Seems to be the fastest on mobile, outrunning even my icthy. To tame safely get an icthy, and stay on the ascension roof. Follow if it dives deeper to re aggro then get back up again, then shoot with toxicant arrows(only on mobile) or tranq spear bolts (not available on mobile it seems). Best tame, has a very high weight and speed and melee dmg, but has a bit of a pain in the ass turning radius. Easy to tame though, on mobile use a soothing balm and some prime meat taken from nearby basilosauruses or normal raw meat (raw meat is better at taming most stuff in the water than fish meat). Best thing to use for though is taming a tuso, as it can survive long and is powerful enough to even escort you and the tuso back to base. Best way to kill is with a high level basilo or another mosa.
very useful to hunt drops on, only issue is jellyfish dismount you and will kill it. in my opinion it's better to use a squid they have more health and the melee is just as good. until wildcard stops jellyfish hitting this thing it's a risk your loose it to a lagging render field.