Atividade diária, uso do ambiente e benefícios do enriquecimento ambiental para Micrurus frontalis

Micrurus frontalis is a specie from the coral-snakes group. Most of the snakes in this group have fossoral and cryptozoic habits, which makes it difficult to understand the biology of Micrurus species in nature. In this way, the maintenance of snakes in captivity, carried out in well-assembled and enriched enclosures, which can help the biology’s knowledge and the behavioral observation that are difficult to be detected in natural environment, including daily activity. In this work, through the monitoring of an individual of M.frontalis over 60 days, it was possible to characterize the daily activity and the environment use by the snake, and to conclude that M.frontalis presents diurnal activity, with greater activity in the hours of higher temperature during the colder periods, and in the hotter seasons, avoid exposure during the higher temperatures. The snake also mostly uses the lower stratum of the enclosure, but sporadically explores the upper stratum. This work also presents a study on the food and sensorial enrichment use, unprecedented in snakes. The different environmental enrichment techniques are used in order to favor the adaptation of the captive animal to the environment, reduce stress, promote well-being and stimulate natural behaviors typical of the species worked on. The snake's prey were packed in different materials placed at different points and strata of the enclosure, aiming to progressively difficult the access to the prey. The unprecedented results show that food enrichment can be successfully used in snakes, and brings benefits to the animal, including breaking routine, reducing stereotyped behaviors and reducing sedentary lifestyle, common in captive snakes.

Micrurus frontalis é uma das espécies que constituem o grupo das cobras-corais. As serpentes desse grupo apresentam, em sua maioria, hábitos fossoriais e criptozoicos, o que dificulta o conhecimento da biologia das espécies de Micrurus na natureza. Dessa forma, a manutenção de serpentes em cativeiro, realizada em recintos bem montados e enriquecidos pode auxiliar no conhecimento da biologia e na observação de comportamentos difíceis de serem observados em ambiente natural, entre eles a atividade diária. Neste trabalho, através do monitoramento de um indivíduo de M.frontalis ao longo de 60 dias, foi possível caracterizar a atividade diária e o uso do ambiente pela serpente, e concluir que M.frontalis apresenta atividade diurna, com maior atividade nos horários de temperaturas mais elevadas durante os períodos mais frios, e nas épocas mais quentes evita-se expor durante as temperaturas mais elevadas. A serpente também utiliza majoritariamente o estrato inferior do recinto, mas esporadicamente explora o estrato superior. Este trabalho também apresenta um estudo sobre o uso do enriquecimento ambiental alimentar e sensorial, inédito em serpentes. As diferentes técnicas de enriquecimento ambiental são utilizadas a fim de favorecer a adaptação do animal cativo ao meio, reduzir o estresse, promover o bem-estar e estimular comportamentos naturais típicos da espécie trabalhada. As presas da serpente foram acondicionadas em diferentes materiais colocados em pontos e estratos variados do recinto, visando dificultar progressivamente o acesso à presa. Os resultados inéditos mostram que o enriquecimento ambiental alimentar pode ser utilizado com sucesso em serpentes, e que traz benefícios ao animal, entre eles a quebra da rotina, a redução de comportamentos estereotipados e a redução do sedentarismo, comum em serpentes cativas.

Snake venom color and L-amino acid oxidase: An evidence of long-term captive Crotalus durissus terrificus venom plasticity.

The venom color variation of Crotalus durissus terrificus (Cdt) is attributed to the presence of the toxin L-amino acid oxidase (LAAO). During the venom milking routine of Instituto Butantan, we have noticed that most venoms of captive Cdt specimens show a yellowish color, while most venoms of wild specimens are white. Here we describe a comparative analysis of long-term captive (LTC) and recently wild-caught (RWC) Cdt, focusing on LAAO variation. For the identification of LAAO in individual venoms, four different approaches were employed: evaluation of the enzymatic activity, SDS-PAGE, Western blotting, and ELISA. In addition, mass spectrometry analysis was performed using pooled samples. Although some variation among these methodologies was observed, it was possible to notice that the presence of LAAO was significantly higher in the venom of LTC individuals. LAAO was identified in 60-80% LTC specimens and in only 10-12% of RWC specimens. Furthermore, this enzyme accounts for 5.6% of total venom proteins of LTC Cdt pooled venom, while it corresponds to only 0.7% of RWC Cdt pooled venom. These findings strongly suggest that captive maintenance increases the expression of LAAO in Cdt venom.

Compositional and functional investigation of individual and pooled venoms from long-term captive and recently wild-caught Bothrops jararaca snakes.

Intraspecific venom variability has been extensively reported in a number of species and is documented to be the result of several factors. However, current evidence for snake venom variability related to captivity maintenance is controversial. Here we report a compositional and functional investigation of individual and pooled venoms from long-term captive (LTC) and recently wild-caught (RWC) B. jararaca snakes. The composition of individual venoms showed a remarkable variability in terms of relative abundance of toxins (evidenced by 1-DE and RP-HPLC), enzymatic activities (proteolytic, PLA2, and LAAO) and coagulant activity, even among captive specimens. Thus, no compositional and functional pattern could be established to assign each individual venom to a specific group. Conversely, pooled venom from LTC and RWC snakes showed no significant differences regarding protein composition (characterized by 1-DE and shotgun proteomics), enzymatic activities (proteolytic, PLA2 and LAAO) and biological function (coagulant, hemorrhagic and lethal activities), except for edematogenic activity, which was more prominent in RWC venom pool. Additionally, both pooled venoms displayed similar immunoreactivity with the bothropic antivenom produced by Instituto Butantan. Taken together, our results highlight the complexity and the high intraspecific variation of B. jararaca venom, that is not influenced at a discernible extent by captivity maintenance. BIOLOGICAL SIGNIFICANCE: Bothrops jararaca snakes are one of the main causes of snakebites in Southeastern Brazil. Due to its medical interest, the venom of this species is the most studied and characterized among Brazilian snakes and captive B. jararaca specimens are maintained for long periods of time in our venom production facility. However, knowledge on the influence of captivity maintenance on B. jararaca venom variability is scarce. In this report, we described a high compositional and functional variability of individual venoms from LTC and RWC B. jararaca snakes, which are not observed between LTC and RWC pooled venoms. This intraspecific variability is more likely to be due to genetic/populational differences rather than "captivity vs wild" conditions. In this regard, data generated by the present work support the use of venom from captive and wild snakes for antivenom production and scientific research. Moreover, the data generated by this study highlight the importance of analyzing individual venom samples in studies involving intraspecific venom variability.

Compositional and functional investigation of individual and pooled venoms from long-term captive and recently wild-caught Bothrops jararaca snakes

Intraspecific venom variability has been extensively reported in a number of species and is documented to be the result of several factors. However, current evidence for snake venom variability related to captivity maintenance is controversial. Here we report a compositional and functional investigation of individual and pooled venoms from long-term captive (LTC) and recently wild-caught (RWC) B. jararaca snakes. The composition of individual venoms showed a remarkable variability in terms of relative abundance of toxins (evidenced by 1-DE and RP-HPLC), enzymatic activities (proteolytic, PLA2, and LAAO) and coagulant activity, even among captive specimens. Thus, no compositional and functional pattern could be established to assign each individual venom to a specific group. Conversely, pooled venom from LTC and RWC snakes showed no significant differences regarding protein composition (characterized by 1-DE and shotgun proteomics), enzymatic activities (proteolytic, PLA2 and LAAO) and biological function (coagulant, hemorrhagic and lethal activities), except for edematogenic activity, which was more prominent in RWC venom pool. Additionally, both pooled venoms displayed similar immunoreactivity with the bothropic antivenom produced by Instituto Butantan. Taken together, our results highlight the complexity and the high intraspecific variation of B. jararaca venom, that is not influenced at a discernible extent by captivity maintenance. Biological significance: Bothrops jararaca snakes are one of the main causes of snakebites in Southeastern Brazil. Due to its medical interest, the venom of this species is the most studied and characterized among Brazilian snakes and captive B. jararaca specimens are maintained for long periods of time in our venom production facility. However, knowledge on the influence of captivity maintenance on B. jararaca venom variability is scarce. In this report, we described a high compositional and functional variability of individual venoms from LTC and RWC B. jararaca snakes, which are not observed between LTC and RWC pooled venoms. This intraspecific variability is more likely to be due to genetic/populational differences rather than "captivity vs wild" conditions. In this regard, data generated by the present work support the use of venom from captive and wild snakes for antivenom production and scientific research. Moreover, the data generated by this study highlight the importance of analyzing individual venom samples in studies involving intraspecific venom variability.