Cannibalistic behavior in Rhopalurus laticauda Thorell, 1876 and Tityus silvestris Pocock, 1897 (Scorpiones: Buthidae) under captivity in the extreme north of the Brazilian Amazon

Scorpions are predators, with diets ranging from insects to other arachnids. Despite this, their predatory habits, especially in the Brazilian Amazon, are still poorly understood. This study documents, for the first time, cannibalistic events in the species Rhopalurus laticauda Thorell, 1876 and Tityus silvestris Pocock, 1987, both species found in Roraima. The first species is more common in open areas known as lavrado, while the second inhabits humid forests. During the study, we observed that, in most cases, the individuals involved in cannibalistic acts were of similar sizes. Only in one case, an adult preyed on a juvenile. These interactions, frequently associated with territorial disputes and for food, culminated in confrontations in which the weaker individual was subjugated. Our data, obtained under controlled captive conditions, revealed an aggressive and competitive behavior among scorpions of these species. It is important to highlight that similar behaviors were recorded in videos collected during field expeditions, suggesting that cannibalism also occurs in natural environments. The subjugated animals are consumed entirely in many cases, and in others, only parts of the consumed animals were found. These results contribute significantly to the understanding of the population dynamics of scorpions in the Amazon, indicating that intraspecific competition may be an important factor in the regulation of these populations.