UIE-E - Artigos em revistas nacionais
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- A checklist of the blennioid fishes (Teleostei, Blennioidei) occurring in Portuguese watersPublication . Oliveira, Rui Filipe; Almada, Vítor Carvalho; Almeida, Armando J.; Santos, Ricardo Serrão; Gonçalves, Emanuel JoãoTwenty species of blennioide fishes have been cited from Portuguese waters. A survey of the published literature and personal observations by the authors allowed to confirm the presence of eighteen species: Clinitrachus argentatus, Labrisomus nuchipinnis, Tripterygion delaisi, Blennius ocellaris, Coryphoblennius galerita. Lipophrys canevae, L. dalmatinus, L. pholis, L. trigloides, Parablennius gattorugine, P. pilicornis, P. rouxi, P. ruber, P. incognitus, P. sanguinolentus-parvicornis, Salaria fluviatilis, S. pavo and Ophioblennius atlanticus atlanticus. A check-list is provided with information on the geographic distribution of the confirmed occurences of the blennioid species in portuguese waters.
- A new northern limit for the distribution range of Lipophrys canevae (Pisces: Blenniidae) in the Atlantic OceanPublication . Almada, Vítor Carvalho; Oliveira, Rui Filipe; Gonçalves, Emanuel João; Almeida, Armando J.; Barata, Eduardo NunoIn this note, the occurence of Lipophris canevae at Arrábida (Portugal) is reported, which extends 160 Km north the known range ot this species in the Atlantic coast of the Iberian Peninsula. This species has been consistently found at Arrábida since 1987. The presence of a crest on the head of the males, which is considered a rare secondary sexual character in the Mediterranean populations, is very common in the specimens known from portuguese waters, even in the females, where it is vestigial. The meristic and morphometric data from specimens known from portuguese waters are summarized. At Arrábida, the nests occur in the midlittoral zone, often in the transition to the sublittoral, and remain out of water for several hours during low tide. Breeding takes place during Spring and Summer. ------ SUMÁRIO ----- Na presente nota, descreve-se a ocorrência Lipophris canevae na costa da Arrábida (Portugal), o que estende 160 Km para norte e distribuição conhecida para esta espécie na costa atlântica da Península Ibérica. A ocorrência desta espécie na Arrábida tem sido registada regularmente desde 1987. A presença de uma crista na cabeça dos machos, que para as populações mediterrânicas é considerada um carácter sexual secundário raro, ocorre com grande frequência nos espéciemens conhecudis das águas portuguesas, inclusive nas fêmeas embora nestas seja vestigial. Resumem-se os dados merísticos e morfométricos para os exemplares até agora capturados na costa portuguesa. Na Arrábida, os ninhos ocorrem no médio-litoral, por vezes na transição para o infra-litoral, e permanecem emersos durante várias horas na baixa-mar. A reprodução tem lugar na Primavera e Verão.
- Sobre o uso de estatística de simulação em estudos de comportamentoPublication . Almada, Vítor Carvalho; Oliveira, Rui FilipeNeste artigo discutimos sucintamente as potencialidades da estatística de simulação nas ciências do comportamento. São apresentadas duas aplicações: uma desenvolvida por Estabrook e Estabrook (1 989) para a análise de tabelas de contingência e uma outra desenvolvida na nossa unidade de investigação para testes de verosimilhança. Ambos os procedimentos superam os problemas de valores esperados baixos que limitam o uso da estatística X2 em muitas circunstâncias, e oferecem ainda a possibilidade de se avaliar a significância de células/classes específicas. ------- ABSTRACT ------ In this paper we discuss briefly the potential of simulation statistics in the behavioural sciences. We present two applications: one developed by Estabrook and Estabrook ( 1989) for the analysis of contingency tables and another developed in our research unit for goodness-of-fit tests. Both procedures overcome the problems of low expected values that limit the use of X2 statistic in many ciscunstances, and offer the possibility of assessing the significance of specific cells/ /classes.
- Sexo, mentiras e handicaps: Reflexões sobre os mecanismos de selecção sexualPublication . Oliveira, Rui FilipeNo presente artigo o autor revê os diferentes modelos de selecção sexual, nomeadamente a teoria dos descendentes atractivos, a teoria dos bons genes e a teoria do enviezamento sensorial. E analisado o caso particular da possível acção dos mecanismos de selecção sexual nos sistemas de reprodução em arenas, nas quais os machos se agregam para cortejar, uma vez que estes sistemas potenciam a competição entre os machos e as situações de escolha de parceiros sexuais por parte das fêmeas. Neste contexto é dada especial atenção a dois fenómenos: (a) a possível existência de mecanismos de escolha passivos por parte das fêmeas que gerem padrões consitentes de preferências, como é o caso conhecido das preferências por machos com territórios centrais nas arenas em relação a machos com territórios periféricos; (b) a possibilidade de existirem beneficios não-genéticos para as fêmeas em sistemas de arenas que expliquem os padrões de preferências detectados. Finalmente é discutido o modelo do handicap da imunocompetência e apresentam-se evidências que apontam para um papel dos androgénios como mediadores fisiológicos de qualidades fenotípicas dos machos.
- Short-term social modulation of 11-ketotestosterone levels in males of the cichlid fish Oreochromis mossambicus during male-female interactionsPublication . Borges, Rita Alexandra; Oliveira, Rui Filipe; Almada, Vítor Carvalho; Canário, Adelino V. M.After 48 hours of social isolation male individuals of Oreochromis mossambicus were allowed to interact with a conspecific female in the same aquarium during a period of up to six hours. Colouration exhibited, and frequencie countering and agonistic behaviours performed by the males were recorded before and after social isolation (T0) and six hours after the introduction of the female (T6). Male androgen (testosterone and 11-ketotestosterone, 11-KT) concentrations measured in the urine, at T0 were not correlated to subsequent levels of agonistic and sexual behaviours. However, behavioural interactions were correlated to 11-KT levels at T6. These results suggest a short-term social modulation of 11-KT levels by male-female interaction.
- Chorusing by male european fiddler crabs, Uca tangeri: A study of visual communication netwoksPublication . Burford, Fiona R. L.; McGregor, Peter K.; Oliveira, Rui FilipeChorusing behaviour, in which males aggregate and advertise to attract females, has been extensively studied in acoustically signalling orthopterans and anurans. Species which agregate and signal visually have comparanble behaviour but chorusing aspects has been studied infrequently. Male fiddler crabs (genus Uca) signal by waving and enlarged claw and form signalling aggregations, therefore, they have a potential to form a visual chorus. This study investigated the chorusing behaviour of male eurpoean fiddler crabs, Uca tangeri. The timing of waving by groups of three males (trios) was studied when each male was alone and when all three males were present. When waving in a trio, the male with the largest claw significantly increased the lenght of its interwave interval and some such males tend to wave soon after the other males. This pattern of waving may enhance the effectiveness of the large-claw males signal by avoiding visual object grouping and by allowing females to assess relative claw size more readily.
- Male display characters, gonadal maturation and androgens in the cichlid fish Oreochromis mossambicusPublication . Oliveira, Rui Filipe; Almada, Vítor CarvalhoThe relationships between gonadal maturation and the expression of behavioral and morphological display characters in O. mossambicus was investigated and the possible role of androgens in the coordination of this process was evaluated using genital papilla size as a bioassay for androgen levels. Morphological and behavioral displaying characters were found to be correlated among themselves. The sexually dimorphic characters were correlated with gonad maturation and androgen levels, but not with the gonado-somatic index. Gonad maturation and androgen levels were closely related. Territoriality and other behavioral variables involved in reproduction were also correlated with gonad maturation and androgen levels. These data suggest that in O. mossambicus androgens play a mediating role between gonadal maturation and the expression of display characters, both morphological and behavioral.
- Video playback techniques in behavioural researchPublication . Oliveira, Rui Filipe; McGregor, Peter K.; Schlupp, Ingo; Rosenthal, Gil G.Inexistente
- Considerations on the use of video playbacks as visual stimuli: The Lisbon workshop consensusPublication . Oliveira, Rui Filipe; Rosenthal, Gil G.; Schlupp, Ingo; McGregor, Peter K.; Cuthill, Innes C.; Endler, John A.; Fleishman, Leo J.; Zeil, Jochen; Barata, Eduardo Nuno; Burford, Fiona R. L.; Gonçalves, David; Haley, Michael; Jakobsson, Sven; Jennions, Michael D.; Körner, Kay; Lindström, Leena; Peake, Thomas; Pilastro, Andrea; Pope, Denise S.; Roberts, Sam G. B.; Rowe, Candy; Smith, Jerome; Waas, Joseph R.This paper is the consensus of a workshop that critically evaluated the utility and problems of video playbacks as stimuli in studies of visual behavior. We suggest that video playback is probably suitable for studying motion, shape, texture, size, and brightness. Studying color is problematic because video systems are specifically designed for humans. Any difference in color perception must lead to a different color sensation in most animals. Another potentially problematic limitation of video images is that they lack depth cues derived from stereopsis, accommodation, and motion parallax. Nonetheless, when used appropriately, video playback allows an unprecedented range of questions in visual communication to be addressed. It is important to note that most of the potential limitations of video playback are not unique to this technique but are relevant to all studies of visual signaling in animals.
- Human exploitation of male fiddler crab claws: Behavioural consequences and implications for conservationPublication . Oliveira, Rui Filipe; Machado, José Luis Gorjão H. C.; Jordão, Joana; Burford, Fiona R. L.; Latruffe, Claire; McGregor, Peter K.Male fiddler crabs have one of their feeding claws greatly enlarged, which may comprise up to 40% of their weight. In southern Portugal (Ria Formosa) the major claw of the fiddler crab Uca tangeri is a local delicacy. Fishermen break off the male major claw and throw the crab back into the mudflat to regenerate a new one. Approximately 38 % of the males sampled had a missing or a regenerating claw. Although individuals are not removed from the population the operational sex ratio is biased towards females since other males and females behave towards clawless males as if they were females. Moreover, removing the major claw from males prevents them from signalling (waving display) to females to attract them to their breeding burrows and it also places them at a disadvantage if they have to defend their burrows from males with intact claws. Thus, the harvesting of male fiddler crab claws has potential consequences at the population level. In this paper we investigated these potential consequences by comparing an exploited population of fiddler crabs at Ria Formosa with a remote population at the Mira estuary that is not under human exploitation. The unexploited population has significantly larger males and a significantly higher density of burrows. The operational sex ratio is also significantly different between the two populations with a female-biased sex ratio in the exploited population. These preliminary results suggest that claw harvesting in fiddler crabs has a measurable effect at the population level. The consequences of this type of fishery in which the individuals are not removed from the population but the population structure is potentially affected need further investigation.