Survival strategies of first-instar scorplings of Olivierus martensii

 

Ecdysis (molting, changing skin) is the way that scorpions and many other arthropods grow. This is a risky part of an young scorpions life, especially during the first molts. Yiyuan Guo and co-workers have recently published a study on the strategies used by first-instar scorplings of Olivierus martensii (Karsch, 1879) (Buthidae) to optimize survival (the article use the old name for this species, Mesobuthus martensii). 

The study shows that newborn scorpions exhibit special aggregate molting behavior, which increases their chances of survival. This aggregating behavior makes it easier for the mother scorpion to keep the scorplings on her back, even though this behavior is also observed when scorplings molt away from the mother's back. The cooperative nature of aggregate molting in first-instars combined with staying on the mother's back and in her care is probably an essential role in increasing the survival of the young scorplings.

Abstract:
Ecdysis is a well-known developmental feature among arthropods. Because the aggregate and synchronous molting of first-instar scorpions is markedly different from the common independent molting behavior of older scorpions and most arthropods, knowledge on the biological benefits of the unusual behavior of first-instar scorpions remain limited. Before the molting of newborn scorpions, their mothers exhibited a remarkable ability to efficiently locate the fallen offspring and help them climb onto their back, which was supported by strong maternal behavior because they climbed more swiftly than the 7-day postpartum scorpions. Most newborn scorpions molted and survived on the mother’s back, with a survival rate of approximately 100%, and most newborn scorpions survived via aggregate molting behavior on sand in the absence of mothers (89.83% ± 1.91%). The important role of the mother scorpion was further highlighted in mothers with one to five first-instar scorpions.While all first-instar scorpions individually or reciprocally molted and survived on the mother’s back, only 52.00% ± 7.14% to 79.20% ± 4.24% of newborn scorpions isolated from the mother could individually or reciprocally molt and survive on the sand, and the aggregated states of first-instar scorpions strengthened as their numbers on sand increased before molting. These results highlight collaborative molting as an evolutionary driving force for newborn scorpions. Taken together, both maternal care and collaborative aggregate molting behavior enhanced the survival of first-instar scorpions before and after molting, and these benefits for first-instar scorpions play essential and evolutionary roles in scorpion survival.

Reference:
Guo Y, Li S, Lu S, Wang X, Cao Z, Wu Y. Special Survival Strategy of First-Instar Scorpions Revealed by Synchronous Molting Behavior from Social Facilitation of Maternal Care and Reciprocal Aggregation. Insects. 2024;15(9). [Open Access]