The blue whale reaches sexual maturity at around 10 years of age. (marinemammalcenter.org)
After a male dog or cat reaches sexual maturity at six to nine months of age, they are able to breed any time they are exposed to a receptive female. (pmcofedmond.com)
Dogs that are spayed and neutered before sexual maturity seem to have an increased risk of future bone cancer. (1800petmeds.com)