Leg Autotomy and Regeneration in Crab Spiders Ebrechtella tricuspidata (Araneae: Thomisidae)

Arachnids evade predation by intentionally sacrificing body parts, with leg autotomy playing a crucial role in their survival and reproductive strategies. Our study primarily employed field surveys and laboratory experiments to examine the frequency of autotomy and its effects on predation and mating in Ebrechtella tricuspidata (Araneae: Thomisidae). Leg loss was common in wild populations, with approximately 17.11% of all surveyed spiders missing at least leg, the most frequently lost leg is one of the second pair of appendages, and the highest rate of autotomy occurs in July. Additionally, we found that some individuals exhibit regenerative capacity following autotomy. We focused on the effects of leg autotomy on E. tricuspidata in two contexts: predation and mating. In laboratory conditions, the loss of two legs significantly impacted the individual’s predatory efficiency. Additionally, individuals missing two legs exhibited significantly poorer mating performance than intact individuals. We suggest that E. tricuspidata may employ a synergistic strategy of “autotomy-regeneration” to mitigate survival risks, thereby reducing the negative impacts of leg loss on predation and mating.