Effects of nutritional stress on reproductive output in the scorpion Tityus pusillus Pocock, 1893 (Scorpiones, Buthidae)

Nutritional stress in females may have adverse reproductive effects such as reduced fertility and high juvenile offspring mortality. In this study, we investigated the effects of dietary stress on the reproductive output of the scorpion Tityus pusillus Pocock, 1893, in which we tested the hypothesis that compared with well-fed females, those subjected to nutritional stress would have a longer gestational period, produce offspring of lower weight, and suffer higher rates of mortality rates. Females were mated and divided into two treatment groups: those fed weekly (n = 37) and those fed on alternate weeks (n = 43). Compared with the well-fed females, we observed higher mortality (81.4% vs. 59.5%), a longer gestational period (21.3 vs. 12.7 weeks), and a larger number of offspring, albeit with higher mortality (8 and 64.1% vs, 3.5 and 45.2%, respectively) in the less frequently fed females. However, litter weights in both groups were found to be similar (less fed: 0.013 g; well fed, 0.014 g). These findings reveal that nutritional stress causes changes in the progeny of inadequately fed T. pusillus females, thereby contributing to higher offspring mortality, and indicate that T. pusillus females vary their reproductive strategies depending on resource availability.