re: johan christian mandal

Thankyou for your previous help. I discovered that the christian mandal I was chasing was actually born Johan Christian Mandal and only used the name christian when he emmigrated on the Hovding to NZ in 1872. On the passenger list I found his wife named as Maren but no maiden name. I also think that Johans' father may be Lars Mandahl and his mother Christine, though am unable to find her maiden name either. This family looks like the females all take on their married names for some reason. The 1865 census does not show her maiden name. I have also been unable to find Johans wife (Maren) or daughter (Julie) name on the census. They are not with him on census night. The Mandahl name seems extremely rare so am interested in finding why and how the name came about. I would appreciate any help you can give me. Thanks Kymm