I found that while trying to find info on dwarf type manta's.
I found this from here:
Members of the genus Manta:
There are approximately 7 species and subspecies in this genus: M. birostris (Atlantic Manta) · M. birostris ehrenbergi · M. birostris · M. ehrenbergii · M. ehrengergi · M. pinchoti · M. raya
That's too many types for me to read about right now.
---edit added this
Mantas are filter feeders: they feed on plankton, fish larvae and the like, passively filtered from the water passing through their gills as they swim. The small prey organisms are caught on flat horizontal plates of russet-coloured spongy tissue, that span the spaces between the manta's gill bars.
I don't know if the little fishies would be in much danger or not....maybe if they don't move out of the way.
The turtle is a female and she is brain damaged it seems, got hit by a boat in the sea and was rescued.
Went there myself during one ofothe previous bank holidays and had a lovely time, got talking to a lad who was feeding the seahorses and he was quite informative about some of the brisih ones.