Estimated at around 30 years, it's accepted as the average period between birth of parents & their offspring
The growth rate 
for Wolffia microscopica may be calculated from its doubling time of 30 hours = 
1.25 days... [DOC] [TLE] Killer Whale Facts [PAR] While the killer whale carries the name whale as part of its description this ... a 
whale pod and separate a young defenseless child from its parents in order to ... 
birth the average gestation period (the period between fertilization and birth) for 
... in captivity however are estimated to have a lifespan of less than 25  30 years.