Summary.The identification of breeding stocks of Atlantic eels presents a dilemma which should be solved by genetic analyses. The eye lens crystallins are encoded by a family of genes which differentiate vertebrates. The eye lens tissue from two Atlantic eels,Anguilla anguillaandA. rostrata,and a Pacific control,A. japonica,were separated by electrofocusing. The isoelectric points (pI) of 34 lens protein bands were calibrated. The distributions of those proteins in the sampled populations supplement the existing evidence on the genetic diversity of eels and support the original biometrical description of two Atlantic species.