26 April, 2019

Tityus serrulatus - A natural born killer

A very tabloid headline for this post, but I felt I couldn't plagiarize the nice original article title "Selected to survive and kill". Scorpion stings in Brazil have increased in the last decade and the main culprit has been Tityus serrulatus Lutz and Mello, 1922 (Buthidae). This very invasive species has spread in Brazil in the last decades and has adapted very well to urban habitat. In addition, the species can reproduce by parthenogenesis, making this species a very expanding taxa.

Ricardo Jose Gonzaga Pimenta and co-workers have recently published a study on how well Tityus serrulatus handles food and water deprivation. The authors found that this medical important scorpion has an impressive capacity to survive starvation for long periods. Lack of water, on the other hand, caused a large decrease in survival rates. Reproduction occurred throughout the year for food-deprived scorpions and controls, but not in the water-deprived groups.

The results of this study have implications for how scorpion control should be conducted for this expanding, hard to kill, dangerous species in urban areas.

Annually, more than 1.2 million scorpion stings and more than 3,000 deaths occur worldwide. Tityus serrulatus Lutz and Mello, 1922 (Scorpiones, Buthidae) is the most medically relevant species in Brazil where it is spreading rapidly and causing over 90,000 cases of envenomation yearly. We monitored T. serrulatus longevity and ability to reproduce under conditions of food and/or water deprivation. We found that T. serrulatus is highly tolerant to food deprivation, with individuals enduring up to 400 days without food. On the other hand, access to water played a pivotal role in T. serrulatus survival. Food and water deprived scorpions showed weight reduction. Reproduction occurred throughout the year for fooddeprived scorpions and controls, but not in the water-deprived groups. Remarkably, fooddeprived animals were able to give birth after 209 days of starvation. Tityus serrulatus resistance to food and water deprivation is likely to be an additional factor underlying this species’ geographic expansion and the difficulties encountered in controlling it.

Pimenta RJG, Brandao-Dias PFP, Leal HG, Carmo AOD, Oliveira-Mendes BBR, Chavez-Olortegui C, et al. Selected to survive and kill: Tityus serrulatus, the Brazilian yellow scorpion. PLoS One. 2019;14(4):e0214075. [Open Access]

Thanks to Matt Simon for informing me about this article!

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