RESUMO

In recent years, SE Brazil, the most populous region in the country with an estimated population of 88 million, has been experiencing an alarming increase in scorpions accidents (scorpionism), mainly caused by the yellow scorpion (Tityus serrulatus), or "escorpião amarelo" in Portuguese. This species is considered particularly dangerous to humans and can reproduce by parthenogenesis favouring rapid dispersal and colonization of new environments. Since the 1940s, owing to the growing danger represented by scorpionism, public control policies have been developed, including active search for scorpions, together with the use of toxic substances applied in places most likely to serve as their refuges. Even so, the number of accidents is increasing year by year, presently at an alarming rate. It seems evident that the increase in accidents is directly (or primarily) related to the lack of predators that in healthy environmental conditions would naturally control scorpion populations. However, due to environmental changes, leading to a lack of predators, scorpions have been gradually invading the urban environment. Arachnids and insects in general, as well as some other invertebrates, are preyed upon by anuran amphibians (toads, frogs and tree frogs). Toads (family Bufonidae) are nocturnal, large, and highly voracious animals, capable of actively exploring extensive areas and consuming large numbers of insects and arachnids daily. One of the most common toad species in southeastern Brazil is Rhinella icterica. Both R. icterica and T. serrulatus inhabit the same nocturnal environment. The predatory action of toads, specifically on scorpions, is practically unknown from behavioural and toxinological points of view. Thus, we studied the predatory behaviour of this toad against the yellow scorpion and evaluated the resistance of the amphibian to scorpion venom. Our results show that R. icterica is a voracious predator of T. serrulatus and is extremely resistant to its venom. Human/toad relationship throughout western history has always been very conflicted and possibly one of the factors that most has contributed to human ignorance of the role of these amphibians in maintaining ecological balance. Presently, the control of scorpionism is being performed through active search and/or the use of chemical agents, although showing little efficacy in reducing human accidents. In the medium or long term, more effective actions taking into account the biology of scorpions and their predators have never been taken to reduce these accidents.

Assuntos

RESUMO

In recent years, SE Brazil, the most populous region in the country with an estimated population of 88 million, has been experiencing an alarming increase in scorpions accidents (scorpionism), mainly caused by the yellow scorpion (Tityus serrulatus), or "escorpião amarelo" in Portuguese. This species is considered particularly dangerous to humans and can reproduce by parthenogenesis favouring rapid dispersal and colonization of new environments. Since the 1940s, owing to the growing danger represented by scorpionism, public control policies have been developed, including active search for scorpions, together with the use of toxic substances applied in places most likely to serve as their refuges. Even so, the number of accidents is increasing year by year, presently at an alarming rate. It seems evident that the increase in accidents is directly (or primarily) related to the lack of predators that in healthy environmental conditions would naturally control scorpion populations. However, due to environmental changes, leading to a lack of predators, scorpions have been gradually invading the urban environment. Arachnids and insects in general, as well as some other invertebrates, are preyed upon by anuran amphibians (toads, frogs and tree frogs). Toads (family Bufonidae) are nocturnal, large, and highly voracious animals, capable of actively exploring extensive areas and consuming large numbers of insects and arachnids daily. One of the most common toad species in southeastern Brazil is Rhinella icterica. Both R. icterica and T. serrulatus inhabit the same nocturnal environment. The predatory action of toads, specifically on scorpions, is practically unknown from behavioural and toxinological points of view. Thus, we studied the predatory behaviour of this toad against the yellow scorpion and evaluated the resistance of the amphibian to scorpion venom. Our results show that R. icterica is a voracious predator of T. serrulatus and is extremely resistant to its venom. Human/toad relationship throughout western history has always been very conflicted and possibly one of the factors that most has contributed to human ignorance of the role of these amphibians in maintaining ecological balance. Presently, the control of scorpionism is being performed through active search and/or the use of chemical agents, although showing little efficacy in reducing human accidents. In the medium or long term, more effective actions taking into account the biology of scorpions and their predators have never been taken to reduce these accidents.

RESUMO

RESUMO O declínio de anfíbios no mundo está cada vez maior e a perda de riqueza, muitas vezes, está associada a áreas agrícolas. O uso de agrotóxicos, em especial daqueles à base de glifosato, é cada vez maior e novas formulações estão sendo desenvolvidas. O presente trabalho avaliou a toxicidade aguda de um composto comercial com o princípio ativo glifosato e os efeitos comportamentais e morfológicos em girinos de Physalaemus cuvieri e Rhinella icterica. O primeiro mostrou-se mais sensível em relação ao formulado comercial do que o segundo e não houve diferenças significativas em relação às mudanças comportamentais e o aumento das concentrações do formulado entre as espécies, porém houve alterações morfológicas de peso e comprimento dos girinos de ambas espécies.

ABSTRACT The decline of amphibians in the world is increasing and the loss of wealth is often associated with agricultural areas. The use of pesticides, especially those based on glyphosate is increasing and new formulations are being developed. This study evaluated the acute toxicity of a commercial compound with glyphosate and behavioral and morphological effects on Physalaemus cuvieri and Rhinella icterica tadpoles; the former was more sensitive to the commercially formulated compound than R. icterica and there were no significant differences in relation to behavioral changes and increase compound concentrations among species, but there were morphological changes of weight and length of tadpoles of both species.

RESUMO

O objetivo deste estudo foi identificar parasitos intestinais em sapo cururu – Rhinella icterica (Anura: Bufonidae) – na região urbana de Lages, estado de Santa Catarina, Brasil. Dezesseis espécimes de Rhinella ictericaforam coletados de julho a outubro de 2010. Os sapos foram necropsiados e removidos os intestinos. Amostras de fezes foram coletadas e processadas por sedimentação espontânea e todo o intestino foi examinado. Todos os sapos apresentaram ovos nas fezes e a forma adulta de Acanthocephalus ranae foi detectada no intestino de 100% dos sapos. Este é o primeiro registro desta espécie no estado de Santa Catarina, região sul do Brasil. Palavras-chave: Acanthocephala, Rhinella icterica, Bufonidae, sapo brasileiro.

The aim of this study was to identify intestinal parasites in the yellow cururu toad – Rhinella icterica (Anura: Bufonidae) – in the urban region of Lages, state of Santa Catarina, Brazil. Sixteen specimens of Rhinella icterica were collected from July to October 2010. The toads were necropsied for removal of the intestine. Stools were collected and processed by spontaneous sedimentation and the whole length of the intestine was examined. All of the toads presented eggs in their feces and the adult form of Acanthocephalus ranae was detected in the intestine of 100% of the toads. This is the first report of this species in the state of Santa Catarina, southern Brazil.

Assuntos

RESUMO

O objetivo deste estudo foi identificar parasitos intestinais em sapo cururu Rhinella icterica (Anura: Bufonidae) na região urbana de Lages, estado de Santa Catarina, Brasil. Dezesseis espécimes de Rhinella ictericaforam coletados de julho a outubro de 2010. Os sapos foram necropsiados e removidos os intestinos. Amostras de fezes foram coletadas e processadas por sedimentação espontânea e todo o intestino foi examinado. Todos os sapos apresentaram ovos nas fezes e a forma adulta de Acanthocephalus ranae foi detectada no intestino de 100% dos sapos. Este é o primeiro registro desta espécie no estado de Santa Catarina, região sul do Brasil. Palavras-chave: Acanthocephala, Rhinella icterica, Bufonidae, sapo brasileiro.(AU)

The aim of this study was to identify intestinal parasites in the yellow cururu toad Rhinella icterica (Anura: Bufonidae) in the urban region of Lages, state of Santa Catarina, Brazil. Sixteen specimens of Rhinella icterica were collected from July to October 2010. The toads were necropsied for removal of the intestine. Stools were collected and processed by spontaneous sedimentation and the whole length of the intestine was examined. All of the toads presented eggs in their feces and the adult form of Acanthocephalus ranae was detected in the intestine of 100% of the toads. This is the first report of this species in the state of Santa Catarina, southern Brazil.(AU)

Assuntos

RESUMO

In this work we report an observation of an ornitophagy event on Certhiaxis cinnamomeus by Rhinella icterica occurred in the central region of Rio Grande do Sul, Brazil.

Reportamos um evento de ornitofagia por Rhinella icterica sobre Certiaxis cinnamomeus ocorrido em 2010, na região central do Estado do Rio Grande do Sul (29°41S, 53°48W), Brasil.

Assuntos

RESUMO

Os anfíbios apresentam dois tipos de glândulas cutâneas: as mucosas e as granulosas. As secreções produzidas nas suas glândulas de sua pele apresentam componentes químicos diversos que têm sido estudados com relação as suas atividades biológicas, com efeito anestésico, alucinógeno e até antimicrobiano. Devido à diversidade de espécies no Brasil e ainda poucos estudos dessa natureza, o presente estudo objetivou investigar a atividade antimicrobiana do veneno das glândulas parotóides do sapo Rhinella icterica, procedentes do Distrito de Rubião Junior, Botucatu, estado de São Paulo. Foi avaliado o efeito de diferentes concentrações do veneno sobre colônias de bactérias Escherichia coli e Staphylococcusaureus, bem como o tempo necessário para a ação antimicrobiana. Observou-se que o veneno extraído apresentou atividade antimicrobiana leve para as duas bactérias estudadas, porém com maior ação para S. aureus. O veneno agiu somente em concentrações maiores de 50 mg/mL, com maior eficiência na concentração de 100 mg/mL, em tempo igualou superior a 30 minutos para S. aureus e a partir de 15 minutos para E. coli. Estes dados poderão servir de base para estudos futuros envolvendo o isolamento das substâncias do veneno que apresentaram atividade antimicrobiana e as concentrações mínimas necessárias para a referida ação.

Assuntos

RESUMO

Amphibians exhibit two types of cutaneous glands: mucous and granular. The secretion produced in their skin glands exhibit several chemical components. These substances have been studied regarding biological activity, showing aenesthetic, hallucinogen and antimicrobial effects, among others. Due to the diversity of Brazilian species, and considered that only few studies assessed this issue, the present study aim to investigate the antimicrobial activity of the poison produced by the parotoid macroglands of the toad Rhinella icterica originated from Rubião Júnior, Botucatu, São Paulo state. We assessed the effect of different poison concentrations on Escherichia coli e Staphylococcus aureus cultures, as well as the time required for antimicrobial action to perform. R. icterica poison presented weak antimicrobial activity for both bacteria considered, with a stronger effect on S. aureus. The poison acts in concentrations higher than 50 mg/mL, with a larger effectiveness at 100mg/mL. Time required for action was equal or superior than 30 minutes for S. aureus and superior than 15 minutes to E. coli. These data may support future studies involving the isolation of the substances confering antimicrobial activity to the poison of R. icterica, as well as the minimum concentrations required for the refered action.

Os anfíbios apresentam dois tipos de glândulas cutâneas: as mucosas e as granulosas. As secreções produzidas nas suas glândulas de sua pele apresentam componentes químicos diversos que têm sido estudados com relação as suas atividades biológicas, com efeito anestésico, alucinógeno e até antimicrobiano. Devido à diversidade de espécies no Brasil e ainda poucos estudos dessa natureza, o presente estudo objetivou investigar a atividade antimicrobiana do veneno das glândulas parotóides do sapo Rhinella icterica, procedentes do Distrito de Rubião Junior, Botucatu, estado de São Paulo. Foi avaliado o efeito de diferentes concentrações do veneno sobre colônias de bactérias Escherichia coli e Staphylococcus aureus, bem como o tempo necessário para a ação antimicrobiana. Observou-se que o veneno extraído apresentou atividade antimicrobiana leve para as duas bactérias estudadas, porém com maior ação para S. aureus. O veneno agiu somente em concentrações maiores de 50 mg/mL, com maior eficiência na concentração de 100 mg/mL, em tempo igualou superior a 30 minutos para S. aureus e a partir de 15 minutos para E. coli. Estes dados poderão servir de base para estudos futuros envolvendo o isolamento das substâncias do veneno que apresentaram atividade antimicrobiana e as concentrações mínimas necessárias para a referida ação.