Fitness implications of nonlethal injuries in scorpions: females, but not males pay reproductive costs

The ability to detach a body part in response to a predation attempt is known as autotomy, and it is perhaps the most intensively studied form of nonlethal injury in animals. Although autotomy enhances survival, it may impose reproductive costs to both males and females. We experimentally investigated how autotomy affects the reproductive success of males and females of a scorpion species. Individuals of Ananteris balzani autotomize the last abdominal segments ("tail"), losing the anus and leading to lifelong constipation since regeneration does not occur. Although male "tail" is used during courtship and sperm transfer, autotomy had no effect on male mating success. The combined effect of increased mortality and reduced fecundity resulted in autotomized females producing nearly 35% less offspring than intact females. In conclusion, the negative effects of "tail" autotomy are clearly sex-dependent, probably because the factors that influence reproductive success in males and females are markedly different.