Mark Gruner was born on December 29, 1958 in Fort Leonard Wood, Missouri, USA. He is an actor, known for Jaws 2 (1978), Fantastic Planet (1973) and Dan August (1970).ounger brother of David Gruner. Mark and David were both members of ANTA (American National Theater and Academy)and have several stage productions to their credit as well as TV roles, films, voice-overs, and commercials.