Poor Man's Shark Fin 窮 人 的 魚 翅

In Cantonese, it's called 魚 翅 瓜 (yu4 chi3 gua1) shark fin melon. But I call it 窮 人 0既 魚 翅 (kung4 yan4 ge3 yu4 chi3) poor man's shark fin. We grow these melons in our backyard and use them to make a tasty soup with chicken and 蠔 豉 (hou4 si6) dried oysters. When the melon is boiled into soup, it has shiny, translucent strands that resemble shark fin. That's why it's called shark fin melon.
I have never seen 魚 翅 瓜 for sale in the market, either here in the U.S. or in HK. But judging from this
HK government website, they must grow it in HK. The first seeds that we got were from a Chinese friend who got them from her relatives in HK. Whether the seeds came from HK or 廣 東 省 (gong2 dung1 saang2) Guangdong Province, I don't know.
Has anyone seen 魚 翅 瓜 for sale in HK? 我 出 年 五 月 返 香 港 0係 街 市 買 瓜 菜 就 會 特 別 留 意.