To tame a space dolphin you will need element sometimes you may need alot, you find them in the space biome in Genesis part 2

First pet it,it will swim away don't worry just follow it, once it slows you pet it again(try to avoid hiting their head or you will bounce away) then you can feed it 1 element and it will swim away again,once slows again pet it 2 times and fed it 3 element it will swim away again, once slows again pet it 3 times and feed it 5 element it will swim away, once slowed again pet it 3 times and feed it 10 element, repeat till tamed the element increments you feed it go 1,3,5,10 then repeat

Be Carful Of Viodwryms (tek wyverns) while out there, they are very aggressive and agroo range is very far so be carful

If the one you want is in a group you can pet the ones you don't want to get them to swim away and leave you alone

Their saddle unlocks at level 120 you may be wondering how to get the saddle engram if level 105 is max level, we'll to get higher level you can either ascend on alpha any map for 15+ max levels, (I find manticore on scorched earth to be easiest way to ascend) find all explorer notes on all story maps for 10+ max levels, and you can also use chibis, kevel up the chibi and it will allow you to gain more max levels

Happy asking

-Van