For people confusing whether or not they lose aggro when tamed on mobile,here's the answer I got after taming and testing around 100 of those dolphins.
1.They will become invincible (literally) by any creature if you tame them when there's no aggressive dinos around in your render distance(both land and sea dinos count)
2.They will become living rage shark baits if you tame the when there are aggressive dinos AROUND or IN THE RENDER DISTANCE.And by that I mean they will aggro creatures more than any tame in the game now calling even megs out of render distance and eels from boarderline render range.They essentially became sea pachyrhinos in constant rage pheromones buff for aggressive creatures.
So here's my tame.Tame them ONLY in herbivore island inner shore if you want the invisible buff and kill any shark or manta that spawned in there before taming them.
Best for killing scorpions on bottom of ocean floor since they don't take torpor. Scorpions down there will knock any other animals out. Once you kill it, hit it with a pickaxe to gather black pearls. Very useful for the next update with tek gear.
!!!find any animal you may have lost on mobile !!!!!!
Go to your profile and it should say tames _/_ tap that and then it will show you all the animals you’ve tamed that are alive. Then go to the one you lost and hit request! Hope this helps anyone who needs it.