Short‐ and long‐term effects of an extreme case of autotomy: does “tail” loss and subsequent constipation decrease the locomotor performance of male and female scorpions?

Abstract

In many taxa, individuals voluntarily detach a body part as a form to increase their chances of escaping predation. This defense mechanism, known as autotomy, has several consequences, such as changes in locomotor performance that may affect fitness. Scorpions of the genus Ananteris autotomize the “tail”, which in fact corresponds to the last abdominal segments. After autotomy, individuals lose nearly 25% of their body mass and the last portion of the digestive tract, including the anus, which prevents defecation and leads to constipation, because regeneration does not occur. Here, we experimentally investigated the short‐ and long‐term effects of tail loss on the locomotor performance of Ananteris balzani. In a short‐term experiment, the maximum running speed (MRS) of males and females did not change after autotomy. Moreover, the relative mass of the lost tail did not affect the change in MRS after autotomy. In a long‐term experiment, autotomy had a negative effect on the MRS of males, but not of females. Autotomized over‐fed individuals suffered from severe constipation but were not slower than autotomized normally fed individuals. In conclusion, tail loss has no immediate effect on the locomotor performance of scorpions. The long‐term decrease in the locomotor performance of autotomized males may impair mate searching. However, because death by constipation takes several months, males have a long time to find mates and reproduce. Thus, the prolonged period between autotomy and death by constipation is crucial for understanding the evolution of one of the most extreme cases of autotomy in nature.

Autotomy does not affect the locomotor performance of a scorpion

“…The study of García‐Hernández and Machado (2022) strengthened our current understanding of the impact of autotomy on the locomotor performance of animals, especially invertebrates. Similar studies previously have been mainly focused on vertebrates, such as lizards (Bateman & Fleming 2009), and similar result has been reported in several lizard species.…”

“…Following the previous studies, García‐Hernández and Machado (2022) addressed the issue and published their results recently in Integrative Zoology . They investigated the short‐term (within 12 days) and long‐term (13–64 days) effects of tail loss on the locomotor performance of adult Ananteris balzani by examining the maximum running speed (MRS) of two groups of individuals: intact ones and autotomized ones.…”

“…2011). Thus, the result of García‐Hernández and Machado (2022) provided a new perspective in understanding the evolution of one of the most extreme cases of autotomy. It also inspires future studies to look into the response of immature scorpions to autotomy.…”