To get the exact species I'll have to check the reevaluation of the species complex by Manjaji-Matsumoto and Last 2008 but this is either Himantura leoparda, H. uarnak or H. undulata. They're quite similar.
Sydney Aquarium lists them as Reticulate Whiprays (which would be H.uarnak), but looking at H.leoparda and undulata I agree it could easily be one of those instead.
