Nope, first one is better, Tony...
Second one yeah the Spider is centered but the composition is flat/boring. With the first, all of the Spider is there, and being to one side, a much more interesting and busy composition is achieved by including the neighbourhood around the Spider. Too many Spider pics focus on just it and ignore the neighbourhood which is just as fascinating. Your first pic makes your image of the Tarantula much more unique.
Composition is a skill unto itself. Many people focus just on one aspect but foget the context. That's composition. That's why I love my wee 4" f/5 refractor as much as my 17.5" dobbie - very different composition possibilities
Alex