A Look at Biologically immortal species

"Of particular interest is the Turritopsis nurticula.  Life is dynamic and this example is familiar in nature.  The pattern mirrors the universe breathing: expanding and contracting." -- Christie Ewen

Biologically immortal species

See also List of long-living organisms

Life defined as biologically immortal is still susceptible to causes of death besides aging, including disease and trauma, as defined above. Notable immortal species include:

• Bacteria (as a colony) — Bacteria reproduce through cell division. A parent bacterium splits itself into two identical daughter cells. These daughter cells then split themselves in half. This process repeats, thus making the bacterium colony essentially immortal.
  Recent research, however, suggests that even bacteria as a colony may eventually die since each succeeding generation is slightly smaller, weaker, and more likely to die than the previous.^[11]
• Hydra can be considered biologically immortal as they do not undergo senescence or aging.
• Turritopsis nutricula, a jellyfish, after becoming a sexually mature adult, can transform itself back into a child (the polyp stage) using the cell conversion process of transdifferentiation.Turritopsis nutricula repeats this cycle, meaning that it may have an indefinite lifespan.^[12]
• Bristlecone Pines are speculated to be potentially immortal; the oldest known living specimen is over 4800 years old.

REFERENCE: http://en.wikipedia.org/wiki/Immortality