Do organisms with higher fitness mean that they have survive to an advanced age? Why or why not?

No. Having a higher fitness in biology means surviving to reproductive age, finding a mate, and producing offspring. The more offspring an organism produces during its lifetime, the greater its biological fitness, regardless of how long the organism lives. If an organsim produces 5 offspring during their lifetime and dies at an early age, they would still be considered more fit than an organism that lived a long life and did not produce any offspring.