Negligible Senescence

A very few species do not age or age very slowly and are often cited as evidence that aging is not a fundamental and inescapable property of living organisms. Theorists consider an organism negligibly senescent if it does not exhibit any measurable decline in survival characteristics such as strength or mobility with age and also does not exhibit any measurable reduction in reproductive ability with age.

Some examples:

The Aldebra giant tortoise has a measured maximum life span (so far) of 255 years.

The Rougheye rockfish (Sebastes aleutianus) has been measured at 205 years.

Lobsters are also believed to be negligibly senescent and even apparently have increased reproductive capacity with age

Organisms that do not age or age very slowly still die of predator attack, accident, starvation, exposure to adverse environmental conditions, and diseases. Extremely old specimens are therefore extremely rare. In some cases, measuring the age of a caught wild specimen requires killing the animal in order to measure age marks (similar to tree rings) on internal bones.  We therefore have no way of knowing the maximum age that could be achieved by one of these organisms.

www.programmed-aging.org

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