Scientists from Brazil for the first time demonstrated that toads can hunt Scorpions and they are not afraid of poison even ten spiders. The authors believe that combating prejudices against these amphibians in Brazil can help to reduce the number of Scorpions and people who suffer from their bites. The article is tentatively accepted in the journal Toxicon.
In Brazil, every year tens of thousands of people get the bites of Scorpions, in most cases, the yellow Scorpion Tityus serrulatus. Every year the number of victims is significantly increased, die from the poison mostly children and the elderly (although mortality does not exceed 1 percent). Tityus serrulatus is found in all regions of Brazil and neighboring countries. Such prevalence could be related to the fact that Scorpions are unable to reproduce by parthenogenesis: females can produce offspring without mating.
One of the environmental factors that lead to an annual increase in the number of Scorpions — the lack of predators. In natural conditions, spiders eat frogs, which are very common in Brazil and should play an important role in restoring balance. However, in the literature there is little information on feeding frogs and Scorpions that is sustainable if these frogs to poison.
Brazilian scientists led by Carlos Jared (Jared Carlos) from the Instituto Butantan offered ten toad species Rhinella icterica two of the Scorpion Tityus serrulatus and recorded the reaction of the amphibians. Then each toad got poison Scorpio: the half — lethal dose established in experiment on mice, and others — five times more. Lethal dose with poison two Scorpions. After the injection, researchers evaluated the condition of the animals and offered them cockroaches, to monitor behavioural reactions.
Toad has noticed the Scorpions and immediately tried to catch them. Nine amphibians have successfully hunted and ate their prey and another failed to catch arachnids. Some amphibians in the process received the bites in the mouth, but after that they didn’t have any symptoms of poisoning.