US alligator first in world to get artificial tail

A seven-foot-long alligator in US has become the first in the world to be given a prosthetic tail.
The 11-year-old reptile, called Mr Stubbs, could not swim after his back end was bitten off by another alligator eight years ago.
The Herpetological Society in Phoenix, US fitted Mr Stubbs with a 3-foot-long prosthetic tail made of two types of silicone rubber, attached firmly with nylon straps.
It will take months, however, before Mr Stubbs learns how to properly use the tail, USA Today reported.
"The fact he doesn't try to bite it (the tail) is a good sign. Learning how to use it is going to take a lot of training," said Russ Johnson, president of the Phoenix Herpetological Society.

Using cameras and a computer, Justin Georgi, an assistant professor in the department of anatomy at Midwestern University in Glendale, Arizona, studied Mr Stubbs for weeks.

Georgi would attach reflective dots to the gator, whose jaws were secured with electrical tape before each session. The dots would form a 3-D computer model, allowing Georgi to see exactly how Mr Stubbs got around.
Georgi used the research to devise the tail's specifications. It had to be buoyant, and weigh just 3-4kg. It also had to be flexible, so when Mr Stubbs wiggled his rear stump, the tail would swing to propel him forward.

Sarah Jarvis, research associate in The CORE Institute in Phoenix crafted the tail from silicone rubber, The Arizona Republic reported.
With a mold and findings in hand, Jarvis used Body Double and Dragon Skin - two types of silicone rubber - to create a tail. It included a sheath that would fit over Mr Stubbs' stub.
Jarvis painted the prosthetic so the gator would not have to go around with a translucent tail. She tried to match nature's colours, using green, black, brown and red.
More tails will need to be crafted in the future, because alligators grow throughout their lifetimes and there may be as many as 60 or 70 years ahead for Mr Stubbs, based on a gator's expected life span.