Introdução da truta arco-íris (Oncorhynchus mykiss) e suas conseqüências para a comunidade aquática dos rios de altitude do sul do Brasil

A introdução de espécies exóticas é uma prática que acompanha a história da humanidade, sendo as espécies introduzidas a base da nutrição e economia em vários países. Porém, esse processo contínuo tem levado a uma homogeneização da flora e fauna global. Os ecossistemas aquáticos, que têm recebido menor atenção que os terrestres, têm sofrido perda de diversidade, hibridação, introdução de patógenos, degradação do habitat além da necessidade e alto custo de controle das espécies introduzidas. O desenvolvimento da aqüicultura tem acelerado a introdução de peixes exóticos, que são a base dessa produção em países como o Brasil. Além desta, entre as razões para a introdução citam-se o esporte, a manipulação ecológica com controle de organismos indesejáveis, o melhoramento dos estoques, a ornamentação ou ainda introduções acidentais. No Rio Grande do Sul, nos rios dos Campos de Cima da Serra estão ocorrendo introduções da espécie exótica truta arco- íris (Oncorhynchus mykiss) desde meados da década de 90 como forma de estímulo ao turismo rural. O objetivo dessa prática é a pesca esportiva, que atrai turistas de várias regiões. Porém, os rios da região possuem várias espécies de peixes endêmicas e as conseqüências dessa prática sobre a biota aquática são desconhecidas. O objetivo do presente trabalho é avaliar o efeito da introdução da truta arco-íris sobre o ecossistema de rios de baixa ordem no município de São José dos Ausentes – RS, Brasil. Para tanto foi descrita a biologia da truta arco- íris no novo ambiente, verificando sua alimentação, movimentação, presença e viabilidade da reprodução. A ictiofauna autóctone dos rios com ausência e presença de trutas foi comparada, bem como o efeito da predação sobre a macrofauna bentônica. A ictiofauna foi amostrada com o uso da pesca elétrica, sendo o conteúdo estomacal das trutas avaliado sazonalmente. Três trutas foram marcadas e acompanhadas por ii biotelemetria para determinação da sua área de vida. Um experimento com ninhos artificiais foi conduzido para verificação da sobrevivência de ovos de trutas nas condições dos rios de São José dos Ausentes. O experimento de exclusão de peixes foi feito a fim de avaliar o efeito da predação sobre a macrofauna bentônica, comparando a macrofauna em rios com e sem trutas. Os resultados indicaram que a truta arco- íris tem como alimento principal os invertebrados bentônicos, porém as maiores classes de tamanho incluem peixes em seus alimentos principais. Logo após sua introdução a movimentação é restrita, porém alguns exemplares foram capturados em um rio onde não foi feita introdução dessa espécie. Apesar de baixa, a sobrevivência dos adultos ocorre, assim como a reprodução. A sobrevivência dos ovos também é baixa, porém, uma pós-larva foi encontrada. A ictiofauna autóctone é diferenciada nos rios com presença de truta, apresentando menor riqueza e diversidade e uma tendência a diminuição da biomassa. A macrofauna bentônica também é diferenciada, apesar de não ser possível atribuir essa diferença somente à presença das trutas.

Involvement of serotoninergic receptors in the anteroventral preoptic region on hypoxia-induced hypothermia

Hypoxia causes a regulated decrease in body temperature (Tb). There is circumstantial evidence that the neurotransmitter serotonin (5-HT) in the anteroventral preoptic region (AVPO) mediates this response. However, which 5-HT receptor(s) is (are) involved in this response has not been assessed. Thus, we investigated the participation of the 5-HT receptors (5-HT(1), 5-HT(2), and 5-HT(7)) in the AVPO in hypoxic hypothermia. To this end, Tb of conscious Wistar rats was monitored by biotelemetry before and after intra-AVPO microinjection of methysergide (a 5-HT(1) and 5-HT(2) receptor antagonist, 0.2 and 2 mu g/100 nL), WAY-100635 (a 5-HT(1A) receptor antagonist, 0.3 and 3 mu g/100 nL), and SB-269970 (a 5-HT(7) receptor antagonist, 0.4 and 4 mu/100 nL), followed by 60 min of hypoxia exposure (7% O(2)). During the experiments, the mean chamber temperature was 24.6 +/- 0.7 degrees C (mean +/- SE) and the mean room temperature was 23.5 +/- 0.8 degrees C (mean +/- SE). Intra-AVPO microinjection of vehicle or 5-HT antagonists did not change Tb during normoxic conditions. Exposure of rats to 7% of inspired oxygen evoked typical hypoxia-induced hypothermia after vehicle microinjection, which was not affected by both doses of methysergide. However, WAY-100635 and SB-269970 treatment attenuated the drop in Tb in response to hypoxia. The effect was more pronounced with the 5-HT7 antagonist since both doses (0.4 and 4 mu g/0.1 mu L) were capable of attenuating the hypothermic response. As to the 5-HT(1A) antagonist, the attenuation of hypoxia-induced hypothermia was only observed at the higher dose. Therefore, the present results are consistent with the notion that 5-HT acts on both 5-HT(1A) and 5-HT7 receptors in the AVPO to induce hypothermia, during hypoxia. (c) 2005 Elsevier B.V All rights reserved.

Efeitos cardiovasculares da anestesia dissociativa na reposição volêmica com colóide e solução hipertônica em cães: avaliação biotelemétrica

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

5-HT2A serotoninergic receptor in the locus coeruleus participates in the first phase of lipopolysaccharide-induced fever

This study was aimed at testing the hypothesis that serotoninergic receptors in the locus coeruleus (LC) play a role in bacterial lipopolysaccharide-induced fever. To this end, 5-HT1A (WAY-100635; 3 mu g/100 nL) and 5-HT2A (ketanserin; 2 mu g/100 nL) antagonists were microinjected into the LC and body temperature was monitored by biotelemetry. Intra-LC microinjections of ketanserin or WAY-100635 caused no change in body temperature of euthermic animals. 5-HT2A antagonism abolished the first phase of the lipopolysaccharide-induced fever. Taken together, these results indicate that serotonin acting on 5-HT2A receptors in the LC mediates the first phase of the febrile response, whereas 5-HT1A receptors are not involved in the lipopolysaccharide-induced fever.

Methodology proposal for acquisition of biotelemetric data in a real time

This work presents a methodological proposal for acquisition of biometric data through telemetry basing its development on a research-action and a case study. Nowadays, the qualified professionals of physical evaluation have to use specific devices to obtain biometric signals and data. These devices in the most of the time are high cost and difficult to use and handling. Therefore, the methodological proposal was elaborate in order to develop, conceptually, a bio telemetric device which could acquire the desirable biometric signals: oxymetry, biometrics, corporal temperature and pedometry which are essential for the area of physical evaluation. It was researched the existent biometrics sensors, the possible ways for the remote transmission of signals and the computer systems available so that the acquisition of data could be possible. This methodological proposal of remote acquisition of biometrical signals is structured in four modules: Acquisitor of biometrics data; Converser and transmitter of biometric signals; Receiver and Processor of biometrics signals and Generator of Interpretative Graphs. The modules aim the obtention of interpretative graphics of human biometric signals. In order to validate this proposal a functional prototype was developed and it is presented in the development of this work.

Aspectos farmacológicos da cetamina S(+) associada ou não ao midazolam, em cães

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

A crucial role for IL-6 in the CNS of rats during fever induced by the injection of live E. coli

Interleukin (IL)-1 beta, tumor necrosis factor (TNF)-alpha, and IL-6 have been established as important mediators of fever induced by lipopolysaccharide (LPS) from Gram-negative bacteria. Whether these pro-inflammatory cytokines are also important in mediating fever induced by live bacteria remains less certain. We therefore investigated the following: (1) the synthesis of TNF-alpha, IL-1 beta, and IL-6 during E. coli-induced fever and (2) the effect of blocking the action of cytokines within the brain on E. coli-induced fever. Body or tail skin temperature (bT or Tsk, respectively) was measured by biotelemetry or telethermometry, every 30 min, during 6 or 24 h. Depending on the number of colony-forming units (CFU) injected i.p., administration of E. coli induced a long-lasting increase in bT of male Wistar rats. The duration of fever did not correlate with the number of CFU found in peritoneal cavity or blood. Because 2.5 x 10(8) CFU induced a sustained fever without inducing a state of sepsis/severe infection, this dose was used in subsequent experiments. The E. coli-induced increase in bT was preceded by a decrease in Tsk, reflecting a thermoregulatory response. TNF-alpha, IL-1 beta, and IL-6 were detected at 3 h in serum of animals injected i.p. with E. coli. In the peritoneal exudates, TNF-alpha, IL-1 beta, and IL-6 were detected at 0.5 and 3 h after E. coli administration. Moreover, both IL-1 beta and IL-6, but not TNF-alpha, were found in the cerebrospinal fluid (CSF) and hypothalamus of animals injected with E. coli. Although pre-treatment (i.c.v., 2 mu l, 15 min before) with anti-IL-6 antibody (anti-IL-6, 5 mu g) reduced E. coli-induced fever, pre-treatment with either IL-1 receptor antagonist (IL-1ra, 200 mu g) or soluble TNF receptor I (sTNFRI, 500 ng) had no effect on the fever response. In conclusion, replicating E. coli promotes an integrated thermoregulatory response in which the central action of IL-6, but not IL-1 and TNF, appears to be important.

Environmental influence on the seasonal movements of satellite-tracked ocean sunfish Mola mola in the north-east Atlantic

Determining the habitat use of mobile marine species is important for understanding responses to climate change and aids the implementation of management and conservation measures. Inference of preferred habitat use has been greatly improved by combining satellite-based oceanographic data with animal tracking techniques. Although there have been several satellite-tracking studies on ocean sunfish Mola mola, limited information is available about either horizontal or vertical environmental preferences. In this study, both geographical movements and diving behaviour of ocean sunfish were explored together with the environmental factors influencing this species’ space use in the north-east Atlantic.

Environmental influence on the seasonal movements of satellite-tracked ocean sunfish Mola mola in the north-east Atlantic

Determining the habitat use of mobile marine species is important for understanding responses to climate change and aids the implementation of management and conservation measures. Inference of preferred habitat use has been greatly improved by combining satellite-based oceanographic data with animal tracking techniques. Although there have been several satellite-tracking studies on ocean sunfish Mola mola, limited information is available about either horizontal or vertical environmental preferences. In this study, both geographical movements and diving behaviour of ocean sunfish were explored together with the environmental factors influencing this species’ space use in the north-east Atlantic.

Context dependency of trait repeatability and its relevance for management and conservation of fish populations

Repeatability of behavioural and physiological traits is increasingly a focus for animal researchers, for which fish have become important models. Almost all of this work has been done in the context of evolutionary ecology, with few explicit attempts to apply repeatability and context dependency of trait variation toward understanding conservation-related issues. Here, we review work examining the degree to which repeatability of traits (such as boldness, swimming performance, metabolic rate and stress responsiveness) is context dependent. We review methods for quantifying repeatability (distinguishing between within-context and across-context repeatability) and confounding factors that may be especially problematic when attempting to measure repeatability in wild fish. Environmental factors such temperature, food availability, oxygen availability, hypercapnia, flow regime and pollutants all appear to alter trait repeatability in fishes. This suggests that anthropogenic environmental change could alter evolutionary trajectories by changing which individuals achieve the greatest fitness in a given set of conditions. Gaining a greater understanding of these effects will be crucial for our ability to forecast the effects of gradual environmental change, such as climate change and ocean acidification, the study of which is currently limited by our ability to examine trait changes over relatively short time scales. Also discussed are situations in which recent advances in technologies associated with electronic tags (biotelemetry and biologging) and respirometry will help to facilitate increased quantification of repeatability for physiological and integrative traits, which so far lag behind measures of repeatability of behavioural traits.

Small MPAs do not protect cuttlefish (Sepia officinalis)

Marine reserves have been widely implemented as tools for biodiversity conservation and fisheries management, amongst other goals. A large number of empirical studies have focused on their effects on reef fish populations. Yet, few studies have looked at their effectiveness on semelparous species such as cephalopods, in spite of their commercial importance in many coastal regions across the globe. In this study we combine behavioural (biotelemetry) and demographic (experimental fishing) data to understand the effects of the Luiz Saldanha Marine Park (LSMP) on local populations of cuttlefish, Sepia officinalis. We used a beyond-BACI design to analyze the possible effect of the implementation of a no-take area on the abundance and biomass of this species and acoustic telemetry data to assess its site fidelity and movements within the study area. Results indicate that there was no detectable effect of the implementation of the no-take area on the abundance or biomass of cuttlefish. We found evidence that acoustically tagged adult cuttlefish leave the reserve a few days or weeks after tagging. The fact that cuttlefish have low site fidelity inside the reserve and large movements across and beyond the study area explains why there is no increase in the population inside the MPA. These results suggest that small coastal marine reserves such as the LSMP are not effective in providing long term protection to cuttlefish populations and, probably, those of other short-lived, highly mobile cephalopods. (C) 2013 Elsevier B.V. All rights reserved.