Small reptiles such as lizards have the ability to regenerate tails, while it was not known whether much larger crocodiles had this trait.
The alligators of America are one of the closest relatives of dinosaurs living in modern times and can grow up to about 4 meters. While smaller reptiles, such as lizards, have the ability to renew their tails, much larger crocodiles have not been studied much on whether they can renew their gigantic tails.
A team of researchers from Arizona State University and the Louisiana Department of wildlife and Fisheries found that young crocodiles were able to Re-grow their tails by three-quarters of a foot, or 18 percent of their total body length.
An interdisciplinary team of scientists used advanced imaging techniques, along with applied Anatomy and tissue Organization study methods, to study the structure of these re-growing tails. The team discovered that these new tails are complex structures surrounded by binding tissue intertwined with blood vessels and nerves, and have a central skeleton made up of cartilage. For now, it is estimated that being able to Re-grow their tails gives crocodiles a functional advantage in the bleak aquatic environment in which they live.
“Aside from its size, what makes a crocodile interesting is that the re-growing tail exhibits both regeneration (regeneration) and wound healing traces within the same structure.”the paper’s lead author, Cindy Xu, says.
“The regrowth of cartilage, blood vessels, nerves and scales was consistent with previous studies of lizard tail regeneration, both in our laboratory and in other laboratories. However, we were stunned when we discovered that there was wound-like connective tissue in the re-growing crocodile tail instead of skeletal muscle. The comparative Sciences of the future are of great importance for us to understand why regenerative capacity varies between different reptiles and animal groups.”
“The range of regenerative abilities between species is quite fascinating; it is clear that creating a new novelization is expensive.”says Jeanne Wilson-Rawls, co-senior author of the paper.
The re-grown tail in crocodiles differs from the original tail. Re-growing scales, frequent flakes, and lack of dorsal slits (top right). In the re-grown tail, the bone (yellow) in the original tail is replaced by the undivided cartilage tube (bronze).
“The biologists in our Alligator Research and Management Program have been at Arizona State University for years. They are happy to work with Kusumi.”says biologist Ruth M., director of the Louisiana Department of wildlife and Fisheries ” Elsey
“In the field, we see aligators with traces of possible re-growth in the tail tissue, but their skills in this regard have led the current study to detail histological changes associated with a possible partial regeneration or wound healing capacity.”
Crocodiles, lizards and humans are included in a group of animals called “amniotes” with a spine on their back. The interdisciplinary team had previously worked on the tail regeneration of lizards, while the growth of these complex new tails in aligators provides more advanced information about the process in amniotes.
Article: Xu, C., Palade, J., Fisher, R. E., Smith, C. I., Clark, A. R., Sampson, S., … & Kusumi, K. (2020). Anatomical and histological analyses reveal that tail repair is coupled with regrowth in wild-caught, juvenile American alligators (Alligator mississippiensis). Scientific reports, 10(1), 1-17.