show Abstracthide AbstractSea urchins are marine invertebrates of extreme diversity of life span. Red sea urchin S. franciscanus is among the longest living creatures of the Ocean. Its lifetime is estimated to exceed a century, while the green sea urchin L. variegatus hardly survives more than 3 years. We sequenced and compared the genomes of these animals aiming at determination of the genetic basis of their longevity difference. List of genes related to the longevity of other animal species was created and used for homology search among the genomic data obtained in this study. Aminoacid sequences of longevity related proteins of S. fransciscanus and L. variegatus as well as from a set of model species, were aligned and grouped on the basis of the species lifespan. Aminoacid residues specific for a longevity group were identified. Proteins containing aminoacids whose identity correlated with the lifespan were clustered on the basis of their function.