I have now, after much research, decided that I've never had alligator in China. It was all probably actual crocodile meat. There are only two alligator species in the world, Alligator mississippiensis, the American alligator, and Alligator sinensis, the Chinese alligator.
The Chinese alligator, also known as the Yangze alligator is a critically endengered species which was, in 2003, nearly extinct with only 100 remaining. Thanks to conservation efforts, that number has risen and they are being bred artificially in Anhui Yangtze Alligator National Nature Reserve in Anhui province. Over 1,000 specimens have been released into the wild and they have laid 428 eggs in the wild, with 279 of them hatching naturally, according to monitors.
It is strictly illegal to eat or even possess Chinese alligators.
Alligator meat is advertised but is in all probability crocodile. I suspect that this is not deliberate fraud but a linguistic error. The most common name in Mandarin for both alligator and crocodile are the same, 鳄鱼 (è yú), just as mice and rats are considered to be the same, as are hares and rabbits.
This confusion doesn't arise with the Chinese alligator which has a number of names in Mandarin.
鼍 (tuó) , 鮀 (tuó) 鼍龙 (tuó lóng), 猪婆龙 (zhū pó lóng) or 扬子鳄 (yáng zǐ è).
I did, however, eat what I was told was alligator in Jamaica in the 1970s and see no reason to doubt it wasn't the genuine thing.