Sea spiders can regrow their anuses, scientists discover - Livescience.com

(Image credit: Shutterstock)(opens in new tab)Sea spiders possess a remarkable, previously unknown ability: They can regrow their rear ends.

In a new study, published Jan. 23 in the journal Evolution(opens in new tab), researchers tested this assumption by amputating body parts from 23 juvenile and 23 adult P. litorale sea spiders.

During the experiments, the sea spiders had varying parts of their posterior sections removed, such as their back legs, hindgut, anus, various muscle regions and reproductive organs, which include gonoducts in females and gonopores in males.

The adults were unable to regenerate the lost body parts and most died from their injuries, although a couple of individuals that sustained less-extensive damage were able to survive for up to two years after the experiments.

The adults' inability to regrow lost body parts is likely why the juveniles' regenerative skills have gone unnoticed until now, researchers noted in the paper.

(Image credit: Shutterstock)(opens in new tab)The team now wants to discover the exact mechanism that triggers the regeneration in sea spiders and compare it with other arthropods' regenerative abilities.