Hepatic lipidosis due to obesity in a free-living snake (Boa constrictor amarali)

Background: Liver performs several important functions to the maintenance of physiological mechanisms. Some liver diseases may directly affect anatomical and physiological aspects of this organ, and may lead to a permanent liver injury. In snakes, the most common causes of liver disease are infections, however, approaches on non-infectious liver diseases are scarce. Therefore, the objective of this study was to describe macroscopically and microscopically liver alterations in a Boa constrictor amarali snake.Case: A adult male boa (Boa constrictor amarali) snake of 110 cm of length and weight of 3.270 kg from free-living conditions, and without previous history was rescued in an urban area and taken by the Environmental Police to the Laboratory for Teaching and Research in Wild Animals (LAPAS) of the Federal University of Uberlândia’s (UFU) Veterinary Hospital, in Uberlândia MG, Brazil. The animal died and a significant amount of adipose tissue was found throughout the extension of the coelomic cavity at necropsy, limiting the visualization of its internal organs. Fragments of altered organs were collected and packed in a universal collector containing a 10% buffered formalin solution. These samples were sent to the Animal Pathology Laboratory (LPA) of the UFU. Macroscopically, the stomach presented a reddish mucosa, and mucous contents. The liver was pale, with a yellowish color and a friable consistency. Microscopically, dilated hepatic sinusoids filled with red blood cells were observed; the hepatocytes were enlarged, and its cytoplasm were filled with vacuoles of varied sizes that did not stain (severe diffuse lipidosis). It was also found occurrence of multifocal areas with loss of tissue architecture, and hepatocytes in karyolysis, charactering necrosis; and a discrete amount of multifocal mononuclear inflammatory infiltrate (multifocal hepatitis).[...]

Hepatic lipidosis due to obesity in a free-living snake (Boa constrictor amarali)

Background: Liver performs several important functions to the maintenance of physiological mechanisms. Some liver diseases may directly affect anatomical and physiological aspects of this organ, and may lead to a permanent liver injury. In snakes, the most common causes of liver disease are infections, however, approaches on non-infectious liver diseases are scarce. Therefore, the objective of this study was to describe macroscopically and microscopically liver alterations in a Boa constrictor amarali snake.Case: A adult male boa (Boa constrictor amarali) snake of 110 cm of length and weight of 3.270 kg from free-living conditions, and without previous history was rescued in an urban area and taken by the Environmental Police to the Laboratory for Teaching and Research in Wild Animals (LAPAS) of the Federal University of Uberlândias (UFU) Veterinary Hospital, in Uberlândia MG, Brazil. The animal died and a significant amount of adipose tissue was found throughout the extension of the coelomic cavity at necropsy, limiting the visualization of its internal organs. Fragments of altered organs were collected and packed in a universal collector containing a 10% buffered formalin solution. These samples were sent to the Animal Pathology Laboratory (LPA) of the UFU. Macroscopically, the stomach presented a reddish mucosa, and mucous contents. The liver was pale, with a yellowish color and a friable consistency. Microscopically, dilated hepatic sinusoids filled with red blood cells were observed; the hepatocytes were enlarged, and its cytoplasm were filled with vacuoles of varied sizes that did not stain (severe diffuse lipidosis). It was also found occurrence of multifocal areas with loss of tissue architecture, and hepatocytes in karyolysis, charactering necrosis; and a discrete amount of multifocal mononuclear inflammatory infiltrate (multifocal hepatitis).[...](AU)

Body-size influence on defensive behavior of Amazonian moths: an ecophysiological approach

Ectotherm locomotion is restricted by low temperatures, and many species, such as some flying insects, need to achieve thermal thresholds before taking off. Body size influences heat exchange between an animal and the environment. Therefore, larger animals have higher thermal inertia, and necessarily spend more time in pre-flight warming up, a critical period when they remain exposed and more susceptible to predators. Thus, one could expect larger animals, along their evolutionary history, to have developed a more diversified repertoire of defensive behaviors when compared to their smaller counterparts. Moths are an interesting model for testing this hypothesis, as they exhibit considerable variation in body size and many species present pre-flight warming up by muscle shivering, an evidence of thermal restriction on locomotion. I registered the responses of 76 moths immediately after simulating the attack of a predator and then associated behavioral response to body size. I conducted the experiments at 20 and 25ºC to check for possible thermal restrictions on behavior, and identified animals to the family level to check for the effects of a common phylogenetic history. When disturbed at 25ºC, smaller moths tend to fly, while larger ones tend to run. At 20ºC almost all moths ran, including the smaller ones, indicating a possible thermal restriction on flight. Corroborating the proposed hypothesis, a more diversified repertoire of defensive behaviors was registered among larger moths. An alternative interpretation would be that common behaviors among related moths could be explained by common phylogenetic histories. However, two facts support the physiological restriction hypothesis: (1) the analysis within Sphingidae and Geometridae (not closely related families) showed similar results to those of the overall analysis, and (2) a more diverse repertoire of defensive behaviors was associated to the lower, and therefore more restrictive to locomotion, temperature (20ºC).

A locomoção de animais ectotérmicos é restringida por temperaturas baixas, e muitas espécies, como alguns insetos, precisam atingir certas temperaturas antes de voar. O tamanho corpóreo influencia as trocas de calor entre um organismo e o ambiente, dessa forma, animais maiores, por apresentarem maior inércia térmica, passam mais tempo aquecendo-se antes do vôo, período em que ficam mais expostos à predação. Assim, seria esperado que, ao longo de sua história evolutiva, animais maiores desenvolvessem repertório de comportamentos defensivos mais diversificado que os menores. As mariposas são um grupo interessante para testar essa hipótese por apresentarem grande variação de tamanho e aquecerem-se com tremor muscular antes do vôo, uma evidência da restrição térmica à locomoção. Registrei o comportamento de 76 mariposas imediatamente após uma simulação de ataque de um predador, associando a resposta observada ao tamanho corpóreo. Conduzi os experimentos a 20 e 25ºC para averiguar eventuais restrições térmicas sobre o comportamento defensivo e identifiquei os animais até o nível de família para verificar os efeitos de história filogenética comum. Quando perturbadas a 25ºC, mariposas menores tenderam a voar, enquanto as maiores correram. A 20ºC, quase todos os animais correram, incluindo os menores, evidenciando possível restrição térmica ao vôo. As mariposas maiores apresentam repertório de comportamentos defensivos mais diversificado, corroborando a hipótese proposta. Uma interpretação alternativa seria a de que respostas comportamentais similares poderiam ser explicadas por uma história filogenética comum. Entretanto, duas evidências apóiam a hipótese de restrições fisiológicas à locomoção: (1) a análise com Sphinghidae e Geometridae (famílias distantes filogeneticamente) apresentou o mesmo resultado que a análise geral e (2) foi detectada associação entre maior repertório de comportamentos defensivos e temperatura experimental mais baixa e, portanto, mais restritiva à locomoção.

Desenvolvimento de diferentes populações de Cydia pomonella (Lepidoptera: Tortricidae) em temperaturas variáveis e consequências na modelagem fenológica

A maioria dos organismos vivos são ectotérmicos, com exceção de pássaros e mamíferos. A temperatura corporal (Tc) de um ectotérmico é resultado da troca de calor entre o organismo e o meio ambiente e esta afeta a maioria das funções biológicas. Por exemplo, os insetos, para mudarem de estágio de desenvolvimento, requerem um mínimo de energia acumulada (calor). Para as pragas, a maioria dos modelos fenológicos é baseada na relação entre características do de desenvolvimento (ex., crescimento) e a temperatura do ar. Todavia, a utilização destes modelos ainda é limitada em razão da falta de exatidão na estimativa das temperaturas máximas e mínimas de desenvolvimento para a maioria das pragas. O objetivo deste trabalho foi avaliar a importância dos fatores: resistência a inseticidas e termoperíodo, assim como discutir os métodos de modelagem para o inseto endofítico Cydia pomonella. Para tal, se submeteu larvas e pupas de 4 linhagens diferentes desta espécie: sensível (Sv), resistente a diflubenzuron (Rdfb), resistente a deltametrina (Rdelta) e resistente ao granulovírus (Rgv), a 4 termoperíodos (15°C-20°C, 20°C-25°C, 25°C-30°C e 30°C- 35°C). Os parâmetros avaliados foram: taxa de crescimento, mortalidade, razão sexual e temperatura base, mínima e ótima de desenvolvimento do inseto. Com o auxílio dos valores obtidos nestes parâmetros, modelos lineares e curvilineares foram desenvolvidos, comparados entre si e com modelos obtidos por autores a temperaturas constantes. Os resultados mostraram que em condições de temperaturas variáveis a resistência implica em mudanças nos parâmetros biológicos (taxa de crescimento, mortalidade e razão sexual) e que o termoperíodo acelera o crescimento de larvas e pupas de carpocapsa. Com o auxílio dos modelos obtidos, foi realizada uma simulação do período de desenvolvimento de C. pomonella utilizando...

The majority living organisms are ectotherms except birds and mammals. The body temperature (Tb) of an ectotherm results from the energy balance between this the organisms and its environment. The Tb determines most of the biological functions. For instance, a minimum of heat accumulation by insects is needed to pass from a development stage to another during their life cycle. For insect pests, most of phenological models are based on life history trait (e.g., growth) and air temperature. Unfortunately, the use of phenological models is limited since there is a lack of accuracy estimatives in maximum and minimum temperatures. The aim this work was to study the importance of two factors ((i) the insecticide resistance, (ii) the thermoperiod) and the modelling methods to design a phenological model for the the endophyte insect Cydia pomonella. Four strains of C. pomonella: (i) Sv (susceptible strain), (ii) Rdfb (resistant to diflubenzuron), (iii) RD (resistant to deltamethrin), RGv (resistant to C. pomonella granulovirus) and 4 thermoperiods (15°C-20°C, 20°C-25°C, 25°C-30°C e 30°C-35°C) were used. Measured parameters were the development rate, the mortality, the sex ratio, the Toptm, Tmin and Tmax of the development rate. Based on the obtained values for each parameter, linear and curvilinear phenological models were made and compared between them and with those obtained at constant temperature by some authors. Thus, in fluctuating thermal conditions, it was shown that insecticide resistance involved aftereffects on life-history traits as the development rate, the mortality and sex ratio. Also, it was shown that the C. pomonella development rate at larval stage is higher in thermoperiodic conditions. With the models the development of C. pomonella was simulated using air and micro-habitat temperatures for two areas of apple orchards in Europe (e.g., Valais in Switzerland and la Drôme