughout the year
50

Biologia de Dermanyssus gallinae (De Geer, 1778) (Acari, Dermanyssidae) em condições de laboratorio

Tucci, Edna Clara 16 December 2004 (has links)
Orientador: Angelo Pires do Prado / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-04T02:34:32Z (GMT). No. of bitstreams: 1 Tucci_EdnaClara_D.pdf: 3392011 bytes, checksum: 0b7d93dc6082c6f65f16af39858355d2 (MD5) Previous issue date: 2004 / Resumo: O presente trabalho teve o objetivo de estudar os seguintes parâmetros biológicos de Dermanyssus gallinae: ciclo biológico em condições de laboratório sob as temperaturas de 15, 20, 25, 30 e 35 oC, fecundidade, fertilidade, influência do jejum na fertilidade e determinação das exigências térmicas. A duração média dos diferentes estágios do ciclo (em horas), obtidos nas diferentes temperaturas foi de: pré-oviposição: 86,74h (15 °C), 24h (20 °C), 24,21h (25 °C), 24,24h (30 °C) e 24,05h (35 °C); ovo: 214,30h (15 °C), 67,7h (20 °C), 42,11h (25 °C), 38,70h (30 °C) e 51,77h (35 °C); larva 163,44h (15 °C), 34,73h (20 °C), 29,44h (25 °C), 24,85h (30 °C), 32,23h (35 °C); protoninfa: 81,25h (15 °C), 73,06h (20 °C), 30,35h (25 °C), 25,66h (30 °C) , 26,4h (35 °C); deutoninfa: 145,02h (15 °C), 63,63h (20 °C), 38,37h (25 °C), 27,24h (30 °C), 37,6h (35 °C); duração total do ciclo: 690,75h (28 dias) sob 15 °C, 263,12h (11 dias) sob (20 °C), 164,63h (7 dias) sob 25 °C, 140,69h (6 dias) sob 30 °C e 172,04h(7 dias) sob 35 °C. D. gallinae desenvolveu-se melhor sob a temperatura de 30 °C, apresentando a maior viabilidade nas diferentes fases e o menor tempo de desenvolvimento. A duração do ciclo de D.gallinae diminuiu com o aumento da temperatura, indo de 690,75 a 15 °C a 140,69 a 30 °C. Sob 35 ° houve um aumento na duração do ciclo e uma baixa na viabilidade de todas as fases sugerindo que em épocas de muito calor a população de D. gallinae pode baixar ou até desaparecer por um determinado período. O período de pré oviposição não variou sob as temperaturas de 20 °C, 25 °C, 30 °C e 35 °C. No experimento onde fêmeas foram mantidas sob jejum de 1 a 12 dias, a oviposição ocorreu até o 11º dia, sendo a maior porcentagem de oviposição até o terceiro dia, reduzindo a partir do quarto dia. Recomenda-se que o intervalo de 3 dias entre as alimentações seja o mais adequado para manutenção de D. gallinae em laboratório. Intervalos entre as alimentações de 4 ou mais dias não são recomendados por devido à baixa fecundidade verificada nesses período (menor de 67,1%). A maior porcentagem das fêmeas (58,1%) ovipôs após a primeira alimentação. A partir da segunda esta porcentagem foi diminuindo até a oitava alimentação, quando apenas uma fêmea foi recuperada e que morreu antes de ovipor. No presente experimento as fêmeas de D. gallinae foram capazes de realizar um total de 7 oviposições com uma produção total de 25 ovos. Foram determinadas as exigências térmicas para D. gallinae obtendo-se os valores de temperatura base (Tb) , constante térmica (k), coeficiente de determinação (R2) e equação de regressão para o período de pré-oviposição, ovo, larva, protoninfa, deutoninfa. Com relação às exigências térmicas, foram encontrados diferentes valores para cada estágio de desenvolvimento de D. gallinae. Com base em mapas de isotermas, estimou-se a ocorrência de D. gallinae no Estado de São Paulo, verificando-se que o ácaro pode se desenvolver continuamente no Estado de São Paulo, com diminuição da população no inverno, ocorrendo de 15 a 42 gerações/ano / Abstract: The purpose of this work was to study the biological cycle of D. gallinae in the laboratory at temperatures of 15, 20, 25, 30 and 35ºC, to determine the fecundity, the fertility and the influence of fasting on fertility, as well as the thermal requirements for D. gallinae. The mean cycle duration of the different phases (in hours), at different temperatures was: Pre-oviposition: 86,7h at 15 °C; 24h at 20 °C; 24,21h at 25 °C; 24,24h at 30 °C and 24,05h at 35 °C. Egg: 214,30h at 15 °C; 67,7h at 20 °C; 42,11h at 25 °C; 38,70h at 30 °C and 51,77h at 35 °C. Larva: 163,44h at 15 °C; 34,73h at 20 °C; 29,44h at 25 °C; 24,85h at 30 °C and 32,23h at 35 °C. Protonymph: 81,25h at 15 °C; 73,06h at 20 °C; 30,35h at 25 °C; 25,66h at 30 °C and 26,4h at 35 °C. Deutonymph: 145,02h at 15 °C); 63,63h at 20 °C; 38,37h at 25 °C; 27,24h at 30 °Ca and 37,6h at 35 °C. Total cycle lenght: 690,75h (28 days) at 15 °C, 263,12h (11 days) at sob 20 °C, 164,63h (7 days) at 25 °C, 140,69h (6 days) at 30 °C and 172,04h (7 days) at 35 °C. The development of D. gallinae was higher at temperature of 30 °C, exhibiting the highest viability in the different phases and the shorter development time. The cycle time of D.gallinae decreased with the increase of temperature, from 690,75 at 15 °C to 140,69 at 30 °C. At 35 °C there was an increase in the cycle length and a drop in viability in all phases, suggesting that in warmer seasons D. gallinae population may decrease or even disappear for a period of time. No variations were found in pre-oviposition time at temperatures of 20 °C, 25 °C, 30 °C and 35 °C. In the experiment where female samples were kept from 1 to 12 days of fasting, oviposition occurred up to the 11th day, with the highest rate up to the 3rd day, decreasing from the 4th day. We recommend that the interval of three days between feedings is the most adequate to maintain D. gallinae in the laboratory. Four or more days of interval between feedings are not recommended due to the low fecundity, less than 67,1%, found during those periods of time. The results on fecundity showed that the females began to lay eggs just after the first blood meal and continued to lay eggs up to the seventh day after the meal. The highest percentage of females (58%) laid eggs after the first meal. After the second meal this pencentage began to decrease until the eighth meal, when only one female was present, but it died before it was able to lay eggs. Dermanyssus gallinae females had a total of 7 oviposition cycles totaling 25 eggs. The thermal requirements for D. gallinae were determined, for basal temperature (Tb), thermal constant (k), determination coefficient (R2) and regression equations for preoviposition, egg, larva, protonymph and deutonymph phases. Different values for thermal requirements were found for each developmental phase of D. gallinae. Based on isothermal maps the incidence of D. gallinae in São Paulo State was estimated, verifying that it can develop continuously in São Paulo State, with a decrease in its population numbers during the winter, varying from 15 to 42 generations per year / Doutorado / Parasitologia / Doutor em Parasitologia

Page generated in 0.0462 seconds