
The postcard that started my collection (postmarked 1911)
Approximately five years ago, while shopping at a “Marché aux Vieux Papiers” (antique paper market) in Paris, France, I purchased a postcard which I found quite amusing. It was a hand-tinted photo card of a gentleman holding a large fish and in the corner it said 1er Avril [April 1st]. There was a goofy romantic feel to the pose, which is what caught my eye.

More romantic than childhood prank (postmarked 1907)
I was familiar with the French tradition of Poisson d’ Avril [April Fish] in which children tape paper fish cut-outs secretively to friends and family member’s backs as a “prank”. The “fish” is synonymous with our “fool” on April 1st, although without malice. School children will even try to sneak a fish onto their teacher’s back during school day. However, the postcard I purchased clearly had a romantic bent and was hardly the childhood prank of today.
After much research (which is still incomplete), I believe I have uncovered the correlation between romance and Poisson d’Avril. Maquereau in French means “mackerel” – the fish depicted on the postcards and probably the true origin of Poisson d’Avril. It also has another meaning in slang – “matchmaker” or “pimp”. This may be attributed to the unique breeding behavior of the male maquereau in spring.

A woman with a basket full of chocolate fish (postmarked 1912)
As early the 16th century, when a new calendar was adopted starting the new year on January 1st instead of April 1st [a topic for another day], there was a tradition of giving small gifts on April 1st. Around the turn-of-the-20th-century, shops carried decorated papier mâché fish boxes from small sizes (for jewelry and candies) to large sizes (for umbrellas, etc.). Chocolatiers made molded chocolate fish wrapped in fancy foil. You will still find fish candies for sale at all of the chocolatiers around April 1st in France.

Example of an illustrated Poisson d’Avril postcard (postmarked 1934)
From my research and collecting of April 1st postcards, French Poisson d’Avril cartes postales lost popularity prior to WWII and contemporary April 1st postcards are hard to find. After World War I, the tinted photo postcards slowly were replaced with illustrated fish postcards. April 1st postcards were far more popular in France than any other country. Those depicting fish and/or having a romantic theme seem to be restricted to France.
I currently own over 400 Poisson d’Avril postcards. If you are interested, they are all uploaded to my Flickr account. My research is far from complete and I would love to hear your ideas about April 1st postcards from any country