Anthonie Johannes Swalve, shown above in a photo contributed by Willem Vlietstra, was born Anthonie Johannes Koster on Nov. 8, 1876, to Helena Catrina Koster. A little more than two years later, Anthonie took the last name Swalve when Freerk Bellinga Swalve married Helena. This was noted on their marriage certificate, which I found on the now-nonexistent Genlias.nl site.
Some believe this may mean Anthonie was the son of Helena and Freerk, and some believe this may mean he was the son of Helena and another man. I have been unable to confirm via digital research and so would be interested to know if anyone has more information on Anthonie, who also went by the name A.J. It’s also probably worth noting that, despite traditional Dutch naming conventions wherein the first born son takes the name of the father’s father, in this case A.J. was named after his maternal grandfather, Anthonie (or Anthonij) Johannes Koster.
As for the photo itself, I find it to be a bit perplexing. A.J. is clearly has an anchor on his shirt and is posing with cooper props. If anyone can elaborate on that, I would be interested as well! He looks to me to be 15 or younger, which would date this photo sometime before 1891.