Re: i was wondering how old the octopus is compared to other species

Hi John,

Thanks for your question. You may be surprised to know that many 
cephalopods (the group of molluscs that include octopus, cuttlefish, squid 
and nautilus) live less than a year, and the giant Pacific octopus, which 
has one of the longest documented life spans, survives for only four 
years. The lifespan of octopus species has been the subject of much 
research as they seem to show intelligence - a trait normally only found 
in long-lived animals, after all why spend all that energy growing a 
complex brain if you don't live very long? Also, they have very little 
social structure, and intelligence is often linked to complex societies 
(e.g. primates like us!). 

In contrast the approximate maximum lifespans of some other animals are as 
follows;

MAMMALS         YEARS
Elephant        69
Horse           50
Hippopotamus    49
Chimpanzee      40
Grizzly Bear    32
Bison           30
Lion            30
Tiger           25
Elk             22
Mountain Lion   20
Beaver          19
Wolf            16
Squirrel        16
Chipmunk        12
House Mouse     4

BIRDS           YEARS
Turkey Buzzard  118
Swan            102
Parrot           80
Great Horned Owl 68
English Sparrow  23
Canary           22
Humming Bird      8

REPTILES        YEARS
Giant Tortoise  152
Box Turtle      123
Alligator        68
Snapping Turtle  57
Cobra            28

AMPHIBIANS      YEARS
Giant Salamander 55
Toad             36
Bullfrog         30
Newt              7

FISH            YEARS
Catfish          60
Eel              55
Carp             47

INSECTS         YEARS
Cicada           17
Ant (queen)      15
Mayfly (larva)   a few months
Mayfly (adult)   1-2 days

However, extreme old age is seldom seen in the wild. Animals living under 
natural conditions rarely approach their maximum possible age because of 
very high death rates due to infant mortality, diseases, predators, bad 
weather, accidents, or competition for food and shelter. Therefore, most  
reliable information about maximum lifespan comes from zoos, where 
accurate records are kept and animals live under conditions almost ideally 
suited to prolong life. A mouse whose life is measured in months in the 
wild can survive years of captivity.

As a general rule, large animals tend to live longer than their smaller 
relatives, but there are many exceptions. For example, man is longer-lived 
than any other mammal. After us, in age, come the elephant, hippopotamus, 
horse, rhinoceros, the bears, the big cats and many others which are 
larger in size. In general, birds live longer than mammals, and certain 
reptiles possibly the longest of all. A giant tortoise is known to have 
lived 152 years on the island of Mauritius and then was killed 
accidentally or it might have lived a century longer. Even the common box 
turtle often reaches the 50-year mark. It is an interesting observation 
that there seems to have been no change in the life span of dogs, cats, 
horses and cows during thousands of years of domestication by man.

Anyhow, I hope that answers your question.

Dr David Hubble, UK