Lifespan is 20 years on average for a Devil Ray also known as the Manta Ray Manta ray is their actual name. so it'd make more sense if you said: Lifespan is 20 years on average for a Manta Ray also known as the Manta Ray. just so you know.
The first Opel Manta A was introduced in September 1970. The production was carried out till 1975, which by then Opel were ready to introduce their second Manta Model; Manta B. Its production ran from 1975 throughout 1988.