We aren't in any immediate danger of knock-on effects either, as the jetsetting jellyfish-ettes seem to be integrating quite harmlessly into their new homes (though some shrimp might disagree). The rather damp phoenix-stylings of the hydrozoan have obviously made them a hot topic in genetics, but don't expect to buy your immortality pills just yet - this is one life extension option that isn't even remotely applicable to humans.

Haven't you seen Hulk?