Although at the moment there are 3 "semi" recognized species of JD the most common and scientifically valid is Rocio octofasciata, but there are 2 more that may or may not be considered valid, R. gemmata, and R. ocotal.
I have found that if you go from one cenote to another, there are slight, yet noticeable differences. In Cristalino they may be more elongate than in Jardin de Eden, some may have a more bulldog like muzzle. Whether of not this is enough to warrant separation as species, is another story.
Here are a couple videos I took in 2 different cenotes, where I found them.