Observations on regeneration of the pedipalp and legs of scorpions

 

Morphological anomalies in scorpions are well known. Some are inborne teratologies, others are caused becaused a failed molting process or due to accidents from predators attacs and similar. Scorpions can survive the loss of or damages to some of the appendages, but loss of the last part of the tail will usually cause death after a certain time as the anal organs are gone and the scorpion will die of constipation. 

Lost or damaged appendages can be reganerated completly or partly in scorpions during future molts. Martin Watz and Jason Dunlop have recently published a study on this topic and presented two cases of regeneration observed in scorpions in captivity relating to the pedipalp and legs. 

Abstract:
Two examples of scorpion limb regeneration following unsuccessful molts are documented based on material held in captivity. An Opisthacanthus asper (Peters, 1861) (Hormuridae) shows a relatively rare example of pedipalp regeneration in which the lost tibia and tarsus was replaced by a smaller, curved element of uncertain homology to either the fixed or free finger. A comparable abnormal palp described in the literature hints that pedipalps can only regenerate a structure of this form, regardless of the site of amputation. An Olivierus caucasicus (Nordmann, 1840) (Buthidae) is described in which claws (pretarsus) of leg III regenerated directly at the distal end of the tibia, while in leg IV the claws regenerated at the end of a truncated section of the metatarsus. This supports previous observations that scorpions can only regenerate the pretarsus of the leg, again irrespective of where on the limb the original breakage occurred.

Reference:
Watz M, Dunlop JA. Observations on regeneration of the pedipalp and legs of scorpions. Euscorpius. 2022(345):1-5. [Open Access]

Thanks to Martin Watz for sending me their article!