Genetic documentation of filial cannibalism in nature

Cannibalism is widespread in natural populations of fishes, where the stomachs of adults frequently contain conspecific juveniles. Furthermore, field observations suggest that guardian males routinely eat offspring from their own nests. However, recent genetic paternity analyses have shown that fish nests often contain embryos not sired by the nest-tending male (because of cuckoldry events, egg thievery, or nest piracy). Such findings, coupled with the fact that several fish species have known capabilities for distinguishing kin from nonkin, raise the possibility that cannibalism by guardian males is directed primarily or exclusively toward unrelated embryos in their nests. Here, we test this hypothesis by collecting freshly cannibalized embryos from the stomachs of several nest-tending darter and sunfish males in nature and determining their genetic parentage by using polymorphic microsatellite markers. Our molecular results clearly indicate that guardian males do indeed consume their own genetic offspring, even when unrelated (foster) embryos are present within the nest. These data provide genetic documentation of filial cannibalism in nature. Furthermore, they suggest that the phenomenon may result, at least in part, from an inability of guardians to differentiate between kin and nonkin within their own nests.

Efficiency of uniparental male and female care against egg predators in two closely related syntopic harvestmen

Although the benefits of maternal care have been investigated in many species, the caring role of males in species with exclusive paternal care has received less attention. We experimentally quantified the protective role of paternal care in the harvestman Iporangaia pustulosa. Additionally, we compared the effectiveness of paternal care against predation in this species with a syntopic harvestman with maternal care, Acutisoma proximum. We demonstrated that nearly one-third of the unprotected Iporangaia clutches disappeared entirely in 12 days, while the other two-thirds suffered a mean reduction of 55% in egg number. Conversely, 50% of the control clutches did not suffer any reduction, and only one was entirely consumed by predators. We also demonstrated that the mucus coat that covers Iporangaia clutches has an important deterrent role against predation by conspecifics: 58.3% of the clutches without mucus were attacked and three of them were entirely consumed, whereas only three clutches with mucus were attacked, suffering a reduction of up to three eggs. Iporangaia males were as efficient as Acutisoma females in protecting eggs. However, unattended Acutisoma eggs were attacked 20% more frequently than unattended Iporangaia eggs. Unattended Iporangaia eggs are protected by a mucus coat that prevents or decreases predation rate, whereas Acutisoma eggs are more susceptible to predation, probably because they lack this mucus coat. Thus, besides the fact that Iporangaia males efficiently protect the offspring against egg predators, females also contribute to egg protection by providing a mucus coat that deters egg predators. (C) 2009 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.

Costs and benefits of temporary brood desertion in a Neotropical harvestman (Arachnida: Opiliones)

Brood desertion is a life history strategy that allows parents to minimize costs related to parental care and increase their future fecundity. The harvestman Neosadocus maximus is an interesting model organism to study costs and benefits of temporary brood desertion because females abandon their clutches periodically and keep adding eggs to their clutches for some weeks. In this study, we tested if temporary brood desertion (a) imposes a cost to caring females by increasing the risk of egg predation and (b) offers a benefit to caring females by increasing fecundity as a result of increased foraging opportunities. With intensive field observations followed by a model selection approach, we showed that the proportion of consumed eggs was very low during the day and it was not influenced by the frequency of brood desertion. The proportion of consumed eggs was higher at night and it was negatively related to the frequency of brood desertion. However, frequent brood desertion did not result in higher fecundity, measured both as the number of eggs added to the current clutch and the probability of laying a second clutch over the course of the reproductive season. Considering that harvestmen are sensitive to dehydration, brood desertion during the day may attenuate the physiological stress of remaining exposed on the vegetation. Moreover, since brood desertion is higher during the day, when egg predation pressure is lower, caring females could be adjusting their maternal effort to the temporal variation in predation risk, which is regarded as the main cost of brood desertion in ectotherms.

Sexual selection in Pomatoschistus – nests, sperm competition, and paternal care

Sexual selection arises through variation in reproductive success. This thesis investigates different aspects important in sexual selection, namely nest building, sperm competition, paternity and paternal care, and their mutual interrelationships. In the studied species, the sand goby (Pomatoschistus minutus) and the common goby (Pomatoschistus microps), sperm competition did arise when small males, so called sneakers, sneaked into other males nests and released sperm. They seemed to use female behaviour as their prime cue for a sneaking opportunity. However, also nest-holders, both with and without eggs, were found to fertilize eggs in the nests of other males. Clearly, nest-holding males tried to prevent other males from spreading their sperm in their nests, since they showed aggression towards such males. A nest building experiment indicated that the small nest-openings found in the sneaker male treatment were sexually selected through protection against sneaking or by female choice. Yet, no behavioural or genetical support for the hypothesis that the nest functions as a physical or visual defence, or that sneaker males prefer to sneak upon nests with wide nest-openings, were found in the other studies. Still, individual nest-holding males showed a higher mucus preparation effort inside the nest in the presence of a sneaker male than when alone. In close relatives, such mucus contains sperm, suggesting an importance in sperm competition. However, the mucus may also have pheromone and anti-bacterial functions and may constitute a mating effort, as found in other gobies. Both a behavioural and a mate choice experiment suggested that the males were not less eager to spawn in the presence of a sneaker male. Sneak intrusion did not affect nest defence, fanning or filial cannibalism, nor had paternity an effect on filial cannibalism. This and various life history aspects, together with the fact that the parasitic male only fertilized a fraction of the clutches, would predict females to ignore sneaker males. This was also the case, as the presence of sneaker males was found not to affect female spawning decision. Still, several females spawned in two nests, which coincided with parasitic spawnings, suggesting a cost of disturbance for the females and thus a substantial cost to the nest-holding males in terms of lost mating success. However, females paid attention to other traits in their choice of mate since spawning was associated with sand volume of the nest, but not with nest-opening width. Also, female (but not male) courtship was correlated with partial clutch filial cannibalism, indicating that females are able to anticipate future male cannibalism. In a partial correlation of nest opening, sand volume, male courtship display, displacement fanning and male size, a large number of traits were correlated both positively and negatively with regard to how we may expect them to be appreciated by females. For instance, males which fan well also build large nests or display intensely (but not both). Together with all the other results of this thesis, this shows the entangled selection pressures working on breeding animals, as well as the different male and female tactics employed to maximize their reproduction.

Temperamento e comportamento materno-filial de ovinos das raças Corriedale e Ideal e sua relação com a sobrevivência dos cordeiros

O experimento foi conduzido na Estação Experimental da Embrapa, Bagé, Rio Grande do Sul, entre março de 2005 e fevereiro de 2006. O objetivo foi avaliar o comportamento materno-filial e o temperamento de ovelhas e cordeiros e relacioná-los com a sobrevivência dos cordeiros. Foram utilizadas 47 ovelhas da raça Corriedale, com peso médio de 52,1kg, e 45 ovelhas da raça Ideal, com peso médio de 49,5kg, em um delineamento inteiramente casualizado. O temperamento foi avaliado por meio dos testes: escore de comportamento materno (ECM), tempo de fuga, tipo de marcha e distância de fuga. As ovelhas da raça Corriedale apresentaram maiores valores no teste tipo de marcha que as ovelhas da raça Ideal. Os cordeiros da raça Corriedale eram os mais pesados e tinham maior índice de sobrevivência, quando comparados com os da raça Ideal. A raça não afetou o escore de comportamento materno. Ovelhas reativas (ECM=1), que fogem e não retornam aos seus cordeiros, se isolaram menos do rebanho antes do parto, protegeram menos suas crias, desmamaram-nas mais cedo e tiveram menor peso em relação às não-reativas. A reatividade das ovelhas prejudicou o cuidado materno com os cordeiros e essa característica deve ser considerada pelo setor produtivo.

Comportamentos violentos de adolescentes e coabitação parento-filial

OBJETIVO: Analisar a associação entre comportamentos violentos de adolescentes e a coabitação parento-filial. MÉTODOS: Estudo transversal de base populacional realizado na área urbana de Pelotas, RS, em 2002, com amostragem em múltiplos estágios. Foram entrevistados 960 adolescentes com utilização de questionário auto-aplicado. As variáveis dependentes (uso de armas e envolvimento em brigas no último ano foram referidos pelos adolescentes) e a variável independente coabitação parento-filial foram submetidas a análise pelo teste de qui-quadrado e razão de prevalências, ajustada para idade, sexo, nível socioeconômico e relato de uso na vida e recente de álcool, tabaco ou drogas ilícitas. RESULTADOS: O envolvimento em brigas no último ano foi referido por 23% dos sujeitos e o uso de armas por 9,6%. A razão de prevalência de ocorrência desses comportamentos foi de 1,38 (IC95%: 0,71; 2,68, p = 0,34) para envolvimento em brigas e de 1,68 (IC95%: 1,06; 2,67, p = 0,03) para uso de armas, tendo como referência sujeitos que coabitavam com pai, com mãe ou com ambos. CONCLUSÕES: A coabitação parento-filial deve ser considerada em políticas de prevenção ao uso de armas por crianças e adolescentes, mas recomenda-se o cuidado de não estigmatizar crianças e adolescentes que não coabitam com pais e mães.

Expectativas de responsabilidade filial e orientação da responsabilidade no cuidado aos idosos

RESUMO: Muitos desenvolvimentos demográficos e estruturais ocorreram nas relações intergeracionais, os quais provocaram um impacto nas ligações familiares, tais como o aumento da longevidade e as alterações da dinâmica estrutural e social da família, tendo sido colocado em causa a vitalidade das obrigações familiares e solidariedade familiar, nomeadamente entre pais e filhos adultos. Assim, com este estudo pretendeu-se verificar a presença de solidariedade entre pais e os seus filhos adultos, assim como as expectativas de responsabilidade filial dos pais e as suas opiniões e preferências no que se refere à orientação da responsabilidade para família/ serviços públicos no cuidado aos idosos. De forma a alcançar os objectivos, foi aplicado um questionário a 97 alunos, da Universidade Sénior da Póvoa de Santa Iria, com 55 ou mais anos e que tivessem pelo menos um filho adulto. Foi possível chegar à conclusão de que existe solidariedade entre pais e filhos adultos, assim como os pais consideram que existe uma responsabilidade mista (família/Estado) no cuidado aos idosos e que preferem os apoios formais em detrimento dos informais (familiares) – contrariando a orientação familística. Contudo, apesar disso continuam a apresentar expectativas elevadas em relação à responsabilidade que os filhos devem ter para com os pais, nomeadamente a nível da dimensão de apoio emocional, sendo a dimensão de apoio instrumental a excepção. Desta forma, é possível concluir que há uma tendência por parte da população inquirida em preferir a complementaridade de apoios formais e informais, com consequente especialização de tarefas: instrumental e emocional, respectivamente-----------ABSTRACT: Intergenerational relations have been affected by demographical and structural changes that had impact on family relationships. The increase in life expectancy and the changes in the families’ structural and social dynamics have put at risk the vitality of family obligations and solidarity, namely between parents and adult children. Therefore, this research aimed at studying the existence of solidarity between parents and adult children as well as the parents’ expectations towards their children’s responsibilities and their views and preferences on family and welfare state responsibility as far as elderly people are concerned. In order to achieve this, a questionnaire was devised and subsequently applied to 97 participants attending the Universidade Sénior in Póvoa de Santa Iria, aged 55 or older, with at least one adult child. The results indicate that there is solidarity between parents and adult children and that parents consider that both the family and the state should share the responsibility towards elderly people. Moreover, the study proves that formal support is preferred to the detriment of an informal one (family), which contradicts the familistic approach. However, parents evince high expectations as far as children responsibility towards them is concerned, specially in terms of emotional support. This does not apply, however, to the instrumental support domain. In conclusion, the study indicates that the participants tend to prefer the complementariness of formal and informal support with subsequent task specialisation: instrumental and emotional, respectively.

Desenvolvimento de atividades de qualidade e segurança alimentar na empresa Aviludo, filial do Prior Velho

Dissertação para obtenção do Grau de Mestre em Tecnologia e Segurança Alimentar

Brotherly love and filial obedience: the commemorative programme of the Avis princes at Santa Maria da Vitória, Batalha

This dissertation focuses on a rare 15th century commemorative programme that has thus far received little scholarly attention: the collective monument erected in the Founder’s Chapel, at the Monastery of Santa Maria da Vitória, Batalha, to house the remains of four Avis princes, members of what would become known as ‘the Illustrious Generation’. A patron is proposed for the commission of this erudite monument - the princes’ eldest brother, king Duarte I - arguing its integration into a broader propaganda programme to glorify the memory of the Avis dynasty founder, king João I. The dissertation then proceeds to discuss various highly innovative features of the monument, such as its pseudo-architectural character, its use of sophisticated heraldry and personal badges, the apparent absence of religious iconography on the tombs and, importantly, the collective nature of the programme, key to its interpretation. Using a semiotic approach, a discussion is also offered on the way the various formal, iconographic and conceptual novelties of the princes’ monument impacted on the 15th century monumental landscape in Portugal. Finally, the monument and the chapel housing it are looked at through the prism of the various readings that successive generations of viewers have projected onto it, from the time of its creation to the turn of the 20th century, in order to offer a more comprehensive understanding of the object as it stands today.

Behavioural responses to human skin extracts and antennal phenotypes of sylvatic first filial generation and long rearing laboratory colony Rhodnius prolixus

Chagas disease is a major public health issue and is mainly spread by Triatominae insects (Hemiptera: Reduviidae). Rhodnius prolixus is the main vector species in Northern South America. Host-seeking behaviour in R. prolixus is mediated by different compounds that are produced by and emanate from the host or microbiota on the host's skin. We tested the behavioural responses of sylvatic first filial generation (F1) and colony insects to extracts of human skin with a dual choice olfactometer. In addition, we compared the antennal phenotypes in both populations. No statistical differences were found between the two populations at the behavioural level. Both showed a preference for face and feet extracts and this effect was abolished for face extracts after treatment with an antibacterial gel. The observation of the antennal phenotype showed that there were differences between both groups in the total length, total surface area and number and density of bristles. However, the number and density of chemoreceptive sensilla (basiconic and thin and thick-walled trichoids) and the total density of sensilla did not show statistically significant differences. These results demonstrate that colony insects, which have only been fed with living hens for the last 30 years, are attracted by human skin extracts in a similar way as F1 sylvatic insects.

Cannibalism studies on eggs and newly hatched caterpillars in a wild population of Ascia monuste (Godart) (Lepidoptera, Pieridae)

Ascia monuste (Godart), also known as cabbage caterpillar, is considered herbivorous and specialist in Brassicaceae; however, it performs cannibalism. Experiments carried out in this work aimed to quantify the cannibalism occurrence in A. monuste, to verify whether cannibalism interferes in the species performance and to check whether cannibalism is influenced by the population size. The parameters used in order to evaluate the performance were time of development, adults weight and size, fecundity, oviposition and survival rate. Cannibalism occurred in all larval instars. There was a tendency to increase the cannibalism practice as the number of co-specific increased (potential preys). Cannibalism was more intense in larvae at the end of larval development. Generally, cannibalism did not interfere in the population performance. The most probable hypothesis for the occurrence of cannibalism in the conditions here studied would be the hypothesis of cannibalism as having the function of population control.

New method for rearing Spodoptera frugiperda in laboratory shows that larval cannibalism is not obligatory

New method for rearing Spodoptera frugiperda in laboratory shows that larval cannibalism is not obligatory. Here we show, for the first time, that larvae of the fall armyworm (FAW), Spodoptera frugiperda (Lepidoptera, Noctuidae), can be successfully reared in a cohort-based manner with virtually no cannibalism. FAW larvae were reared since the second instar to pupation in rectangular plastic containers containing 40 individuals with a surprisingly ca. 90% larval survivorship. Adult females from the cohort-based method showed fecundity similar to that already reported on literature for larvae reared individually, and fertility higher than 99%, with the advantage of combining economy of time, space and material resources. These findings suggest that the factors affecting cannibalism of FAW larvae in laboratory rearings need to be reevaluated, whilst the new technique also show potential to increase the efficiency of both small and mass FAW rearings.